Application

Wisej.Web.Application

Namespace: Wisej.Web

Assembly: Wisej.Framework (3.5.0.0)

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 application'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.wisej.

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 the client browser's information.

ClientCertificate

X509Certificate2: EXPERIMENTAL: Provides the client certificate fields issued by the client in response to the server's request for the client's identity. Since 3.5.6

ClientId

String: Returns the current unique client id.

Clients

ClientCollection: Returns a collection of all the unique client browsers using the application.

CommandManager

CommandManager: Returns the current CommandManager.

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 the Update method.

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 the method 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.

LicenseInfo

Object: Returns a dynamic object containing the currently loaded license information. Since 3.1.3

These are the currently available fields (may change in future releases):

• Valid: Whether the license is valid. Note that a license may be expired and valid if the product release date is within the license expiration date.

• LicenseKey: License key loaded from web.config or assigned to LicenseKey.

• ProductName: Full name of the licensed product.

• CustomerName: Name of the registered customer that owns the license.

• ExpirationDate: Expiration date for the product free updates.

Retrieve the values either using a dynamic object or a property indexer:

  string productName = Application.LicenseInfo.ProductName;
  string customerName = Application.LicenseInfo["CustomerName"];

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.

Services

ServiceProvider: Returns the ServiceProvider implementation used by Wisej.NET to manage Dependency Injection across the application. Since 3.1

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: Returns 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.

AlertAsync(message)

Instructs the browser to display a dialog with an optional message, and to wait until the user dismisses the dialog.

Parameter	Type	Description
message	String	A string you want to display in the alert dialog.

Returns: Task. An awaitable Task that represents the asynchronous operation.

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.

ConfirmAsync(message)

Instructs the browser to display a dialog with an optional message, and to wait until the user either confirms or cancels the dialog. until the user dismisses the dialog.

Parameter	Type	Description
message	String	A string you want to display in the confirm dialog.

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

Dispose()

Download(filePath, fileName, ondownload)

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.
ondownload	Action<String>	Optional callback invoked when fileName is downloaded.

Download(image, fileName, ondownload)

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.
ondownload	Action<String>	Optional callback invoked when fileName is downloaded.

Download(stream, fileName, ondownload)

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.
ondownload	Action<String>	Optional callback invoked when fileName is downloaded.

DownloadAndOpen(target, filePath, fileName, ondownload)

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.
ondownload	Action<String>	Optional callback invoked when fileName is downloaded.

DownloadAndOpen(target, image, fileName, ondownload)

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.
ondownload	Action<String>	Optional callback invoked when fileName is downloaded.

DownloadAndOpen(target, stream, fileName, ondownload)

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.
ondownload	Action<String>	Optional callback invoked when fileName is downloaded.

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);

GetInstance<T>(reference, builder)

Returns a session-static instance of T . Since 3.2.7

Parameter	Type	Description
T		Type of the singleton object.
reference	SessionReference<T>	Thread-static reference to the T singleton.
builder	Func<T>	Optional method for the creation of an instance of T .

Returns: T. The singleton instance of T associated with the current session.

This utility method simplifies the management of session-static (or session singleton) instances. It should be used to convert traditional static variables to session-static instances when changing an application designed for single users to a multi-user system. The code below shows how to use this feature together with the ThreadStaticAttribute to manage session-static instances and, at the same time, improve the speed of the code that relies on the singleton objects. Using the ThreadStaticAttribute backing field allows the code that retrieves the session-static instance to quickly check the last instance and compare the session id and avoid accessing the dictionary for every access within the same request. Otherwise the code would have to always store a local variable in order to speed up multiple operations using the same static field.

public class MyStatics {

  // Thread-static singleton.
  [ThreadStatic] private static SessionReference<MyStatics> _instance;
  
  // Previously static fields (or properties).
  public int Counter;

  // Session singleton.
  public MyStatics Instance
    => Application.GetInstance(ref _instance);
    
  public static void DoSomething()
  {
    // was MyStatics.Counter++;
    MyStatics.Instance.Counter++;
  }
}

If the class a private constructor (to simulate a static class) or required initialization code or arguments, use the optional builder method:

public class MyStatics {

  private MyStatics() { };
  
  // Thread-static singleton.
  [ThreadStatic] private static SessionReference<MyStatics> _instance;
  
  // Previously static fields (or properties).
  public int Counter;

  // Session singleton.
  public MyStatics Instance
    => Application.GetInstance(ref _instance, () => new MyStatics());
    
  public static void DoSomething()
  {
    // was MyStatics.Counter++;
    MyStatics.Instance.Counter++;
  }
}