Websocket description

The Websocket is a non visual (don't appear in the screen at runtime) control that allows to establish a bidirectional connection between the app and the app server. This means that we can send to the server certain message, but we can also receive messages from the server.

Websocket at designtime

The Websocket control put at your disposition the below designtime properties or variables. Designtime means here that these properties are only available in designtime and not in runtime.

• Top property
• Left property
• Width property
• Height property
• Locked property

Websocket at runtime

The Websocket control put at your disposition the below runtime properties or variables. You can set almost all these variables in designtime, and, they are also available to be use when the app is running. Note that we named here these variables in a capitalized way, because is like you can see it in the designtime control's inspector, however, at runtime we use the lower camel case way.

• Name property
• Url property
• Protocols property
• Status property
• Code property
• Reason property
• Message property

Websocket methods

The Websocket control put at your disposition the below methods. You can use these methods in runtime in order to perform various control related tasks.

• open() method
• send() method
• close() method

Websocket events

The Websocket control put at your disposition the below events handlers:

• Open event
• Message event
• Close event
• Error event

Websocket designtime properties

Websocket Top property

Designtime. Integer variable. The Top property stores the top position of the control in pixels. This value is only take in consideration at designtime, since this is a non visual control, which do not appear in the screen at runtime.

Websocket Left property

Designtime. Integer variable. The Left property stores the left position of the control in pixels. This value is only take in consideration at designtime, since this is a non visual control, which do not appear in the screen at runtime.

Websocket Width property

Designtime. Integer variable. The Width property stores the width of the control in pixels. This value is only take in consideration at designtime, since this is a non visual control, which do not appear in the screen at runtime.

Websocket Height property

Designtime. Integer variable. The Height property stores the height of the control in pixels. This value is only take in consideration at designtime, since this is a non visual control, which do not appear in the screen at runtime.

Websocket Locked property

Designtime. Boolean variable. The Locked property determines if the control can be moved or resized in app view designer or not. This value is only take in consideration at designtime, since this is a non visual control, which do not appear in the screen at runtime.

Websocket runtime properties

Websocket Name property

Runtime. String variable. The Name control property stores the name of the Websocket control as you set in designtime. The Name property value must be unique for the same app view, dialog or frame, that is, it's possible to have more than one "http1" in the app, if that controls resides in different app views, dialogs or frames. Note that you must consider this variable as read only: change the name of a control in runtime can cause unexpected results.

Websocket Url property

Runtime. String variable. The Url control property stores the URL of the Websocket server to connect with. Set this variable before call to the control open() method.

Websocket Protocols property

Runtime. String variable. The Protocols control property stores a comma separated string with the optional protocols, which specifies protocols that the Websocket server must support for the connection to be successful. You can leave this variable empty when no needed.

Websocket Status property

Runtime. Number variable. The Status control property has a "0" (zero) value indicating that the connection has not yet been established. A value of "1" indicates that the connection is established and communication is possible (then you can use the control open() method). A value of "2" indicates that the connection is going through the closing handshake. And finally a value of "3" indicates that the connection has been closed or could not be opened.

Websocket Code property

Runtime. Number variable. The Code control property is available in the control Close event and can have one of the below values:

Websocket Reason property

Runtime. Number variable. The Reason control property is available in the control Close event and stores the reason for the Websocket connection close.

Websocket Message property

Runtime. Mixed variable. The Message control property is available in the control Message event and stores the message that has been sent to the app from the websocket server.

Websocket runtime methods

Websocket open() method

Runtime method. You can use this Websocket control method to open the connection with the Websocket server. The open() method is expected to be fired after call to this control method. This method don't require any arguments.

// Open the Websocket connection views.view1.websocket1.open();

Websocket send() method

Runtime method. You can use this Websocket control method to send a message to the websocket server. This method require the below argument:

// Send a message to the websocket server views.view1.websocket1.send('Hello there!');

Websocket close() method

Runtime method. You can use this Websocket control method to gracefully close the connection with the websocket server. This method don't require any arguments.

// Close the connection with the websocket server views.view1.websocket1.close();

Websocket events

Websocket Open event

The Open event hander is fired after call to the open() method and the websocket connection has been established.

Websocket Message event

The Message event hander is fired when the app receive a message from the websocket server. The message is stored in the control Message property.

Websocket Close event

The Close event hander is fired when the connection with the websocket server has been closed. Look at the Status, Code and Reason properties for more information about the connection close reason.

Websocket Error event

The Error event hander is fired when an error occurs. Look at the Status, Code and Reason properties for more information about the error.

Websocket events variables

The below JavaScript variables are available in all the referred Websocket control events handlers:

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