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  • Is there an application that can automatically set Graphics Properties when docking?

    - by Ken Liu
    I have a dual display setup with my laptop (Dell, with integrated graphics, WinXP). The problem is that whenever I hook up the laptop to the monitor I have to go to Graphics Properties (Intel Graphics Media Driver for Mobile) and set the display resolution, window position, etc. Note that this screen is different than the built-in one you usually see in WinXP. 1) Is there an app that can save display settings properly so they will come back when I dock again? 2) Barring this, run a script or a macro to automatically set up the display the way I want it. 3) Or, can I write a .Net program that does this for me? Extra points if there is an Open source app that can do this.

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  • View controller/NIB architecture for non-navigation application with transitions?

    - by Ben
    I'm tinkering with an app that doesn't use the UINavigation root view control system, so I don't have natural ownership for each app "view". I essentially have two basic views, a document list view, and a document edit view. I'm playing with UIView animation for getting from a selected document to the edit view. I also have a toolbar that exists in both "views". Because I don't have UINavigation running the show for me, I have a tendency to just throw more and more stuff into one NIB and one view controller that owns the whole container. But now I'm trying to figure out how to segue from the document list view to the edit view if the edit view lives inside a different NIB, preserving the toolbar too. Anyone have thoughts or experience on app structures like this? I find the docs lacking on best practices around code/UI structure for anything except trivial one-screen apps or full-on navigation apps. Thanks!

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  • What is the best way to maintain an entity's original properties when they are not included in MVC binding from edit page?

    - by kingdango
    I have an ASP.NET MVC view for editing a model object. The edit page includes most of the properties of my object but not all of them -- specifically it does not include CreatedOn and CreatedBy fields since those are set upon creation (in my service layer) and shouldn't change in the future. Unless I include these properties as hidden fields they will not be picked up during Binding and are unavailable when I save the modified object in my EF 4 DB Context. In actuality, upon save the original values would be overwritten by nulls (or some type-specific default). I don't want to drop these in as hidden fields because it is a waste of bytes and I don't want those values exposed to potential manipulation. Is there a "first class" way to handle this situation? Is it possible to specify a EF Model property is to be ignored unless explicitly set?

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  • Tab Bar and Nav Controller: Where did I go wrong in my Interface Builder wiring?

    - by editor
    Even if you don't know how I've shot myself in the foot, a story which I've tried to lay out below, if you think I've done a good job showing the parameters of my problem I'd appreciate an upvote so that I might be able to grab some attention for my question. I've been working on an iPhone application in XCode and Interface Builder of the Tab Bar project type. After getting a table view of topics (business sectors) working fine I realized that I would need to add a Navigation Control to allow the user to drill into a subtopics (subsectors) table. As a green Objective-C developer, that was confusing, but I managed to get it working by reading various documentation trying out a few different IB options. My current setup is a Tab Bar Controller with Tab 1 as a Navigation Controller and Tab 2 a plain view with a Table View placed into it. The wiring works: I can log when table rows are selected and I'm ready to push a new View Controller onto the stack so that I can display the subtopics Table View. My problem: For some reason the first tab's Table View is a delegate and dataSource of the second ta. It doesn't make sense to me and I can't figure out why that's the only setup that works. Here is the wiring: Navigation Controller (Sectors) is a delegate of Tab Bar Navigation Bar is a delegate of Navigation Controller (Sectors) View Contoller (Sectors) has a view of Table View Table View (in Navigation Controller (Sectors)) is a delegate of First View Controller (Companies) Table View (in Navigation Controller (Sectors)) is a dataSource outlet of First View Controller (Companies) First View Controller (Companies) First View Contoller (Sectors) has a view of Table View Table View (in First View Controller (Companies)) is not hooked up to a dataSource outlet and is not a delegate When I click the tab buttons and look at the Inspector I see that the first tab is correctly hooked up to my MainWindow.xib and the second tab has selected a nib called SecondView.xib. It's in the File's Owner of MainWindow.xib where I inherit UITableViewDataSource and UITableViewDelegate (and also UITabBarControllerDelegate) in the .h, and in the .m where I implement the delegate methods. Why does this setup only work when the Table View in my first tab (View Controller (Sectors)) is a delegate and dataSource of the second tab? I'm confused: why wouldn't it need to be hooked up to the Navigation Controller-enabled tab in which the Table View is seen (Navigation Controller (Sectors))? The Table View seen on the second tab has neither dataSource and is not a delegate. I'm having trouble getting a pushViewController to fire (self.navigationController is not nil but the new View Controller still doesn't load) and I suspect that I need to work out this IB wiring issue before I can troubleshoot why the Nav Controller won't push a new View Controller onto the stack. if(nil == self.navigationController) { NSLog(@"self.navigationController is nil."); } else { NSLog(@"self.navigationController is not nil."); SectorList *subsectorViewController = [[SectorList alloc] initWithNibName:@"SectorList" bundle:nil]; subsectorViewController.title = @"Subsectors"; [[self navigationController] pushViewController:subsectorViewController animated:YES]; [subsectorViewController release]; }

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  • What is the default fontsize, fontname and shadow for titles in Navigation Bar?

    - by user292952
    I'm trying to have a button on the self.navigationItem.rightButton that toggles a segmented control that is placed in self.navgivationItem.titleView .. this will however remove the title that is first set by self.title when the navbar is created .. I dont know if my approach is bad but I figured I could rotate between a UILabel and the Segmented Control in the titleView. It works as I would like it to, however I cant figure out what size and font and shadowoffset and shadowcolor the default titles in a navigation bar is .. could you help me with a solution that either not force me to override the navigationItem.titleView or help me figure out the information needed to make a UILabel look exactly like the default titles. Thankful for any help.

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  • iPhone: How do I override the back button in a Navigation Controller?

    - by Angelo Stracquatanio
    Hello, In my app I have a basic Navigation Controller. For all of my views, except one, the controller works as it should. However, for one view in particular, I would like the 'back' button to not go back to the previous view, but to go to one I set. In particular it is going to go back 2 views and skip over one. After doing some research I found that I can intercept the view when it disappears, so I tried to put in code to have it navigate to the page I would like: - (void)viewWillDisappear:(BOOL)animated { [super viewWillDisappear:animated]; //i set a flag to know that the back button was pressed if (viewPushed) { viewPushed = NO; } else { // Here, you know that back button was pressed mainMenu *mainViewController = [[mainMenu alloc] initWithNibName:@"mainMenu" bundle:nil]; [self.navigationController pushViewController:mainViewController animated:YES]; [mainViewController release]; } } That didn't work, so does anyone have any ideas? Thanks!!

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  • Windows 7, file properties, date modified, how do you show seconds?

    - by Jordan W.
    Anyone know a way to immediately show the seconds of a file's date modified property in the GUI? So if you create a file, any file in any directory, right-click and choose Properties, the date modified (if it's recent) will say something like "dd/mm/yyy hh:mm, one minute ago" - reminder this is in Windows 7. Windows XP did it normally. Then they changed something. If you wait a while, eventually you'll see the seconds, I'm not sure how long a while is, but this is incredibly annoying if you want to troubleshoot something that relies on the seconds of timestamps... is there a setting? registry key I can change perhaps? I'm literally using Chrome, pasting in the path of the directory to be able to see the seconds quickly (as a workaround) but would be nice to be able to use Win7.

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  • How to resolve Resharper's "unused property" warning on properties solely for Display/Value Members?

    - by JYelton
    I have defined two properties "Name" and "ID" for an object which I use for the DisplayMember and ValueMember of a ComboBox with a BindingList datasource. I recently installed Resharper to evaluate it. Resharper is giving me warnings on the object that the two properties are unused. Sample code: BindingList<ClassSample> SampleList = new BindingList<ClassSample>(); // populate SampleList cmbSampleSelector.DisplayMember = "Name"; cmdSampleSelector.ValueMember = "ID"; cmbSampleSelector.DataSource = SampleList; private class ClassSample { private string _name; private string _id; public string Name // Resharper believes this property is unused { get { return _name; } } public string ID // Resharper believes this property is unused { get {return _id; } } public ClassSample(string Name, string ID) { _name = Name; _id = ID; } } Am I doing something wrong or is Resharper clueless about this particular usage?

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  • conceptually different entities with a few similar properties should be stored in one table or more?

    - by Haghpanah
    Assume A and B are conceptually different entities that have a few similar properties and of course their own specific properties. In database design, should I put those two entities in one big aggregated table or two respectively designed tables. For instance, I have two types of payment; Online-payment and Manual-payment with following definition, TABLE [OnlinePayments] ( [ID] [uniqueidentifier], [UserID] [uniqueidentifier], [TrackingCode] [nvarchar](32), [ReferingCode] [nvarchar](32), [BankingAccID] [uniqueidentifier], [Status] [int], [Amount] [money], [Comments] [nvarchar](768), [CreatedAt] [datetime], [ShopingCartID] [uniqueidentifier], ) And TABLE [ManualPayments] ( [ID] [uniqueidentifier], [UserID] [uniqueidentifier], [BankingAccID] [uniqueidentifier], [BankingOrgID] [uniqueidentifier], [BranchName] [nvarchar](64), [BranchCode] [nvarchar](16), [Amount] [money], [SlipNumber] [nvarchar](64), [SlipImage] [image], [PaidAt] [datetime], [Comments] [nvarchar](768), [CreatedAt] [datetime], [IsApproved] [bit], [ApprovedByID] [uniqueidentifier], ) One of my friends told me that creating two distinct tables for such similar entities is not a well design method and they should be put in one single table for the sake of performance and ease of data manipulations. I’m now wondering what to do? What is the best practice in such a case?

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  • Is there an difference between transient properties defined in the data model, or in the custom subc

    - by mystify
    I was reading that setting the value of a transient property always results in marking the managed object as "dirty". However, what I don't get is this: If I make a subclass of NSManagedObject and use some extra properties which I don't need to be persistet, how does Core Data know about them and how can it mark the object as dirty when I access these? Again, they're not defined in the data model, so Core Data has no really good hint that they are there. Or does Core Data use some kind of introspection to analyze my custom class and figure out what properties I have in there?

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  • Magento - How can I move the Navigation Block to be in the right column?

    - by Hank
    I've been editing Magento's default CSS to change the look and have come to a point where I want to move around some content blocks. I've killed off the left column through CSS .col-left { display: none; } And then increased the width of the main content part to create a 'two column layout'. What I want to do now is move the navigation for the categories into the right column. I just have no idea how... How do I move content blocks around in Magento? :/

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  • RoR: Where is the "rails/info/properties" route defined?

    - by Dave Paroulek
    I'm running Rails 2.3.4. When I create a new rails project, the public/index.html file has a link named "About your application's environment" that points to "rails/info/properties". In dev mode, it gives a summary of the runtime environment. However, in production mode, it gives a 404 page cannot be found. Could someone point me in the direction of how and where the "rails/info/properties" route is configured? I'd just like to understand how it's set up.

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  • Javascript looping only through defined properties of array. How?

    - by Beck
    For example if i'm keeping array of references via id like that: if(typeof channel_boards[misc.channel_id] == 'undefined') { channel_boards[misc.channel_id] = $('<div class="channel" channel_id="'+misc.channel_id+'"></div>').appendTo('#board'); } And then i'm looping through array to find required reference. I'm looping through undefined properties as well. Is it possible to loop only through defined properties? for(i=0;i<channel_boards.length;i++) { if(channel_boards[i] != undefined) { if(channel_boards[i].attr('channel_id') != visible) {channel_boards[i].addClass('hidden_board');} else {channel_boards[i].removeClass('hidden_board');} } } Maybe i should change the way i'm storing references? Via object for example, but how i'll be able to find proper reference via id number.

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  • jQuery mobile 1.1.0 slider: JS-object properties access?

    - by Koniak
    EDIT: This could be seen as a pure javascript objects question. The code can be found here: jquery.mobile-1.1.0.js I need to access properties of a jQuery mobile JS-object but is not sure how that is possible. In the jquery.mobile-1.1.0.js and mobile.slider is the following (see extend on line 5967): $.widget( "mobile.slider", $.mobile.widget, { ... _create: function() { ... $.extend( this, { slider: slider, handle: handle, valuebg: valuebg, dragging: false, beforeStart: null, userModified: false, mouseMoved: false }); Primarily the property I would like to read is the "dragging". I know i can execute the methods using: $("#slider").slider("refresh") Is there a similair way to access the properties? Thanks

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  • Convert IIS / Tomcat Web Application to a multi-server environment.

    - by bill_the_loser
    I have an existing web application built in .Net, running on IIS that leverages a java servlet that we have running on Tomcat 5.5. We need to scale the application and I'm confused about what relates to our situation and what we need to do to get the servlet running on multiple servers. Right now I have 4 servers that can each individually process results, it almost seems like all I should have to do is add the ajp13 worker processes from three additional machines to the machine hosting the load balancer worker. But I can't imagine it should be that easy. What do I need to do to distribute the Tomcat load to the extra three machines? Thanks. Update: The current configuration is using a workers2.properties configuration file. From all of the documentation online I have not been able to determine the distinction between the workers.properties and the workers2.properties. Most of the examples that I have found are configuring the workers.properties and revolve around adding workers and registering them in the worker.list element. The workers2.properties does not appears to have a worker.list element and the syntax is different enough between the workers.properties and the workers2.properties that I'm doubtful that I can add that element. If I just add my multiple AJP workers to the workers2.properties file do I need to worry about the apparent lack of a worker.list element? [ajp13:localhost:8009] channel=channel.socket:localhost:8009 group=lb [ajp13:host2.mydomain.local:8009] channel=channel.socket:host2.mydomain.local:8009 group=lb [ajp13:host3.mydomain.local:8009] channel=channel.socket:host3.mydomain.local:8009 group=lb A couple of side notes... One I've noticed that sometime Tomcat doesn't seem to reload my changes and I don't know why. Also, I have no idea why this configuration has a workers2.properties and not a workers.properties. I've been assuming that it's based on version but I haven't seen anything to back up that assumption.

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  • How to auto-generate early bound properties for Entity specific (ie Local) Option Set text values?

    - by Daryl
    After spending a year working with the Microsoft.Xrm.Sdk namespace, I just discovered yesterday the Entity.FormattedValues property contains the text value for Entity specific (ie Local) Option Set texts. The reason I didn't discover it before, is there is no early bound method of getting the value. i.e. entity.new_myOptionSet is of type OptionSetValue which only contains the int value. You have to call entity.FormattedValues["new_myoptionset"] to get the string text value of the OptionSetValue. Therefore, I'd like to get the crmsrvcutil to auto-generate a text property for local option sets. i.e. Along with Entity.new_myOptionSet being generated as it currently does, Entity.new_myOptionSetText would be generated as well. I've looked into the Microsoft.Crm.Services.Utility.ICodeGenerationService, but that looks like it is mostly for specifying what CodeGenerationType something should be... Is there a way supported way using CrmServiceUtil to add these properties, or am I better off writing a custom app that I can run that can generate these properties as a partial class to the auto-generated ones? Edit - Example of the code that I would like to be generated Currently, whenever I need to access the text value of a OptionSetValue, I use this code: var textValue = OptionSetCache.GetText(service, entity, e => e.New_MyOptionSet); The option set cache will use the entity.LogicalName, and the property expression to determine the name of the option set that I'm asking for. It will then query the SDK using the RetrieveAttriubteRequest, to get a list of the option set int and text values, which it then caches so it doesn't have to hit CRM again. It then looks up the int value of the New_MyOptionSet of the entity and cross references it with the cached list, to get the text value of the OptionSet. Instead of doing all of that, I can just do this (assuming that the entity has been retrieved from the server, and not just populated client side): var textValue = entity.FormattedValues["new_myoptionset"]; but the "new_myoptionset" is no longer early bound. I would like the early bound entity classes that gets generated to also generate an extra "Text" property for OptionSetValue properties that calls the above line, so my entity would have this added to it: public string New_MyOptionSetText { return this.GetFormattedAttributeValue("new_myoptionset"); // this is a protected method on the Entity class itself... }

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  • How do I link (dependency) properties in my ViewModel?

    - by mos
    Simplified example: I have an object that models a user. Users have a first name and a last name. The UserViewModel has a dependency property for my Models.User object. In the declaration of the UserView's xaml, I want to bind a couple of TextBlocks to the first and last name properties. What is the correct way to do this? Should I have readonly DependencyProperties for the name fields, and when the dependency property User is set, update them? Can the name fields be regular C# properties instead? Or, should I bind like this: <TextBlock Text="{Binding User.FirstName}" />

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  • (WinForm/.net) Databind List Of Classes To A DataGridView. But Not Show Certain Public Properties

    - by Pyronaut
    I'm not even sure if i'm doing this correctly. But basically I have a list of objects that are built out of a class. From there, I am binding the list to a datagrid view that is on a Windows Form (C#) From there, it shows all the public properties of the object, in the datagrid view. However there is some properties that i still need accessible from other parts of my application, but aren't really required to be visible in the DataGridView. So is there an attribute or something similar that I can write above the property to exclude it from being shown. P.S. Im binding at runtime. So i cannot edit the columns via the designer. P.P.S. Please no answers of just making public variables (Although if that is the only way, let me know :)).

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  • Are there alternative ways to implementing an "active link" navigation without using server side languages?

    - by Mel
    By "active" I mean to have the link pointing to the current page classed as "active." This way the link's appearance can be modified using css. Is it possible to implement an active link navigation without using a server side language? I would like to only use CSS/HTML/jQuery if possible. If there are, what are those methods? Assuming you want to create the following structure: <ul id="nav"> <li class="active">Home</li> <li>About</li> <li>Contact</li> </ul>

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  • Adventures in MVVM &ndash; My ViewModel Base

    - by Brian Genisio's House Of Bilz
    More Adventures in MVVM First, I’d like to say: THIS IS NOT A NEW MVVM FRAMEWORK. I tend to believe that MVVM support code should be specific to the system you are building and the developers working on it.  I have yet to find an MVVM framework that does everything I want it to without doing too much.  Don’t get me wrong… there are some good frameworks out there.  I just like to pick and choose things that make sense for me.  I’d also like to add that some of these features only work in WPF.  As of Silveright 4, they don’t support binding to dynamic properties, so some of the capabilities are lost. That being said, I want to share my ViewModel base class with the world.  I have had several conversations with people about the problems I have solved using this ViewModel base.  A while back, I posted an article about some experiments with a “Rails Inspired ViewModel”.  What followed from those ideas was a ViewModel base class that I take with me and use in my projects.  It has a lot of features, all designed to reduce the friction in writing view models. I have put the code out on Codeplex under the project: ViewModelSupport. Finally, this article focuses on the ViewModel and only glosses over the View and the Model.  Without all three, you don’t have MVVM.  But this base class is for the ViewModel, so that is what I am focusing on. Features: Automatic Command Plumbing Property Change Notification Strongly Typed Property Getter/Setters Dynamic Properties Default Property values Derived Properties Automatic Method Execution Command CanExecute Change Notification Design-Time Detection What about Silverlight? Automatic Command Plumbing This feature takes the plumbing out of creating commands.  The common pattern for commands in a ViewModel is to have an Execute method as well as an optional CanExecute method.  To plumb that together, you create an ICommand Property, and set it in the constructor like so: Before public class AutomaticCommandViewModel { public AutomaticCommandViewModel() { MyCommand = new DelegateCommand(Execute_MyCommand, CanExecute_MyCommand); } public void Execute_MyCommand() { // Do something } public bool CanExecute_MyCommand() { // Are we in a state to do something? return true; } public DelegateCommand MyCommand { get; private set; } } With the base class, this plumbing is automatic and the property (MyCommand of type ICommand) is created for you.  The base class uses the convention that methods be prefixed with Execute_ and CanExecute_ in order to be plumbed into commands with the property name after the prefix.  You are left to be expressive with your behavior without the plumbing.  If you are wondering how CanExecuteChanged is raised, see the later section “Command CanExecute Change Notification”. After public class AutomaticCommandViewModel : ViewModelBase { public void Execute_MyCommand() { // Do something } public bool CanExecute_MyCommand() { // Are we in a state to do something? return true; } }   Property Change Notification One thing that always kills me when implementing ViewModels is how to make properties that notify when they change (via the INotifyPropertyChanged interface).  There have been many attempts to make this more automatic.  My base class includes one option.  There are others, but I feel like this works best for me. The common pattern (without my base class) is to create a private backing store for the variable and specify a getter that returns the private field.  The setter will set the private field and fire an event that notifies the change, only if the value has changed. Before public class PropertyHelpersViewModel : INotifyPropertyChanged { private string text; public string Text { get { return text; } set { if(text != value) { text = value; RaisePropertyChanged("Text"); } } } protected void RaisePropertyChanged(string propertyName) { var handlers = PropertyChanged; if(handlers != null) handlers(this, new PropertyChangedEventArgs(propertyName)); } public event PropertyChangedEventHandler PropertyChanged; } This way of defining properties is error-prone and tedious.  Too much plumbing.  My base class eliminates much of that plumbing with the same functionality: After public class PropertyHelpersViewModel : ViewModelBase { public string Text { get { return Get<string>("Text"); } set { Set("Text", value);} } }   Strongly Typed Property Getters/Setters It turns out that we can do better than that.  We are using a strongly typed language where the use of “Magic Strings” is often frowned upon.  Lets make the names in the getters and setters strongly typed: A refinement public class PropertyHelpersViewModel : ViewModelBase { public string Text { get { return Get(() => Text); } set { Set(() => Text, value); } } }   Dynamic Properties In C# 4.0, we have the ability to program statically OR dynamically.  This base class lets us leverage the powerful dynamic capabilities in our ecosystem. (This is how the automatic commands are implemented, BTW)  By calling Set(“Foo”, 1), you have now created a dynamic property called Foo.  It can be bound against like any static property.  The opportunities are endless.  One great way to exploit this behavior is if you have a customizable view engine with templates that bind to properties defined by the user.  The base class just needs to create the dynamic properties at runtime from information in the model, and the custom template can bind even though the static properties do not exist. All dynamic properties still benefit from the notifiable capabilities that static properties do. For any nay-sayers out there that don’t like using the dynamic features of C#, just remember this: the act of binding the View to a ViewModel is dynamic already.  Why not exploit it?  Get over it :) Just declare the property dynamically public class DynamicPropertyViewModel : ViewModelBase { public DynamicPropertyViewModel() { Set("Foo", "Bar"); } } Then reference it normally <TextBlock Text="{Binding Foo}" />   Default Property Values The Get() method also allows for default properties to be set.  Don’t set them in the constructor.  Set them in the property and keep the related code together: public string Text { get { return Get(() => Text, "This is the default value"); } set { Set(() => Text, value);} }   Derived Properties This is something I blogged about a while back in more detail.  This feature came from the chaining of property notifications when one property affects the results of another, like this: Before public class DependantPropertiesViewModel : ViewModelBase { public double Score { get { return Get(() => Score); } set { Set(() => Score, value); RaisePropertyChanged("Percentage"); RaisePropertyChanged("Output"); } } public int Percentage { get { return (int)(100 * Score); } } public string Output { get { return "You scored " + Percentage + "%."; } } } The problem is: The setter for Score has to be responsible for notifying the world that Percentage and Output have also changed.  This, to me, is backwards.    It certainly violates the “Single Responsibility Principle.” I have been bitten in the rear more than once by problems created from code like this.  What we really want to do is invert the dependency.  Let the Percentage property declare that it changes when the Score Property changes. After public class DependantPropertiesViewModel : ViewModelBase { public double Score { get { return Get(() => Score); } set { Set(() => Score, value); } } [DependsUpon("Score")] public int Percentage { get { return (int)(100 * Score); } } [DependsUpon("Percentage")] public string Output { get { return "You scored " + Percentage + "%."; } } }   Automatic Method Execution This one is extremely similar to the previous, but it deals with method execution as opposed to property.  When you want to execute a method triggered by property changes, let the method declare the dependency instead of the other way around. Before public class DependantMethodsViewModel : ViewModelBase { public double Score { get { return Get(() => Score); } set { Set(() => Score, value); WhenScoreChanges(); } } public void WhenScoreChanges() { // Handle this case } } After public class DependantMethodsViewModel : ViewModelBase { public double Score { get { return Get(() => Score); } set { Set(() => Score, value); } } [DependsUpon("Score")] public void WhenScoreChanges() { // Handle this case } }   Command CanExecute Change Notification Back to Commands.  One of the responsibilities of commands that implement ICommand – it must fire an event declaring that CanExecute() needs to be re-evaluated.  I wanted to wait until we got past a few concepts before explaining this behavior.  You can use the same mechanism here to fire off the change.  In the CanExecute_ method, declare the property that it depends upon.  When that property changes, the command will fire a CanExecuteChanged event, telling the View to re-evaluate the state of the command.  The View will make appropriate adjustments, like disabling the button. DependsUpon works on CanExecute methods as well public class CanExecuteViewModel : ViewModelBase { public void Execute_MakeLower() { Output = Input.ToLower(); } [DependsUpon("Input")] public bool CanExecute_MakeLower() { return !string.IsNullOrWhiteSpace(Input); } public string Input { get { return Get(() => Input); } set { Set(() => Input, value);} } public string Output { get { return Get(() => Output); } set { Set(() => Output, value); } } }   Design-Time Detection If you want to add design-time data to your ViewModel, the base class has a property that lets you ask if you are in the designer.  You can then set some default values that let your designer see what things might look like in runtime. Use the IsInDesignMode property public DependantPropertiesViewModel() { if(IsInDesignMode) { Score = .5; } }   What About Silverlight? Some of the features in this base class only work in WPF.  As of version 4, Silverlight does not support binding to dynamic properties.  This, in my opinion, is a HUGE limitation.  Not only does it keep you from using many of the features in this ViewModel, it also keeps you from binding to ViewModels designed in IronRuby.  Does this mean that the base class will not work in Silverlight?  No.  Many of the features outlined in this article WILL work.  All of the property abstractions are functional, as long as you refer to them statically in the View.  This, of course, means that the automatic command hook-up doesn’t work in Silverlight.  You need to plumb it to a static property in order for the Silverlight View to bind to it.  Can I has a dynamic property in SL5?     Good to go? So, that concludes the feature explanation of my ViewModel base class.  Feel free to take it, fork it, whatever.  It is hosted on CodePlex.  When I find other useful additions, I will add them to the public repository.  I use this base class every day.  It is mature, and well tested.  If, however, you find any problems with it, please let me know!  Also, feel free to suggest patches to me via the CodePlex site.  :)

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  • Metro: Understanding Observables

    - by Stephen.Walther
    The goal of this blog entry is to describe how the Observer Pattern is implemented in the WinJS library. You learn how to create observable objects which trigger notifications automatically when their properties are changed. Observables enable you to keep your user interface and your application data in sync. For example, by taking advantage of observables, you can update your user interface automatically whenever the properties of a product change. Observables are the foundation of declarative binding in the WinJS library. The WinJS library is not the first JavaScript library to include support for observables. For example, both the KnockoutJS library and the Microsoft Ajax Library (now part of the Ajax Control Toolkit) support observables. Creating an Observable Imagine that I have created a product object like this: var product = { name: "Milk", description: "Something to drink", price: 12.33 }; Nothing very exciting about this product. It has three properties named name, description, and price. Now, imagine that I want to be notified automatically whenever any of these properties are changed. In that case, I can create an observable product from my product object like this: var observableProduct = WinJS.Binding.as(product); This line of code creates a new JavaScript object named observableProduct from the existing JavaScript object named product. This new object also has a name, description, and price property. However, unlike the properties of the original product object, the properties of the observable product object trigger notifications when the properties are changed. Each of the properties of the new observable product object has been changed into accessor properties which have both a getter and a setter. For example, the observable product price property looks something like this: price: { get: function () { return this.getProperty(“price”); } set: function (value) { this.setProperty(“price”, value); } } When you read the price property then the getProperty() method is called and when you set the price property then the setProperty() method is called. The getProperty() and setProperty() methods are methods of the observable product object. The observable product object supports the following methods and properties: · addProperty(name, value) – Adds a new property to an observable and notifies any listeners. · backingData – An object which represents the value of each property. · bind(name, action) – Enables you to execute a function when a property changes. · getProperty(name) – Returns the value of a property using the string name of the property. · notify(name, newValue, oldValue) – A private method which executes each function in the _listeners array. · removeProperty(name) – Removes a property and notifies any listeners. · setProperty(name, value) – Updates a property and notifies any listeners. · unbind(name, action) – Enables you to stop executing a function in response to a property change. · updateProperty(name, value) – Updates a property and notifies any listeners. So when you create an observable, you get a new object with the same properties as an existing object. However, when you modify the properties of an observable object, then you can notify any listeners of the observable that the value of a particular property has changed automatically. Imagine that you change the value of the price property like this: observableProduct.price = 2.99; In that case, the following sequence of events is triggered: 1. The price setter calls the setProperty(“price”, 2.99) method 2. The setProperty() method updates the value of the backingData.price property and calls the notify() method 3. The notify() method executes each function in the collection of listeners associated with the price property Creating Observable Listeners If you want to be notified when a property of an observable object is changed, then you need to register a listener. You register a listener by using the bind() method like this: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { // Simple product object var product = { name: "Milk", description: "Something to drink", price: 12.33 }; // Create observable product var observableProduct = WinJS.Binding.as(product); // Execute a function when price is changed observableProduct.bind("price", function (newValue) { console.log(newValue); }); // Change the price observableProduct.price = 2.99; } }; app.start(); })(); In the code above, the bind() method is used to associate the price property with a function. When the price property is changed, the function logs the new value of the price property to the Visual Studio JavaScript console. The price property is associated with the function using the following line of code: // Execute a function when price is changed observableProduct.bind("price", function (newValue) { console.log(newValue); }); Coalescing Notifications If you make multiple changes to a property – one change immediately following another – then separate notifications won’t be sent. Instead, any listeners are notified only once. The notifications are coalesced into a single notification. For example, in the following code, the product price property is updated three times. However, only one message is written to the JavaScript console. Only the last value assigned to the price property is written to the JavaScript Console window: // Simple product object var product = { name: "Milk", description: "Something to drink", price: 12.33 }; // Create observable product var observableProduct = WinJS.Binding.as(product); // Execute a function when price is changed observableProduct.bind("price", function (newValue) { console.log(newValue); }); // Change the price observableProduct.price = 3.99; observableProduct.price = 2.99; observableProduct.price = 1.99; Only the last value assigned to price, the value 1.99, appears in the console: If there is a time delay between changes to a property then changes result in different notifications. For example, the following code updates the price property every second: // Simple product object var product = { name: "Milk", description: "Something to drink", price: 12.33 }; // Create observable product var observableProduct = WinJS.Binding.as(product); // Execute a function when price is changed observableProduct.bind("price", function (newValue) { console.log(newValue); }); // Add 1 to price every second window.setInterval(function () { observableProduct.price += 1; }, 1000); In this case, separate notification messages are logged to the JavaScript Console window: If you need to prevent multiple notifications from being coalesced into one then you can take advantage of promises. I discussed WinJS promises in a previous blog entry: http://stephenwalther.com/blog/archive/2012/02/22/windows-web-applications-promises.aspx Because the updateProperty() method returns a promise, you can create different notifications for each change in a property by using the following code: // Change the price observableProduct.updateProperty("price", 3.99) .then(function () { observableProduct.updateProperty("price", 2.99) .then(function () { observableProduct.updateProperty("price", 1.99); }); }); In this case, even though the price is immediately changed from 3.99 to 2.99 to 1.99, separate notifications for each new value of the price property are sent. Bypassing Notifications Normally, if a property of an observable object has listeners and you change the property then the listeners are notified. However, there are certain situations in which you might want to bypass notification. In other words, you might need to change a property value silently without triggering any functions registered for notification. If you want to change a property without triggering notifications then you should change the property by using the backingData property. The following code illustrates how you can change the price property silently: // Simple product object var product = { name: "Milk", description: "Something to drink", price: 12.33 }; // Create observable product var observableProduct = WinJS.Binding.as(product); // Execute a function when price is changed observableProduct.bind("price", function (newValue) { console.log(newValue); }); // Change the price silently observableProduct.backingData.price = 5.99; console.log(observableProduct.price); // Writes 5.99 The price is changed to the value 5.99 by changing the value of backingData.price. Because the observableProduct.price property is not set directly, any listeners associated with the price property are not notified. When you change the value of a property by using the backingData property, the change in the property happens synchronously. However, when you change the value of an observable property directly, the change is always made asynchronously. Summary The goal of this blog entry was to describe observables. In particular, we discussed how to create observables from existing JavaScript objects and bind functions to observable properties. You also learned how notifications are coalesced (and ways to prevent this coalescing). Finally, we discussed how you can use the backingData property to update an observable property without triggering notifications. In the next blog entry, we’ll see how observables are used with declarative binding to display the values of properties in an HTML document.

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  • Ubuntu Upgrade breaks firefox

    - by Dennis
    I upgraded ubuntu, but the upgrade broke firefox, adobe flash plugin and corrupted the package database. I ran the suggested catalog repair, no change. I ran apt-get -f install, no change. I ran apt purge packageName, no change. How can I resolve this circular dependency? Here are some details: installArchives() failed: dpkg: dependency problems prevent configuration of adobe-flashplugin: firefox (12.0+build1-0ubuntu0.12.04.1) breaks adobe-flashplugin (<= 11.1.102.63-0precise1) and is installed. Version of adobe-flashplugin to be configured is 10.0.32.18-1intrepid1. dpkg: error processing adobe-flashplugin (--configure): dependency problems - leaving unconfigured No apport report written because MaxReports is reached already dpkg: dependency problems prevent configuration of adobe-flash-properties-gtk: adobe-flash-properties-gtk depends on adobe-flashplugin (= 11.2.202.235-0precise1); however: Version of adobe-flashplugin on system is 10.0.32.18-1intrepid1. dpkg: error processing adobe-flash-properties-gtk (--configure): dependency problems - leaving unconfigured No apport report written because MaxReports is reached already Errors were encountered while processing: adobe-flashplugin adobe-flash-properties-gtk Error in function: dpkg: dependency problems prevent configuration of adobe-flash-properties-gtk: adobe-flash-properties-gtk depends on adobe-flashplugin (= 11.2.202.235-0precise1); however: Version of adobe-flashplugin on system is 10.0.32.18-1intrepid1. dpkg: error processing adobe-flash-properties-gtk (--configure): dependency problems - leaving unconfigured

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