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  • Iterating Through N Level Children

    - by bobber205
    This seems like something neat that might be "built into" jQuery but I think it's still worth asking. I have a problem where that can easily be solved by iterating through all the children of a element. I've recently discovered I need to account for the cases where I would need to do a level or two deeper than the "1 level" (just calling .children() once) I am currently doing. jQuery.each(divToLookAt.children(), function(index, element) { //do stuff } ); This is what I'm current doing. To go a second layer deep, I run another loop after doing stuff code for each element. jQuery.each(divToLookAt.children(), function(index, element) { //do stuff jQuery.each(jQuery(element).children(), function(indexLevelTwo, elementLevelTwo) { //do stuff } ); } ); If I want to go yet another level deep, I have to do this all over again. This is clearly not good. I'd love to declare a "level" variable and then have it all take care of. Anyone have any ideas for a clean efficient jQueryish solution? Thanks!

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  • Why does java.util.concurrent.ArrayBlockingQueue use 'while' loops instead of 'if' around calls to

    - by theFunkyEngineer
    I have been playing with my own version of this, using 'if', and all seems to be working fine. Of course this will break down horribly if signalAll() is used instead of signal(), but if only one thread at a time is notified, how can this go wrong? Their code here - check out the put() and take() methods; a simpler and more-to-the-point implementation can be seen at the top of the JavaDoc for Condition. Relevant portion of my implementation below. public Object get() { lock.lock(); try { if( items.size() < 1 ) hasItems.await(); Object poppedValue = items.getLast(); items.removeLast(); hasSpace.signal(); return poppedValue; } catch (InterruptedException e) { e.printStackTrace(); return null; } finally { lock.unlock(); } } public void put(Object item) { lock.lock(); try { if( items.size() >= capacity ) hasSpace.await(); items.addFirst(item); hasItems.signal(); return; } catch (InterruptedException e) { e.printStackTrace(); } finally { lock.unlock(); } } P.S. I know that generally, particularly in lib classes like this, one should let the exceptions percolate up.

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  • serializeArray doesn't include submit-button value

    - by guzh
    Hi, I got two submit buttons in a form. One that deletes the post, and one to edit it. I want to display a fancybox with either the edit-form or a message saying that the user deleted the post. It's all decided by which button was pushed, with a "if(isset)"-sentence in edit.php. However I can't figure out how to get the value of the button within the serializeArray.. I tried with .click(function() instead, but that didn't send anything to the fancybox.. $("#form").bind("submit", function() { $.ajax({ type : "POST", cache : false, url : "edit.php", data : $(this).serializeArray(), success: function(data) { $.fancybox(data); } }); return false; }); The form looks like this: <form method='post' action='' id="form"> <input type='submit' value='Edit' name='edit' /> <input type='submit' value='Delete' name='delete' onClick="return slett('<?php echo $oppgave->name; ?>')"/> <input name='oppgaveID' type='hidden' value='<?php echo $oppgave->id; ?>' /> </form> I would really appreciate it if someone could help me! Thanks in advance!

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  • Scoping problem with Javascript callback

    - by nazbot
    I am having some trouble getting a callback function to work. Here is my code: SomeObject.prototype.refreshData = function() { var read_obj = new SomeAjaxCall("read_some_data", { }, this.readSuccess, this.readFail); } SomeObject.prototype.readSuccess = function(response) { this.data = response; this.someList = []; for (var i = 0; i < this.data.length; i++) { var systemData = this.data[i]; var system = new SomeSystem(systemData); this.someList.push(system); } this.refreshList(); } Basically SomeAjaxCall is making an ajax request for data. If it works we use the callback 'this.readSuccess' and if it fails 'this.readFail'. I have figured out that 'this' in the SomeObject.readSuccess is the global this (aka the window object) because my callbacks are being called as functions and not member methods. My understanding is that I need to use closures to keep the 'this' around, however, I have not been able to get this to work. If someone is able show me what I should be doing I would appreciate it greatly. I am still wrapping my head around how closures work and specifically how they would work in this situation. Thanks!

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  • How to detect if a RGB is fully transparent?

    - by omega
    In java, I want to make a fully transparent RGBA, and I do that by using public static int getTransparentRGB() { int r = 0; int g = 0; int b = 0; int a = 0; int new_pixel = (a << 24) | (r << 16) | (g << 8) | b; return new_pixel; } Color color = new Color(getTransparentRGB()); System.out.println(color.getAlpha()); // -> 255 ?! I purposely keep all rgba values 0. However after I create the Color object with the rgba value as the constructor, if I call .getAlpha(), I get 255 even though I made the rgb value with a 0 alpha. If it returns 255, how could I tell the difference between a Color object that wasn't transparent, because that would also have a 255 alpha. I expect the color object to return a 0 alpha based on the function above. Does anyone know whats going on? Thanks

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  • jquery help assigning multiple mouse events using a .each() to hide/show icons and show background c

    - by Ronedog
    Need some help assigning a mouseover event to display some icons that start out hidden. For every <li> in the ul, I have icons. When the user mouses over the <li> I want the span tag with a class called "icons" to be displayed. When the mouse out event occurs remove the class and/or just hide the span. The problem for me is how to assign event so just the span tag and its contents appear and disapear when the mouse hovers over the <li>. Heres the HTML: <ul id="nav"> <li>Cat 1 <span class="icons"> <div>stuff here</div> </span> </li> <li>Cat 2 <span class="icons"> <div>stuff here</div> </span> <ul> <li>Sub Cat 2A <span class="icons"> <div>2A stuff here</div> </span> </li> </ul> </li> </ul> Heres my jquery code. $('#nav li').each(function(){ //Add Background Shading o Mouseover to all Rows in the menu $(this).mouseover(function(){ $(this).addClass("background_grey").removeClass("icons"); }) $(this).mouseout(function(){ $(this).removeClass("background_grey").addClass("icons"); }); }); Thanks for the help.

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  • BlackBerry Field class extension will not paint.

    - by jlindenbaum
    Using JRE 5.0.0, simulator device is an 8520. On a screen I am using a FlowFieldManager(Manager.VERTICAL_SCROLL) and adding Fields to it to show data. When I do this.flowManager = new FlowFieldManager(Manager.VERTICAL_SCROLL); Field field = new Field() { protected void paint(Graphics graphics) { graphics.drawTest("Test", 0, 0); } protected void layout(int width, int height) { this.setExtend(300, 300); // just testing } } this.flowManager.add(field); The screen renders correctly and 'Test' appears on the screen. If, on the other hand, I try and abstract this into a class called CustomField with the same properties and add it to the flow manager the render will not happen. Debugging shows that the device enters into the Object, into the layout function, but not the paint function. I can't figure out why the paint function is not called when I extend Field. The 4.5 API says that layout and paint are the only functions that I really need to extend. (getPreferredWidth and getPreferredHeight will be used to calculate screen sizes etc.) Thanks in advance.

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  • Template Syntax in C++

    - by Crystal
    I don't understand templates really and was trying to run a simple find the minimum for ints, doubles, chars. First question, why is template<typename T> sometimes used, and other times template<>? Second question, I do not know what I am doing wrong with the following code below: #include <iostream> template <typename T> T minimum(T arg1, T arg2) { return arg1 < arg2 ? arg1 : arg2; } template <typename T> // first I tried template <> instd of above, but wasn't sure the difference T minimum<const char *>(const char *arg1, const char *arg2) { return strcmp(arg1, arg2) ? arg2 : arg1; } int main() { std::cout << minimum<int>(4, 2) << '\n'; std::cout << minimum<double>(2.2, -56.7) << '\n'; std::cout << minimum(2.2, 2) << '\n'; } Compile Errors: error C2768: 'minimum' : illegal use of explicit template arguments error C2783: 'T minimum(const char *,const char *)' : could not deduce template argument for 'T' : see declaration of 'minimum' : error C2782: 'T minimum(T,T)' : template parameter 'T' is ambiguous : see declaration of 'minimum' Third, in getting familiar with separating .h and .cpp files, if I wanted this minimum() function to be a static function of my class, but it was the only function in that class, would I have to have a template class as well? I originally tried doing it that way instead of having it all in one file and I got some compile errors as well that I can't remember right now and was unsure how I would do that. Thanks!

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  • Problem Initializing an Array Of Structs

    - by FallSe7en
    I am trying to initialize the following array of the following struct, but my code isn't compiling. Can anybody help me out? The struct/array: struct DiningCarSeat { int status; int order; int waiterNum; Lock customerLock; Condition customer; DiningCarSeat(seatNum) { char* tempLockName; sprintf(tempLockName, "diningCarSeatLock%d", seatNum); char* tempConditionName; sprintf(tempConditionName, "diningCarSeatCondition%d", seatNum); status = 0; order = 0; waiterNum = -1; customerLock = new Lock(tempLockName); customer = new Condition(tempConditionName); } } diningCarSeat[DINING_CAR_CAPACITY]; The relevant errors: ../threads/threadtest.cc: In constructor `DiningCarSeat::DiningCarSeat(int)': ../threads/threadtest.cc:58: error: no matching function for call to `Lock::Lock()' ../threads/synch.h:66: note: candidates are: Lock::Lock(const Lock&) ../threads/synch.h:68: note: Lock::Lock(char*) ../threads/threadtest.cc:58: error: no matching function for call to `Condition::Condition()' ../threads/synch.h:119: note: candidates are: Condition::Condition(const Condition&) ../threads/synch.h:121: note: Condition::Condition(char*) ../threads/threadtest.cc:63: error: expected primary-expression before '.' token ../threads/threadtest.cc:64: error: expected primary-expression before '.' token ../threads/threadtest.cc: At global scope: ../threads/threadtest.cc:69: error: no matching function for call to `DiningCarSeat::DiningCarSeat()' ../threads/threadtest.cc:51: note: candidates are: DiningCarSeat::DiningCarSeat(const DiningCarSeat&) ../threads/threadtest.cc:58: note: DiningCarSeat::DiningCarSeat(int) Thanks in advance!

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  • Struct containing a Map in a Map? (C++/STL)

    - by karok
    I was wondering if it was possible to create a struct containing a number of variables and a map in a map. What I have at the moment: typedef std::map<std::string,double> lawVariables; struct ObjectCustomData { std::string objectType; bool global_lock; std::map<std::string, lawVariables> lawData; }; This struct is then passed on to another function as a single data block for that object. The structure setup is as follows: Each object has a data block that contains: its ObjectType, a bool for a lock, and a varying number of "laws" that could look like this: law1 -> var_a = 39.3; -> var_g = 8.1; law8 -> var_r = 83.1; -> var_y = 913.3; -> var_a = 9.81; Firstly, I'm unsure whether I should be using a Map within a Map and secondly even if this would be valid, I'm unsure how to fill it with data and how to recall it afterwards. I looked at maps because then I can search (on a name) if a certain object has a certain law, and if that law has certain variables. (sorry for the first messy post appearance, hope this is better :) )

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  • Windows File I/O Reading

    - by eyeanand
    Currently working on open/read images in VC++. Some examples i came across on the internet use Windows.h I/O routines like ReadFile...but there seems to be inconsistency in there declaration. Here's what i have got. //So i have this function to load file BYTE* LoadFile ( int* width, int* height, long* size, LPCWSTR bmpfile ) { BITMAPFILEHEADER bmpheader; BITMAPINFOHEADER bmpinfo; DWORD bytesread = 0; HANDLE file = CreateFile ( bmpfile , GENERIC_READ, FILE_SHARE_READ,NULL, OPEN_EXISTING, FILE_FLAG_SEQUENTIAL_SCAN, NULL ); if ( NULL == file ) return NULL; if ( ReadFile ( file, &bmpheader, sizeof ( BITMAPFILEHEADER ),&bytesread, NULL ) == false ) { CloseHandle ( file ); return NULL; } . . . return appropriate value; } Now the ReadFile API function is declared as follows in WinBase.h WINBASEAPI BOOL WINAPI ReadFile( In HANDLE hFile, Out LPVOID lpBuffer, In DWORD nNumberOfBytesToRead, _Out_opt_ LPDWORD lpNumberOfBytesRead, _Inout_opt_ LPOVERLAPPED lpOverlapped ); And in MSDN examples... They call this function like this. ReadFile(hFile, chBuffer, BUFSIZE, &dwBytesRead, NULL) Which expects that "bytesRead" is sort of out parameter. so it gives me number of bytes read. But in my code ..it is giving error message. 'ReadFile' : cannot convert parameter 4 from 'LPDWORD *' to 'LPDWORD' so i just initialized bytesRead to 0 and passed by value.( which is wrong..but just to check if it works ). then it gives this exception Unhandled exception at 0x774406ae in ImProc.exe: 0xC0000005: Access violation writing location 0x00000000. Kindly suggest . Kindly tell if any code i missed out....including while forming the question itself. Thanks.

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  • Unit Conversion from feet to meters

    - by user1742419
    I have to write a program that reads in a length in feet and inches and outputs the equivalent length in meters and centimeters. I have to create three functions: one for input, one or more for calculating, and one for output; And include a loop that lets the user repeat this computation for new input values until the user says he or she wants to end the program. I can't seem to get the input from one function to be used in the conversion function and then outputted by the next function. How do I do that? Thank you. #include <iostream> #include <conio.h> using namespace std; double leng; void length(double leng); double conv(double leng); void output(double leng); int main() { length(leng); conv(leng); output(leng); _getche(); return 0; } void length(double leng) { cout<<"Enter a length in feet, then enter a length in inches if needed: "; cin>>leng; return; } double conv(double leng) { return leng = leng * .3048; } void output(double leng) { cout<<"Your input is converted to "<<leng; return; }

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  • Doing a DELETE request from <a> tag without constructing forms?

    - by Mike Trpcic
    Is there any way to force an <a href> to do a delete request when clicked instead of a regular GET? The "Rails" way is to dynamically generate a <form> tag that adds the appropriate params so that it gets routed to the right place, however I'm not too fond of that much DOM manipulation for such a simple task. I thought about going the route of something like: $("a.delete").click(function(){ var do_refresh = false; $.ajax({ type: "DELETE", url: "my/path/to/delete", success: function(){ do_refresh = true; }, failure: function(){ alert("There is an error"); } }); return do_return; //If this is false, no refresh would happen. If it //is true, it will do a page refresh. }); I'm not sure if the above AJAX stuff will work, as it's just theoretical. Is there any way to go about this? Note: Please don't recommend that I use the rails :method => :delete on link_to, as I'm trying to get away from using the rails helpers in many senses as they pollute your DOM with obtrusive javascript. I'd like this solution to be put in an external JS file and be included as needed.

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  • Looping through array values using JQuery and show them on separate lines

    - by user3192948
    I'm building a simple shopping cart where visitors can select a few items they want, click on the "Next" button, and see the confirmation list of things they just selected. I would like to have the confirmation list shown on each line for each item selected. HTML selection <div id="c_b"> <input type="checkbox" value="razor brand new razor that everyone loves, price at $.99" checked> <input type="checkbox" value="soap used soap for a nice public shower, good for your homies, price at $.99" checked> <input type="checkbox" value="manpacks ultimate choice, all in 1, price at $99"> </div> <button type='button' id='confirm'>Next</button> HTML confirmation list <div id='confirmation_list' style='display:none;'> <h2>You have selected item 1</h2> <h2>Your have selected item 2 </h2> </div> JS $(function(){ $('#confirm').click(function(){ var val = []; $(':checkbox:checked').each(function(i){ val[i] = $(this).val(); }); }); }); I ultimately want to replace the words 'Your have selected item 2' in h2s with the values selected from each check box. With the code above I'm able to collect the values of each checkbox into an array val, but having difficulty looping through and displaying them. Any advice would be appreciated.

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  • What does the `new` keyword do

    - by Mike
    I'm following a Java tutorial online, trying to learn the language, and it's bouncing between two semantics for using arrays. long results[] = new long[3]; results[0] = 1; results[1] = 2; results[2] = 3; and: long results[] = {1, 2, 3}; The tutorial never really mentioned why it switched back and forth between the two so I searched a little on the topic. My current understanding is that the new operator is creating an object of "array of longs" type. What I do not understand is why do I want that, and what are the ramifications of that? Are there certain "array" specific methods that won't work on an array unless it's an "array object"? Is there anything that I can't do with an "array object" that I can do with a normal array? Does the Java VM have to do clean up on objects initialized with the new operator that it wouldn't normally have to do? I'm coming from C, so my Java terminology, may not be correct here, so please ask for clarification if something's not understandable.

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  • Allowing user to type only one "."

    - by Tartar
    I am trying to implement a simple javascript-html calculator. What i want to do is,typing only one '.' by the user. How can i control this ? Here is the code that i tried. I can already find the number of '.' but i'am confused now also this replaceAll function is not replacing '.' with empty string. String.prototype.replaceAll = function(search, replace) { //if replace is null, return original string otherwise it will //replace search string with 'undefined'. if(!replace) return this; return this.replace(new RegExp('[' + search + ']', 'g'), replace); }; function calculate(){ var value = document.calculator.text.value; var valueArray = value.split(""); var arrayLenght = valueArray.length; var character = "."; var charCount = 0; for(i=0;i<arrayLenght;i++){ if (valueArray[i]===character) { charCount += 1; } } if(charCount>1){ var newValue=value.replaceAll(".",""); alert(newValue); } }

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  • How to open a chat window in sender and receiver side [on hold]

    - by DEEPS
    When i am trying to send a message from sender the chat window is always opening in senders side instead of receiver side.so please give a correct code to display chat box in both side. (HTML 5, JAVASCRIPT,JQUERY). This is client side code: //Send private message function sendPvtMsg(data) { var pvtmsg = data; socket.emit('message',JSON.stringify({msg: 'pvtMsg', data: { from: userName, to: toChat, pvtmsg: data }}),roomId); } socket.on('message',function(data) { var command = JSON.parse(data); var itemName = command.msg; var rec_data = command.data.message; var sender = command.data.name; //Receive message from server if (itemName == "message") { document.getElementById("chat").value += sender + " : " + rec_data + "\n"; } //Receive private message else if (itemName == "pvtMsg") { var to = command.data.to; var from = command.data.from; //To display message to sender and receiver if (userName == to || userName == from) { var pvtmsg = command.data.pvtmsg; document.getElementById("chat").value += from + "( to " + to + ")" + " : " + pvtmsg + "\n"; } } function createChatBox(chatboxtitle,minimizeChatBox) { if ($("#chatbox_"+chatboxtitle).length > 0) { if ($("#chatbox_"+chatboxtitle).css('display') == 'none') { $("#chatbox_"+chatboxtitle).css('display','block'); restructureChatBoxes(); } $("#chatbox_"+chatboxtitle+" .chatboxtextarea").focus(); return; }

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  • Aborting $.post() / responsive search results

    - by Emphram Stavanger
    I have the following kludgey code; HTML <input type="search" id="search_box" /> <div id="search_results"></div> JS var search_timeout, search_xhr; $("#search_box").bind("textchange", function(){ clearTimeout(search_timeout); search_xhr.abort(); search_term = $(this).val(); search_results = $("#search_results"); if(search_term == "") { if(search_results.is(":visible")) search_results.stop().hide("blind", 200); } else { if(search_results.is(":hidden")) search_results.stop().show("blind", 200); } search_timeout = setTimeout(function () { search_xhr = $.post("search.php", { q: search_term }, function(data){ search_results.html(data); }); }, 100); }); (uses the textchange plugin by Zurb) The problem I had with my original more simple code was that it was horribly unresponsive. Results would appear seconds later, especially when typed slower, or when Backspace was used, etc. I made all this, and the situation isn't much better. Requests pile up. My original intention is to use .abort() to cancel out whatever previous request is still running as the textchange event is fired again (as per 446594). This doesn't work, as I get repeated errors like this in console; Uncaught TypeError: Cannot call method 'abort' of undefined How can I make .abort() work in my case? Furthermore, is this approach the best way to fetch 'realtime' search results? Much like Facebook's search bar, which gives results as the user types, and seems to be very quick on its feet.

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  • Javascript trouble changing opacity

    - by Ghilliedrone
    I'm making script that fades 3 pictures out in order, but the pictures' opacity aren't changing. The if statements are reached but the pictures do not change. The first picture changes to 1 opacity on the page load, so I don't see why it wouldn't work in my function. window.onload = function() { document.getElementById("img1").style.opacity = 1; setInterval(swapPictures, 2000); }; var swapPictures = function(){ if(typeof swapPictures.img1v === 'undefined'){ swapPictures.img1v = true; } if(typeof swapPictures.img2v === 'undefined'){ swapPictures.img2v = false; } if(typeof swapPictures.img3v === 'undefined'){ swapPictures.img3v = false; } if(swapPictures.img1v && !swapPictures.img2v && !swapPictures.img3v){ swapPictures.img1v = !swapPictures.img1v; swapPictures.img2v = !swapPictures.img2v; document.getElementById("img1").style.opacity = .4; document.getElementById("imgtwo").style.opactiy = 1; }else if(!swapPictures.img1v && swapPictures.img2v && !swapPictures.img3v){ swapPictures.img2v = !swapPictures.img2v; swapPictures.img3v = !swapPictures.img3v; document.getElementById("imgtwo").style.opacity = .4; document.getElementById("imgthree").style.opactiy = 1; }else if(!swapPictures.img1v && !swapPictures.img2v && swapPictures.img3v){ swapPictures.img3v = !swapPictures.img3v; swapPictures.img1v = !swapPictures.img1v; document.getElementById("imgthree").style.opacity = .4; document.getElementById("img1").style.opactiy = 1; } };

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  • what this json must work?

    - by user1772630
    hi i search alot for get a respone from php back and if that respone is ok do someting and if its false do something else(!!!!!!!! WHENE I HAVE OTHER OUTPUT FROM THAT PHP !!!!!!) this is my index file <head> <script src="jquery-1.7.2.js" type="text/javascript"></script> <script src="js.js" type="text/javascript"></script> </head> <body> <p> click </p> <input type="text" id="who"> <br> <input type="text" id="why"> <div id="bg" align="center"> </div> </body> this is my JS file $(document).ready(function(){ $('p').click(function(){ var who = $('input#who').val(); var why = $('input#why').val(); $.post('file.php',{who:who,why:why},function(data) { if(data.success){ alert(data.message); } else{ alert('ERROR:' + data.message); } }); }); }); and this is my file.php <?php $response = array('success' => 'true', 'code' => "jQuery('#bg').html('\"Javascript\", \"json\", \"PHP\"');"); echo json_encode($response); ?> my question : 1- why this is not work i get alert (error:undifined) 2- how i can get some result from that php file when its have other output like this: <?php echo "1"; echo "2"; echo "3"; and now echo that json ?> thanks :(

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  • Receive Ajax and display output in a Photo?

    - by user1709469
    how to Receive Ajax and display output in a Photo? Images should be displayed inside the div tag After each of Bayer text, change the text to change the photo content The photos displayed are written in the form Thanks this code <script> function AjaxRequest() { var xmlhttp = null; if (window.XMLHttpRequest) { // code for IE7+, Firefox, Chrome, Opera, Safari xmlhttp = new XMLHttpRequest(); } // else // code for IE6, IE5 return xmlhttp; } function ajaxAction() { var font_category = document.getElementById("ajaxField").value; var xmlHttp = AjaxRequest(); xmlHttp.open("POST" , "ajax.php?message=" + message , true); xmlHttp.onreadystatechange = function() { if(xmlHttp.readyState == 1) response.innerHTML = "Loading..."; if (xmlHttp.readyState == 4 && xmlHttp.status == 200) response.innerHTML = xmlHttp.responseText; } xmlHttp.send(null); } </script> <textarea id="ajaxField12" name="message" rows="2" cols="20" value="Send" onchange="javascript:ajaxAction();"> </textarea> <div id="ajaxResponse" height="42" width="42"> </div>

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  • Using FiddlerCore to capture HTTP Requests with .NET

    - by Rick Strahl
    Over the last few weeks I’ve been working on my Web load testing utility West Wind WebSurge. One of the key components of a load testing tool is the ability to capture URLs effectively so that you can play them back later under load. One of the options in WebSurge for capturing URLs is to use its built-in capture tool which acts as an HTTP proxy to capture any HTTP and HTTPS traffic from most Windows HTTP clients, including Web Browsers as well as standalone Windows applications and services. To make this happen, I used Eric Lawrence’s awesome FiddlerCore library, which provides most of the functionality of his desktop Fiddler application, all rolled into an easy to use library that you can plug into your own applications. FiddlerCore makes it almost too easy to capture HTTP content! For WebSurge I needed to capture all HTTP traffic in order to capture the full HTTP request – URL, headers and any content posted by the client. The result of what I ended up creating is this semi-generic capture form: In this post I’m going to demonstrate how easy it is to use FiddlerCore to build this HTTP Capture Form.  If you want to jump right in here are the links to get Telerik’s Fiddler Core and the code for the demo provided here. FiddlerCore Download FiddlerCore on NuGet Show me the Code (WebSurge Integration code from GitHub) Download the WinForms Sample Form West Wind Web Surge (example implementation in live app) Note that FiddlerCore is bound by a license for commercial usage – see license.txt in the FiddlerCore distribution for details. Integrating FiddlerCore FiddlerCore is a library that simply plugs into your application. You can download it from the Telerik site and manually add the assemblies to your project, or you can simply install the NuGet package via:       PM> Install-Package FiddlerCore The library consists of the FiddlerCore.dll as well as a couple of support libraries (CertMaker.dll and BCMakeCert.dll) that are used for installing SSL certificates. I’ll have more on SSL captures and certificate installation later in this post. But first let’s see how easy it is to use FiddlerCore to capture HTTP content by looking at how to build the above capture form. Capturing HTTP Content Once the library is installed it’s super easy to hook up Fiddler functionality. Fiddler includes a number of static class methods on the FiddlerApplication object that can be called to hook up callback events as well as actual start monitoring HTTP URLs. In the following code directly lifted from WebSurge, I configure a few filter options on Form level object, from the user inputs shown on the form by assigning it to a capture options object. In the live application these settings are persisted configuration values, but in the demo they are one time values initialized and set on the form. Once these options are set, I hook up the AfterSessionComplete event to capture every URL that passes through the proxy after the request is completed and start up the Proxy service:void Start() { if (tbIgnoreResources.Checked) CaptureConfiguration.IgnoreResources = true; else CaptureConfiguration.IgnoreResources = false; string strProcId = txtProcessId.Text; if (strProcId.Contains('-')) strProcId = strProcId.Substring(strProcId.IndexOf('-') + 1).Trim(); strProcId = strProcId.Trim(); int procId = 0; if (!string.IsNullOrEmpty(strProcId)) { if (!int.TryParse(strProcId, out procId)) procId = 0; } CaptureConfiguration.ProcessId = procId; CaptureConfiguration.CaptureDomain = txtCaptureDomain.Text; FiddlerApplication.AfterSessionComplete += FiddlerApplication_AfterSessionComplete; FiddlerApplication.Startup(8888, true, true, true); } The key lines for FiddlerCore are just the last two lines of code that include the event hookup code as well as the Startup() method call. Here I only hook up to the AfterSessionComplete event but there are a number of other events that hook various stages of the HTTP request cycle you can also hook into. Other events include BeforeRequest, BeforeResponse, RequestHeadersAvailable, ResponseHeadersAvailable and so on. In my case I want to capture the request data and I actually have several options to capture this data. AfterSessionComplete is the last event that fires in the request sequence and it’s the most common choice to capture all request and response data. I could have used several other events, but AfterSessionComplete is one place where you can look both at the request and response data, so this will be the most common place to hook into if you’re capturing content. The implementation of AfterSessionComplete is responsible for capturing all HTTP request headers and it looks something like this:private void FiddlerApplication_AfterSessionComplete(Session sess) { // Ignore HTTPS connect requests if (sess.RequestMethod == "CONNECT") return; if (CaptureConfiguration.ProcessId > 0) { if (sess.LocalProcessID != 0 && sess.LocalProcessID != CaptureConfiguration.ProcessId) return; } if (!string.IsNullOrEmpty(CaptureConfiguration.CaptureDomain)) { if (sess.hostname.ToLower() != CaptureConfiguration.CaptureDomain.Trim().ToLower()) return; } if (CaptureConfiguration.IgnoreResources) { string url = sess.fullUrl.ToLower(); var extensions = CaptureConfiguration.ExtensionFilterExclusions; foreach (var ext in extensions) { if (url.Contains(ext)) return; } var filters = CaptureConfiguration.UrlFilterExclusions; foreach (var urlFilter in filters) { if (url.Contains(urlFilter)) return; } } if (sess == null || sess.oRequest == null || sess.oRequest.headers == null) return; string headers = sess.oRequest.headers.ToString(); var reqBody = sess.GetRequestBodyAsString(); // if you wanted to capture the response //string respHeaders = session.oResponse.headers.ToString(); //var respBody = session.GetResponseBodyAsString(); // replace the HTTP line to inject full URL string firstLine = sess.RequestMethod + " " + sess.fullUrl + " " + sess.oRequest.headers.HTTPVersion; int at = headers.IndexOf("\r\n"); if (at < 0) return; headers = firstLine + "\r\n" + headers.Substring(at + 1); string output = headers + "\r\n" + (!string.IsNullOrEmpty(reqBody) ? reqBody + "\r\n" : string.Empty) + Separator + "\r\n\r\n"; BeginInvoke(new Action<string>((text) => { txtCapture.AppendText(text); UpdateButtonStatus(); }), output); } The code starts by filtering out some requests based on the CaptureOptions I set before the capture is started. These options/filters are applied when requests actually come in. This is very useful to help narrow down the requests that are captured for playback based on options the user picked. I find it useful to limit requests to a certain domain for captures, as well as filtering out some request types like static resources – images, css, scripts etc. This is of course optional, but I think it’s a common scenario and WebSurge makes good use of this feature. AfterSessionComplete like other FiddlerCore events, provides a Session object parameter which contains all the request and response details. There are oRequest and oResponse objects to hold their respective data. In my case I’m interested in the raw request headers and body only, as you can see in the commented code you can also retrieve the response headers and body. Here the code captures the request headers and body and simply appends the output to the textbox on the screen. Note that the Fiddler events are asynchronous, so in order to display the content in the UI they have to be marshaled back the UI thread with BeginInvoke, which here simply takes the generated headers and appends it to the existing textbox test on the form. As each request is processed, the headers are captured and appended to the bottom of the textbox resulting in a Session HTTP capture in the format that Web Surge internally supports, which is basically raw request headers with a customized 1st HTTP Header line that includes the full URL rather than a server relative URL. When the capture is done the user can either copy the raw HTTP session to the clipboard, or directly save it to file. This raw capture format is the same format WebSurge and also Fiddler use to import/export request data. While this code is application specific, it demonstrates the kind of logic that you can easily apply to the request capture process, which is one of the reasonsof why FiddlerCore is so powerful. You get to choose what content you want to look up as part of your own application logic and you can then decide how to capture or use that data as part of your application. The actual captured data in this case is only a string. The user can edit the data by hand or in the the case of WebSurge, save it to disk and automatically open the captured session as a new load test. Stopping the FiddlerCore Proxy Finally to stop capturing requests you simply disconnect the event handler and call the FiddlerApplication.ShutDown() method:void Stop() { FiddlerApplication.AfterSessionComplete -= FiddlerApplication_AfterSessionComplete; if (FiddlerApplication.IsStarted()) FiddlerApplication.Shutdown(); } As you can see, adding HTTP capture functionality to an application is very straight forward. FiddlerCore offers tons of features I’m not even touching on here – I suspect basic captures are the most common scenario, but a lot of different things can be done with FiddlerCore’s simple API interface. Sky’s the limit! The source code for this sample capture form (WinForms) is provided as part of this article. Adding Fiddler Certificates with FiddlerCore One of the sticking points in West Wind WebSurge has been that if you wanted to capture HTTPS/SSL traffic, you needed to have the full version of Fiddler and have HTTPS decryption enabled. Essentially you had to use Fiddler to configure HTTPS decryption and the associated installation of the Fiddler local client certificate that is used for local decryption of incoming SSL traffic. While this works just fine, requiring to have Fiddler installed and then using a separate application to configure the SSL functionality isn’t ideal. Fortunately FiddlerCore actually includes the tools to register the Fiddler Certificate directly using FiddlerCore. Why does Fiddler need a Certificate in the first Place? Fiddler and FiddlerCore are essentially HTTP proxies which means they inject themselves into the HTTP conversation by re-routing HTTP traffic to a special HTTP port (8888 by default for Fiddler) and then forward the HTTP data to the original client. Fiddler injects itself as the system proxy in using the WinInet Windows settings  which are the same settings that Internet Explorer uses and that are configured in the Windows and Internet Explorer Internet Settings dialog. Most HTTP clients running on Windows pick up and apply these system level Proxy settings before establishing new HTTP connections and that’s why most clients automatically work once Fiddler – or FiddlerCore/WebSurge are running. For plain HTTP requests this just works – Fiddler intercepts the HTTP requests on the proxy port and then forwards them to the original port (80 for HTTP and 443 for SSL typically but it could be any port). For SSL however, this is not quite as simple – Fiddler can easily act as an HTTPS/SSL client to capture inbound requests from the server, but when it forwards the request to the client it has to also act as an SSL server and provide a certificate that the client trusts. This won’t be the original certificate from the remote site, but rather a custom local certificate that effectively simulates an SSL connection between the proxy and the client. If there is no custom certificate configured for Fiddler the SSL request fails with a certificate validation error. The key for this to work is that a custom certificate has to be installed that the HTTPS client trusts on the local machine. For a much more detailed description of the process you can check out Eric Lawrence’s blog post on Certificates. If you’re using the desktop version of Fiddler you can install a local certificate into the Windows certificate store. Fiddler proper does this from the Options menu: This operation does several things: It installs the Fiddler Root Certificate It sets trust to this Root Certificate A new client certificate is generated for each HTTPS site monitored Certificate Installation with FiddlerCore You can also provide this same functionality using FiddlerCore which includes a CertMaker class. Using CertMaker is straight forward to use and it provides an easy way to create some simple helpers that can install and uninstall a Fiddler Root certificate:public static bool InstallCertificate() { if (!CertMaker.rootCertExists()) { if (!CertMaker.createRootCert()) return false; if (!CertMaker.trustRootCert()) return false; } return true; } public static bool UninstallCertificate() { if (CertMaker.rootCertExists()) { if (!CertMaker.removeFiddlerGeneratedCerts(true)) return false; } return true; } InstallCertificate() works by first checking whether the root certificate is already installed and if it isn’t goes ahead and creates a new one. The process of creating the certificate is a two step process – first the actual certificate is created and then it’s moved into the certificate store to become trusted. I’m not sure why you’d ever split these operations up since a cert created without trust isn’t going to be of much value, but there are two distinct steps. When you trigger the trustRootCert() method, a message box will pop up on the desktop that lets you know that you’re about to trust a local private certificate. This is a security feature to ensure that you really want to trust the Fiddler root since you are essentially installing a man in the middle certificate. It’s quite safe to use this generated root certificate, because it’s been specifically generated for your machine and thus is not usable from external sources, the only way to use this certificate in a trusted way is from the local machine. IOW, unless somebody has physical access to your machine, there’s no useful way to hijack this certificate and use it for nefarious purposes (see Eric’s post for more details). Once the Root certificate has been installed, FiddlerCore/Fiddler create new certificates for each site that is connected to with HTTPS. You can end up with quite a few temporary certificates in your certificate store. To uninstall you can either use Fiddler and simply uncheck the Decrypt HTTPS traffic option followed by the remove Fiddler certificates button, or you can use FiddlerCore’s CertMaker.removeFiddlerGeneratedCerts() which removes the root cert and any of the intermediary certificates Fiddler created. Keep in mind that when you uninstall you uninstall the certificate for both FiddlerCore and Fiddler, so use UninstallCertificate() with care and realize that you might affect the Fiddler application’s operation by doing so as well. When to check for an installed Certificate Note that the check to see if the root certificate exists is pretty fast, while the actual process of installing the certificate is a relatively slow operation that even on a fast machine takes a few seconds. Further the trust operation pops up a message box so you probably don’t want to install the certificate repeatedly. Since the check for the root certificate is fast, you can easily put a call to InstallCertificate() in any capture startup code – in which case the certificate installation only triggers when a certificate is in fact not installed. Personally I like to make certificate installation explicit – just like Fiddler does, so in WebSurge I use a small drop down option on the menu to install or uninstall the SSL certificate:   This code calls the InstallCertificate and UnInstallCertificate functions respectively – the experience with this is similar to what you get in Fiddler with the extra dialog box popping up to prompt confirmation for installation of the root certificate. Once the cert is installed you can then capture SSL requests. There’s a gotcha however… Gotcha: FiddlerCore Certificates don’t stick by Default When I originally tried to use the Fiddler certificate installation I ran into an odd problem. I was able to install the certificate and immediately after installation was able to capture HTTPS requests. Then I would exit the application and come back in and try the same HTTPS capture again and it would fail due to a missing certificate. CertMaker.rootCertExists() would return false after every restart and if re-installed the certificate a new certificate would get added to the certificate store resulting in a bunch of duplicated root certificates with different keys. What the heck? CertMaker and BcMakeCert create non-sticky CertificatesI turns out that FiddlerCore by default uses different components from what the full version of Fiddler uses. Fiddler uses a Windows utility called MakeCert.exe to create the Fiddler Root certificate. FiddlerCore however installs the CertMaker.dll and BCMakeCert.dll assemblies, which use a different crypto library (Bouncy Castle) for certificate creation than MakeCert.exe which uses the Windows Crypto API. The assemblies provide support for non-windows operation for Fiddler under Mono, as well as support for some non-Windows certificate platforms like iOS and Android for decryption. The bottom line is that the FiddlerCore provided bouncy castle assemblies are not sticky by default as the certificates created with them are not cached as they are in Fiddler proper. To get certificates to ‘stick’ you have to explicitly cache the certificates in Fiddler’s internal preferences. A cache aware version of InstallCertificate looks something like this:public static bool InstallCertificate() { if (!CertMaker.rootCertExists()) { if (!CertMaker.createRootCert()) return false; if (!CertMaker.trustRootCert()) return false; App.Configuration.UrlCapture.Cert = FiddlerApplication.Prefs.GetStringPref("fiddler.certmaker.bc.cert", null); App.Configuration.UrlCapture.Key = FiddlerApplication.Prefs.GetStringPref("fiddler.certmaker.bc.key", null); } return true; } public static bool UninstallCertificate() { if (CertMaker.rootCertExists()) { if (!CertMaker.removeFiddlerGeneratedCerts(true)) return false; } App.Configuration.UrlCapture.Cert = null; App.Configuration.UrlCapture.Key = null; return true; } In this code I store the Fiddler cert and private key in an application configuration settings that’s stored with the application settings (App.Configuration.UrlCapture object). These settings automatically persist when WebSurge is shut down. The values are read out of Fiddler’s internal preferences store which is set after a new certificate has been created. Likewise I clear out the configuration settings when the certificate is uninstalled. In order for these setting to be used you have to also load the configuration settings into the Fiddler preferences *before* a call to rootCertExists() is made. I do this in the capture form’s constructor:public FiddlerCapture(StressTestForm form) { InitializeComponent(); CaptureConfiguration = App.Configuration.UrlCapture; MainForm = form; if (!string.IsNullOrEmpty(App.Configuration.UrlCapture.Cert)) { FiddlerApplication.Prefs.SetStringPref("fiddler.certmaker.bc.key", App.Configuration.UrlCapture.Key); FiddlerApplication.Prefs.SetStringPref("fiddler.certmaker.bc.cert", App.Configuration.UrlCapture.Cert); }} This is kind of a drag to do and not documented anywhere that I could find, so hopefully this will save you some grief if you want to work with the stock certificate logic that installs with FiddlerCore. MakeCert provides sticky Certificates and the same functionality as Fiddler But there’s actually an easier way. If you want to skip the above Fiddler preference configuration code in your application you can choose to distribute MakeCert.exe instead of certmaker.dll and bcmakecert.dll. When you use MakeCert.exe, the certificates settings are stored in Windows so they are available without any custom configuration inside of your application. It’s easier to integrate and as long as you run on Windows and you don’t need to support iOS or Android devices is simply easier to deal with. To integrate into your project, you can remove the reference to CertMaker.dll (and the BcMakeCert.dll assembly) from your project. Instead copy MakeCert.exe into your output folder. To make sure MakeCert.exe gets pushed out, include MakeCert.exe in your project and set the Build Action to None, and Copy to Output Directory to Copy if newer. Note that the CertMaker.dll reference in the project has been removed and on disk the files for Certmaker.dll, as well as the BCMakeCert.dll files on disk. Keep in mind that these DLLs are resources of the FiddlerCore NuGet package, so updating the package may end up pushing those files back into your project. Once MakeCert.exe is distributed FiddlerCore checks for it first before using the assemblies so as long as MakeCert.exe exists it’ll be used for certificate creation (at least on Windows). Summary FiddlerCore is a pretty sweet tool, and it’s absolutely awesome that we get to plug in most of the functionality of Fiddler right into our own applications. A few years back I tried to build this sort of functionality myself for an app and ended up giving up because it’s a big job to get HTTP right – especially if you need to support SSL. FiddlerCore now provides that functionality as a turnkey solution that can be plugged into your own apps easily. The only downside is FiddlerCore’s documentation for more advanced features like certificate installation which is pretty sketchy. While for the most part FiddlerCore’s feature set is easy to work with without any documentation, advanced features are often not intuitive to gleam by just using Intellisense or the FiddlerCore help file reference (which is not terribly useful). While Eric Lawrence is very responsive on his forum and on Twitter, there simply isn’t much useful documentation on Fiddler/FiddlerCore available online. If you run into trouble the forum is probably the first place to look and then ask a question if you can’t find the answer. The best documentation you can find is Eric’s Fiddler Book which covers a ton of functionality of Fiddler and FiddlerCore. The book is a great reference to Fiddler’s feature set as well as providing great insights into the HTTP protocol. The second half of the book that gets into the innards of HTTP is an excellent read for anybody who wants to know more about some of the more arcane aspects and special behaviors of HTTP – it’s well worth the read. While the book has tons of information in a very readable format, it’s unfortunately not a great reference as it’s hard to find things in the book and because it’s not available online you can’t electronically search for the great content in it. But it’s hard to complain about any of this given the obvious effort and love that’s gone into this awesome product for all of these years. A mighty big thanks to Eric Lawrence  for having created this useful tool that so many of us use all the time, and also to Telerik for picking up Fiddler/FiddlerCore and providing Eric the resources to support and improve this wonderful tool full time and keeping it free for all. Kudos! Resources FiddlerCore Download FiddlerCore NuGet Fiddler Capture Sample Form Fiddler Capture Form in West Wind WebSurge (GitHub) Eric Lawrence’s Fiddler Book© Rick Strahl, West Wind Technologies, 2005-2014Posted in .NET  HTTP   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Creating a dynamic proxy generator with c# – Part 3 – Creating the constructors

    - by SeanMcAlinden
    Creating a dynamic proxy generator with c# – Part 1 – Creating the Assembly builder, Module builder and caching mechanism Creating a dynamic proxy generator with c# – Part 2 – Interceptor Design For the latest code go to http://rapidioc.codeplex.com/ When building our proxy type, the first thing we need to do is build the constructors. There needs to be a corresponding constructor for each constructor on the passed in base type. We also want to create a field to store the interceptors and construct this list within each constructor. So assuming the passed in base type is a User<int, IRepository> class, were looking to generate constructor code like the following:   Default Constructor public User`2_RapidDynamicBaseProxy() {     this.interceptors = new List<IInterceptor<User<int, IRepository>>>();     DefaultInterceptor<User<int, IRepository>> item = new DefaultInterceptor<User<int, IRepository>>();     this.interceptors.Add(item); }     Parameterised Constructor public User`2_RapidDynamicBaseProxy(IRepository repository1) : base(repository1) {     this.interceptors = new List<IInterceptor<User<int, IRepository>>>();     DefaultInterceptor<User<int, IRepository>> item = new DefaultInterceptor<User<int, IRepository>>();     this.interceptors.Add(item); }   As you can see, we first populate a field on the class with a new list of the passed in base type. Construct our DefaultInterceptor class. Add the DefaultInterceptor instance to our interceptor collection. Although this seems like a relatively small task, there is a fair amount of work require to get this going. Instead of going through every line of code – please download the latest from http://rapidioc.codeplex.com/ and debug through. In this post I’m going to concentrate on explaining how it works. TypeBuilder The TypeBuilder class is the main class used to create the type. You instantiate a new TypeBuilder using the assembly module we created in part 1. /// <summary> /// Creates a type builder. /// </summary> /// <typeparam name="TBase">The type of the base class to be proxied.</typeparam> public static TypeBuilder CreateTypeBuilder<TBase>() where TBase : class {     TypeBuilder typeBuilder = DynamicModuleCache.Get.DefineType         (             CreateTypeName<TBase>(),             TypeAttributes.Class | TypeAttributes.Public,             typeof(TBase),             new Type[] { typeof(IProxy) }         );       if (typeof(TBase).IsGenericType)     {         GenericsHelper.MakeGenericType(typeof(TBase), typeBuilder);     }       return typeBuilder; }   private static string CreateTypeName<TBase>() where TBase : class {     return string.Format("{0}_RapidDynamicBaseProxy", typeof(TBase).Name); } As you can see, I’ve create a new public class derived from TBase which also implements my IProxy interface, this is used later for adding interceptors. If the base type is generic, the following GenericsHelper.MakeGenericType method is called. GenericsHelper using System; using System.Reflection.Emit; namespace Rapid.DynamicProxy.Types.Helpers {     /// <summary>     /// Helper class for generic types and methods.     /// </summary>     internal static class GenericsHelper     {         /// <summary>         /// Makes the typeBuilder a generic.         /// </summary>         /// <param name="concrete">The concrete.</param>         /// <param name="typeBuilder">The type builder.</param>         public static void MakeGenericType(Type baseType, TypeBuilder typeBuilder)         {             Type[] genericArguments = baseType.GetGenericArguments();               string[] genericArgumentNames = GetArgumentNames(genericArguments);               GenericTypeParameterBuilder[] genericTypeParameterBuilder                 = typeBuilder.DefineGenericParameters(genericArgumentNames);               typeBuilder.MakeGenericType(genericTypeParameterBuilder);         }           /// <summary>         /// Gets the argument names from an array of generic argument types.         /// </summary>         /// <param name="genericArguments">The generic arguments.</param>         public static string[] GetArgumentNames(Type[] genericArguments)         {             string[] genericArgumentNames = new string[genericArguments.Length];               for (int i = 0; i < genericArguments.Length; i++)             {                 genericArgumentNames[i] = genericArguments[i].Name;             }               return genericArgumentNames;         }     } }       As you can see, I’m getting all of the generic argument types and names, creating a GenericTypeParameterBuilder and then using the typeBuilder to make the new type generic. InterceptorsField The interceptors field will store a List<IInterceptor<TBase>>. Fields are simple made using the FieldBuilder class. The following code demonstrates how to create the interceptor field. FieldBuilder interceptorsField = typeBuilder.DefineField(     "interceptors",     typeof(System.Collections.Generic.List<>).MakeGenericType(typeof(IInterceptor<TBase>)),       FieldAttributes.Private     ); The field will now exist with the new Type although it currently has no data – we’ll deal with this in the constructor. Add method for interceptorsField To enable us to add to the interceptorsField list, we are going to utilise the Add method that already exists within the System.Collections.Generic.List class. We still however have to create the methodInfo necessary to call the add method. This can be done similar to the following: Add Interceptor Field MethodInfo addInterceptor = typeof(List<>)     .MakeGenericType(new Type[] { typeof(IInterceptor<>).MakeGenericType(typeof(TBase)) })     .GetMethod     (        "Add",        BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic,        null,        new Type[] { typeof(IInterceptor<>).MakeGenericType(typeof(TBase)) },        null     ); So we’ve create a List<IInterceptor<TBase>> type, then using the type created a method info called Add which accepts an IInterceptor<TBase>. Now in our constructor we can use this to call this.interceptors.Add(// interceptor); Building the Constructors This will be the first hard-core part of the proxy building process so I’m going to show the class and then try to explain what everything is doing. For a clear view, download the source from http://rapidioc.codeplex.com/, go to the test project and debug through the constructor building section. Anyway, here it is: DynamicConstructorBuilder using System; using System.Collections.Generic; using System.Reflection; using System.Reflection.Emit; using Rapid.DynamicProxy.Interception; using Rapid.DynamicProxy.Types.Helpers; namespace Rapid.DynamicProxy.Types.Constructors {     /// <summary>     /// Class for creating the proxy constructors.     /// </summary>     internal static class DynamicConstructorBuilder     {         /// <summary>         /// Builds the constructors.         /// </summary>         /// <typeparam name="TBase">The base type.</typeparam>         /// <param name="typeBuilder">The type builder.</param>         /// <param name="interceptorsField">The interceptors field.</param>         public static void BuildConstructors<TBase>             (                 TypeBuilder typeBuilder,                 FieldBuilder interceptorsField,                 MethodInfo addInterceptor             )             where TBase : class         {             ConstructorInfo interceptorsFieldConstructor = CreateInterceptorsFieldConstructor<TBase>();               ConstructorInfo defaultInterceptorConstructor = CreateDefaultInterceptorConstructor<TBase>();               ConstructorInfo[] constructors = typeof(TBase).GetConstructors();               foreach (ConstructorInfo constructorInfo in constructors)             {                 CreateConstructor<TBase>                     (                         typeBuilder,                         interceptorsField,                         interceptorsFieldConstructor,                         defaultInterceptorConstructor,                         addInterceptor,                         constructorInfo                     );             }         }           #region Private Methods           private static void CreateConstructor<TBase>             (                 TypeBuilder typeBuilder,                 FieldBuilder interceptorsField,                 ConstructorInfo interceptorsFieldConstructor,                 ConstructorInfo defaultInterceptorConstructor,                 MethodInfo AddDefaultInterceptor,                 ConstructorInfo constructorInfo             ) where TBase : class         {             Type[] parameterTypes = GetParameterTypes(constructorInfo);               ConstructorBuilder constructorBuilder = CreateConstructorBuilder(typeBuilder, parameterTypes);               ILGenerator cIL = constructorBuilder.GetILGenerator();               LocalBuilder defaultInterceptorMethodVariable =                 cIL.DeclareLocal(typeof(DefaultInterceptor<>).MakeGenericType(typeof(TBase)));               ConstructInterceptorsField(interceptorsField, interceptorsFieldConstructor, cIL);               ConstructDefaultInterceptor(defaultInterceptorConstructor, cIL, defaultInterceptorMethodVariable);               AddDefaultInterceptorToInterceptorsList                 (                     interceptorsField,                     AddDefaultInterceptor,                     cIL,                     defaultInterceptorMethodVariable                 );               CreateConstructor(constructorInfo, parameterTypes, cIL);         }           private static void CreateConstructor(ConstructorInfo constructorInfo, Type[] parameterTypes, ILGenerator cIL)         {             cIL.Emit(OpCodes.Ldarg_0);               if (parameterTypes.Length > 0)             {                 LoadParameterTypes(parameterTypes, cIL);             }               cIL.Emit(OpCodes.Call, constructorInfo);             cIL.Emit(OpCodes.Ret);         }           private static void LoadParameterTypes(Type[] parameterTypes, ILGenerator cIL)         {             for (int i = 1; i <= parameterTypes.Length; i++)             {                 cIL.Emit(OpCodes.Ldarg_S, i);             }         }           private static void AddDefaultInterceptorToInterceptorsList             (                 FieldBuilder interceptorsField,                 MethodInfo AddDefaultInterceptor,                 ILGenerator cIL,                 LocalBuilder defaultInterceptorMethodVariable             )         {             cIL.Emit(OpCodes.Ldarg_0);             cIL.Emit(OpCodes.Ldfld, interceptorsField);             cIL.Emit(OpCodes.Ldloc, defaultInterceptorMethodVariable);             cIL.Emit(OpCodes.Callvirt, AddDefaultInterceptor);         }           private static void ConstructDefaultInterceptor             (                 ConstructorInfo defaultInterceptorConstructor,                 ILGenerator cIL,                 LocalBuilder defaultInterceptorMethodVariable             )         {             cIL.Emit(OpCodes.Newobj, defaultInterceptorConstructor);             cIL.Emit(OpCodes.Stloc, defaultInterceptorMethodVariable);         }           private static void ConstructInterceptorsField             (                 FieldBuilder interceptorsField,                 ConstructorInfo interceptorsFieldConstructor,                 ILGenerator cIL             )         {             cIL.Emit(OpCodes.Ldarg_0);             cIL.Emit(OpCodes.Newobj, interceptorsFieldConstructor);             cIL.Emit(OpCodes.Stfld, interceptorsField);         }           private static ConstructorBuilder CreateConstructorBuilder(TypeBuilder typeBuilder, Type[] parameterTypes)         {             return typeBuilder.DefineConstructor                 (                     MethodAttributes.Public | MethodAttributes.SpecialName | MethodAttributes.RTSpecialName                     | MethodAttributes.HideBySig, CallingConventions.Standard, parameterTypes                 );         }           private static Type[] GetParameterTypes(ConstructorInfo constructorInfo)         {             ParameterInfo[] parameterInfoArray = constructorInfo.GetParameters();               Type[] parameterTypes = new Type[parameterInfoArray.Length];               for (int p = 0; p < parameterInfoArray.Length; p++)             {                 parameterTypes[p] = parameterInfoArray[p].ParameterType;             }               return parameterTypes;         }           private static ConstructorInfo CreateInterceptorsFieldConstructor<TBase>() where TBase : class         {             return ConstructorHelper.CreateGenericConstructorInfo                 (                     typeof(List<>),                     new Type[] { typeof(IInterceptor<TBase>) },                     BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic                 );         }           private static ConstructorInfo CreateDefaultInterceptorConstructor<TBase>() where TBase : class         {             return ConstructorHelper.CreateGenericConstructorInfo                 (                     typeof(DefaultInterceptor<>),                     new Type[] { typeof(TBase) },                     BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic                 );         }           #endregion     } } So, the first two tasks within the class should be fairly clear, we are creating a ConstructorInfo for the interceptorField list and a ConstructorInfo for the DefaultConstructor, this is for instantiating them in each contructor. We then using Reflection get an array of all of the constructors in the base class, we then loop through the array and create a corresponding proxy contructor. Hopefully, the code is fairly easy to follow other than some new types and the dreaded Opcodes. ConstructorBuilder This class defines a new constructor on the type. ILGenerator The ILGenerator allows the use of Reflection.Emit to create the method body. LocalBuilder The local builder allows the storage of data in local variables within a method, in this case it’s the constructed DefaultInterceptor. Constructing the interceptors field The first bit of IL you’ll come across as you follow through the code is the following private method used for constructing the field list of interceptors. private static void ConstructInterceptorsField             (                 FieldBuilder interceptorsField,                 ConstructorInfo interceptorsFieldConstructor,                 ILGenerator cIL             )         {             cIL.Emit(OpCodes.Ldarg_0);             cIL.Emit(OpCodes.Newobj, interceptorsFieldConstructor);             cIL.Emit(OpCodes.Stfld, interceptorsField);         } The first thing to know about generating code using IL is that you are using a stack, if you want to use something, you need to push it up the stack etc. etc. OpCodes.ldArg_0 This opcode is a really interesting one, basically each method has a hidden first argument of the containing class instance (apart from static classes), constructors are no different. This is the reason you can use syntax like this.myField. So back to the method, as we want to instantiate the List in the interceptorsField, first we need to load the class instance onto the stack, we then load the new object (new List<TBase>) and finally we store it in the interceptorsField. Hopefully, that should follow easily enough in the method. In each constructor you would now have this.interceptors = new List<User<int, IRepository>>(); Constructing and storing the DefaultInterceptor The next bit of code we need to create is the constructed DefaultInterceptor. Firstly, we create a local builder to store the constructed type. Create a local builder LocalBuilder defaultInterceptorMethodVariable =     cIL.DeclareLocal(typeof(DefaultInterceptor<>).MakeGenericType(typeof(TBase))); Once our local builder is ready, we then need to construct the DefaultInterceptor<TBase> and store it in the variable. Connstruct DefaultInterceptor private static void ConstructDefaultInterceptor     (         ConstructorInfo defaultInterceptorConstructor,         ILGenerator cIL,         LocalBuilder defaultInterceptorMethodVariable     ) {     cIL.Emit(OpCodes.Newobj, defaultInterceptorConstructor);     cIL.Emit(OpCodes.Stloc, defaultInterceptorMethodVariable); } As you can see, using the ConstructorInfo named defaultInterceptorConstructor, we load the new object onto the stack. Then using the store local opcode (OpCodes.Stloc), we store the new object in the local builder named defaultInterceptorMethodVariable. Add the constructed DefaultInterceptor to the interceptors field collection Using the add method created earlier in this post, we are going to add the new DefaultInterceptor object to the interceptors field collection. Add Default Interceptor private static void AddDefaultInterceptorToInterceptorsList     (         FieldBuilder interceptorsField,         MethodInfo AddDefaultInterceptor,         ILGenerator cIL,         LocalBuilder defaultInterceptorMethodVariable     ) {     cIL.Emit(OpCodes.Ldarg_0);     cIL.Emit(OpCodes.Ldfld, interceptorsField);     cIL.Emit(OpCodes.Ldloc, defaultInterceptorMethodVariable);     cIL.Emit(OpCodes.Callvirt, AddDefaultInterceptor); } So, here’s whats going on. The class instance is first loaded onto the stack using the load argument at index 0 opcode (OpCodes.Ldarg_0) (remember the first arg is the hidden class instance). The interceptorsField is then loaded onto the stack using the load field opcode (OpCodes.Ldfld). We then load the DefaultInterceptor object we stored locally using the load local opcode (OpCodes.Ldloc). Then finally we call the AddDefaultInterceptor method using the call virtual opcode (Opcodes.Callvirt). Completing the constructor The last thing we need to do is complete the constructor. Complete the constructor private static void CreateConstructor(ConstructorInfo constructorInfo, Type[] parameterTypes, ILGenerator cIL)         {             cIL.Emit(OpCodes.Ldarg_0);               if (parameterTypes.Length > 0)             {                 LoadParameterTypes(parameterTypes, cIL);             }               cIL.Emit(OpCodes.Call, constructorInfo);             cIL.Emit(OpCodes.Ret);         }           private static void LoadParameterTypes(Type[] parameterTypes, ILGenerator cIL)         {             for (int i = 1; i <= parameterTypes.Length; i++)             {                 cIL.Emit(OpCodes.Ldarg_S, i);             }         } So, the first thing we do again is load the class instance using the load argument at index 0 opcode (OpCodes.Ldarg_0). We then load each parameter using OpCode.Ldarg_S, this opcode allows us to specify an index position for each argument. We then setup calling the base constructor using OpCodes.Call and the base constructors ConstructorInfo. Finally, all methods are required to return, even when they have a void return. As there are no values on the stack after the OpCodes.Call line, we can safely call the OpCode.Ret to give the constructor a void return. If there was a value, we would have to pop the value of the stack before calling return otherwise, the method would try and return a value. Conclusion This was a slightly hardcore post but hopefully it hasn’t been too hard to follow. The main thing is that a number of the really useful opcodes have been used and now the dynamic proxy is capable of being constructed. If you download the code and debug through the tests at http://rapidioc.codeplex.com/, you’ll be able to create proxies at this point, they cannon do anything in terms of interception but you can happily run the tests, call base methods and properties and also take a look at the created assembly in Reflector. Hope this is useful. The next post should be up soon, it will be covering creating the private methods for calling the base class methods and properties. Kind Regards, Sean.

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  • An Honest look at SharePoint Web Services

    - by juanlarios
    INTRODUCTION If you are a SharePoint developer you know that there are two basic ways to develop against SharePoint. 1) The object Model 2) Web services. SharePoint object model has the advantage of being quite rich. Anything you can do through the SharePoint UI as an administrator or end user, you can do through the object model. In fact everything that is done through the UI is done through the object model behind the scenes. The major disadvantage to getting at SharePoint this way is that the code needs to run on the server. This means that all web parts, event receivers, features, etc… all of this is code that is deployed to the server. The second way to get to SharePoint is through the built in web services. There are many articles on how to manipulate web services, how to authenticate to them and interact with them. The basic idea is that a remote application or process can contact SharePoint through a web service. Lots has been written about how great these web services are. This article is written to document the limitations, some of the issues and frustrations with working with SharePoint built in web services. Ultimately, for the tasks I was given to , SharePoint built in web services did not suffice. My evaluation of SharePoint built in services was compared against creating my own WCF Services to do what I needed. The current project I'm working on right now involved several "integration points". A remote application, installed on a separate server was to contact SharePoint and perform an task or operation. So I decided to start up Visual Studio and built a DLL and basically have 2 layers of logic. An integration layer and a data layer. A good friend of mine pointed me to SOLID principles and referred me to some videos and tutorials about it. I decided to implement the methodology (although a lot of the principles are common sense and I already incorporated in my coding practices). I was to deliver this dll to the application team and they would simply call the methods exposed by this dll and voila! it would do some task or operation in SharePoint. SOLUTION My integration layer implemented an interface that defined some of the basic integration tasks that I was to put together. My data layer was about the same, it implemented an interface with some of the tasks that I was going to develop. This gave me the opportunity to develop different data layers, ultimately different ways to get at SharePoint if I needed to. This is a classic SOLID principle. In this case it proved to be quite helpful because I wrote one data layer completely implementing SharePoint built in Web Services and another implementing my own WCF Service that I wrote. I should mention there is another layer underneath the data layer. In referencing SharePoint or WCF services in my visual studio project I created a class for every web service call. So for example, if I used List.asx. I created a class called "DocumentRetreival" this class would do the grunt work to connect to the correct URL, It would perform the basic operation of contacting the service and so on. If I used a view.asmx, I implemented a class called "ViewRetrieval" with the same idea as the last class but it would now interact with all he operations in view.asmx. This gave my data layer the ability to perform multiple calls without really worrying about some of the grunt work each class performs. This again, is a classic SOLID principle. So, in order to compare them side by side we can look at both data layers and with is involved in each. Lets take a look at the "Create Project" task or operation. The integration point is described as , "dll is to provide a way to create a project in SharePoint". Projects , in this case are basically document libraries. I am to implement a way in which a remote application can create a document library in SharePoint. Easy enough right? Use the list.asmx Web service in SharePoint. So here we go! Lets take a look at the code. I added the List.asmx web service reference to my project and this is the class that contacts it:  class DocumentRetrieval     {         private ListsSoapClient _service;      d   private bool _impersonation;         public DocumentRetrieval(bool impersonation, string endpt)         {             _service = new ListsSoapClient();             this.SetEndPoint(string.Format("{0}/{1}", endpt, ConfigurationManager.AppSettings["List"]));             _impersonation = impersonation;             if (_impersonation)             {                 _service.ClientCredentials.Windows.ClientCredential.Password = ConfigurationManager.AppSettings["password"];                 _service.ClientCredentials.Windows.ClientCredential.UserName = ConfigurationManager.AppSettings["username"];                 _service.ClientCredentials.Windows.AllowedImpersonationLevel =                     System.Security.Principal.TokenImpersonationLevel.Impersonation;             }     private void SetEndPoint(string p)          {             _service.Endpoint.Address = new EndpointAddress(p);          }          /// <summary>         /// Creates a document library with specific name and templateID         /// </summary>         /// <param name="listName">New list name</param>         /// <param name="templateID">Template ID</param>         /// <returns></returns>         public XmlElement CreateLibrary(string listName, int templateID, ref ExceptionContract exContract)         {             XmlDocument sample = new XmlDocument();             XmlElement viewCol = sample.CreateElement("Empty");             try             {                 _service.Open();                 viewCol = _service.AddList(listName, "", templateID);             }             catch (Exception ex)             {                 exContract = new ExceptionContract("DocumentRetrieval/CreateLibrary", ex.GetType(), "Connection Error", ex.StackTrace, ExceptionContract.ExceptionCode.error);                             }finally             {                 _service.Close();             }                                      return viewCol;         } } There was a lot more in this class (that I am not including) because i was reusing the grunt work and making other operations with LIst.asmx, For example, updating content types, changing or configuring lists or document libraries. One of the first things I noticed about working with the built in services is that you are really at the mercy of what is available to you. Before creating a document library (Project) I wanted to expose a IsProjectExisting method. This way the integration or data layer could recognize if a library already exists. Well there is no service call or method available to do that check. So this is what I wrote:   public bool DocLibExists(string listName, ref ExceptionContract exContract)         {             try             {                 var allLists = _service.GetListCollection();                                return allLists.ChildNodes.OfType<XmlElement>().ToList().Exists(x => x.Attributes["Title"].Value ==listName);             }             catch (Exception ex)             {                 exContract = new ExceptionContract("DocumentRetrieval/GetList/GetListWSCall", ex.GetType(), "Unable to Retrieve List Collection", ex.StackTrace, ExceptionContract.ExceptionCode.error);             }             return false;         } This really just gets an XMLElement with all the lists. It was then up to me to sift through the clutter and noise and see if Document library already existed. This took a little bit of getting used to. Now instead of working with code, you are working with XMLElement response format from web service. I wrote a LINQ query to go through and find if the attribute "Title" existed and had a value of the listname then it would return True, if not False. I didn't particularly like working this way. Dealing with XMLElement responses and then having to manipulate it to get at the exact data I was looking for. Once the check for the DocLibExists, was done, I would either create the document library or send back an error indicating the document library already existed. Now lets examine the code that actually creates the document library. It does what you are really after, it creates a document library. Notice how the template ID is really an integer. Every document library template in SharePoint has an ID associated with it. Document libraries, Image Library, Custom List, Project Tasks, etc… they all he a unique integer associated with it. Well, that's great but the client came back to me and gave me some specifics that each "project" or document library, should have. They specified they had 3 types of projects. Each project would have unique views, about 10 views for each project. Each Project specified unique configurations (auditing, versioning, content types, etc…) So what turned out to be a simple implementation of creating a document library as a repository for a project, turned out to be quite involved.  The first thing I thought of was to create a template for document library. There are other ways you can do this too. Using the web Service call, you could configure views, versioning, even content types, etc… the only catch is, you have to be working quite extensively with CAML. I am not fond of CAML. I can do it and work with it, I just don't like doing it. It is quite touchy and at times it is quite tough to understand where errors were made with CAML statements. Working with Web Services and CAML proved to be quite annoying. The service call would return a generic error message that did not particularly point me to a CAML statement syntax error, or even a CAML error. I was not sure if it was a security , performance or code based issue. It was quite tough to work with. At times it was difficult to work with because of the way SharePoint handles metadata. There are "Names", "Display Name", and "StaticName" fields. It was quite tough to understand at times, which one to use. So it took a lot of trial and error. There are tools that can help with CAML generation. There is also now intellisense for CAML statements in Visual Studio that might help but ultimately I'm not fond of CAML with Web Services.   So I decided on the template. So my plan was to create create a document library, configure it accordingly and then use The Template Builder that comes with the SharePoint SDK. This tool allows you to create site templates, list template etc… It is quite interesting because it does not generate an STP file, it actually generates an xml definition and a feature you can activate and make that template available on a site or site collection. The first issue I experienced with this is that one of the specifications to this template was that the "All Documents" view was to have 2 web parts on it. Well, it turns out that using the template builder , it did not include the web parts as part of the list template definition it generated. It backed up the settings, the views, the content types but not the custom web parts. I still decided to try this even without the web parts on the page. This new template defined a new Document library definition with a unique ID. The problem was that the service call accepts an int but it only has access to the built in library int definitions. Any new ones added or created will not be available to create. So this made it impossible for me to approach the problem this way.     I should also mention that one of the nice features about SharePoint is the ability to create list templates, back them up and then create lists based on that template. It can all be done by end user administrators. These templates are quite unique because they are saved as an STP file and not an xml definition. I also went this route and tried to see if there was another service call where I could create a document library based no given template name. Nope! none.      After some thinking I decide to implement a WCF service to do this creation for me. I was quite certain that the object model would allow me to create document libraries base on a template in which an ID was required and also templates saved as STP files. Now I don't want to bother with posting the code to contact WCF service because it's self explanatory, but I will post the code that I used to create a list with custom template. public ServiceResult CreateProject(string name, string templateName, string projectId)         {             string siteurl = SPContext.Current.Site.Url;             Guid webguid = SPContext.Current.Web.ID;                        using (SPSite site = new SPSite(siteurl))             {                 using (SPWeb rootweb = site.RootWeb)                 {                     SPListTemplateCollection temps = site.GetCustomListTemplates(rootweb);                     ProcessWeb(siteurl, webguid, web => Act_CreateProject(web, name, templateName, projectId, temps));                 }//SpWeb             }//SPSite              return _globalResult;                   }         private void Act_CreateProject(SPWeb targetsite, string name, string templateName, string projectId, SPListTemplateCollection temps) {                         var temp = temps.Cast<SPListTemplate>().FirstOrDefault(x => x.Name.Equals(templateName));             if (temp != null)             {                             try                 {                                         Guid listGuid = targetsite.Lists.Add(name, "", temp);                     SPList newList = targetsite.Lists[listGuid];                     _globalResult = new ServiceResult(true, "Success", "Success");                 }                 catch (Exception ex)                 {                     _globalResult = new ServiceResult(false, (string.IsNullOrEmpty(ex.Message) ? "None" : ex.Message + " " + templateName), ex.StackTrace.ToString());                 }                                       }        private void ProcessWeb(string siteurl, Guid webguid, Action<SPWeb> action) {                        using (SPSite sitecollection = new SPSite(siteurl)) {                 using (SPWeb web = sitecollection.AllWebs[webguid]) {                     action(web);                 }                     }                  } This code is actually some of the code I implemented for the service. there was a lot more I did on Project Creation which I will cover in my next blog post. I implemented an ACTION method to process the web. This allowed me to properly dispose the SPWEb and SPSite objects and not rewrite this code over and over again. So I implemented a WCF service to create projects for me, this allowed me to do a lot more than just create a document library with a template, it now gave me the flexibility to do just about anything the client wanted at project creation. Once this was implemented , the client came back to me and said, "we reference all our projects with ID's in our application. we want SharePoint to do the same". This has been something I have been doing for a little while now but I do hope that SharePoint 2010 can have more of an answer to this and address it properly. I have been adding metadata to SPWebs through property bag. I believe I have blogged about it before. This time it required metadata added to a document library. No problem!!! I also mentioned these web parts that were to go on the "All Documents" View. I took the opportunity to configure them to the appropriate settings. There were two settings that needed to be set on these web parts. One of them was a Project ID configured in the webpart properties. The following code enhances and replaces the "Act_CreateProject " method above:  private void Act_CreateProject(SPWeb targetsite, string name, string templateName, string projectId, SPListTemplateCollection temps) {                         var temp = temps.Cast<SPListTemplate>().FirstOrDefault(x => x.Name.Equals(templateName));             if (temp != null)             {                 SPLimitedWebPartManager wpmgr = null;                               try                 {                                         Guid listGuid = targetsite.Lists.Add(name, "", temp);                     SPList newList = targetsite.Lists[listGuid];                     SPFolder rootFolder = newList.RootFolder;                     rootFolder.Properties.Add(KEY, projectId);                     rootFolder.Update();                     if (rootFolder.ParentWeb != targetsite)                         rootFolder.ParentWeb.Dispose();                     if (!templateName.Contains("Natural"))                     {                         SPView alldocumentsview = newList.Views.Cast<SPView>().FirstOrDefault(x => x.Title.Equals(ALLDOCUMENTS));                         SPFile alldocfile = targetsite.GetFile(alldocumentsview.ServerRelativeUrl);                         wpmgr = alldocfile.GetLimitedWebPartManager(PersonalizationScope.Shared);                         ConfigureWebPart(wpmgr, projectId, CUSTOMWPNAME);                                              alldocfile.Update();                     }                                        if (newList.ParentWeb != targetsite)                         newList.ParentWeb.Dispose();                     _globalResult = new ServiceResult(true, "Success", "Success");                 }                 catch (Exception ex)                 {                     _globalResult = new ServiceResult(false, (string.IsNullOrEmpty(ex.Message) ? "None" : ex.Message + " " + templateName), ex.StackTrace.ToString());                 }                 finally                 {                     if (wpmgr != null)                     {                         wpmgr.Web.Dispose();                         wpmgr.Dispose();                     }                 }             }                         }       private void ConfigureWebPart(SPLimitedWebPartManager mgr, string prjId, string webpartname)         {             var wp = mgr.WebParts.Cast<System.Web.UI.WebControls.WebParts.WebPart>().FirstOrDefault(x => x.DisplayTitle.Equals(webpartname));             if (wp != null)             {                           (wp as ListRelationshipWebPart.ListRelationshipWebPart).ProjectID = prjId;                 mgr.SaveChanges(wp);             }         }   This Shows you how I was able to set metadata on the document library. It has to be added to the RootFolder of the document library, Unfortunately, the SPList does not have a Property bag that I can add a key\value pair to. It has to be done on the root folder. Now everything in the integration will reference projects by ID's and will not care about names. My, "DocLibExists" will now need to be changed because a web service is not set up to look at property bags.  I had to write another method on the Service to do the equivalent but with ID's instead of names.  The second thing you will notice about the code is the use of the Webpartmanager. I have seen several examples online, and also read a lot about memory leaks, The above code does not produce memory leaks. The web part manager creates an SPWeb, so just dispose it like I did. CONCLUSION This is a long long post so I will stop here for now, I will continue with more comparisons and limitations in my next post. My conclusion for this example is that Web Services will do the trick if you can suffer through CAML and if you are doing some simple operations. For Everything else, there's WCF! **** fireI apologize for the disorganization of this post, I was on a bus on a 12 hour trip to IOWA while I wrote it, I was half asleep and half awake, hopefully it makes enough sense to someone.

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  • Trying to convert simple midlet application to Android application but running into problems.

    - by chobo2
    Hi I am trying to do some threading in Android so I took an old threading assignment I had done fora midlet and took out the midlet code and replaced it with android code(such as textview). package com.assignment1; import android.app.Activity; import android.os.Bundle; import android.widget.TextView; public class Threading extends Activity { private TextView tortose; private TextView hare; private Thread hareThread; private Thread torotoseThread; private int num = 0; private int num2 = 0; public Threading() { } /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); tortose = (TextView) findViewById(R.id.TextView01); hare = (TextView) findViewById(R.id.TextView02); Hare newHare = new Hare(); hareThread = new Thread(newHare); hareThread.start(); Torotose newTortose = new Torotose(); torotoseThread = new Thread(newTortose); torotoseThread.start(); //updateDisplay(); } private synchronized void check(int value1, int value2) { if((value1-value2) >= 10) { try { wait(); } catch(Exception ex) { System.out.println(ex); } } } private synchronized void getGoing(int value1, int value2) { if((value1-value2) == 0) { try { notify(); } catch(Exception ex) { System.out.println(ex); } } } private class Hare extends Thread { public void run() { while(true) { num++; hare.setText(Integer.toString(num)); check(num, num2); try { // are threads different in andriod apps? Thread.sleep(100); // hareThread.sleep(100); } catch(Exception ex) { System.out.println(ex); } } } } private class Torotose extends Thread { public void run() { while(true) { num2++; tortose.setText(Integer.toString(num2)); getGoing(num,num2); try { Thread.sleep(200); //torotoseThread.sleep(200); } catch(Exception ex) { System.out.println(ex); } } } } } First it wanted me to change my threads to like static threads.So is this just how Android does it? Next when I run this code it just crashes with some unexpected error. I am not sure what the error is but when I try to debug it and goes to like to create a new "hare" object it shows me this. // Compiled from ClassLoader.java (version 1.5 : 49.0, super bit) public abstract class java.lang.ClassLoader { // Method descriptor #8 ()V // Stack: 3, Locals: 1 protected ClassLoader(); 0 aload_0 [this] 1 invokespecial java.lang.Object() [1] 4 new java.lang.RuntimeException [2] 7 dup 8 ldc <String "Stub!"> [3] 10 invokespecial java.lang.RuntimeException(java.lang.String) [4] 13 athrow Line numbers: [pc: 0, line: 4] Local variable table: [pc: 0, pc: 14] local: this index: 0 type: java.lang.ClassLoader // Method descriptor #14 (Ljava/lang/ClassLoader;)V // Stack: 3, Locals: 2 protected ClassLoader(java.lang.ClassLoader parentLoader); 0 aload_0 [this] 1 invokespecial java.lang.Object() [1] 4 new java.lang.RuntimeException [2] 7 dup 8 ldc <String "Stub!"> [3] 10 invokespecial java.lang.RuntimeException(java.lang.String) [4] 13 athrow Line numbers: [pc: 0, line: 5] Local variable table: [pc: 0, pc: 14] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 14] local: parentLoader index: 1 type: java.lang.ClassLoader // Method descriptor #17 ()Ljava/lang/ClassLoader; // Stack: 3, Locals: 0 public static java.lang.ClassLoader getSystemClassLoader(); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 6] // Method descriptor #19 (Ljava/lang/String;)Ljava/net/URL; // Stack: 3, Locals: 1 public static java.net.URL getSystemResource(java.lang.String resName); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 7] Local variable table: [pc: 0, pc: 10] local: resName index: 0 type: java.lang.String // Method descriptor #23 (Ljava/lang/String;)Ljava/util/Enumeration; // Signature: (Ljava/lang/String;)Ljava/util/Enumeration<Ljava/net/URL;>; // Stack: 3, Locals: 1 public static java.util.Enumeration getSystemResources(java.lang.String resName) throws java.io.IOException; 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 8] Local variable table: [pc: 0, pc: 10] local: resName index: 0 type: java.lang.String // Method descriptor #29 (Ljava/lang/String;)Ljava/io/InputStream; // Stack: 3, Locals: 1 public static java.io.InputStream getSystemResourceAsStream(java.lang.String resName); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 9] Local variable table: [pc: 0, pc: 10] local: resName index: 0 type: java.lang.String // Method descriptor #31 ([BII)Ljava/lang/Class; // Signature: ([BII)Ljava/lang/Class<*>; // Stack: 3, Locals: 4 protected final java.lang.Class defineClass(byte[] classRep, int offset, int length) throws java.lang.ClassFormatError; 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 10] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: classRep index: 1 type: byte[] [pc: 0, pc: 10] local: offset index: 2 type: int [pc: 0, pc: 10] local: length index: 3 type: int // Method descriptor #39 (Ljava/lang/String;[BII)Ljava/lang/Class; // Signature: (Ljava/lang/String;[BII)Ljava/lang/Class<*>; // Stack: 3, Locals: 5 protected final java.lang.Class defineClass(java.lang.String className, byte[] classRep, int offset, int length) throws java.lang.ClassFormatError; 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 11] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: className index: 1 type: java.lang.String [pc: 0, pc: 10] local: classRep index: 2 type: byte[] [pc: 0, pc: 10] local: offset index: 3 type: int [pc: 0, pc: 10] local: length index: 4 type: int // Method descriptor #42 (Ljava/lang/String;[BIILjava/security/ProtectionDomain;)Ljava/lang/Class; // Signature: (Ljava/lang/String;[BIILjava/security/ProtectionDomain;)Ljava/lang/Class<*>; // Stack: 3, Locals: 6 protected final java.lang.Class defineClass(java.lang.String className, byte[] classRep, int offset, int length, java.security.ProtectionDomain protectionDomain) throws java.lang.ClassFormatError; 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 12] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: className index: 1 type: java.lang.String [pc: 0, pc: 10] local: classRep index: 2 type: byte[] [pc: 0, pc: 10] local: offset index: 3 type: int [pc: 0, pc: 10] local: length index: 4 type: int [pc: 0, pc: 10] local: protectionDomain index: 5 type: java.security.ProtectionDomain // Method descriptor #46 (Ljava/lang/String;Ljava/nio/ByteBuffer;Ljava/security/ProtectionDomain;)Ljava/lang/Class; // Signature: (Ljava/lang/String;Ljava/nio/ByteBuffer;Ljava/security/ProtectionDomain;)Ljava/lang/Class<*>; // Stack: 3, Locals: 4 protected final java.lang.Class defineClass(java.lang.String name, java.nio.ByteBuffer b, java.security.ProtectionDomain protectionDomain) throws java.lang.ClassFormatError; 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 13] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: name index: 1 type: java.lang.String [pc: 0, pc: 10] local: b index: 2 type: java.nio.ByteBuffer [pc: 0, pc: 10] local: protectionDomain index: 3 type: java.security.ProtectionDomain // Method descriptor #52 (Ljava/lang/String;)Ljava/lang/Class; // Signature: (Ljava/lang/String;)Ljava/lang/Class<*>; // Stack: 3, Locals: 2 protected java.lang.Class findClass(java.lang.String className) throws java.lang.ClassNotFoundException; 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 14] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: className index: 1 type: java.lang.String // Method descriptor #52 (Ljava/lang/String;)Ljava/lang/Class; // Signature: (Ljava/lang/String;)Ljava/lang/Class<*>; // Stack: 3, Locals: 2 protected final java.lang.Class findLoadedClass(java.lang.String className); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 15] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: className index: 1 type: java.lang.String // Method descriptor #52 (Ljava/lang/String;)Ljava/lang/Class; // Signature: (Ljava/lang/String;)Ljava/lang/Class<*>; // Stack: 3, Locals: 2 protected final java.lang.Class findSystemClass(java.lang.String className) throws java.lang.ClassNotFoundException; 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 16] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: className index: 1 type: java.lang.String // Method descriptor #17 ()Ljava/lang/ClassLoader; // Stack: 3, Locals: 1 public final java.lang.ClassLoader getParent(); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 17] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader // Method descriptor #19 (Ljava/lang/String;)Ljava/net/URL; // Stack: 3, Locals: 2 public java.net.URL getResource(java.lang.String resName); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 18] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: resName index: 1 type: java.lang.String // Method descriptor #23 (Ljava/lang/String;)Ljava/util/Enumeration; // Signature: (Ljava/lang/String;)Ljava/util/Enumeration<Ljava/net/URL;>; // Stack: 3, Locals: 2 public java.util.Enumeration getResources(java.lang.String resName) throws java.io.IOException; 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 19] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: resName index: 1 type: java.lang.String // Method descriptor #29 (Ljava/lang/String;)Ljava/io/InputStream; // Stack: 3, Locals: 2 public java.io.InputStream getResourceAsStream(java.lang.String resName); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 20] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: resName index: 1 type: java.lang.String // Method descriptor #52 (Ljava/lang/String;)Ljava/lang/Class; // Signature: (Ljava/lang/String;)Ljava/lang/Class<*>; // Stack: 3, Locals: 2 public java.lang.Class loadClass(java.lang.String className) throws java.lang.ClassNotFoundException; 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 21] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: className index: 1 type: java.lang.String // Method descriptor #62 (Ljava/lang/String;Z)Ljava/lang/Class; // Signature: (Ljava/lang/String;Z)Ljava/lang/Class<*>; // Stack: 3, Locals: 3 protected java.lang.Class loadClass(java.lang.String className, boolean resolve) throws java.lang.ClassNotFoundException; 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 22] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: className index: 1 type: java.lang.String [pc: 0, pc: 10] local: resolve index: 2 type: boolean // Method descriptor #67 (Ljava/lang/Class;)V // Signature: (Ljava/lang/Class<*>;)V // Stack: 3, Locals: 2 protected final void resolveClass(java.lang.Class clazz); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 23] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: clazz index: 1 type: java.lang.Class Local variable type table: [pc: 0, pc: 10] local: clazz index: 1 type: java.lang.Class<?> // Method descriptor #19 (Ljava/lang/String;)Ljava/net/URL; // Stack: 3, Locals: 2 protected java.net.URL findResource(java.lang.String resName); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 24] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: resName index: 1 type: java.lang.String // Method descriptor #23 (Ljava/lang/String;)Ljava/util/Enumeration; // Signature: (Ljava/lang/String;)Ljava/util/Enumeration<Ljava/net/URL;>; // Stack: 3, Locals: 2 protected java.util.Enumeration findResources(java.lang.String resName) throws java.io.IOException; 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 25] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: resName index: 1 type: java.lang.String // Method descriptor #76 (Ljava/lang/String;)Ljava/lang/String; // Stack: 3, Locals: 2 protected java.lang.String findLibrary(java.lang.String libName); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 26] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: libName index: 1 type: java.lang.String // Method descriptor #79 (Ljava/lang/String;)Ljava/lang/Package; // Stack: 3, Locals: 2 protected java.lang.Package getPackage(java.lang.String name); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 27] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: name index: 1 type: java.lang.String // Method descriptor #81 ()[Ljava/lang/Package; // Stack: 3, Locals: 1 protected java.lang.Package[] getPackages(); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 28] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader // Method descriptor #83 (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/net/URL;)Ljava/lang/Package; // Stack: 3, Locals: 9 protected java.lang.Package definePackage(java.lang.String name, java.lang.String specTitle, java.lang.String specVersion, java.lang.String specVendor, java.lang.String implTitle, java.lang.String implVersion, java.lang.String implVendor, java.net.URL sealBase) throws java.lang.IllegalArgumentException; 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 29] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: name index: 1 type: java.lang.String [pc: 0, pc: 10] local: specTitle index: 2 type: java.lang.String [pc: 0, pc: 10] local: specVersion index: 3 type: java.lang.String [pc: 0, pc: 10] local: specVendor index: 4 type: java.lang.String [pc: 0, pc: 10] local: implTitle index: 5 type: java.lang.String [pc: 0, pc: 10] local: implVersion index: 6 type: java.lang.String [pc: 0, pc: 10] local: implVendor index: 7 type: java.lang.String [pc: 0, pc: 10] local: sealBase index: 8 type: java.net.URL // Method descriptor #94 (Ljava/lang/Class;[Ljava/lang/Object;)V // Signature: (Ljava/lang/Class<*>;[Ljava/lang/Object;)V // Stack: 3, Locals: 3 protected final void setSigners(java.lang.Class c, java.lang.Object[] signers); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 30] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: c index: 1 type: java.lang.Class [pc: 0, pc: 10] local: signers index: 2 type: java.lang.Object[] Local variable type table: [pc: 0, pc: 10] local: c index: 1 type: java.lang.Class<?> // Method descriptor #100 (Ljava/lang/String;Z)V // Stack: 3, Locals: 3 public void setClassAssertionStatus(java.lang.String cname, boolean enable); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 31] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: cname index: 1 type: java.lang.String [pc: 0, pc: 10] local: enable index: 2 type: boolean // Method descriptor #100 (Ljava/lang/String;Z)V // Stack: 3, Locals: 3 public void setPackageAssertionStatus(java.lang.String pname, boolean enable); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 32] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: pname index: 1 type: java.lang.String [pc: 0, pc: 10] local: enable index: 2 type: boolean // Method descriptor #106 (Z)V // Stack: 3, Locals: 2 public void setDefaultAssertionStatus(boolean enable); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 33] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader [pc: 0, pc: 10] local: enable index: 1 type: boolean // Method descriptor #8 ()V // Stack: 3, Locals: 1 public void clearAssertionStatus(); 0 new java.lang.RuntimeException [2] 3 dup 4 ldc <String "Stub!"> [3] 6 invokespecial java.lang.RuntimeException(java.lang.String) [4] 9 athrow Line numbers: [pc: 0, line: 34] Local variable table: [pc: 0, pc: 10] local: this index: 0 type: java.lang.ClassLoader } So I am not sure where I went wrong. Thanks

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