Application

Wisej.Web.Application

Namespace: Wisej.Web

Assembly: Wisej.Framework (2.2.0.0)

Represent a Wisej application session. Provides methods and events to manage the application in the context of the current session.

C#

public class Application : IWisejComponent, IDisposable, IWisejSynchronized

VB.NET

Public Class Application
    Inherits IWisejComponent
    Implements IDisposable, IWisejSynchronized

This class provides several static methods, properties and events that allow the application to manage all sorts of features related to the current session:

• Save and retrieve session variable. Use Session to store and retrieve session variable. The property is a dynamic object and a Dictionary, therefore you can access its properties directly or through the indexer.

    Application.Session.myValue = 12;
    Application.Session["myValue"] = 12;
  

• Manage cookies. Use Cookies to manage browser's cookies.

• Read server variables. Use ServerVariables to retrieve all the data made available by the server. Some of the variables in the collection are also available directly: ServerPort, ServerName, UserAgent, etc.

• Read the application's URL. Use Uri, Url, StartupUri, and StartupUrl.

• Read the applications's system information. Use StartupPath, ProductName, ProductVersion, etc.

• Listen to the application's global events. See SessionTimeout , BeginRequest, ApplicationStart, ApplicationExitApplicationRefresh, BrowserSizeChangedResponsiveProfileChanged, CultureChanged, and many more.

• Retrieve browser related information. Use the Browser to read the client browser type, OS, version, capabilities, screen size, browser size, language, and state. The Browser object is updated automatically when the user resizes the browser or the page is reloaded.

• Control the client browser. Start a Download, execute JavaScript functions or scriptlets using Call or Eval. Make the browser navigate to a different URL using Navigate or simply Reload the page.

• Manage the main page or current desktop. MainPage lets you change the Page object that fills the browser and "navigate" from page to page. Desktop lets you change the active Desktop object on the client browser.

• Manage all live components in the session. Through the Application class you can find, iterate, inspect all live components of any type. See OpenForms for all the currently created (visible or invisible) instances of Form. OpenPages returns all the created Page objects. FindComponent and FindComponents provide an easy way to find any component in the session or to iterate the list of components that match a custom expression.

• Start background tasks in context. StartTask provides a powerful way to start a background task on the server that can keep interacting with the client browser while running independently.

• Manage the application's theme. Use LoadTheme to load a Wisej theme into the application. Or use the Theme object to read all sorts of information from the current ClientTheme.

• Terminate the application without waiting for the session to timeout. Use Exit to terminate the current session and free all the related memory.

There is a lot more exposed by the Application class. You can inspect all the properties and methods in Visual Studio through IntelliSense or online at docs.

Properties

ActiveProfile

ClientProfile: Returns or sets the current client responsive profile.

This is the profile that best matches the current browser on the client. It is updated automatically on every request.

Browser

ClientBrowser: Returns or sets the client browser information.

ClientFingerprint

UInt32: Returns the unique client "fingerprint" ID. It can be used to distinguish client devices.

The client fingerprint is generated by hashing all the available information returned by the browser (OS, user agent, version, etc.) and it's not guaranteed to be unique.

CommonAppDataPath

String: Returns the path for the application data that is shared among all users.

CommonAppDataRegistry

RegistryKey: Returns the registry key for the application data that is shared among all users.

CompanyName

String: Returns the company name associated with the application stored in the AssemblyCompanyAttribute.

Configuration

Configuration: Returns the current Configuration.

Cookies

CookieCollection: Collection of cookies.

Current

IWisejComponent: Returns the application component instance that an application can store and use later to restore the context when updating client widgets during an out-of-bound call using Update

Threads that are not started using StartTask don't have any knowledge of the current session and don't have a way to communicate with the client The Current property returns the instance of the Application class that is bound to the current session. It can be used just like any other component with Update or RunInContext to restore the session for the current thread. The advantage of using Current instead of the instance of a control or a page is to avoid to keep a reference to a component that may be disposed by the application.

var current = Application.Current;
var thread = new Thread(() => {
  Application.Update(current, () => {
  
    // code here is running in context.
    
  });
});

CurrentCulture

CultureInfo: Returns or sets the current CultureInfo for the session.

Desktop

Desktop: Returns or sets the current Desktop.

EnableUnloadConfirmation

Boolean: Returns or sets whether the browser will ask the user to confirm unloading the current page.

This property attaches the window.onbeforeunload event. See https://developer.mozilla.org/en-US/docs/Web/API/WindowEventHandlers/onbeforeunload. It's not possible to determine whether the page is being unloaded because the user is trying to close the tab, close the browser, or is refreshing the page, or is taking any other action that may reload the page.

ExecutablePath

String: Returns the path for the application's main assembly.

FavIcon

Image: Returns or sets the favicon to display in the browser.

FavIconSource

String: Returns or sets the URL to the favicon to display in the browser.

Hash

String: Returns or sets the hash part of the URL on the client.

IsAuthenticated

Boolean: Returns a value indicating whether the session has been authenticated.

IsDisposed

Boolean: Indicates that the current application instance, which corresponds to the session, has been terminated and disposed.

IsExpired

Boolean: Returns true when the current session has expired.

IsSecure

Boolean: Returns true if this session is running in secure mode (https:// and wss://)

IsTerminated

Boolean: Returns true when the current session has been terminated.

IsWebSocket

Boolean: Returns true if the current session is connected using WebSocket.

LicenseKey

String: Returns or sets the runtime server license key.

Setting the LicenseKey programmatically has to be done before the application is loaded. The best place is the static constructor for the Program static class, or the static constructor of the main window (if defined in Default.js).

static class Program
{
  static Program()
  {
    Application.LicenseKey = "...";
  }
}

MainPage

Page: Returns or sets the current full page window.

OpenForms

FormCollection: Returns a collection of open forms owned by the application.

OpenPages

PageCollection: Returns a collection of open pages owned by the application.

Platform

ClientPlatform: The name of the currently loaded platform.

ProductName

String: Returns the product name associated with this application.

ProductVersion

String: Returns the product version associated with this application stored either in AssemblyInformationalVersionAttribute or AssemblyFileVersionAttribute.

QueryString

NameValueCollection: Returns the parameters used to launch the application.

RightToLeft

Boolean: Returns or sets whether all the controls in the applications should operate using the right-to-left mode.

The value of this property is updated automatically when the current language changes if the value of "rightToLeft" in the application configuration file is set to "auto".

RuntimeMode

Boolean: Returns true when the application is running in not in design, debug or test mode.

ServerName

String: Returns the server's host name, DNS alias, or IP address as it would appear in self-referencing URLs.

ServerPort

Int32: Returns the port number to which the request was sent.

ServerVariables

NameValueCollection: Returns the server variables.

Session

Object: Provides a generic storage for session-based objects.

SessionCount

Int32: Returns the total number of currently active sessions.

SessionId

String: Returns the unique current session ID.

ShowConsole

Boolean: Shows or hides the debug console on the browser.

Displays a simple HTMl only debug console. Works with any browser also when the developer tools are not available.

ShowLoader

Boolean: Returns or sets whether the browser is blocked by the Ajax loader.

StartupPath

String: Returns the root path of the web application.

StartupUri

Uri: Returns the URI used to start the application.

StartupUrl

String: Returns the URL used to start the application.

Theme

ClientTheme: Returns or sets the current ClientTheme.

You can create and modify a new custom theme using the ClientTheme class. The new theme can be based on an existing theme, can be empty, or can be initialized from a JSON string.

// create a new custom theme cloned from the current theme.
var myTheme = new ClientTheme("MyTheme", Application.Theme);

// alter the buttonFace color.
myTheme.Colors.buttonFace = "red";

// update the current session using the new custom theme.
Application.Theme = myTheme;

You may also alter a global theme shared by all sessions.

// change the buttonFace color in the current theme.
// if the theme is one of the global themes, i.e. it was loaded
// using Application.LoadTheme(name), then the change is also global.
Application.Theme.Colors.buttonFace = "red";

// since the theme objects are all dynamic and use a special DynamicObject
// class part of the Wisej Framework, you can also use a string indexer
// to address any field.
Application.Theme.Colors["buttonFace"] = "red";

Title

String: Returns or sets the page title in the browser.

Uri

Uri: Returns the current Uri used either to launch or reload the application. It may be different from StartupUri.

Url

String: Returns the current URL used either to launch or reload the application. It may be different from StartupUrl.

User

IPrincipal: Returns the security information for the current request.

UserAgent

String: Returns the raw user agent string of the client browser.

UserHostAddress

String: Returns the IP host address of the remote client.

UserHostName

String: Gets the DNS name of the remote client.

UserIdentity

WindowsIdentity: Returns the WindowsIdentity type for the current user.

UserLanguages

String[]: Gets a sorted string array of client language preferences.

Methods

AddEventFilter(filter)

Adds an event filter to monitor all the incoming events before they are routed to their respective component.

Parameter	Type	Description
filter	IEventFilter	An object that implements the IEventFilter interface to add to the filter list.

AddTranslation(text, translation)

Adds the text and corresponding translation to the default locale on the client.

Parameter	Type	Description
text	String	The text to translate.
translation	String	The translation override.

Call(function, args)

Executes the JavaScript function on the client.

Parameter	Type	Description
function	String	The name of the function to execute.
args	Object[]	The arguments to pass to the function.

Call(function, callback, args)

Executes the JavaScript function on the client and receives the return value (or null) in the callback method.

Parameter	Type	Description
function	String	The name of the function to execute.
callback	Action<Object>	Asynchronous callback method that receives the return value.
args	Object[]	The arguments to pass to the function.

CallAsync(function, args)

Asynchronously executes the JavaScript function on the client and returns an awaitable Task with the result of the remote call.

Parameter	Type	Description
function	String	The name of the function to execute.
args	Object[]	The arguments to pass to the function.

Returns: Task<Object>. An awaitable Task that represents the asynchronous operation.

CancelFullScreen()

Cancels the fullscreen mode.

Download(filePath, fileName)

Downloads the specified file on the client.

Parameter	Type	Description
filePath	String	The file to download.
fileName	String	The name of the file to save on the client.

Download(image, fileName)

Downloads the specified image to the client.

Parameter	Type	Description
image	Image	The image to download.
fileName	String	The name of the file to save on the client.

Download(stream, fileName)

Downloads the bytes in the stream to the client.

Parameter	Type	Description
stream	Stream	The stream to send to the client.
fileName	String	The file name the client will use to save the stream.

DownloadAndOpen(target, filePath, fileName)

Downloads the specified file on the client.

Parameter	Type	Description
target	String	Specifies where to open the file. Leave empty or use "_self" to open in the current tab, _blank to open in a new tab.
filePath	String	The file to download.
fileName	String	The name of the file to save on the client.

DownloadAndOpen(target, image, fileName)

Downloads the specified image to the client.

Parameter	Type	Description
target	String	Specifies where to open the file. Leave empty or use "_self" to open in the current tab, _blank to open in a new tab.
image	Image	The image to download.
fileName	String	The name of the file to save on the client.

DownloadAndOpen(target, stream, fileName)

Downloads the bytes in the stream to the client.

Parameter	Type	Description
target	String	Specifies where to open the file. Leave empty or use "_self" to open in the current tab, _blank to open in a new tab.
stream	Stream	The stream to send to the client.
fileName	String	The file name the client will use to save the stream.

EndPolling()

Stops the polling requests from the client.

Eval(script)

Executes the JavaScript script on the client.

Parameter	Type	Description
script	String	The script to evaluate.

Eval(script, callback)

Executes the JavaScript script on the client and receives the return value (or null) in the callback method.

Parameter	Type	Description
script	String	The script to evaluate.
callback	Action<Object>	Asynchronous callback method that receives the return value.

EvalAsync(script)

Asynchronously executes the JavaScript script on the client and returns an awaitable Task with the result of the remote call.

Parameter	Type	Description
script	String	The script to evaluate.

Returns: Task<Object>. An awaitable Task that represents the asynchronous operation.

Exit()

Terminates the application and the corresponding session.

FindComponent(match)

Find the first component that matches the conditions defined in the predicate function.

Parameter	Type	Description
match	Predicate<IWisejComponent>	A custom Predicate expression used to match the IWisejComponent to find.

Returns: IWisejComponent. The first IWisejComponent qualified by the match expression.

This method lets an application find any live component in the current session.

  // Find the first component that is a Button with Text = "OK"
  var button = Application.FindComponent(c => c is Button && ((Button)c).Text == "OK");

FindComponents(match)

Finds all the components that match the conditions in the predicate function.

Parameter	Type	Description
match	Predicate<IWisejComponent>	A custom Predicate expression used to match the list of IWisejComponent objects to find.

Returns: IList<IWisejComponent>. The list of IWisejComponent instances qualified by the match expression.

This method lets an application iterate through all the live components in the current session.

  // List all text boxes that are read only in all forms.
  var list = Application.FindComponents(c => c is TextBox && ((TextBox)c).ReadOnly);

LoadAssembly(filePath)

Loads an assembly given the file name or path.

Parameter	Type	Description
filePath	String	The file name or full path for the assembly to load.

Returns: Assembly. The loaded Assembly.

This method loads the assembly and, if the assembly contains Wisej components that need embedded resources - like JavaScript classes or CSS styles - that are embedded in the assembly, notifies the client with the URL to load the additional resources dynamically.

LoadComponent(filePath, className)

Creates an instance of the specified component from the assembly.

Parameter	Type	Description
filePath	String	The file name or full path for the assembly to load.
className	String

Returns: IWisejComponent. An instance of a Wisej component implementing the IWisejComponent interface.

LoadPackages(packages, callback)

Parameter	Type	Description
packages	IEnumerable<Package>
callback	Action<Boolean>

LoadPackagesAsync(packages)

Parameter	Type	Description
packages	IEnumerable<Package>

Returns: Task<Boolean>.

LoadTheme(name, mixins)

Changes the current theme.

Parameter	Type	Description
name	String	Name of the theme resource. Use only the name without the path and without the extension.
mixins	String[]	Optional list of theme mixins. If null, the default theme mixins are always applied.

MapPath(path)

Returns the full file path in relation to the application's project directory.

Parameter	Type	Description
path	String

Returns: String. The full path relative to the current application's root directory.

Navigate(url, target)

Navigate to the specified URL.

Parameter	Type	Description
url	String	URL to navigate to.
target	String	The target browser window: _self, _blank, etc.

Play(type)

Plays one of the built-in sounds

Parameter	Type	Description
type	MessageBoxIcon	One of MessageBoxIcon value that identifies the sound to play.

Play(soundUrl)

Plays a sound.

Parameter	Type	Description
soundUrl	String	A string representing either a sound file URL or a base64 data URL.

Post(callback)

Executes the callback method after all processing is completed and before updating the client.

Parameter	Type	Description
callback	Action	Method to invoke after the request has completed but before sending the response to the server.

The Post() method is similar to the BeginInvoke() method used by desktop applications. It allows you to execute a block of code out of sync with the current execution flow.

void Test() {

  Application.Post(() => {
    this.listBox.Items.Add("1");
  });
  
  this.listBox.Items.Add("2");
  
  // The items will be added in this order: "2", "1".
}

Print(window)

Prints the specified window.

Parameter	Type	Description
window	IWisejWindow	The window to print

The window is printed without the caption or the borders, if present.

Print()

Prints the entire browser window.

Reload()

Causes the application to reload on the browser.

RemoveEventFilter(filter)

Removes the filter from the list of registered event filters.

Parameter	Type	Description
filter	IEventFilter	An object that implements the IEventFilter interface to remove from the filter list.

RequestFullScreen()

Requests the browser to enable fullscreen mode if supported.

RunInContext(context, action)

Executes the callback in context.

Parameter	Type	Description
context	IWisejComponent	The application context to update. It can be any Wisej component or the IWisejComponent returned by the property Context.
action	Action	Function to execute in context. The code in the function can access all the static Application properties when executed from an out-of-bound thread.

StartPolling(interval)

Instructs the client to start polling the server for UI changes at the specified interval when a WebSocket connection is not available.

Parameter	Type	Description
interval	Int32	Polling interval in milliseconds. The minimum is 1000ms.

Calling this method when IsWebSocket is true has no effect. Use client side polling when you know that your code will start a background task that needs to update the client asynchronously (push updates) and your server or clients don't support WebSocket connections. Once the background tasks are completed call EndPolling to reduce the incoming requests from the client.

// this has not effect when the client and server are connected using WebSocket.
Application.StartPolling(1000);

Application.StartTask(() => {

  for (int i = 0; i < 100; i++) {
    this.label1.Text = "Counting..." + i;
    Thread.Sleep(1000);
  }
  
  // this has not effect when the client and server are NOT connected using WebSocket.
  Application.Update(this);

  // this has not effect when the client and server are connected using WebSocket.
  Application.EndPolling();

});

Throws:

• ArgumentOutOfRangeException The interval specified is less than 1.

StartTask(action)

Starts a new task within the current application context and returns immediately. See also BackgroundTasks.

Parameter	Type	Description
action	Action	Start method invoked by the new task when it starts up.

Returns: Task. An awaitable Task.

The task runs in the background but it's still capable of updating the client asynchronously when working with WebSocket by calling the Update method to push the UI updates to the client browser. If you want to support background updates for clients or servers that can't use the WebSocket connection, you can either add a Timer component to the parent container to force period requests to the server, or you can use the StartPolling and EndPolling methods.

Application.StartTask(() => {

  for (int i = 0; i < 100; i++) {
  
    this.label1.Text = "Counting..." + i;
    
    // just wait a bit or it's too fast.
    Thread.Sleep(1000);
    Application.Update(this);
  }
});

StartTask<T>(action)

Starts a new task with a return value within the current application context and returns immediately. See also BackgroundTasks.

Parameter	Type	Description
T
action	Func<T>	Start method invoked by the new task when it starts up.

Returns: Task<T>.

The task runs in the background but it's still capable of updating the client asynchronously when working with WebSocket by calling the Update method to push the UI updates to the client browser. The generics overload of StartTask allows the task to return a value. You can use this with the async/await pattern and asynchronously wait for the task to complete. If you want to support background updates for clients or servers that can't use the WebSocket connection, you can either add a Timer component to the parent container to force period requests to the server, or you can use the StartPolling and EndPolling methods.

string text = await Application.StartTask(() => {

  string value = "";
  for (int i = 0; i < 100; i++) {
  
    value += i.ToString();
    
    // just wait a bit or it's too fast.
    Thread.Sleep(100);
  }
  return value;
});

this.label.Text = text;
Application.Update(this);

Note that you don't have to specify the type in the angular brackets, the compiler will automatically detect the type from the return value of the asynchronous function.

StartTimer(dueTime, period, callback)

Starts a Timer bound to the current session context.

Parameter	Type	Description
dueTime	Int32	The amount of time, in milliseconds, to delay before invoking the callback .
period	Int32	The time interval between invocations, in milliseconds.
callback	Action	A callback method to invoke at the specified intervals.

Returns: Timer. An instance of Timer.

You must save a reference to the returned Timer or the Garbage Collector will stop and dispose the timer. To alter the invocation period user Timer.Changer(), or stop the timer simply use Timer.Dispose(). See system.threading.

Update(context, action)

Executes the optional callback in context and pushes all the pending updates to the client when in WebSocket mode.

Parameter	Type	Description
context	IWisejComponent	The application context to update. It can be any Wisej component or the IWisejComponent returned by the property Context.
action	Action	Function to execute in context. The code in the function can access all the static Application properties when executed from an out-of-bound thread.

Use this method when you need to update the client asynchronously from an out-of-bound thread (different thread, not originating from a client request). You can call this method at the end of the code that updates the UI:

Application.StartTask(() => {

    for (int i = 0; i < 100; i++) {
    
      this.label1.Text = "Counting..." + i;
      
      // just wait a bit or it's too fast.
      Thread.Sleep(1000);
    }
    
    Application.Update(this);

});

Or you can use the optional action function to enclose the code that updates the UI in a block and ensure that the client is updated when the code block exits:

Application.StartTask(() => {

    Application.Update(this, () => {
    
      for (int i = 0; i < 100; i++) {
    
        this.label1.Text = "Counting..." + i;
      
        // just wait a bit or it's too fast.
        Thread.Sleep(1000);
      }
    });

});

Events

ActiveWindowChanged

EventHandler Fired when the active window changes.

ApplicationExit

EventHandler Fired when the application is about to shut down.

ApplicationRefresh

EventHandler Fired when the application is reloaded in the browser because the user hit refresh or changed the URL.

ApplicationStart

EventHandler Fired when the application is started, after the Main method is called.

BeforeInstallPrompt

EventHandler Fired when the browser fires the "beforeinstallprompt" event. Corresponds to BeforeInstallPromptEvent.

BeginRequest

EventHandler Fired at the beginning of every request.

BrowserSizeChanged

EventHandler Fired when the user resizes the browser.

BrowserTabActivated

EventHandler Fired when the user activates the browser tab.

BrowserTabDeactivated

EventHandler Fired when the user deactivates the browser tab.

CultureChanged

EventHandler Fired when the CurrentCulture changes.

EndRequest

EventHandler Fired at the end of every request.

FocusedControlChanged

EventHandler Fired when the focused control changes.

HashChanged

HashChangedEventHandler Fired when the hash part of the URL changes on the client side.

Idle

EventHandler Fired when the current thread has completed processing all the events and before the response is sent back to the client.

ResponsiveProfileChanged

ResponsiveProfileChangedEventHandler Fired when the active responsive profile is changed.

RightToLeftChanged

EventHandler Fired when the RightToLeft value changes.

SessionTimeout

HandledEventHandler Fired when the session is about to time out.

The default behavior built-in Wisej is to display a dialog asking the user to prolong the session. Set Handled to true to stop the default behavior.

ThemeChanged

EventHandler Fired when the current theme is changed.

ThreadException

ThreadExceptionEventHandler Fired when a thread exception is thrown.

Implements

Name	Description
IWisejComponent	All wisej components implement this interface.