Search Results

Search found 37088 results on 1484 pages for 'object element'.

Page 579/1484 | < Previous Page | 575 576 577 578 579 580 581 582 583 584 585 586  | Next Page >

  • Rails 3: Link_to :remote => true with JQuery?

    - by Derek
    Question update: I have figured out that importing JQuery (even without using it at all) is causing :remote => true to not work properly. I get the following error in the Chrome console: Uncaught TypeError: Object [object Object] has no method 'dispatchEvent' (prototype.js:5653) And when the link is clicked, it throws the same error again before redirecting. Responder.erb.html <ul> <% @choices.each_with_index do |choice, index| %> <li><%= link_to choice, { :action => "submit_response", :id => @id, :response => index }, :remote => true %></li> <% end %> </ul> Example generated HTML: <ul> <li><a href="/poller/submit_response/yni?response=0" data-remote="true">True</a></li> <li><a href="/poller/submit_response/yni?response=1" data-remote="true">False</a></li> </ul>

    Read the article

  • Why do I get "request for member in something not a struct or union" from this code?

    - by pyroxene
    I'm trying to teach myself C by coding up a linked list. I'm new to pointers and memory management and I'm getting a bit confused. I have this code: /* Remove a node from the list and rejiggle the pointers */ void rm_node(struct node **listP, int index) { struct node *prev; struct node *n = *listP; if (index == 0) { *listP = *listP->next; free(n); return; } for (index; index > 0; index--) { n = n->next; if (index == 2) { prev = n; } } prev->next = n->next; free(n); } to remove an element from the list. If I want to remove the first node, I still need some way of referring to the list, which is why the listP arg is a double pointer, so it can point to the first element of the list and allow me to free the node that used to be the head. However, when I try to dereference listP to access the pointer to the next node, the compiler tells me error: request for member ‘next’ in something not a structure or union . What am I doing wrong here? I think I might be hopelessly mixed up..?

    Read the article

  • In Safari, using jQuery a Form Input Text Field does not receive focus after alert is displayed. Why

    - by Rob
    I have an ASPX web form. I use jQuery to simply my Javascript. I use a Javascript validation script to validate each of the form fields' values. If an error occurs, I popup an alert with an error message. Then I transfer focus to the underlying element. Here are examples I have tried. Using jQuery: var Form_FieldDef = function(name) { this.name = name; this.SetFocus = function() { $('#' + this.name)[0].focus(); } this.Validate = function() { var isvalid = true; if ( $.trim($('#' + this.name).val()) == '') { alert("Your entry is empty"); this.SetFocus(); isvalid = false; } return isvalid; } } This works on IE7, IE8, Opera, Chrome, and Firefox. It does not work on Safari 4 on PC. I don't have a Mac. So I changed the SetFocus method to this. this.SetFocus = function() { var fld = document.getElementById(this.name); if (fld != null) fld.focus(); } This works on IE7, IE8, Opera, Chrome, and Firefox. It does not work on Safari 4 on PC. I stepped through the code with VS 2008 debugger, and I'm calling the focus method on the underlying element.

    Read the article

  • Concurrent connections in C# socket

    - by Chu Mai
    There are three apps run at the same time, 2 clients and 1 server. The whole system should function as following: The client sends an serialized object to server then server receives that object as a stream, finally the another client get that stream from server and deserialize it. This is the sender: TcpClient tcpClient = new TcpClient(); tcpClient.Connect("127.0.0.1", 8888); Stream stream = tcpClient.GetStream(); BinaryFormatter binaryFormatter = new BinaryFormatter(); binaryFormatter.Serialize(stream, event); // Event is the sending object tcpClient.Close(); Server code: TcpListener listener = new TcpListener(IPAddress.Parse("127.0.0.1"), 8888); listener.Start(); Console.WriteLine("Server is running at localhost port 8888 "); while (true) { Socket socket = listener.AcceptSocket(); try { Stream stream = new NetworkStream(socket); // Typically there should be something to write the stream // But I don't knwo exactly what should the stream write } catch (Exception e) { Console.WriteLine("Exception: " + e.Message); Console.WriteLine("Disconnected: {0}", socket.RemoteEndPoint); } } The receiver: TcpClient client = new TcpClient(); // Connect the client to the localhost with port 8888 client.Connect("127.0.0.1", 8888); Stream stream = client.GetStream(); Console.WriteLine(stream); when I run only the sender and server, and check the server, server receives correctly the data. The problem is when I run the receiver, everything is just disconnected. So where is my problem ? Could anyone point me out ? Thanks

    Read the article

  • How can I determine whether or not to add project items using IWizard?

    - by taarskog
    Hi, I am generating entity wrappers in VS2010 based on dynamic objects in a CRM system. In addition to the entity code, I want to add an EntityBase of which all entities inherit from. If the file exists in the project from before, it should not be added. I am using an IWizard implementation to give the generator the object names etc. Is it possible in the IWizard implementation to determine whether or not to add an item if it exists in the project from before? How do I get a hold of the project handle and its items in or before the ShouldAddProjectItem method? My code so far (not completed): public class EntityWizardImplementation : IWizard { public void BeforeOpeningFile(ProjectItem projectItem) { //Note: Nothing here. } public void ProjectFinishedGenerating(Project project) { //Note: Nothing here. } public void ProjectItemFinishedGenerating(ProjectItem projectItem) { //Note: Nothing here. } public void RunFinished() { //Note: Nothing here. } public void RunStarted(object automationObject, Dictionary<string, string> replacementsDictionary, WizardRunKind runKind, object[] customParams) { try { var window = new WizardWindow(); // Replace parameters gathered from the wizard replacementsDictionary.Add("$crmEntity$", window.CrmEntity); replacementsDictionary.Add("$crmOrganization$", window.CrmOrganization); replacementsDictionary.Add("$crmMetadataServiceUrl$", window.CrmMetadataUrl); window.Close(); } catch (SoapException se) { MessageBox.Show(se.ToString()); } catch (Exception e) { MessageBox.Show(e.ToString()); } } public bool ShouldAddProjectItem(string filePath) { // This is where I assume it is correct to handle the preexisting file. return true; } }

    Read the article

  • HTML+CSS: 'a' width doesn't work

    - by Budda
    I have the following code: CSS part: <style type="text/css"> .menu { width:200px; } .menu ul { list-style-image:none; list-style-type:none; } .menu li { margin:2px; } .menu A { height:25px; width:170px; background:url(./images/button-51.png); padding:2px 5px ; } .menu A:link { height:25px; width:170px; background:url(./images/button-51.png); padding:2px 5px ; } </style> HTML part: Everything work fine, but when I add 'DOCTYPE' element in the beginning of the HTML document: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> the width of 'a' element is not taken into account. Question 1: Why? Question 2: How to fix that? Thanks a lot!

    Read the article

  • Storing large numbers of varying size objects on disk

    - by Foredecker
    I need to develop a system for storing large numbers (10's to 100's of thousands) of objects. Each object is email-like - there is a main text body, and several ancillary text fields of limited size. A body will be from a few bytes, to several KB in size. Each item will have a single unique ID (probably a GUID) that identifies it. The store will only be written to when an object is added to it. It will be read often. Deletions will be rare. The data is almost all human readable text so it will be readily compressible. A system that lets me issue the I/Os and mange the memory and caching would be ideal. I'm going to keep the indexes in memory, using it to map indexes to the single (and primary) key for the objects. Once I have the key, then I'll load it from disk, or the cache. The data management system needs to be part of my application - I do not want to depend on OS services. Or separately installed packages. Native (C++) would be best, but a manged (C#) thing would be ok. I believe that a database is an obvious choice, but this needs to be super-fast for look up and loading into memory of an object. I am not experienced with data base tech and I'm concerned that general relational systems will not handle all this variable sized data efficiently. (Note, this has nothing to do with my job - its a personal project.) In your experience, what are the viable alternatives to a traditional relational DB? Or would a DB work well for this?

    Read the article

  • Laravel4: Checking many-to-many relationship attribute even when it does not exist

    - by Simo A.
    This is my first time with Laravel and also Stackoverflow... I am developing a simple course management system. The main objects are User and Course, with a many-to-many relationship between them. The pivot table has an additional attribute, participant_role, which defines whether the user is a student or an instructor within that particular course. class Course extends Eloquent { public function users() { return $this->belongsToMany('User')->withPivot('participant_role')->withTimestamps(); } } However, there is an additional role, system admin, which can be defined on the User object. And this brings me mucho headache. In my blade view I have the following: @if ($course->pivot->participant_role == 'instructor') { // do something here... } This works fine when the user has been assigned to that particular $course and there is an entry for this user-course combination in the pivot table. However, the problem is the system administrator, who also should be able to access course details. The if-clause above gives Trying to get property of non-object error, apparently because there is no entry in the pivot table for system administrator (as the role is defined within the User object). I could probably solve the problem by using some off-the-shelf bundle for handling role-based permissions. Or I could (but don't want to) do something like this with two internal if-clauses: if (!empty($course->pivot)) { if ($course->pivot->participant_role == 'instructor') { // do something... } } Other options (suggested in partially similar entries in Stackoverflow) would include 1) reading all the pivot table entries to an array, and use in_array to check if a role exists, or even 2) SQL left join to do this on database level. However, ultimately I am looking for a compact one-line solution? Can I do anything similar to this, which unfortunately does not seem to work? if (! empty ($course->pivot->participant_role == 'instructor') ) { // do something... } The shorter the answer, the better :-). Thanks a lot!

    Read the article

  • Good C++ array class for dealing with large arrays of data in a fast and memory efficient way?

    - by Shane MacLaughlin
    Following on from a previous question relating to heap usage restrictions, I'm looking for a good standard C++ class for dealing with big arrays of data in a way that is both memory efficient and speed efficient. I had been allocating the array using a single malloc/HealAlloc but after multiple trys using various calls, keep falling foul of heap fragmentation. So the conclusion I've come to, other than porting to 64 bit, is to use a mechanism that allows me to have a large array spanning multiple smaller memory fragments. I don't want an alloc per element as that is very memory inefficient, so the plan is to write a class that overrides the [] operator and select an appropriate element based on the index. Is there already a decent class out there to do this, or am I better off rolling my own? From my understanding, and some googling, a 32 bit Windows process should theoretically be able address up to 2GB. Now assuming I've 2GB installed, and various other processes and services are hogging about 400MB, how much usable memory do you think my program can reasonably expect to get from the heap? I'm currently using various flavours of Visual C++.

    Read the article

  • JavaScript array random index insertion and deletion

    - by Tomi
    I'm inserting some items into array with randomly created indexes, for example like this: var myArray = new Array(); myArray[123] = "foo"; myArray[456] = "bar"; myArray[789] = "baz"; ... In other words array indexes do not start with zero and there will be "numeric gaps" between them. My questions are: Will these numeric gaps be somehow allocated (and therefore take some memory) even when they do not have assigned values? When I delete myArray[456] from upper example, would items below this item be relocated? EDIT: Regarding my question/concern about relocation of items after insertion/deletion - I want to know what happens with the memory and not indexes. More information from wikipedia article: Linked lists have several advantages over dynamic arrays. Insertion of an element at a specific point of a list is a constant-time operation, whereas insertion in a dynamic array at random locations will require moving half of the elements on average, and all the elements in the worst case. While one can "delete" an element from an array in constant time by somehow marking its slot as "vacant", this causes fragmentation that impedes the performance of iteration.

    Read the article

  • WCF operationcontract with List type unavailable in (Silverlight) client

    - by Dave
    This is the first time I have tried returning a List of data to a Silverlight client, so I'm having trouble getting the client to recognize this operationcontract. All others are fine. I have a method on the server called ReadOwFileData that needs to return a List. ReadOwFileDataCompletedEventArgs shows up in the Object Browser in the client, but not ReadOwFileDataAsync. What I want is similar to the tutorial here. The Dictionary collection type on the client is set to System.Collections.Generic.List. I tried deleting and recreating the service reference. Web.Config on the server is using basicHttpBinding. Here is the operationcontract on the server: [OperationContract] public List<OwFileData> ReadOwFileData(string OrderID) { DataClasses1DataContext db = new DataClasses1DataContext(); var dFileData = (from p in db.OwFileDatas where p.OrderID == OrderID select p).ToList(); List<OwFileData> x = new List<OwFileData>(dFileData); return x; } Incidently, this works fine: [OperationContract] public Customer GetShippingAndContactInfo(string login, string ordernum) { DataClasses1DataContext db = new DataClasses1DataContext(); Customer dInfo = (from p in db.Customers where p.Login == login select p).Single(); return dInfo; } I would like to read this data in the client and place it into an object I created called ObservableCollection. But that obviously can't happen until the client can see the method on the server. I do not know if this is an acceptable start, but this is what is on the client so far. The ReadOwFileDataAsync object is null: void populatefilesReceivedDataSource(string OrderID) { ArtUpload.ServiceReference1.UploadServiceClient client = new ArtUpload.ServiceReference1.UploadServiceClient(); var myList = client.ReadOwFileDataAsync(OrderID); // can I just itterate thru the list instead of 'binding' }

    Read the article

  • how do I remove rows/columns from this matrix using python

    - by banditKing
    My matrix looks like this. ['Hotel', ' "excellent"', ' "very good"', ' "average"', ' "poor"', ' "terrible"', ' "cheapest"', ' "rank"', ' "total reviews"'] ['westin', ' 390', ' 291', ' 70', ' 43', ' 19', ' 215', ' 27', ' 813'] ['ramada', ' 136', ' 67', ' 53', ' 30', ' 24', ' 149', ' 49', ' 310 '] ['sutton place', '489', ' 293', ' 106', ' 39', ' 20', ' 299', ' 24', ' 947'] ['loden', ' 681', ' 134', ' 17', ' 5', ' 0', ' 199', ' 4', ' 837'] ['hampton inn downtown', ' 241', ' 166', ' 26', ' 5', ' 1', ' 159', ' 21', ' 439'] ['shangri la', ' 332', ' 45', ' 20', ' 8', ' 2', ' 325', ' 8', ' 407'] ['residence inn marriott', ' 22', ' 15', ' 5', ' 0', ' 0', ' 179', ' 35', ' 42'] ['pan pacific', ' 475', ' 262', ' 86', ' 29', ' 16', ' 249', ' 15', ' 868'] ['sheraton wall center', ' 277', ' 346', ' 150', ' 80', ' 26', ' 249', ' 45', ' 879'] ['westin bayshore', ' 390', ' 291', ' 70', ' 43', ' 19', ' 199', ' 813'] I want to remove the top row and the 0th column from this and create a new matrix. How do I do this? Normally in java or so Id use the following code: for (int y; y< matrix[x].length; y++) for(int x; x < matrix[Y].length; x++) { if(x == 0 || y == 0) { continue } else { new_matrix[x][y] = matrix[x][y]; } } Is there a way such as this in python to iterate and selectively copy elements? Thanks EDIT Im also trying to convert each matrix element from a string to a float as I iterate over the matrix. This my updated modified code based on the answer below. A = [] f = open("csv_test.csv",'rt') try: reader = csv.reader(f) for row in reader: A.append(row) finally: f.close() new_list = [row[1:] for row in A[1:]] l = np.array(new_list) l.astype(np.float32) print l However Im getting an error --> l.astype(np.float32) print l ValueError: setting an array element with a sequence.

    Read the article

  • Are there any free Xml Diff/Merge tools available?

    - by Russell
    I have several config files in my .net applications which I would like to merge application settings elements etc. I was about to begin doing it manually as I usually do, however thought there must be an XML diff GUI tool available somewhere. The tool would be able to go to the element level to compare and display the differences etc. However Google gave no substantive free tool results and no hints for anything of value. Is such a tool available? That is very useful? For free? Thanks in advance. :) Edit: Here is a bit of clarification of the functionality that would turn my error-prone, tedious manual job into a 1-minute simpler task (and potential to automate): In KDiff3, you can do a diff/merge of entire directories. There is a hierarchical diff which is very accurate, user-friendly and clear. I was interested in finding a similar solution, however instead of directory hierarchy, an XML element hierarchy. If there is no such open source software, I am considering creating one on CodePlex to provide this functionality.

    Read the article

  • problem calculating the position using php

    - by LiveEn
    I have a function below which gets name from a site. Below is the partial code, not complete. The values are passed thru a for loop using php. function funct($$name,$page) { $url="http://testserver.com/client?list=$name&page=$page"; $ch=curl_init(); curl_setopt($ch,CURLOPT_URL,url); $result=curl_exec($ch); $dom = new DOMDocument(); @$dom->loadHTML($result); $xpath=new DOMXPath($dom); $elements = $xpath->evaluate("//div"); foreach ($elements as $element) { $name = $element->getElementsByTagName("name")->item(0)->nodeValue; $position=$position +1; echo $name.$position; } } The code works fine but when i get a name i need to add a position and for each name it will be incremented by 1 to make it contentious. But when the values for the pages are passed, for an example when i move from page 1 to page 2. the count starts again from first, next page... same problem. How can i make it continues on every page?

    Read the article

  • Java scripts conflict on my home page

    - by naveen
    <script type="text/javascript" src="jquery-1.js"></script> <script type="text/javascript" src="mootools.js"></script> <script type="text/javascript" src="slideshow.js"></script> <script type="text/javascript"> //<![CDATA[ window.addEvent('domready', function(){ var data = { '1.jpg': { caption: 'Volcano Asención in Ometepe, Nicaragua.' }, '2.jpg': { caption: 'A Ceibu tree.' }, '3.jpg': { caption: 'The view from Volcano Maderas.' }, '4.jpg': { caption: 'Beer and ice cream.' } }; var myShow = new Slideshow('show', data, {controller: true, height: 400, hu: 'images/', thumbnails: true, width: 500}); }); //]]> </script> <script type="text/javascript"> $(document).ready(function() { //slides the element with class "menu_body" when paragraph with class "menu_head" is clicked $("#firstpane p.menu_head").click(function() { $(this).css({backgroundImage:"url(down.png)"}).next("div.menu_body").slideToggle(300).siblings("div.menu_body").slideUp("slow"); $(this).siblings().css({backgroundImage:"url(left.png)"}); }); //slides the element with class "menu_body" when mouse is over the paragraph $("#secondpane p.menu_head").mouseover(function() { $(this).css({backgroundImage:"url(down.png)"}).next("div.menu_body").slideDown(500).siblings("div.menu_body").slideUp("slow"); $(this).siblings().css({backgroundImage:"url(left.png)"}); }); }); </script> <!--[if lt IE 7]> <script type="text/javascript" src="unitpngfix.js"></script> <![endif]-->

    Read the article

  • C++ privately contructed class

    - by Nona Urbiz
    How can I call a function and keep my constructor private? If I make the class static, I need to declare an object name which the compiler uses to call the constructor, which it cannot if the constructor is private (also the object would be extraneous). Here is the code I am attempting to use (it is not compilable): I want to keep the constructor private because I will later be doing a lot of checks before adding an object, modifying previous objects when all submitted variables are not unique rather than creating new objects. #include <iostream> #include <fstream> #include <regex> #include <string> #include <list> #include <map> using namespace std; using namespace tr1; class Referral { public: string url; map<string, int> keywords; static bool submit(string url, string keyword, int occurrences) { //if(Referrals.all.size == 0){ // Referral(url, keyword, occurrences); //} } private: list<string> urls; Referral(string url, string keyword, int occurrences) { url = url; keywords[keyword] = occurrences; Referrals.all.push_back(this); } }; struct All { list<Referral> all; }Referrals; int main() { Referral.submit("url", "keyword", 1); }

    Read the article

  • Adding to the DOM via Prototype works in Chrome but not Firefox?

    - by zaczap
    I've been working on some Javascript code to add rows to a table dynamically (a small task management system) and it works perfectly in Chrome but not in Firefox. Code in question: var task = new Element('tr', {id:arg}); task.innerHTML = "<td class='notes'>asd</td><td class='check'>*</td>"; //task.innerHTML = "<td class='notes'>&nbsp;</td><td class='check'><input type='checkbox' onclick=\"javascript:complete('"+task.id+"')\" /></td><td class='description'>asd</td><td class='start'>&nbsp;</td><td class='due'></td>"; $('tasks').insert(task); // the commented line above is what the code was originally that does work in chrome When I look at the HTML model in the Firefox debugger, all that is added is: <tr id="arg"><td>asd*</td></tr> Figuring that Chrome might be better at interpreting innerHTML into DOM elements than Firefox, I changed the code to make td elements and add them to my tr element but that didn't improve the situation at all.

    Read the article

  • Printing the "source" class in a log statement with a log4j wrapper

    - by Dur4ndal
    My application has a homebrew logging class that I'm migrating to using log4j under the covers. However, since I'm using the homebrew class to pass the rest of the application's logging statements to log4j, the output statements are logged as coming from the wrapper class instead of the source class. Is there a way to ensure that the "correct" source is being shown besides creating new org.apache.log4j.Logger instances for every log statement? I've also tried using the Logger.log(String callerFQCN, Priority level, Object message, Throwable t) method, but it doesnt seem to be working, for example: public class Logger2 { public static org.apache.log4j.Logger log4JLogger = org.apache.log4j.Logger.getLogger(Logger2.class); public static void warning(Object source, String message) { log(source, message, Level.WARN, null) } private static void log(Object source, String message, Level level, Throwable t) { String className = source.getClass().getName(); System.out.println("Logging class should be " + className); log4JLogger.log(className, loggingLevel, message, t); } } When called by: public void testWarning() { Logger2.warning(new Integer(3), "This should warn"); } Prints: Logging class should be java.lang.Integer 2010-05-25 10:49:57,152 WARN test.Logger2 - This should warn

    Read the article

  • Error In VB.Net code

    - by Michael
    I am getting the error "Format Exception was unhandled at "Do While objectReader.Peek < -1 " and after. any help would be wonderful. 'Date: Class 03/20/2010 'Program Purpose: When code is executed data will be pulled from a text file 'that contains the named storms to find the average number of storms during the time 'period chosen by the user and to find the most active year. between the range of 'years 1990 and 2008 Option Strict On Public Class frmHurricane Private _intNumberOfHuricanes As Integer = 5 Public Shared _intSizeOfArray As Integer = 7 Public Shared _strHuricaneList(_intSizeOfArray) As String Private _strID(_intSizeOfArray) As String Private _decYears(_intSizeOfArray) As Decimal Private _decFinal(_intSizeOfArray) As Decimal Private _intNumber(_intSizeOfArray) As Integer Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 'The frmHurricane load event reads the Hurricane text file and 'fill the combotBox object with the data. 'Initialize an instance of the StreamReader Object and declare variable page 675 on the book Dim objectReader As IO.StreamReader Dim strLocationAndNameOfFile As String = "C:\huricanes.txt" Dim intCount As Integer = 0 Dim intFill As Integer Dim strFileError As String = "The file is not available. Please restart application when available" 'This is where we code the file if it exist. If IO.File.Exists(strLocationAndNameOfFile) Then objectReader = IO.File.OpenText(strLocationAndNameOfFile) 'Read the file line by line until the file is complete Do While objectReader.Peek <> -1 **_strHuricaneList(intCount) = objectReader.ReadLine() _strID(intCount) = objectReader.ReadLine() _decYears(intCount) = Convert.ToDecimal(objectReader.ReadLine()) _intNumber(intCount) = Convert.ToInt32(objectReader.ReadLine()) intCount += 1** Loop objectReader.Close() 'With any luck the data will go to the Data Box For intFill = 0 To (_strID.Length - 1) Me.cboByYear.Items.Add(_strID(intFill)) Next Else MsgBox(strFileError, , "Error") Me.Close() End If End Sub

    Read the article

  • Child elements changing opacity with parent Image

    - by mitch
    I have a <div> element which has a background image. On top of that I have some text that is hidden but when the user hovers over the <div> element that text will show and the <div> opacity will lower. My problem is when you hover over the div all elements inside that change opacity as well. I have looked through stackoverflow to see if anyone has the same problem but all i found were answers that had RGBA using background colors (not images). Here is my css: .pic{ background-image:url(http://www.granitesportsinstitute.com/wp-content/uploads/2014/06/Green-Sea-Turtle-150x150.jpg); -webkit-transition: all .3s ease-in-out; -moz-transition: all .3s ease-in-out; -o-transition: all .3s ease-in-out; transition: all .3s ease-in-out; } .textstuff{ visibility:hidden; } .pic:hover .textstuff{ visibility:visible; color:black; } .pic:hover{ filter: alpha(opacity=30); -moz-opacity: 0.3; -khtml-opacity: 0.3; opacity: 0.3; } HTML HERE: <div class="pic" style="height:150px;width:150px;"> <div class="textstuff">this is text</div> </div>

    Read the article

  • Python: why can't descriptors be instance variables?

    - by Continuation
    Say I define this descriptor: class MyDescriptor(object): def __get__(self, instance, owner): return self._value def __set__(self, instance, value): self._value = value def __delete__(self, instance): del(self._value) And I use it in this: class MyClass1(object): value = MyDescriptor() >>> m1 = MyClass1() >>> m1.value = 1 >>> m2 = MyClass1() >>> m2.value = 2 >>> m1.value 2 So value is a class attribute and is shared by all instances. Now if I define this: class MyClass2(object) value = 1 >>> y1 = MyClass2() >>> y1.value=1 >>> y2 = MyClass2() >>> y2.value=2 >>> y1.value 1 In this case value is an instance attribute and is not shared by the instances. Why is it that when value is a descriptor it can only be a class attribute, but when value is a simple integer it becomes an instance attribute?

    Read the article

  • Embedded Youtube video in a Ruby on Rails page

    - by dan
    Hi, New to programming. I am trying to embed a YouTube video from a link stored in a database named "Promoter" into a ruby-on-rails page (.erb). I've looked at the source the code turns out, but the object video player does not appear (on heroku here: http://blazing-mountain-574.heroku.com/). The code in the home.html.erb file: <h1>Pages#home</h1> <p>Find me in app/views/pages/home.html.erb</p> <object width="640" height="385"> <param name="movie" value="<%= sanitize Promoter.first.link %>"> </param><param name="allowFullScreen" value="true"></param ><param name="allowscriptaccess" value="always"></param> <embed src="<%= sanitize Promoter.first.link %>" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="640" height="385"></embed></object> Is there something real simple that I'm missing?

    Read the article

  • Detailstext in TableView from Coredata Iphone

    - by user554867
    Hey, that is my first question here at stackoverflow. Let me try to be specific as I can. The project is as follows: I am trying to parse an xml file in an iphone app, which works already. I am saving the parsed data into the CoreData of the Iphone. So far so good: I have two elements of the xml file which I want to show in the tableview as the text and the detailtext. Now the strange behaviour occurs: If I take the data of the Core Data and trying to visualize them in the tableview, then both elements are displayed in seperate cells and not as detailtext of the element. If I am just taking a constant string for the detailtext, then it works, but if I am trying to take for every cell a specific element from the Core Data then it is shown seperately in the tableview. I googled a lot, reading here and there. I dont know which code I should show because I dont have a clue where exactly the mistake could be. Maybe someone can answer that immediately because it is a stupid mistake somewhere, which is common. Thanks for your help.

    Read the article

  • Doesn't this defeat the whole purpose of having read-only properties?

    - by flockofcode
    I know how to use properties and I understand that they implicitly call underlying get and set accessors, depending on whether we are writing to or reading from a property. static void Main(string[] args) { A a = new A(); (a.b).i = 100; } class A { private B _b = new B(); public B b { get { return _b; } } } class B { public int i; } What code (a.b).i = 100; essentially does is that first property’s get accessor returns a reference to an object _b, and once we have this reference, we are able to access _b’s members and change their values. Thus, in our example, having read only property only prevents outside code from changing the value of a reference variable _b, but it doesn’t prevent outside code from accessing _b’s members. So it seems that property can only detect whether we are trying to read from or write to a variable ( in our case variable _b ) located on the stack, while it’s not able to detect whether we’re trying to also write to members of an object to which the variable on the stack ( assuming this variable is of reference type ) points to. a) But doesn’t that defeat the whole purpose of having read-only properties? Wouldn’t it be more effective if properties had the ability to also detect whether we’re trying to access members of an object returned by get accessor( assuming backing field is of a reference type )? thank you

    Read the article

  • Playing FLV unexpectedly stops, but why?

    - by Josamoto
    I am trying to play an FLV video that is about 90Mb big, using the following snippet: private function playVideo(url:String):void { var customClient:Object = new Object(); customClient.onMetaData = metaDataHandler; var nc:NetConnection = new NetConnection(); nc.connect(null); var ns:NetStream = new NetStream(nc); ns.client = customClient; ns.play(url); var myVideo:Video = new Video(); myVideo.attachNetStream(ns); addChild(myVideo); function metaDataHandler(infoObject:Object):void { myVideo.width = 640; myVideo.x = stage.stageWidth / 2 - 640 / 2; myVideo.height = 400; myVideo.y = 230; } } The video is not going to be streamed across the internet, in fact, the application will run locally and videos will also be loaded locally from disc. When starting my application, the video starts, but at random locations, playback completely freezes up, without any errors being thrown at all. Does anybody have any idea as to why this might happen?

    Read the article

< Previous Page | 575 576 577 578 579 580 581 582 583 584 585 586  | Next Page >