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  • Parsing data from txt file in J2ME

    - by CSFYPMAIL
    Basically I'm creating an indoor navigation system in J2ME. I've put the location details in a .txt file i.e. Locations names and their coordinates. Edges with respective start node and end node as well as the weight (length of the node). I put both details in the same file so users dont have to download multiple files to get their map working (it could become time consuming and seem complex). So what i did is to seperate the deferent details by typing out location Names and coordinates first, After that I seperated that section from the next section which is the edges by drawing a line with multiple underscores. Now the problem I'm having is parsing the different details into seperate arrays by setting up a command (while manually tokenizing the input stream) to check wether the the next token is an underscore. If it is, (in pseudocode terms), move to the next line in the stream, create a new array and fill it up with the next set of details. I found a some explanation/code HERE that does something similar but still parses into one array, although it manually tokenizes the input. Any ideas on what to do? Thanks Text File Explanation The text has the following format... <--1stSection--  /**   * Section one has the following format   * xCoordinate;yCoordinate;LocationName   */ 12;13;New York City 40;12;Washington D.C. ...e.t.c _________________________ <--(underscore divider) <--2ndSection--  /**   * Its actually an adjacency list but indirectly provides "edge" details.   * Its in this form   * StartNode/MainReferencePoint;Endnode1;distance2endNode1;Endnode2;distance2endNode2;...e.t.c   */ philadelphia;Washington D.C.;7;New York City;2 New York City;Florida;24;Illinois;71 ...e.t.c

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  • How does does ifstream eof() work?

    - by Chan
    Hello everyone, #include <vector> #include <list> #include <map> #include <set> #include <deque> #include <stack> #include <bitset> #include <algorithm> #include <functional> #include <numeric> #include <utility> #include <sstream> #include <iostream> #include <iomanip> #include <cstdio> #include <cmath> #include <cstdlib> #include <ctime> #include <cctype> #include <fstream> using namespace std; int main() { fstream inf( "ex.txt", ios::in ); while( !inf.eof() ) { std::cout << inf.get() << "\n"; } inf.close(); inf.clear(); inf.open( "ex.txt", ios::in ); char c; while( inf >> c ) { std::cout << c << "\n"; } return 0; } I'm really confused about eof() function. Suppose my ex.txt's content is: abc It always reads an extra character and show -1. when reading using eof()? But the inf c gave the correct output which was 'abc'? Can anyone help me explain this? Best regards, Chan Nguyen

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  • C++: Declare static variable in function argument list

    - by MDC
    Is there any way at all in C++ to declare a static variable while passing it to a function? I'm looking to use a macro to expand to the expression passed to the function. The expression needs to declare and initialize a static variable on that particular line (based on the filename and line number using FILE and LINE). int foo(int b) { int c = b + 2; return c; } int main() { int a = 3; a = foo(static int h = 2); //<---- see this! cout << a; return 0; } The problem I'm trying to solve is getting the filename and line number with the FILE and LINE macros provided by the preprocessor, but then creating a lookup table with integer keys leading to the FILE, LINE pairs. For example, the key 89 may map to file foo.cpp, line 20. To get this to work, I'm trying to use local static variables, so that they are initialized only once per line execution. The static variable will be initialized by calling a function that calculates the integer key and adds an entry to the lookup table if it is not there. Right now the program uses a message class to send exception information. I'm writing a macro to wrap this class into a new class: WRAPPER_MACRO(old_class_object) will expand to NewClass(old_class_object, key_value). If I add the static variable declaration as a second line right before this, it should work. The problem is that in most places in the code, the old class object is passed as an argument to a function. So the problem becomes declaring and initializing the static variable somehow with the macro, while keeping the existing function calls.

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  • How to use javascript to get information from the content of another page (same domain)?

    - by hlovdal
    Let's say I have a web page (/index.html) that contains the following <li> <div>item1</div> <a href="/details/item1.html">details</a> </li> and I would like to have some javascript on /index.html to load that /details/item1.html page and extract some information from that page. The page /details/item1.html might contain things like <div id="some_id"> <a href="/images/item1_picture.png">picture</a> <a href="/images/item1_map.png">map</a> </div> My task is to write a greasemonkey script, so changing anything serverside is not an option. To summarize, javascript is running on /index.html and I would like to have the javascript code to add some information on /index.html extracted from both /index.html and /details/item1.html. My question is how to fetch information from /details/item1.html. I currently have written code to extract the link (e.g. /details/item1.html) and pass this on to a method that should extract the wanted information (at first just .innerHTML from the some_id div is ok, I can process futher later). The following is my current attempt, but it does not work. Any suggestions? function get_information(link) { var obj = document.createElement('object'); obj.data = link; document.getElementsByTagName('body')[0].appendChild(obj) var some_id = document.getElementById('some_id'); if (! some_id) { alert("some_id == NULL"); return ""; } return some_id.innerHTML; }

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  • Rails: Added new Action in Controller, but there is no path?

    - by Newbie
    Hello! I try to do following: A user is on his profile page. Now he edits his profile. He klicks on update and the data is saved. Now I want to redirect the user to another kind of profile-edit-page. I did the following in my users_controller.rb: def update @user = User.find(params[:id]) respond_to do |format| if @user.update_attributes(params[:user]) flash[:notice] = 'User was successfully updated.' if(@user.team_id != nil) format.html { redirect_to(@user) } else format.html { redirect_to choose_team_path } end format.xml { head :ok } else format.html { render :action => "edit" } format.xml { render :xml => @user.errors, :status => :unprocessable_entity } end end end def choose_team @user = User.find(params[:id]) end I created a view: /users/choose_team.html.erb Now I get the following error: undefined local variable or method `choose_team_path' for #<UsersController:0x1f56650> So I added choose_team to my routes.rb: map.choose_team 'choose-team', :controller => 'users', :action => 'choose_team' Now, after submitting my first edit form, it redirects me to http://localhost:3000/choose-team and I get following error: Couldn't find User without an ID What I want: If a user has no team_id, he should be redirected to my choose_team.html.erb for choosing a team, else he should be redirected to his profile/show. How to do this?

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  • java /TableModel of Objects/Update Object"

    - by Tomás Ó Briain
    I've a collection of Stock objects that I'm updating about 10/15 variables for in real-time. I'm accessing each Stock by its ID in the collection. I'm also trying to display this in a JTable and have implemented an AbstractTablemodel. It's not working too well. I've a RowMap that I add each ID to as Stocks are added to the TableModel. To update the prices and variables of all the stocks in the TableModel, I want to send a Stock object to an updateModel(Stock s) method. I can find the relevant row by searching the map, but how do I handle this nicely, so I don't have to start iterating through table columns and comparing the values of the cells to the variables of the object to see whether there are any differences?? Basically, i want to send a Stock object to the TableModel and update cells if there are changes and do nothing if there aren't. Any ideas about how to implement a TableModel that might do this? Any pointeres at all would be appreciated. Thanks.

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  • Is it possible, in ASP .net, to reference private assembly in a non-virtual subdirectory?

    - by Bago
    Is it possible to reference a private assembly in asp .net from a sub-folder that is not setup as a virtual directory? In other words, my page is setup in ~/subdir, I don't have access to ~/, and I am not an IIS admin. Can I reference a private assembly? How would I do this? I've tried <%@ Assembly Src="/subdir/bin/Assembly.dll % and <%@ Assembly Src="/subdir/bin/Assembly.dll % , but I get the messages "There is no build provider to match the extension .dll" or "Failed to map to path" respectively. Here is my folder structure: / | -subdir | | - Bin | | | *Assembly.dll | | *Default.aspx I've heard that in web.config might do the trick, but when I've tried it, it doesn't seem to work. Furthermore, I've read that only works in the application .config file. (i.e., the one in ~/). Anyhow, I already tried adding the following to web.config: <runtime> <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1"> <probing privatePath="/subdir/bin" /> <dependentAssembly> <codeBase href="/subdir/bin/Assembly.dll"/> </dependentAssembly> </assemblyBinding> For more background on my problem, I am simply using a shared host, all I have is access to is that subdirectory, and I am trying to use fckeditor.

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  • Is it possible, in ASP.net, to reference private assembly in a non-virtual subdirectory?

    - by Bago
    Is it possible to reference a private assembly in asp .net from a sub-folder that is not setup as a virtual directory? In other words, my page is setup in ~/subdir, I don't have access to ~/, and I am not an IIS admin. Can I reference a private assembly? How would I do this? I've tried <%@ Assembly Src="/subdir/bin/Assembly.dll % and <%@ Assembly Src="/subdir/bin/Assembly.dll % , but I get the messages "There is no build provider to match the extension .dll" or "Failed to map to path" respectively. Here is my folder structure: / | -subdir | | - Bin | | | *Assembly.dll | | *Default.aspx I've heard that in web.config might do the trick, but when I've tried it, it doesn't seem to work. Furthermore, I've read that only works in the application .config file. (i.e., the one in ~/). Anyhow, I already tried adding the following to web.config: <runtime> <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1"> <probing privatePath="/subdir/bin" /> <dependentAssembly> <codeBase href="/subdir/bin/Assembly.dll"/> </dependentAssembly> </assemblyBinding> For more background on my problem, I am simply using a shared host, all I have is access to is that subdirectory, and I am trying to use fckeditor.

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  • Simple search form passing the searched string through GET

    - by Brian Roisentul
    Hi, I'd like my Search form to return the following url after submit: /anuncios/buscar/the_text_I_searched My form is the following: <% form_for :announcement, :url => search_path(:txtSearch) do |f| %> <div class="searchBox" id="basic"> <%= text_field_tag :txtSearch, params[:str_search].blank? ? "Busc&aacute; tu curso r&aacute;pido y f&aacute;cil." : params[:str_search], :maxlength=> 100, :class => "basicSearch_inputField", :onfocus => "if (this.value=='Busc&aacute; tu curso r&aacute;pido y f&aacute;cil.') this.value=''", :onblur => "if(this.value=='') { this.value='Busc&aacute; tu curso r&aacute;pido y f&aacute;cil.'; return false; }" %> <div class="basicSearch_button"> <input type="submit" value="BUSCAR" class="basicSearch_buttonButton" /> <br /><a href="#" onclick="javascript:jQuery('#advance').modal({opacity:60});">Busqueda avanzada</a> </div> </div> <% end %> My routes' line for search_path is this: map.search '/anuncios/buscar/:str_search', :controller => 'announcements', :action => 'search' Well, this will work if I manually type the url I want in the brower, but definitely, if you look at the form's url, you'll find a ":txtSearch" parameter, which is not giving me the actual value of the text field when the form is submitted. And that's what I'd like to get! Could anybody help me on this?

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  • How can I output my MySQL data into following structures?

    - by sky
    Here is the question, how can I output MySQL data into format like : userAge, userMid are the column name, table name Users. <script type="text/javascript"> userAge = new Array('21','36','20'), userMid = new Array('liuple','anhu','jacksen'); </script> Which I'll be using later with following code : var html = ' <table class="map-overlay"> <tr> <td class="user">' + '<a class="username" href="/' + **userMid[index]** + '" target="_blank"><img alt="" src="' + getAvatar(signImgList[index], '72x72') + '"></a><br> <a class="username" href="/' + **userMid[index]** + '" target="_blank">' + userNameList[index] + '</a><br> <span class="info">' + **userSex[index]** + ' ' + **userAge[index]** + '?<br> ' + cityList[index] + '</span>' + '</td> <td class="content">' + picString + somethings[index] + '<br> <span class="time">' + timeList[index] + picTips + '</span></td> </tr> </table> '; PS: I Just been told that i coulnt use JSON to output that format, so i have no idea now .< Thanks!

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  • Can I transform this asynchronous java network API into a monadic representation (or something else

    - by AlecZorab
    I've been given a java api for connecting to and communicating over a proprietary bus using a callback based style. I'm currently implementing a proof-of-concept application in scala, and I'm trying to work out how I might produce a slightly more idiomatic scala interface. A typical (simplified) application might look something like this in Java: DataType type = new DataType(); BusConnector con = new BusConnector(); con.waitForData(type.getClass()).addListener(new IListener<DataType>() { public void onEvent(DataType t) { //some stuff happens in here, and then we need some more data con.waitForData(anotherType.getClass()).addListener(new IListener<anotherType>() { public void onEvent(anotherType t) { //we do more stuff in here, and so on } }); } }); //now we've got the behaviours set up we call con.start(); In scala I can obviously define an implicit conversion from (T = Unit) into an IListener, which certainly makes things a bit simpler to read: implicit def func2Ilistener[T](f: (T => Unit)) : IListener[T] = new IListener[T]{ def onEvent(t:T) = f } val con = new BusConnector con.waitForData(DataType.getClass).addListener( (d:DataType) => { //some stuff, then another wait for stuff con.waitForData(OtherType.getClass).addListener( (o:OtherType) => { //etc }) }) Looking at this reminded me of both scalaz promises and f# async workflows. My question is this: Can I convert this into either a for comprehension or something similarly idiomatic (I feel like this should map to actors reasonably well too) Ideally I'd like to see something like: for( d <- con.waitForData(DataType.getClass); val _ = doSomethingWith(d); o <- con.waitForData(OtherType.getClass) //etc )

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  • C# WinForms populating TreeView from List<myObj>

    - by user743354
    I have this structure of classes: public class L3Message { public int Number { get; set; } public string MessageName { get; set; } public string Device { get; set; } public string Time { get; set; } public string ScramblingCode { get; set; } public List<Parameter> Parameters { get; set; } public L3Message() { Parameters = new List<Parameter>(); } } public class Parameter { public int numOfWhitespaces { get; set; } public string ParameterName { get; set; } public string ParameterValue { get; set; } public Parameter Parent { get; set; } public List<Parameter> SubParameters { get; set; } public Parameter() { SubParameters = new List<Parameter>(); } } So, as return type from one of my Methods I have List of L3Messages (List < L3Message ), and I need to map that to TreeView in WinForms (populate TreeView from that List). If possible, I would like to that in separate thread. How can I achieve that?

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  • Stuck on scrolling GtkViewPort to end.

    - by PP
    I am adding one GtkVBox to GtkViewPort. And I am doing scrolling for GtkViewPort based on two Up/Down Buttons. I need to display last item in VBox as we do in Message Chat Screens (Message Chat list displays/adds newest chat message at bottom of the list) i doing exact thing. so for scrolling at the bottom of the GtkViewPort i am doing in the map event call back. GtkAdjustment* adjustment; adjustment = gtk_viewport_get_vadjustment(GTK_VIEWPORT(viewport_list)); gtk_adjustment_set_value(adjustment, gtk_adjustment_get_upper(adjustment)); So this works perfectly fine. it displays newest added widget in Vbox at the end. on some external events I add new Widgets to my VBox and call above code again to display these newly added widgets. on first add it does not scroll at all but on 2nd add to VBOX it scroll upto 2nd last Widget in the list. Why this might be happening. It there another way of scrolling GtkViewPort to the end? Thanks for reading :)

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  • CodeModel help needed for right-hand singleton.getinstance() assignment.

    - by antarti
    I've been able to generate 99% of what I need with the CodeModel API, but I am stumped here... Using the various "directXX" methods does not add import statements to the generated code, and I can work without the "directXXX" type of methods except for one place in a generated class. Suppose I desire a generated method like: /** * Copies data from this Value-Obj instance, to the returned PERSON instance. * * @return PERSON * */ public PERSON mapVOToPERSON() throws MappingException { Mapper mapper = (com.blah.util.MapperSingleton.getMapperInstance()); return mapper.map(this, PERSON.class); } You can see the right hand of the Mapper assignment in parens. Emitting the entire package+class was the only way I could find to just declare "SomeSingleton.someMethod()" on the right hand side and have the generated code compile. Without the MapperSingleton being added to the object model, there is no import generated... Questions: 1) Is there a way to force an import to be generated? 2) How to declare an expression that gives me the right side of the Mapper assignment within the object model (so that an import of MapperSingleton gets generated. Any help appreciated...

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  • Database schema to store AND, OR relation, association

    - by user455387
    Many thanks for your help on this. In order for an entreprise to get a call for tender it must meet certain requirements. For the first example the enterprise must have a minimal class 4, and have qualification 2 in sector 5. Minimal class is always one number. Qualification can be anything (single, or multiple using AND, OR logical operators) I have created tables in order to map each number to it's given name. Now I need to store requirements in the database. minimal class 4 Sector Qualification 5.2 minimal class 2 Sector Qualifications 3.9 and 3.10 minimal class 3 Sector Qualifications 6.1 or 6.3 minimal class 1 Sector Qualifications (3.1 and 3.2) or 5.6 class Domain < ActiveRecord::Base has_many :domain_classes has_many :domain_sectors has_many :sector_qualifications, :through => :domain_sectors end class DomainClass < ActiveRecord::Base belongs_to :domain end class DomainSector < ActiveRecord::Base belongs_to :domain has_many :sector_qualifications end class SectorQualification < ActiveRecord::Base belongs_to :domain_sector end create_table "domains", :force => true do |t| t.string "name" end create_table "domain_classes", :force => true do |t| t.integer "number" t.integer "domain_id" end create_table "domain_sectors", :force => true do |t| t.string "name" t.integer "number" t.integer "domain_id" end create_table "sector_qualifications", :force => true do |t| t.string "name" t.integer "number" t.integer "domain_sector_id" end

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  • How to call a method after asynchronous task is complete

    - by doctordoder
    I have a class called WikiWebView which is a subclass of UIWebView which loads Wikipedia subjects and is designed to fetch all the links of the webpage, in order to create a sort of site map for the subject. My problem is that I can only create the links once the web page has loaded, but the loading isn't done right after [self loadRequest:requestObj] is called. - (void)loadSubject:(NSString *)subject { // load the actual webpage NSString *wiki = @"http://www.wikipedia.org/wiki/"; NSString *fullURL = [wiki stringByAppendingString:subject]; NSURL *url = [NSURL URLWithString:fullURL]; NSURLRequest *requestObj = [NSURLRequest requestWithURL:url]; [self loadRequest:requestObj]; // [self createLinks]; // need this to be called after the view has loaded } - (void)createLinks { NSString *javascript = @"var string = \"\";" "var arr = document.getElementsByClassName(\"mw-redirect\");" "for (var i = 0; i < arr.length; ++i)" "{" "var redirectLink = arr[i].href;" "string = string + redirectLink + \" \";" "}" "string;"; NSString *links = [self stringByEvaluatingJavaScriptFromString:javascript]; self.links = [links componentsSeparatedByString:@" "]; } I tried the normal delegation technique, which lead to this code being added: - (id)init { if (self = [super init]) { self.delegate = self; // weird } return self; } #pragma mark - UIWebViewDelegate - (void)webViewDidStartLoad:(UIWebView *)webView { ++_numProcesses; } - (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error { --_numProcesses; } - (void)webViewDidFinishLoad:(UIWebView *)webView { --_numProcesses; if (_numProcesses == 0) { [self createLinks]; } } However, the delegate methods are never called.. I've seen similar questions where the answers are to use blocks, but how would I do that in this case?

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  • Shortest Distance From An Array

    - by notyou61
    I have an ajax function which returns the latitudes and longitudes of locations stored in a database. These are returned and placed in an array. A calculation is performed to return their distance from the users current location based on the latitude/longitude. I would like to return only the record with the shortest calculated distance. My code is as follows: Ajax Success // Success success: function (data) { // Obtain Log/Lat navigator.geolocation.getCurrentPosition(function(position) { // Obtain Current Position Lat/Lon glbVar.latitude = position.coords.latitude; glbVar.longitude = position.coords.longitude; // Console Log //console.log('Lat: ' + glbVar.latitude + ' Lon: ' + glbVar.longitude); // Obtain Location Distances for ( var i = 0; i < data.length; i++ ) { // Location Instances var varLocation = data[i]; // Location Distance varLocation.distance = calculateDistance(glbVar.longitude, glbVar.latitude, varLocation.locationLongitude, varLocation.locationLatitude); } // Sort Locations By Distance var sortedData = data.sort(function(a, b) { // Return Locations return a.distance - b.distance; }); // Output Results $.map(sortedData, function(item) { // Obtain Location Distance varLocationsDistance = calculateDistance(glbVar.longitude, glbVar.latitude, item.locationLongitude, item.locationLatitude); // Obtain Location Radius Assignment if (varLocationsDistance <= varLocationRadius) { // Function Return functionReturn = $({locationID : item.locationID + ', Distance : ' + varLocationsDistance + ' m'}); // Return // Function to get the Min value in Array Array.min = function( sortedData ){ functionReturn = Math.min.apply( Math, sortedData ); // console.log(functionReturn); }; } }); }); } The calculateDistance function returns the distance from the users current location and those from the database. The varLocationsDistance <= varLocationRadius "If" statement returns records within a certain distance radius (100 meters), within that statement I would like to return the shortest distance. I am a self taught amateur web developer and as a result may not have provide enough information for an answer, please let me know. Thanks,

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  • sed script to remove file name duplicates

    - by dma_k
    Dear community, I hope the below task will be very easy for sed lovers. I am not sed-guru, but I need to express the following task in sed, as sed is more popular on Linux systems. The input text stream is something which is produced by "make depends" and looks like following: pgm2asc.o: pgm2asc.c ../include/config.h amiga.h list.h pgm2asc.h pnm.h \ output.h gocr.h unicode.h ocr1.h ocr0.h otsu.h barcode.h progress.h box.o: box.c gocr.h pnm.h ../include/config.h unicode.h list.h pgm2asc.h \ output.h database.o: database.c gocr.h pnm.h ../include/config.h unicode.h list.h \ pgm2asc.h output.h detect.o: detect.c pgm2asc.h pnm.h ../include/config.h output.h gocr.h \ unicode.h list.h I need to catch only C++ header files (i.e. ending with .h), make the list unique and print as space-separated list prepending src/ as a path-prefix. This is achieved by the following perl script: make libs-depends | perl -e 'while (<>) { while (/ ([\w\.\/]+?\.h)/g) { $a{$1} = 1; } } print join " ", map { "src/$_" } keys %a;' The output is: src/unicode.h src/pnm.h src/progress.h src/amiga.h src/ocr0.h src/ocr1.h src/otsu.h src/barcode.h src/gocr.h src/../include/config.h src/list.h src/pgm2asc.h src/output.h Please, help to express this in sed.

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  • Scala XML API: Why allow NodeSeq as attribute values?

    - by Synesso
    It seems attribute values are of type Seq[Node]. scala> <a b="1"/>.attribute("b") res11: Option[Seq[scala.xml.Node]] = Some(1) This means you can assign XML as an attribute value. scala> <a b={<z><x/></z>}/>.attribute("b") res16: Option[Seq[scala.xml.Node]] = Some(<z><x></x></z>) scala> <a b={<z><x/></z>}/>.attribute("b").map(_ \ "x") res17: Option[scala.xml.NodeSeq] = Some(<x></x>) scala> new xml.PrettyPrinter(120, 2).format(<a b={<z><x/></z>}/>) res19: String = <a b="<z><x></x></z>"></a> This seems funky to me. I've never seen XML as attribute values in the real world. Why is it allowed? Why is an attribute value simply not of type String?

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  • How can I post an array of string to ASP.NET MVC Controller without a form?

    - by rodbv
    Hi there, I am creating a small app to teach myself ASP.NET MVC and JQuery, and one of the pages is a list of items in which some can be selected. Then I would like to press a button and send a List (or something equivalent) to my controller containing the ids of the items that were selected, using JQuery's Post function. I managed to get an array with the ids of the elements that were selected, and now I want to post that. One way I could do this is to have a dummy form in my page, with a hidden value, and then set the hidden value with the selected items, and post that form; this looks crufty, though. Is there a cleaner way to achieve this, by sending the array directly to the controller? I've tried a few different things but it looks like the controller can't map the data it's receiving. Here's the code so far: function generateList(selectedValues) { var s = { values: selectedValues //selectedValues is an array of string }; $.post("/Home/GenerateList", $.toJSON(s), function() { alert("back") }, "json"); } And then my Controller looks like this public ActionResult GenerateList(List<string> values) { //do something } All I managed to get is a "null" in the controller parameter... Any tips?

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  • Elegant and 'correct' multiton implementation in Objective C?

    - by submachine
    Would you call this implementation of a multiton in objective-c 'elegant'? I have programmatically 'disallowed' use of alloc and allocWithZone: because the decision to allocate or not allocate memory needs to be done based on a key. I know for sure that I need to work with only two instances, so I'm using 'switch-case' instead of a map. #import "Multiton.h" static Multiton *firstInstance = nil; static Multiton *secondInstance = nil; @implementation Multiton + (Multiton *) sharedInstanceForDirection:(char)direction { return [[self allocWithKey:direction] init]; } + (id) allocWithKey:(char)key { return [self allocWithZone:nil andKey:key]; } + (id)allocWithZone:(NSZone *)zone andKey:(char)key { Multiton **sharedInstance; @synchronized(self) { switch (key) { case KEY_1: sharedInstance = &firstInstance; break; case KEY_2: sharedInstance = &secondInstance; break; default: [NSException raise:NSInvalidArgumentException format:@"Invalid key"]; break; } if (*sharedInstance == nil) *sharedInstance = [super allocWithZone:zone]; } return *sharedInstance; } + (id) allocWithZone:(NSZone *)zone { //Do not allow use of alloc and allocWithZone [NSException raise:NSObjectInaccessibleException format:@"Use allocWithZone:andKey: or allocWithKey:"]; return nil; } - (id) copyWithZone:(NSZone *)zone { return self; } - (id) retain { return self; } - (unsigned) retainCount { return NSUIntegerMax; } - (void) release { return; } - (id) autorelease { return self; } - (id) init { [super init]; return self; } PS: I've not tried out if this works as yet, but its compiling cleanly :)

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  • Find if a user is facing a certain Location using Digital Compass by constructing a triangle and usi

    - by Aidan
    Hi Guys, I'm constructing a geolocation based application and I'm trying to figure out a way to make my application realise when a user is facing the direction of the given location (a particular long / lat co-ord). I've done some Googling and checked the SDK but can't really find anything for such a thing. Does anyone know of a way? To clarify Android knows my location, the second location and my orientation. What I want is a way for Android to recognise when my orientation is "facing" the second location (e.g within 90 Degrees or so). We're also assuming that the user is stationary and needs updates every second or so therefore getBearing(); is useless. Alright so we get it has to be math, there appears to be no simple SDK stuff we can use. I did some searching of my own and found Barycentric Co-ords http://www.blackpawn.com/texts/pointinpoly/default.html . So what I'm trying to do now is map the camera's field of view. For Example if the person is facing a certain direction the program should construct a triangle around that field of view, e.g it should make one vertices the phone's position and then go out either side for a set distance making the 2 end points vertices constructing a triangle. If I had this I could then apply Barycentric co-ords to see if the point lay within the newly constructed triangle. Idea's anyone? Example. I could get my current orientation, add 45 to it and go up X distance one side and subtact 45 and go up X distance the other side to find my 2 other points. Though, how would I make android know which way it should go "up" I guess? It would know its baring as this stage so I need it to recognise it's bearing and go out that direction.

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  • crash when using stl vector at instead of operator[]

    - by Jamie Cook
    I have a method as follows (from a class than implements TBB task interface - not currently multithreading though) My problem is that two ways of accessing a vector are causing quite different behaviour - one works and the other causes the entire program to bomb out quite spectacularly (this is a plugin and normally a crash will be caught by the host - but this one takes out the host program as well! As I said quite spectacular) void PtBranchAndBoundIterationOriginRunner::runOrigin(int origin, int time) const // NOTE: const method { BOOST_FOREACH(int accessMode, m_props->GetAccessModes()) { // get a const reference to appropriate vector from member variable // map<int, vector<double>> m_rowTotalsByAccessMode; const vector<double>& rowTotalsForAccessMode = m_rowTotalsByAccessMode.find(accessMode)->second; if (origin != 129) continue; // Additional debug constrain: I know that the vector only has one non-zero element at index 129 m_job->Write("size: " + ToString(rowTotalsForAccessMode.size())); try { // check for early return... i.e. nothing to do for this origin if (!rowTotalsForAccessMode[origin]) continue; // <- this works if (!rowTotalsForAccessMode.at(origin)) continue; // <- this crashes } catch (...) { m_job->Write("Caught an exception"); // but its not an exception } // do some other stuff } } I hate not putting in well defined questions but at the moment my best phrasing is : "WTF?" I'm compiling this with Intel C++ 11.0.074 [IA-32] using Microsoft (R) Visual Studio Version 9.0.21022.8 and my implementation of vector has const_reference operator[](size_type _Pos) const { // subscript nonmutable sequence #if _HAS_ITERATOR_DEBUGGING if (size() <= _Pos) { _DEBUG_ERROR("vector subscript out of range"); _SCL_SECURE_OUT_OF_RANGE; } #endif /* _HAS_ITERATOR_DEBUGGING */ _SCL_SECURE_VALIDATE_RANGE(_Pos < size()); return (*(_Myfirst + _Pos)); } (Iterator debugging is off - I'm pretty sure) and const_reference at(size_type _Pos) const { // subscript nonmutable sequence with checking if (size() <= _Pos) _Xran(); return (*(begin() + _Pos)); } So the only difference I can see is that at calls begin instead of simply using _Myfirst - but how could that possibly be causing such a huge difference in behaviour?

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  • How to understand other people's CSS architectures?

    - by John
    I am reasonably good with CSS. However, when working with someone else's CSS, it's difficult for me to see the "bigger picture" in their architecture (but i have no problem when working with a CSS sheet I wrote myself). For example, I have no problems using Firebug to isolate and fix cross browser compatibility issues, or fixing a floating issue, or changing the height on a particular element. But if I'm asked to do something drastic such as, "I want the right sidebars of pages A, B, C and D to have a red border. I want the right side bars of pages E, F and G to have a blue border if and only if the user mouses over", then it takes me time a long time to map out all the CSS inheritance rules to see the "bigger picture". For some reason, I don't encounter the same difficulty with backend code. After a quick debriefing of how a feature works, and a quick inspection of the controller and model code, I will feel comfortable with the architecture. I will think, "it's reasonable to assume that there will be an Employee class that inherits from the Person Class that's used by a Department controller". If I discover inconvenient details that aren't consistent with overall architectural style, I am confident that I can hammer things back in place. With someone else's CSS work, it's much harder for me to see the "relationships" between different classes, and when and how the classes are used. When there are many inheritance rules, I feel overwhelmed. I'm having trouble articulating my question and issues... All I want to know is, why is it so much harder for me to see the bigger picture in someone else's CSS architecture than compared to someone else's business logic layer? **Does it have any thing to do with CSS being a relatively new technology, and there aren't many popular design patterns?

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  • Mixing stored procedures and ORM

    - by Jason
    The company I work for develops a large application which is almost entirely based on stored procedures. We use classic ASP and SQL Server and the major part of the business logic is contained inside those stored procedures. For example, (I know, this is bad...) a single stored procedure can be used for different purposes (insert, update, delete, make some calculations, ...). Most of the time, a stored procedure is used for operations on related tables, but this is not always the case. We are planning to move to ASP.NET in a near future. I have read a lot of posts on StackOverflow recommending that I move the business logic outside the database. The thing is, I have tried to convince the people who takes the decisions at our company and there is nothing I can do to change their mind. Since I want to be able to use the advantages of object-oriented programming, I want to map the tables to actual classes. So far, my solution is to use an ORM (Entity Framework 4 or nHibernate) to avoid mapping the objects manually (mostly to retrieve the data) and use some kind of Data Access Layer to call the existing stored procedures (for saving). I want your advice on this. Do you think it is a good solution? Any ideas?

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