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  • js code works for one variable(?), how to make it work for many?

    - by jerry87
    I have working code of js, it shows different div for selected option. <html> <head> <script src="http://code.jquery.com/jquery-latest.js"></script> <script type="text/javascript"> $(document).ready(function(){ $('#box1').hide(); $('#box2').hide(); $('#box3').hide(); $("#thechoices").change(function(){ $("#" + this.value).show().siblings().hide(); }); $("#thechoices").change(); }); </script> </head> <body> <select id="thechoices"> <option value="box1">Box 1</option> <option value="box2">Box 2</option> <option value="box3">Box 3</option> </select> <!-- the DIVs --> <div id="boxes"> <div id="box1"><p>Box 1 stuff...</p></div> <div id="box2"><p>Box 2 stuff...</p></div> <div id="box3"><p>Box 3 stuff...</p></div> </div> </body> </html> Please, I have no js experience, so I don't know how to make it work several times on one page for many "thechoices". Something like copy paste but more suitable than this: <script type="text/javascript"> $(document).ready(function(){ $('#box1').hide(); $('#box2').hide(); $('#box3').hide(); $('#box4').hide(); $('#box5').hide(); $('#box6').hide(); $("#thechoices").change(function(){ $("#" + this.value).show().siblings().hide(); }); $("#thechoices2").change(function(){ $("#" + this.value).show().siblings().hide(); }); $("#thechoices").change(); }); $("#thechoices2").change(); }); </script> </head> <body> <select id="thechoices"> <option value="box1">Box 1</option> <option value="box2">Box 2</option> <option value="box3">Box 3</option> </select> <!-- the DIVs --> <div id="boxes"> <div id="box1"><p>Box 1 stuff...</p></div> <div id="box2"><p>Box 2 stuff...</p></div> <div id="box3"><p>Box 3 stuff...</p></div> </div> <select id="thechoices2"> <option value="box4">1</option> <option value="box5">2</option> <option value="box6">3</option> </select> <!-- the DIVs --> <div id="boxes"> <div id="box4"><p>1 stuff...</p></div> <div id="box5"><p>2 stuff...</p></div> <div id="box6"><p>3 stuff...</p></div> </div> I know you can help me, it seems to be simple but I can't handle with this. How can I change my second code to work in the same way but not only for two selectors. I need it for many. Don't want to copy paste the same section like in my second code.

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  • How to create make .so files from code written in c or c++ that are usable from python

    - by None
    Looking at python modules and at code in the "lib-dnyload" directory in the python framework, I noticed whenever code is creating some kind of gui or graphic it imports a non-python file with a .so extension. And there are tons .so files in "lib-dnyload". From googling things I found that these files are called shared objects and are written in c or c++. I have a mac and I use gcc. I want to know how to make shared object files that are accessible via python. Mainly just how to make shared objects with gcc using mac os x.

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  • How do I "step over" jQuery code while debugging?

    - by Scott Rippey
    While stepping through a script that uses jQuery, I just want to test the code I wrote. I don't want to step into the jQuery file -- I'm not debugging jQuery, just my own file. Are there any ways to tell a debugger to not step into the jQuery file? I use Visual Studio + Internet Explorer, as well as Firefox + Firebug for stepping through code ... and both seem to love to step through dozens of jQuery statements. For example, say I have a script like this: $("div").each(function() { $(this).hide(); }); I would like to press "step into" and not see the implementation of ".each()" etc... In C#, this is possible by using the [DebuggerStepThrough()] attribute on a class. But that doesn't help with JavaScript.

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  • How can I get Ruby to treat the index of a string as a character (rather than the ASCII code)?

    - by user336777
    I am checking to see if the last character in a directory path is a '/'. How do you get ruby to treat the specific index of a string as a character rather than the associated ASCII code? For example the following always returns false: dir[dir.length - 1] == '/' This is because dir[dir.length - 1] returns the ASCII code 47 (rather than '/'). Any thoughts on how to interpret 47 as '/'? Or is there a completely different way to handle this in the first place? thanks.

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  • How to find the real problem line in my code with Application Verifier ?

    - by Newbie
    I am now trying to use this Application Verifier debugging tool, but i am stuck, first of all: it breaks the program at a line that is simple variable set line (s = 1; for example) Secondly, now when i run this program under debugger, my program seems to have changed its behaviour: i am drawing image, and now one of the colors has changed o_O, all those parts of the image that i dont draw on, has changed the color to #CDCDCD when it should be #000000, and i already set the default color to zero, still it becomes to #CDCDCD. How do i make any sense to this? Here is the output AV gave me: VERIFIER STOP 00000002: pid 0x8C0: Access violation exception. 14873000 : Invalid address causing the exception 004E422C : Code address executing the invalid access 0012EB08 : Exception record 0012EB24 : Context record AVRF: Noncontinuable verifier stop 00000002 encountered. Terminating process ... The program '[2240] test.exe: Native' has exited with code -1073741823 (0xc0000001).

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  • How can I get class, property, and method data from files without executing their code, similar to R

    - by Chris
    I have a bunch of PHP files with classes, in them (although I can't be 100% sure that they won't have code outside of classes in them too), and I need to parse these files to get information about the classes, such as the names of the classes, the methods, the properties, whether they are private/public/static, etc. I looked at PHP's reflection classes and this is very close to what I want but the reflection doesn't seem to use external files and it appears to need to define the classes first. I need to make sure that none of the code is executed and I will be editing the files so I can't guarantee that they will even be error-free. Any suggestions? Thanks.

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  • Need help with this question: Write Java code which reads numbers from the keyboard.....

    - by Chris
    Write Java code which reads numbers from the keyboard until zero is entered. Only the positive numbers entered are to be added to a variable-sized collection. This is what I have so far: import java.lang.*; import java.util.*; import java.io.*; import java.net.*; public class Demo1App extends Object { public static void main(String[] argStrings) throws Exception { ArrayList myArrayList = new ArrayList(); Scanner input = new Scanner(System.in); System.out.println ("NUMBERS:"); while (int input > 0) { myArrayList.add(input); } while (int input < 0) { System.out.println ("ENTER NUMBERS GREATER THAN 0!"); } } } This code doesn't work, I'm not sure why but any help with it would be appreciated.

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  • Is it good to create a usercontrol for Recursive code in xaml?

    - by user281947
    <Border BorderBrush="#C4C8CC" BorderThickness="0,0,0,1"> <TextBlock x:Name="SectionTitle" FontFamily="Trebuchet MS" FontSize="14" FontWeight="Bold" Foreground="#3D3D3D" /> </Border> I have to use the same above format at many places in a single xaml page, so for this i created a usercontrol and defined the above code inside it. So my question is, What i am doing is it right approach? Will it make the page to load slower then the above code used as it is without defining it in a new user control?

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  • Can we execute methods / code in XCode just like in Visual Studio?

    - by balexandre
    Visual Studio is one of the best developer IDE of all times, and now was improved with multithreading debugging and much more. My question is regarding XCode and the ability to execute code just like we do in Visual Studio. Let's assume an object in a view and I want to run, let's say: [pickerView setHidden:YES]; in a breakpoint just to see if in that break point I could actually hide the object. I can't find any place for this in the XCode Debugger Am I missing something or I can't execute code that is not in the files already? like in Visual Studio Watch List or Immediate Window

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  • Do you leave historical code commented out in classes that you update?

    - by 18Rabbit
    When you need to obsolete a section of code (say either the business rules changed, or the old system has been reworked to use a new framework or something) do you delete it from the file or do you comment it out and then put in the new functionality? If you comment it out, do you leave a note stating why it was removed and what it was originally intended to do? I ask mainly because I've done a lot of contract work for different places over the years and sometimes it's like excavating a tomb to find the actual code that is still being used. Why comment it out and leave it in the file if source control has a record of what used to be there? If you comment out a method do you also comment out/delete any methods that were exclusively used by that method? What do you think the best practices for this should be?

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  • Is it good to create a usercontrol for Recurrsive code in xaml?

    - by user281947
    <Border BorderBrush="#C4C8CC" BorderThickness="0,0,0,1"> <TextBlock x:Name="SectionTitle" FontFamily="Trebuchet MS" FontSize="14" FontWeight="Bold" Foreground="#3D3D3D" /> </Border> I have to use the same above format at many places in a single xaml page, so for this i created a usercontrol and defined the above code inside it. So my question is, what i am doing is it right approach ? Will it make the page to load slower then the above code used as it is without defining it in a new user control?

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  • What is the compatible JQuery line of code for IE7 and IE8?

    - by user144842
    This line of code is working fine for Firefox $("#<%=txt1.ClientID%>").text() but not for IE8 and IE7. See the scenario below in order to understand what I really mean:- Scenario:- Loading .aspx page. populating text box with some data from database. Now user changes data in same text-box at client-side (means page not yet submitted) So here in firefox, the above line of javascript is showing me the actual data came from database, but IE7&8 showing me the changed data. But I want actual data. So i need some compatible code for IE7 & IE8 I hope i explained it well what i need. Thanks in advance

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  • What code commenting style should I use for both C++ and C# ?

    - by ereOn
    Hi, I was recently hired in a company. They have a lot of C++ and C# code source files and almost one different commenting style per file. (Well this is exagerated, but you have the picture) This morning, I show my new collegues how my personnal code was commented and how easy it was to generate a documentation from it (I use Doxygen). I somehow convinced them to use a coherent commenting style. I would suggest using Doxygen for C++ source files and native C# style commenting style for C# files. However, I'm not sure that's the best solution here. Are you aware of a commenting style that would work for both C++ and C# allowing us to generate a documentation from it ? If so, what software/tool should we use ? Having a solution that would work on Linux platforms as well would be even better. Thank you very much.

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  • Where ORMs blur the lines between code and data, how do you decide what logic should be a stored procedure, and what should be coded?

    - by PhonicUK
    Take the following pseudocode: CreateInvoiceAndCalculate(ItemsAndQuantities, DispatchAddress, User); And say CreateInvoice does the following: Create a new entry in an Invoices table belonging to the specified User to be sent to the given DispatchAddress. Create a new entry in an InvoiceItems table for each of the items in ItemsAndQuantities, storing the Item, the Quantity, and the cost of the item as of now (by looking it up from an Items table) Calculate the total amount of the invoice (ex shipping and taxes) and store it in the new Invoice row. At a glace you wouldn't be able to tell if this was a method in my applications code, or a stored procedure in the database that is being exposed as a function by the ORM. And to some extent it doesn't really matter. Now technically none of this is business logic. You're not making any decisions - just performing a calculation and creating records. However some may argue that because you are performing a calculation that affects the business (the total amount to be invoiced) that this isn't something that should be done in a stored procedure and instead should be in code. So for this specific example - why would it be more appropriate to do one or the other? And where do you draw the line? Or does it even particular matter as long as it's sufficiently well documented?

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  • What's new in ASP.Net 4.5 and VS 2012 - part 2

    - by nikolaosk
    This is the second post in a series of posts titled "What's new in ASP.Net 4.5 and VS 2012".You can have a look at the first post in this series, here. Please find all my posts regarding VS 2012, here. In this post I will be looking into the various new features available in ASP.Net 4.5 and VS 2012.I will be looking into the enhancements in the HTML Editor,CSS Editor and Javascript Editor.In order to follow along this post you must have Visual Studio 2012 and .Net Framework 4.5 installed in your machine.Download and install VS 2012 using this link.My machine runs on Windows 8 and Visual Studio 2012 works just fine.I will work fine in Windows 7 as well so do not worry if you do not have the latest Microsoft operating system.1) Launch VS 2012 and create a new Web Forms application by going to File - >New Web Site - > ASP.Net Web Forms Site.2) Choose an appropriate name for your web site.3) I would like to point out the new enhancements in the CSS editor in VS 2012. In the Solution Explorer in the Content folder and open the Site.cssThen when I try to change the background-color property of the html element, I get a brand new handy color-picker. Have a look at the picture below  Please note that the color-picker shows all the colors that have been used in this website. Then you can expand the color-picker by clicking on the arrows. Opacity is also supported. Have a look at the picture below4) There are also mobile styles in the Site.css .These are based on media queries.Please have a look at another post of mine on CSS3 media queries. Have a look at the picture below In this case when the maximum width of the screen is less than 850px there will be a new layout that will be dictated by these new rules. Also CSS snippets are supported. Have a look at the picture below I am writing a new CSS rule for an image element. I write the property transform and hit tab and then I have cross-browser CSS handling all of the major vendors.Then I simply add the value rotate and it is applied to all the cross browser options.Have a look at the picture below.  I am sure you realise how productive you can become with all these CSS snippets. 5) Now let's have a look at the new HTML editor enhancements in VS 2012You can drag and drop a GridView web server control from the Toolbox in the Site.master file.You will see a smart tag (that was only available in the Design View) that you can expand and add fields, format the web server control.Have a look at the picture below 6) We also have available code snippets. I type <video and then press tab twice.By doing that I have the rest of the HTML 5 markup completed.Have a look at the picture below 7) I have new support for the input tag including all the HTML 5 types and all the new accessibility features.Have a look at the picture below   8) Another interesting feature is the new Intellisense capabilities. When I change the DocType to 4.01 and the type <audio>,<video> HTML 5 tags, Intellisense does not recognise them and add squiggly lines.Have a look at the picture below All these features support ASP.Net Web forms, ASP.Net MVC applications and Web Pages. 9) Finally I would like to show you the enhanced support that we have for Javascript in VS 2012. I have full Intellisense support and code snippets support.I create a sample javascript file. I type If and press tab. I type while and press tab.I type for and press tab.In all three cases code snippet support kicks in and completes the code stack. Have a look at the picture below We also have full Intellisense support.Have a look at the picture below I am creating a simple function and then type some sort of XML like comments for the input parameters. Have a look at the picture below. Then when I call this function, Intellisense has picked up the XML comments and shows the variables data types.Have a look at the picture below Hope it helps!!!

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  • Metro Walkthrough: Creating a Task List with a ListView and IndexedDB

    - by Stephen.Walther
    The goal of this blog entry is to describe how you can work with data in a Metro style application written with JavaScript. In particular, we create a super simple Task List application which enables you to create and delete tasks. Here’s a video which demonstrates how the Task List application works: In order to build this application, I had to take advantage of several features of the WinJS library and technologies including: IndexedDB – The Task List application stores data in an IndexedDB database. HTML5 Form Validation – The Task List application uses HTML5 validation to ensure that a required field has a value. ListView Control – The Task List application displays the tasks retrieved from the IndexedDB database in a WinJS ListView control. Creating the IndexedDB Database The Task List application stores all of its data in an IndexedDB database named TasksDB. This database is opened/created with the following code: var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; The msIndexedDB.open() method accepts two parameters: the name of the database to open and the version of the database to open. If a database with a matching version already exists, then calling the msIndexedDB.open() method opens a connection to the existing database. If the database does not exist then the upgradeneeded event is raised. You handle the upgradeneeded event to create a new database. In the code above, the upgradeneeded event handler creates an object store named “tasks” (An object store roughly corresponds to a database table). When you add items to the tasks object store then each item gets an id property with an auto-incremented value automatically. The code above also includes an error event handler. If the IndexedDB database cannot be opened or created, for whatever reason, then an error message is written to the Visual Studio JavaScript Console window. Displaying a List of Tasks The TaskList application retrieves its list of tasks from the tasks object store, which we created above, and displays the list of tasks in a ListView control. Here is how the ListView control is declared: <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> The ListView control is bound to the TaskList.tasks.dataSource data source. The TaskList.tasks.dataSource is created with the following code: // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); }; }; }; // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks }); Notice the success event handler. This handler is called when a database is successfully opened/created. In the code above, all of the items from the tasks object store are retrieved into a cursor and added to a WinJS.Binding.List object named tasks. Because the ListView control is bound to the WinJS.Binding.List object, copying the tasks from the object store into the WinJS.Binding.List object causes the tasks to appear in the ListView: Adding a New Task You add a new task in the Task List application by entering the title of a new task into an HTML form and clicking the Add button. Here’s the markup for creating the form: <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> Notice that the INPUT element includes a required attribute. In a Metro application, you can take advantage of HTML5 Validation to validate form fields. If you don’t enter a value for the newTaskTitle field then the following validation error message is displayed: For a brief introduction to HTML5 validation, see my previous blog entry: http://stephenwalther.com/blog/archive/2012/03/13/html5-form-validation.aspx When you click the Add button, the form is submitted and the form submit event is raised. The following code is executed in the default.js file: // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); The code above retrieves the title of the new task and calls the addTask() method in the tasks.js file. Here’s the code for the addTask() method which is responsible for actually adding the new task to the IndexedDB database: // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", "readwrite"); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } The code above does two things. First, it adds the new task to the tasks object store in the IndexedDB database. Second, it adds the new task to the data source bound to the ListView. The dataSource.insertAtEnd() method is called to add the new task to the data source so the new task will appear in the ListView (with a nice little animation). Deleting Existing Tasks The Task List application enables you to select one or more tasks by clicking or tapping on one or more tasks in the ListView. When you click the Delete button, the selected tasks are removed from both the IndexedDB database and the ListView. For example, in the following screenshot, two tasks are selected. The selected tasks appear with a teal background and a checkmark: When you click the Delete button, the following code in the default.js file is executed: // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); The selected tasks are retrieved with the TaskList selection.getItem() method. In the code above, the deleteTask() method is called for each of the selected tasks. Here’s the code for the deleteTask() method: // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", “readwrite”); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } This code does two things: it deletes the existing task from the database and removes the existing task from the ListView. In both cases, the right task is removed by using the key associated with the task. However, the task key is different in the case of the database and in the case of the ListView. In the case of the database, the task key is the value of the task id property. In the case of the ListView, on the other hand, the task key is auto-generated by the ListView. When the task is removed from the ListView, an animation is used to collapse the tasks which appear above and below the task which was removed. The Complete Code Above, I did a lot of jumping around between different files in the application and I left out sections of code. For the sake of completeness, I want to include the entire code here: the default.html, default.js, and tasks.js files. Here are the contents of the default.html file. This file contains the UI for the Task List application: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Task List</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- TaskList references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/tasks.js"></script> <style type="text/css"> body { font-size: x-large; } form { display: inline; } #appContainer { margin: 20px; width: 600px; } .win-container { padding: 10px; } </style> </head> <body> <div> <!-- Templates --> <div id="taskTemplate" data-win-control="WinJS.Binding.Template"> <div> <span data-win-bind="innerText:title"></span> </div> </div> <h1>Super Task List</h1> <div id="appContainer"> <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> <button id="btnDeleteTasks">Delete</button> <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> </div> </div> </body> </html> Here is the code for the default.js file. This code wires up the Add Task form and Delete button: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { // Get reference to Tasks ListView var tasksListView = document.getElementById("tasksListView"); // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); }); } }; app.start(); })(); Finally, here is the tasks.js file. This file contains all of the code for opening, creating, and interacting with IndexedDB: (function () { "use strict"; // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); }; }; }; // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", "readwrite"); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", "readwrite"); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks, addTask: addTask, deleteTask: deleteTask }); })(); Summary I wrote this blog entry because I wanted to create a walkthrough of building a simple database-driven application. In particular, I wanted to demonstrate how you can use a ListView control with an IndexedDB database to store and retrieve database data.

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  • Metro Walkthrough: Creating a Task List with a ListView and IndexedDB

    - by Stephen.Walther
    The goal of this blog entry is to describe how you can work with data in a Metro style application written with JavaScript. In particular, we create a super simple Task List application which enables you to create and delete tasks. Here’s a video which demonstrates how the Task List application works: In order to build this application, I had to take advantage of several features of the WinJS library and technologies including: IndexedDB – The Task List application stores data in an IndexedDB database. HTML5 Form Validation – The Task List application uses HTML5 validation to ensure that a required field has a value. ListView Control – The Task List application displays the tasks retrieved from the IndexedDB database in a WinJS ListView control. Creating the IndexedDB Database The Task List application stores all of its data in an IndexedDB database named TasksDB. This database is opened/created with the following code: var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; The msIndexedDB.open() method accepts two parameters: the name of the database to open and the version of the database to open. If a database with a matching version already exists, then calling the msIndexedDB.open() method opens a connection to the existing database. If the database does not exist then the upgradeneeded event is raised. You handle the upgradeneeded event to create a new database. In the code above, the upgradeneeded event handler creates an object store named “tasks” (An object store roughly corresponds to a database table). When you add items to the tasks object store then each item gets an id property with an auto-incremented value automatically. The code above also includes an error event handler. If the IndexedDB database cannot be opened or created, for whatever reason, then an error message is written to the Visual Studio JavaScript Console window. Displaying a List of Tasks The TaskList application retrieves its list of tasks from the tasks object store, which we created above, and displays the list of tasks in a ListView control. Here is how the ListView control is declared: <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> The ListView control is bound to the TaskList.tasks.dataSource data source. The TaskList.tasks.dataSource is created with the following code: // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; tasks.dataSource.beginEdits(); if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); } else { tasks.dataSource.endEdits(); }; }; }; // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks }); Notice the success event handler. This handler is called when a database is successfully opened/created. In the code above, all of the items from the tasks object store are retrieved into a cursor and added to a WinJS.Binding.List object named tasks. Because the ListView control is bound to the WinJS.Binding.List object, copying the tasks from the object store into the WinJS.Binding.List object causes the tasks to appear in the ListView: Adding a New Task You add a new task in the Task List application by entering the title of a new task into an HTML form and clicking the Add button. Here’s the markup for creating the form: <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> Notice that the INPUT element includes a required attribute. In a Metro application, you can take advantage of HTML5 Validation to validate form fields. If you don’t enter a value for the newTaskTitle field then the following validation error message is displayed: For a brief introduction to HTML5 validation, see my previous blog entry: http://stephenwalther.com/blog/archive/2012/03/13/html5-form-validation.aspx When you click the Add button, the form is submitted and the form submit event is raised. The following code is executed in the default.js file: // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); The code above retrieves the title of the new task and calls the addTask() method in the tasks.js file. Here’s the code for the addTask() method which is responsible for actually adding the new task to the IndexedDB database: // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } The code above does two things. First, it adds the new task to the tasks object store in the IndexedDB database. Second, it adds the new task to the data source bound to the ListView. The dataSource.insertAtEnd() method is called to add the new task to the data source so the new task will appear in the ListView (with a nice little animation). Deleting Existing Tasks The Task List application enables you to select one or more tasks by clicking or tapping on one or more tasks in the ListView. When you click the Delete button, the selected tasks are removed from both the IndexedDB database and the ListView. For example, in the following screenshot, two tasks are selected. The selected tasks appear with a teal background and a checkmark: When you click the Delete button, the following code in the default.js file is executed: // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); The selected tasks are retrieved with the TaskList selection.getItem() method. In the code above, the deleteTask() method is called for each of the selected tasks. Here’s the code for the deleteTask() method: // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } This code does two things: it deletes the existing task from the database and removes the existing task from the ListView. In both cases, the right task is removed by using the key associated with the task. However, the task key is different in the case of the database and in the case of the ListView. In the case of the database, the task key is the value of the task id property. In the case of the ListView, on the other hand, the task key is auto-generated by the ListView. When the task is removed from the ListView, an animation is used to collapse the tasks which appear above and below the task which was removed. The Complete Code Above, I did a lot of jumping around between different files in the application and I left out sections of code. For the sake of completeness, I want to include the entire code here: the default.html, default.js, and tasks.js files. Here are the contents of the default.html file. This file contains the UI for the Task List application: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Task List</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- TaskList references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/tasks.js"></script> <style type="text/css"> body { font-size: x-large; } form { display: inline; } #appContainer { margin: 20px; width: 600px; } .win-container { padding: 10px; } </style> </head> <body> <div> <!-- Templates --> <div id="taskTemplate" data-win-control="WinJS.Binding.Template"> <div> <span data-win-bind="innerText:title"></span> </div> </div> <h1>Super Task List</h1> <div id="appContainer"> <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> <button id="btnDeleteTasks">Delete</button> <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> </div> </div> </body> </html> Here is the code for the default.js file. This code wires up the Add Task form and Delete button: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { // Get reference to Tasks ListView var tasksListView = document.getElementById("tasksListView"); // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); }); } }; app.start(); })(); Finally, here is the tasks.js file. This file contains all of the code for opening, creating, and interacting with IndexedDB: (function () { "use strict"; // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; tasks.dataSource.beginEdits(); if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); } else { tasks.dataSource.endEdits(); }; }; }; // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks, addTask: addTask, deleteTask: deleteTask }); })(); Summary I wrote this blog entry because I wanted to create a walkthrough of building a simple database-driven application. In particular, I wanted to demonstrate how you can use a ListView control with an IndexedDB database to store and retrieve database data.

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  • Binary data instead of actual image in C#

    - by acadia
    Hello, I am using the below mentioned library to create a barcode which is storing in a specified location as shown below: My question is, is there a way instead of saving it to a png file I get byte data? thanks Code39 code = new Code39("10090"); code.Paint().Save("c:/NewBARCODE.png", ImageFormat.Png); using System; using System.Collections.Generic; using System.Drawing; using System.Drawing.Imaging; using System.Diagnostics; namespace BarCode39 { public class Code39Settings { private int height = 60; public int BarCodeHeight { get { return height; } set { height = value; } } private bool drawText = true; public bool DrawText { get { return drawText; } set { drawText = value; } } private int leftMargin = 10; public int LeftMargin { get { return leftMargin; } set { leftMargin = value; } } private int rightMargin = 10; public int RightMargin { get { return rightMargin; } set { rightMargin = value; } } private int topMargin = 10; public int TopMargin { get { return topMargin; } set { topMargin = value; } } private int bottomMargin = 10; public int BottomMargin { get { return bottomMargin; } set { bottomMargin = value; } } private int interCharacterGap = 2; public int InterCharacterGap { get { return interCharacterGap; } set { interCharacterGap = value; } } private int wideWidth = 2; public int WideWidth { get { return wideWidth; } set { wideWidth = value; } } private int narrowWidth = 1; public int NarrowWidth { get { return narrowWidth; } set { narrowWidth = value; } } private Font font = new Font(FontFamily.GenericSansSerif, 12); public Font Font { get { return font; } set { font = value; } } private int codeToTextGapHeight = 10; public int BarCodeToTextGapHeight { get { return codeToTextGapHeight; } set { codeToTextGapHeight = value; } } } public class Code39 { #region Static initialization static Dictionary<char, Pattern> codes; static Code39() { object[][] chars = new object[][] { new object[] {'0', "n n n w w n w n n"}, new object[] {'1', "w n n w n n n n w"}, new object[] {'2', "n n w w n n n n w"}, new object[] {'3', "w n w w n n n n n"}, new object[] {'4', "n n n w w n n n w"}, new object[] {'5', "w n n w w n n n n"}, new object[] {'6', "n n w w w n n n n"}, new object[] {'7', "n n n w n n w n w"}, new object[] {'8', "w n n w n n w n n"}, new object[] {'9', "n n w w n n w n n"}, new object[] {'A', "w n n n n w n n w"}, new object[] {'B', "n n w n n w n n w"}, new object[] {'C', "w n w n n w n n n"}, new object[] {'D', "n n n n w w n n w"}, new object[] {'E', "w n n n w w n n n"}, new object[] {'F', "n n w n w w n n n"}, new object[] {'G', "n n n n n w w n w"}, new object[] {'H', "w n n n n w w n n"}, new object[] {'I', "n n w n n w w n n"}, new object[] {'J', "n n n n w w w n n"}, new object[] {'K', "w n n n n n n w w"}, new object[] {'L', "n n w n n n n w w"}, new object[] {'M', "w n w n n n n w n"}, new object[] {'N', "n n n n w n n w w"}, new object[] {'O', "w n n n w n n w n"}, new object[] {'P', "n n w n w n n w n"}, new object[] {'Q', "n n n n n n w w w"}, new object[] {'R', "w n n n n n w w n"}, new object[] {'S', "n n w n n n w w n"}, new object[] {'T', "n n n n w n w w n"}, new object[] {'U', "w w n n n n n n w"}, new object[] {'V', "n w w n n n n n w"}, new object[] {'W', "w w w n n n n n n"}, new object[] {'X', "n w n n w n n n w"}, new object[] {'Y', "w w n n w n n n n"}, new object[] {'Z', "n w w n w n n n n"}, new object[] {'-', "n w n n n n w n w"}, new object[] {'.', "w w n n n n w n n"}, new object[] {' ', "n w w n n n w n n"}, new object[] {'*', "n w n n w n w n n"}, new object[] {'$', "n w n w n w n n n"}, new object[] {'/', "n w n w n n n w n"}, new object[] {'+', "n w n n n w n w n"}, new object[] {'%', "n n n w n w n w n"} }; codes = new Dictionary<char, Pattern>(); foreach (object[] c in chars) codes.Add((char)c[0], Pattern.Parse((string)c[1])); } #endregion private static Pen pen = new Pen(Color.Black); private static Brush brush = Brushes.Black; private string code; private Code39Settings settings; public Code39(string code) : this(code, new Code39Settings()) { } public Code39(string code, Code39Settings settings) { foreach (char c in code) if (!codes.ContainsKey(c)) throw new ArgumentException("Invalid character encountered in specified code."); if (!code.StartsWith("*")) code = "*" + code; if (!code.EndsWith("*")) code = code + "*"; this.code = code; this.settings = settings; } public Bitmap Paint() { string code = this.code.Trim('*'); SizeF sizeCodeText = Graphics.FromImage(new Bitmap(1, 1)).MeasureString(code, settings.Font); int w = settings.LeftMargin + settings.RightMargin; foreach (char c in this.code) w += codes[c].GetWidth(settings) + settings.InterCharacterGap; w -= settings.InterCharacterGap; int h = settings.TopMargin + settings.BottomMargin + settings.BarCodeHeight; if (settings.DrawText) h += settings.BarCodeToTextGapHeight + (int)sizeCodeText.Height; Bitmap bmp = new Bitmap(w, h, PixelFormat.Format32bppArgb); Graphics g = Graphics.FromImage(bmp); int left = settings.LeftMargin; foreach (char c in this.code) left += codes[c].Paint(settings, g, left) + settings.InterCharacterGap; if (settings.DrawText) { int tX = settings.LeftMargin + (w - settings.LeftMargin - settings.RightMargin - (int)sizeCodeText.Width) / 2; if (tX < 0) tX = 0; int tY = settings.TopMargin + settings.BarCodeHeight + settings.BarCodeToTextGapHeight; g.DrawString(code, settings.Font, brush, tX, tY); } return bmp; } private class Pattern { private bool[] nw = new bool[9]; public static Pattern Parse(string s) { Debug.Assert(s != null); s = s.Replace(" ", "").ToLower(); Debug.Assert(s.Length == 9); Debug.Assert(s.Replace("n", "").Replace("w", "").Length == 0); Pattern p = new Pattern(); int i = 0; foreach (char c in s) p.nw[i++] = c == 'w'; return p; } public int GetWidth(Code39Settings settings) { int width = 0; for (int i = 0; i < 9; i++) width += (nw[i] ? settings.WideWidth : settings.NarrowWidth); return width; } public int Paint(Code39Settings settings, Graphics g, int left) { #if DEBUG Rectangle gray = new Rectangle(left, 0, GetWidth(settings), settings.BarCodeHeight + settings.TopMargin + settings.BottomMargin); g.FillRectangle(Brushes.Gray, gray); #endif int x = left; int w = 0; for (int i = 0; i < 9; i++) { int width = (nw[i] ? settings.WideWidth : settings.NarrowWidth); if (i % 2 == 0) { Rectangle r = new Rectangle(x, settings.TopMargin, width, settings.BarCodeHeight); g.FillRectangle(brush, r); } x += width; w += width; } return w; } } } }

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  • Configure Cucumber with SentientUser

    - by Corith Malin
    I have an application using the SentientUser gem to provide the current user to my models. On top of that I'm using default scoping to ensure that a user can only ever access data that they own. So a typical model for me looks something like this: class Location < ActiveRecord::Base validates_presence_of :name, :time_zone, :address belongs_to :account belongs_to :address accepts_nested_attributes_for :address default_scope :conditions => { :account_id => User.current.account } end When I run rake cucumber I get an error on the default_scope line about account being nil. My guess is that when the cucumber rake task is run it doesn't have access to the correct application controller to inject the current_user method and thus SentientUser can't get the current user? The error I get is: rake cucumber (in /Users/corithmalin/Documents/Code/Ruby/flavorpulse) /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby -I "/Library/Ruby/Gems/1.8/gems/cucumber-0.6.3/lib:lib" "/Library/Ruby/Gems/1.8/gems/cucumber-0.6.3/bin/cucumber" --profile default Using the default profile... undefined method `account' for nil:NilClass (NoMethodError) /Users/corithmalin/Documents/Code/Ruby/flavorpulse/vendor/rails/activesupport/lib/active_support/whiny_nil.rb:52:in `method_missing' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/app/models/location.rb:9 /Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `gem_original_require' /Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `polyglot_original_require' /Library/Ruby/Gems/1.8/gems/polyglot-0.3.0/lib/polyglot.rb:65:in `require' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/vendor/rails/activesupport/lib/active_support/dependencies.rb:158:in `require' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/vendor/rails/activesupport/lib/active_support/dependencies.rb:265:in `require_or_load' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/vendor/rails/activesupport/lib/active_support/dependencies.rb:224:in `depend_on' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/vendor/rails/activesupport/lib/active_support/dependencies.rb:136:in `require_dependency' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/config/../vendor/rails/railties/lib/initializer.rb:414:in `load_application_classes' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/config/../vendor/rails/railties/lib/initializer.rb:413:in `each' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/config/../vendor/rails/railties/lib/initializer.rb:413:in `load_application_classes' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/config/../vendor/rails/railties/lib/initializer.rb:411:in `each' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/config/../vendor/rails/railties/lib/initializer.rb:411:in `load_application_classes' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/config/../vendor/rails/railties/lib/initializer.rb:197:in `process' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/config/../vendor/rails/railties/lib/initializer.rb:113:in `send' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/config/../vendor/rails/railties/lib/initializer.rb:113:in `run' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/config/environment.rb:9 /Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `gem_original_require' /Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `polyglot_original_require' /Library/Ruby/Gems/1.8/gems/polyglot-0.3.0/lib/polyglot.rb:65:in `require' /Users/corithmalin/Documents/Code/Ruby/flavorpulse/features/support/env.rb:8 /Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `gem_original_require' /Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `polyglot_original_require' /Library/Ruby/Gems/1.8/gems/polyglot-0.3.0/lib/polyglot.rb:65:in `require' /Library/Ruby/Gems/1.8/gems/cucumber-0.6.3/bin/../lib/cucumber/rb_support/rb_language.rb:124:in `load_code_file' /Library/Ruby/Gems/1.8/gems/cucumber-0.6.3/bin/../lib/cucumber/step_mother.rb:85:in `load_code_file' /Library/Ruby/Gems/1.8/gems/cucumber-0.6.3/bin/../lib/cucumber/step_mother.rb:77:in `load_code_files' /Library/Ruby/Gems/1.8/gems/cucumber-0.6.3/bin/../lib/cucumber/step_mother.rb:76:in `each' /Library/Ruby/Gems/1.8/gems/cucumber-0.6.3/bin/../lib/cucumber/step_mother.rb:76:in `load_code_files' /Library/Ruby/Gems/1.8/gems/cucumber-0.6.3/bin/../lib/cucumber/cli/main.rb:48:in `execute!' /Library/Ruby/Gems/1.8/gems/cucumber-0.6.3/bin/../lib/cucumber/cli/main.rb:20:in `execute' /Library/Ruby/Gems/1.8/gems/cucumber-0.6.3/bin/cucumber:8 rake aborted! Command failed with status (1): [/System/Library/Frameworks/Ruby.framework/...] (See full trace by running task with --trace)

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