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  • How to run a javascript function before postback of asp.net button?

    - by Curtis White
    I'm using Javascript to create a DIV element and open up a new page by using onclientclick. This works great. Now, I need to write to it from the server side and this element must be created before it is posted back. How do I get the javascript to execute before the postback? Currently, I have to press the button twice because the element doesn't exist to write too on the first click. To be clear, I need this to execute before the "OnClick" of the button. Update: It looks like the Javascript function is called before the postback but the element is not updated until I run the second postback. Hmm Update: Unfortunately it is a bit more complicated then this. I'm creating a div tag in javascript to open a new window. Inside the div tag, I'm using a databinding syntax <%=Preview% so that I can get access to this element on the server side. From the server side, I'm injecting the code. I'm thinking this may be a chicken-egg problem but not sure. UPDATE! It is not the Javascript not running first. It is the databinding mechanism which is reading the blank variable before I'm able to set it. Hmm

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  • Project Euler #119 Make Faster

    - by gangqinlaohu
    Trying to solve Project Euler problem 119: The number 512 is interesting because it is equal to the sum of its digits raised to some power: 5 + 1 + 2 = 8, and 8^3 = 512. Another example of a number with this property is 614656 = 28^4. We shall define an to be the nth term of this sequence and insist that a number must contain at least two digits to have a sum. You are given that a2 = 512 and a10 = 614656. Find a30. Question: Is there a more efficient way to find the answer than just checking every number until a30 is found? My Code int currentNum = 0; long value = 0; for (long a = 11; currentNum != 30; a++){ //maybe a++ is inefficient int test = Util.sumDigits(a); if (isPower(a, test)) { currentNum++; value = a; System.out.println(value + ":" + currentNum); } } System.out.println(value); isPower checks if a is a power of test. Util.sumDigits: public static int sumDigits(long n){ int sum = 0; String s = "" + n; while (!s.equals("")){ sum += Integer.parseInt("" + s.charAt(0)); s = s.substring(1); } return sum; } program has been running for about 30 minutes (might be overflow on the long). Output (so far): 81:1 512:2 2401:3 4913:4 5832:5 17576:6 19683:7 234256:8 390625:9 614656:10 1679616:11 17210368:12 34012224:13 52521875:14 60466176:15 205962976:16 612220032:17

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  • C ++ virtual function

    - by user2950788
    masters of C++. I am trying to implement polymorphism in C++. I want to write a base class with a virtual function and then redefine that function in the child class. then demonstrate dynamic binding in my driver program. But I just couldn't get it to work. I know how to do it in C#, so I figured that I might have made some syntactical mistakes where I had used C#'s syntax in my C++ code, but these mistakes are not obvious to me at all. So I'd greatly appreciate it if you would correct my mistakes. class polyTest { public: polyTest(); virtual void type(); virtual ~polyTest(); }; void polyTest::type() { cout << "first gen"; } class polyChild: public polyTest { public: void type(); }; void polyChild::type() { cout << "second gen"; } int main() { polyChild * ptr1; polyChild * ptr2; ptr1 = new polyTest(); ptr2 = new polyChild(); ptr1 -> type(); ptr2 -> type(); }

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  • How can I speed up a 1800-line PHP include? It's slowing my pageload down to 10sec/view

    - by somerandomguy
    I designed my code to put all important functions in a single PHP file that's now 1800 lines long. I call it in other PHP files--AJAX processors, for example--with a simple "require_once("codeBank.php")". I'm discovering that it takes about 10 seconds to load up all those functions, even though I have nothing more than a few global arrays and a bunch of other functions involved. The main AJAX processor code, for example, is taking 8 seconds just to do a simple syntax verification (whose operational function is stored in codeBank.php). When I comment out the require_once, my AJAX response time speeds up from 10sec to 40ms, so it's pretty clear that PHP's trying to do something with those 1800 lines of functions. That's even with APC installed, which is surprising. What should I do to get my code speed back to the sub-100ms level? Am I failing to get the cache's benefit somehow? Do I need to cut that single function bank file into different pieces? Are there other subtle things that I could be doing to screw up my response time? Or barring all that, what are some tools to dig further into which PHP operations are hitting speed bumps?

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  • Determining if object is visible and clickable

    - by Alan Mendelevich
    I'm looking for ways to effectively determine if a control is actually visible and clickable. I mean beyond checking Visibility property of the object. I can check RenderSize and that would be [0,0] if any of the parent elements is collapsed. So this is simple too. I can also traverse up the visual tree and see if Opacity of all elements is set to 1. What I don't know how to check nicely are these scenarios: The object is obstructed by some other object. Obviously it's possible to use FindElementsInHostCoordinates() and do computations to find out how much these objects obstruct but this could be an overkill. I can also make a "screenshot" of the object in question and "screenshot" of the whole page and check if pixels where my object should be match the actual object pixels. That sounds like an overkill too. The object is obstructed by a transparent object that still "swallows" clicks (taps). The workarounds for the first problem could still fail in this scenario. Any better ideas? Do I miss something? Thanks!

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  • how to make condition on selection of checkbox in user controler

    - by kumar
    I have a user control <input id="check" type="checkbox" /> <label>&nbsp;</label> <fieldset class="clearfix" id="fieldset-exception"> <legend>Student Information</legend> <div class="fiveper"> <label for="StudentID"> Exception ID: <span><%=Html.EditorFor(x => x.studentid)%></span> </label> <label for="Classroom"> Origination: <span><%=Html.EditorFor(model => model.Classroom)%></span> </label> <label for="Subject"> Age: <span><%=Html.EditorFor(model => model.subject)%></span> </label> </div> $('#btnAll').click(function() { $('#Details input[type=checkbox]').attr('checked', 'checked'); }); I am checking all checkboxes using above code but I need to make condition here that user need to select atleast one checkbox to do something? i have other button to go other page based on this checkbox checked? can anybody tell me how to check that and how to make that condition here? Thanks thanks

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  • Input html tag not parsing properly in php

    - by Akaash
    I have a database with names that I would like displayed in the form of a table with checkboxes. Everything works until I try to place the html tag into my php code. When I put the input tag in it gives me the error: Parse error: syntax error, unexpected T_STRING, expecting ',' or ';' I can't see where I would put a comma or semi colon. <form> <?php $name = $_POST['name']; $host = "mysql16.000webhost.com"; $user_name = "a1611480_akaash"; $pwd = "****"; $database_name = "a1611480_akaash"; $db = mysql_connect($host, $user_name, $pwd); mysql_select_db($database_name); $result = mysql_query("SELECT name FROM Sort"); $var = array(); while ($row = mysql_fetch_array($result)) { $var[] = $row['name']; } $unique = array_unique($var); foreach ($unique as $value) { echo "<p class = Body_text><label>$value</label> <input type="checkbox" name="name" value="$value" /> </p>\n"; } ?> </form>

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  • Can a conforming C# compiler optimize away a local (but unused) variable if it is the only strong re

    - by stakx
    The title says it all, but let me explain: void Case_1() { var weakRef = new WeakReference(new object()); GC.Collect(); // <-- doesn't have to be an explicit call; just assume that // garbage collection would occur at this point. if (weakRef.IsAlive) ... } In this code example, I obviously have to plan for the possibility that the new'ed object is reclaimed by the garbage collector; therefore the if statement. (Note that I'm using weakRef for the sole purpose of checking if the new'ed object is still around.) void Case_2() { var unusedLocalVar = new object(); var weakRef = new WeakReference(unusedLocalVar); GC.Collect(); // <-- doesn't have to be an explicit call; just assume that // garbage collection would occur at this point. Debug.Assert(weakReferenceToUseless.IsAlive); } The main change in this code example from the previous one is that the new'ed object is strongly referenced by a local variable (unusedLocalVar). However, this variable is never used again after the weak reference (weakRef) has been created. Question: Is a conforming C# compiler allowed to optimize the first two lines of Case_2 into those of Case_1 if it sees that unusedLocalVar is only used in one place, namely as an argument to the WeakReference constructor? i.e. is there any possibility that the assertion in Case_2 could ever fail?

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  • Tiny MCE (jquery plugin version) not showing toolbar in IE (works fine in other browsers)

    - by I am Wonder
    I had an implementation working well but for some reason IE decided it was tired of playing nice. I have an advanced implementation of TinyMCE (the jquery plugin version - see http://tinymce.moxiecode.com/examples/example_23.php for details). It still works great in all browsers but IE. In IE it shows the drop-down options for Format, Font family, and Font size, but only as text.. not as a drop down normally looks. All other buttons on the toolbar are missing. (I've tried IE8 and IE8 Compatibility Mode) I get a javascript error: Syntax error Line 36 Char 1. Unfortunately the javascript is being loaded dynamically so this doesn't help me. Here is my implementation code for the TinyMCE editor: $(function () { $('#InputStuffHere').tinymce({ // General options theme: "advanced", plugins: "safari,pagebreak,style,layer,table,save,advhr,advimage,advlink,inlinepopups,preview,media,searchreplace,contextmenu,paste,fullscreen,noneditable,visualchars,nonbreaking,template", // Theme options theme_advanced_buttons1: "bold,italic,underline,strikethrough,|,justifyleft,justifycenter,justifyright,justifyfull,formatselect,fontselect,fontsizeselect,|,hr,removeformat", theme_advanced_buttons2: "cut,copy,paste,pastetext,pasteword,|,search,replace,|,bullist,numlist,|,outdent,indent,blockquote,|,undo,redo,|,link,unlink,image,|,forecolor,backcolor,|,spellchecker", theme_advanced_buttons3 : "", theme_advanced_toolbar_location: "top", theme_advanced_toolbar_align: "left", theme_advanced_statusbar_location: "bottom", theme_advanced_resizing: true, // Drop lists for link/image/media/template dialogs template_external_list_url: "lists/template_list.js", external_link_list_url: "lists/link_list.js", external_image_list_url: "lists/image_list.js", media_external_list_url: "lists/media_list.js", //initialization callback init_instance_callback: "TinyMCEReady", add_form_submit_trigger : false }); }); So... anyone seen anything like this or have any ideas for me? Thank you so much everyone!

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  • C# cross thread dialogue co-operation

    - by John Attridge
    K I am looking at a primarily single thread windows forms application in 3.0. Recently my boss had a progress dialogue added on a separate thread so the user would see some activity when the main thread went away and did some heavy duty work and locked out the GUI. The above works fine unless the user switches applications or minimizes as the progress form sits top most and will not disappear with the main application. This is not so bad if there are lots of little operations as the event structure of the main form catches up with its events when it gets time so minimized and active flags can be checked and thus the dialog thread can hide or show itself accordingly. But if a long running sql operation kicks off then no events fire. I have tried intercepting the WndProc command but this also appears queued when a long running sql operation is executing. I have also tried picking up the processes, finding the current app and checking various memory values isiconic and the like inside the progress thread but until the sql operation finishes none of these get updated. Removing the topmost causes the dialog to disappear when another app activates but if the main app is then brought back it does not appear again. So I need a way to find out if the other thread is minimized or no longer active that does not involve querying the actual thread as that locks until the sql operation finishes. Now I know that this is not the best way to write this and it would be better to have all the heavy processing on separate threads leaving the GUI free but as this is a huge ancient legacy app the time to re-write in that fashion will not be provided so I have to work with what I have got. Any help is appreciated

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  • WordPress update_post_meta values. Delete when empty or just test for ""?

    - by Scott B
    My function below, will take the values from my custom meta fields (after a post has been edited, and save or publish has been clicked) and update or insert the posted meta values. However, if the user leaves this field blank, I believe I want to delete the meta altogether (so I can test for its presence and display accordingly vs just checking for ""). For example, one of my meta options gives the user the ability to add a Custom title to their post, which when present, will populate the page's tag. However, if the field is left empty, I want to default the tag to the_title(), which is simply the Post title used to identify the page/post. Since I'm not deleting the meta on save, its always present after the first time a user enters something in there, get_post_meta($post-ID,'MyCustomTitle', true) is always true. Further, they cannot blank it out by clearing the title field and hitting publish. What am I missing in the save in order to clear the value to "" when the user clears the field? if ($_POST['MyCustomTitle']) { update_custom_meta($postID, $_POST['MyCustomTitle'], 'MyCustomTitle'); } function update_custom_meta($postID, $newvalue, $field_name) { // To create new meta if(!get_post_meta($postID, $field_name)){ add_post_meta($postID, $field_name, $newvalue); }else{ // or to update existing meta update_post_meta($postID, $field_name, $newvalue); } }

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  • Are there any shortcuts/easier(VB) style way for raising events in C#?

    - by Eric
    Example in VB I have a worker class Public Class worker Public Event EventNumber1(ByVal messages As Dictionary(Of Integer, String)) Public Event EventNumber2(ByVal message As String) Public Sub CallEventNumber1() Dim dict As New Dictionary(Of Integer, String) dict.Add(1, "EventNumber1 First message") dict.Add(2, "EventNumber1 Second message") RaiseEvent EventNumber1(dict) End Sub Public Sub CallEventNumber2() RaiseEvent EventNumber2("I am an EventNumber2 Message") End Sub End Class and wire them up in another class with AddHandler _worker.EventNumber1, AddressOf EventNumber1Handler AddHandler _worker.EventNumber2, AddressOf EventNumber2Handler and in C# the worker class class Worker { public delegate void EventNumber1Handler(Dictionary<int, string> messages); public delegate void EventNumber2Handler(string message); public event EventNumber1Handler EventNumber1; public event EventNumber2Handler EventNumber2; public void CallEventNumber1() { Dictionary<int, string> dict = new Dictionary<int, string>(); dict.Add(1, "EventNumber1 First message"); dict.Add(2, "EventNumber1 Second message"); if (EventNumber1 != null) EventNumber1(dict); } public void CallEventNumber2() { if (EventNumber2 != null) EventNumber2("I am an EventNumber2 Message"); } } and wire that up with worker.EventNumber1 += new Worker.EventNumber1Handler(worker_EventNumber1); worker.EventNumber2 += new Worker.EventNumber2Handler(worker_EventNumber2); So I guess my question is do I always need to add the delegate along with the event in c#? Is there any new syntax for c# 3.0/4.0? Regards _Eric

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  • MVC route doesn't work

    - by bill
    Hi All, I have a bunch of Views in a default folder that represent single "static" pages. Everything works as advertised except i tried adding a new page yesterday.. using the exact same routing syntax and cannot for the life of me get it to work. here's is an example of a working route: routes.MapRoute( "OurProgram", // Route name "Our_Program", // URL with parameters new { controller = "Default", action = "OurProgram" } ); The filename is OurProgram and hitting http:// localhost/Our_Program/ opens the correct view which resides in the Views/Default folder. So i added another view into this folder: Views/Default/BuyNow.aspx and added the route: routes.MapRoute( "BuyNow", // Route name "Buy_Now", // URL with parameters new { controller = "Default", action = "BuyNow" } ); And this doesn't open. I have tried the "route debugger http://haacked.com/archive/2008/03/13/url-routing-debugger.aspx" and it correctly identifies the route. I am at a lose. I have tried re-creating the view.. I am using MVC.Net 2.0 and VS 10. Any help is appreciated!

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  • License of popular dictionary word lists (e.g. SOWPODS, TWL)? Copyright? Trademarks?

    - by BobbyJim
    (I'm not sure if this off-topic. I found a lot of voted-up questions about software licenses and this is related. Plus, I'm sure many of us have had the situation that we need to use a dictionary in our code) I'm making a (maybe commercial) word game and need to use a good word dictionary for checking words. The most common dictionaries to use are the SOWPODS or TWL lists that are used Scrabble tournaments; see here: http://www.scrabblist.com/ (I have nothing to do with this site by the way). I've seen loads of websites offering these two dictionaries for download and loads of word games advertise that they use them. However, I cannot find any licensing terms attached to these dictionaries wherever I download them. For the players of my game, I'd want to say what dictionary I'm using (e.g. "this game uses SOWPODS"). However, I'm nervous about what I can do legally. Does anyone know about if you can copyright lists of words? Does anyone know the licenses of TWL and SOWPODS? TWL and SOWPODS don't seem to have trademarks on them but I'd like to know for sure. I cannot find any good sources for this information. EDIT: Great, now the top result for "SOWPODS license" is my stackoverflow question. :)

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  • SCons and dependencies for python function generating source

    - by elmo
    I have an input file data, a python function parse and a template. What I am trying to do is use parse function to get dictionary out of data and use that to replace fields in template. Now to make this a bit more generic (I perform the same action in few places) I have defined a custom function to do so. Below is definition of custom builder and values is a dictionary with { 'name': (data_file, parse_function) } (you don't really need to read through this, I simply put it here for completeness). def TOOL_ADD_FILL_TEMPLATE(env): def FillTemplate(env, output, template, values): out = output[0] subs = {} for name, (node, process) in values.iteritems(): def Process(env, target, source): with open( env.GetBuildPath(target[0]), 'w') as out: out.write( process( source[0] ) ) builder = env.Builder( action = Process ) subs[name] = builder( env, env.GetBuildPath(output[0])+'_'+name+'_processed.cpp', node )[0] def Fill(env, target, source): values = dict( (name, n.get_contents()) for name, n in subs.iteritems() ) contents = template[0].get_contents().format( **values ) open( env.GetBuildPath(target[0]), 'w').write( contents ) builder = env.Builder( action = Fill ) builder( env, output[0], template + subs.values() ) return output env.Append(BUILDERS = {'FillTemplate': FillTemplate}) It works fine when it comes to checking if data or template changed. If it did it rebuilds the output. It even works if I edit process function directly. However if my process function looks like this: def process( node ): return subprocess(node) and I edit subprocess the change goes unnoticed. Is there any way to get correct builds without making process functions being always invoked?

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  • How do I assign a rotating category to database entries in the order the records come in?

    - by Stomped
    I have a table which gets entries from a website, and as those entries go into the database, they need to be assigned the next category on a list of categories that may be changed at any time. Because of this reason I can't do something simple like for mapping the first category of 5 to IDs 1, 6, 11, 16. I've considered reading in the list of currently possibly categories, and checking the value of the last one inserted, and then giving the new record the next category, but I imagine if two requests come in at the same moment, I could potentially assign them both the same category rather then in sequence. So, my current round of thinking is the following: lock the tables ( categories and records ) insert the newest row into records get the newest row's ID select the row previous to the insertl ( by using order by auto_inc_name desc 0, 1 ) take the previous row's category, and grab the next one from the cat list update the new inserted row unlock the table I'm not 100% sure this will work right, and there's possibly a much easier way to do it, so I'm asking: A. Will this work as I described in the original problem? B. Do you have a better/easier way to do this? Thanks ~

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  • Passing the Class<T> in java of a generic list?

    - by Rob Stevenson-Leggett
    I have a method for reading JSON from a service, I'm using Gson to do my serialization and have written the following method using type parameters. public T getDeserializedJSON(Class<T> aClass,String url) { Reader r = getJSONDataAsReader(url); Gson gson = new Gson(); return gson.fromJson(r, aClass); } I'm consuming json which returns just an array of a type e.g. [ { "prop":"value" } { "prop":"value" } ] I have a java class which maps to this object let's call it MyClass. However to use my method I need to do this: RestClient<ArrayList<MyClass>> restClient = new RestClient<ArrayList<MyClass>>(); ArrayList<MyClass> results = restClient.getDeserializedJSON(ArrayList<MyClass>.class, url); However, I can't figure out the syntax to do it. Passing just ArrayList.class doesn't work. So is there a way I can get rid of the Class parameter or how do I get the class of the ArrayList of MyClass?

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  • SFTP in Python? (platform independent)

    - by Mark Wilbur
    I'm working on a simple tool that transfers files to a hard-coded location with the password also hard-coded. I'm a python novice, but thanks to ftplib, it was easy: import ftplib info= ('someuser', 'password') #hard-coded def putfile(file, site, dir, user=(), verbose=True): """ upload a file by ftp to a site/directory login hard-coded, binary transfer """ if verbose: print 'Uploading', file local = open(file, 'rb') remote = ftplib.FTP(site) remote.login(*user) remote.cwd(dir) remote.storbinary('STOR ' + file, local, 1024) remote.quit() local.close() if verbose: print 'Upload done.' if __name__ == '__main__': site = 'somewhere.com' #hard-coded dir = './uploads/' #hard-coded import sys, getpass putfile(sys.argv[1], site, dir, user=info) The problem is that I can't find any library that supports sFTP. What's the normal way to do something like this securely? Edit: Thanks to the answers here, I've gotten it working with Paramiko and this was the syntax. import paramiko host = "THEHOST.com" #hard-coded port = 22 transport = paramiko.Transport((host, port)) password = "THEPASSWORD" #hard-coded username = "THEUSERNAME" #hard-coded transport.connect(username = username, password = password) sftp = paramiko.SFTPClient.from_transport(transport) import sys path = './THETARGETDIRECTORY/' + sys.argv[1] #hard-coded localpath = sys.argv[1] sftp.put(localpath, path) sftp.close() transport.close() print 'Upload done.' Thanks again!

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  • $_POST Variable Detected in Chrome but not in Firefox

    - by user1707973
    I am using 2 images in a form to sort out query results from the database. The form is submitted using the POST method. When i click on the first image, the query results have to be sorted in ascending order, and when i click on the second, the results have to be sorted in the descending order. This is the code for the form: <form name="" action="" method="post"> <input type="hidden" name="typep" value="price" /> <input type="image" name="sort" value="asc" src="images/asc-ar.png" /> <input type="image" name="sort" value="desc" src="images/dsc-ar.png" /> </form> Now this is the code for checking if the $_REQUEST['sort'] variable is set and therefore whether sorting is required or not. if ($_REQUEST['sort'] != "") { $sort = $_REQUEST['sort']; $typep = $_REQUEST['typep']; //query to be executed depending on values of $sort and $typep } Firefox does detect the $_REQUEST['typep'] variable but not the $_REQUEST['sort'] one. This works perfectly in Chrome though. When i test the site in Firefox, it doesn't detect the $_REQUEST['sort'] variable and therefore the if condition evaluates to false and the search results don't get sorted.

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  • How to reference input elements within a specific scope when there are multiple input elements of same kind?

    - by Will Merydith
    How do I select data for input elements within a specific scope? I have the same form multiple times (class "foo-form), and want to ensure I get the values for the hidden inputs within the scope of the form being submitted. Is the scope "this" implied? If not, what is the syntax for selecting input class "foo-text" within the scope of this? Feel free to point me to examples in the jquery docs - I could not find what I was looking for. $('.foo-form').submit(function() { // Store a reference to this form var $thisForm = $(this); }); <form class="foo-form"> <input type="hidden" class="foo-text"/> <input type="submit" class="button" /> </form> <form class="foo-form"> <input type="hidden" class="foo-text"/> <input type="submit" class="button" /> </form> <form class="foo-form"> <input type="hidden" class="foo-text"/> <input type="submit" class="button" /> // user clicks this submit button </form>

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  • CakePHP 2.0: how to access properties of the parent object?

    - by PaulJ
    I just started learning CakePHP 2.0 a few days ago, and there's one thing that is leaving me stumped: say I have an User model and a Posts model: class User extends AppModel { public $name = "User"; public $hasMany=array( 'Post' => array( 'className' => 'Post', 'foreignKey' => 'author_id' ) ); } class Post extends AppModel { public $name = 'Post'; public $belongsTo = array( 'className' = 'User', 'foreignKey' = 'author_id', ); } (Where "author_id" is the foreign key in the posts table that references the Users table's primary key). And now, in the PostsController, I want to access the properties of the user that owns the current post (to show his display name, for example). What would be the proper syntax? I tried: $this->Post->User->find('first', array('conditions' => array('User.id' => "$usuario"))) But it didn't work (I guess it's because the User is the parent of the Post object, not its child). Or should CakePHP load everything automatically, once you've declared the $hasMany and $belongsTo relationships?

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  • Performance difference between functions and pattern matching in Mathematica

    - by Samsdram
    So Mathematica is different from other dialects of lisp because it blurs the lines between functions and macros. In Mathematica if a user wanted to write a mathematical function they would likely use pattern matching like f[x_]:= x*x instead of f=Function[{x},x*x] though both would return the same result when called with f[x]. My understanding is that the first approach is something equivalent to a lisp macro and in my experience is favored because of the more concise syntax. So I have two questions, is there a performance difference between executing functions versus the pattern matching/macro approach? Though part of me wouldn't be surprised if functions were actually transformed into some version of macros to allow features like Listable to be implemented. The reason I care about this question is because of the recent set of questions (1) (2) about trying to catch Mathematica errors in large programs. If most of the computations were defined in terms of Functions, it seems to me that keeping track of the order of evaluation and where the error originated would be easier than trying to catch the error after the input has been rewritten by the successive application of macros/patterns.

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  • Adding functions to Java class libraries

    - by Eric
    I'm using a Java class library that is in many ways incomplete: there are many classes that I feel ought to have additional member functions built in. However, I am unsure of the best practice of adding these member functions. Lets call the insufficient base class A. class A { public A(/*long arbitrary arguments*/) { //... } public A(/*long even more arbitrary arguments*/) { //... } public int func() { return 1; } } Ideally, I would like to add a function to A. However, I can't do that. My choice is between: class B extends A { //Implement ALL of A's constructors here public int reallyUsefulFunction() { return func()+1; } } and class AddedFuncs { public int reallyUsefulFunction(A a) { return a.func()+1; } } The way I see it, they both have advantages and disadvantages. The first choice gives a cleaner syntax than the second, and is more logical, but has problems: Let's say I have a third class, C, within the class library. class C { public A func() { return new A(/*...*/); } } As I see it, there is no easy way of doing this: C c; int useful = c.func().reallyUsefulFunction(); as the type returned by C.func() is an A, not a B, and you can't down-cast. So what is the best way of adding a member function to a read-only library class?

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  • c++ creating ambigram from string

    - by mike_hornbeck
    I have a task to implement "void makeAmbigram(char*)" that will print on screen ambigram of latin string or return something like 'ambigram not possible'. Guess it's just about checking if string contains only of SNOXZHI and printing string backwards. Or am I wrong ? I'm a complete noob when dealing with cpp so that's what I've created : #include <iostream> using namespace std; char[]words; char[]reversed; char[] ret_str(char* s) { if(*s != '\0') ret_str(s+1); return s; } void makeAmbigram(char* c) { /* finding chars XIHNOZS and printing ambigram */ } int main() { cin>>words; reversed = ret_str(words); makeAmbigram(reversed); return 0; } I can reverse string but how to check if my reversed string contains only needed chars ? I've found some function but it's hard or even imposible to implement it for greater amount of chars : http://www.java2s.com/Code/C/String/Findcharacterinstringhowtousestrchr.htm

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  • C# Linq Select Problem in Method Chain.

    - by Gnought
    Note that the _src inherit IQueryable<U> and V inherit new(); I wrote the following statement, there is no syntax error. IQueryable<V> a = from s in _src where (s.Right - 1 == s.Left) select new V(); But if i re-wrote it as follows, the Visual Studio editor complains an error in the "Select" IQueryable<V> d = _src.Where(s => s.Right - 1 == s.Left).Select(s=> new V()); The Error is: The type arguments cannot be inferred from the usage. Try specifying the type arguments explicitly. Candidates are: System.Collections.Generic.IEnumerable<V> Select<U,V>(this System.Collections.Generic.IEnumerable<U>, System.Func<U,V>) (in class Enumerable) System.Linq.IQueryable<V> Select<U,V>(this System.Linq.IQueryable<U>, System.Linq.Expressions.Expression<System.Func<U,V>>) (in class Queryable) Could anyone explain this phenomenon, and what the solution is to fix the error?

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