Use Client-Side Events to Delay Postbacks
Before
the .NET target is deployed, you can code client-side events in JavaScript
and set properties to reference the JavaScript code that handles client-side
events.
You must set the properties in #IF DEFINED -#END
IF conditional compilation code blocks for .NET targets. The beginning
and end tags for these code blocks signal the PowerBuilder native
compiler to ignore the code contained inside them.
The code inside the conditional compilation code blocks is
passed to the Web browser client from the server at runtime. You
use this code to designate JavaScript functions that handle events
on client-side objects. Most events on client-side objects
cause a postback to controls on the server side, because the events
have server-side analogs that are written originally in PowerScript,
then transformed to run in the .NET environment.
If you write any JavaScript code for the client-side events,
the postback to the server is interrupted. To resume a postback,
you can call the submit method for Web Forms
or one of the postback methods generated in the PBDataWindow.JS file.
The PBDataWindow.JS file is generated in the
Scripts subdirectory of the main project directory under the IIS
virtual root.
The postback methods of the PBDataWindow.JS file
are described in Default Event Handlers.
DataWindow property for setting a customized event handler
Properties of the DataWindow class allow you to handle client-side
events in JavaScript code. The JavaScriptFile property specifies
the JS file that contains JavaScript functions for handling individual
client-side events.
contains your customized event handling code. You assign the JavaScriptFile
property in an #IF DEFINED -#END IF code block:
|
1 2 3 |
#IF Defined PBWEBFORM THEN dw_1.JavaScriptFile = �D:ScriptsMyScriptFile.js� #END IF |
DataWindow properties for calling client-side events
See Alphabetical Liist of Web DataWindow Client-Side Events.
To specify a JavaScript function for handling a client-side
event, you must indicate the function to call in the corresponding
Web DataWindow property. The name of the corresponding property
consists of the name of the client-side event with an “OnClient” prefix.
For example, the property corresponding to the ItemChanged event
is OnClientItemChanged.
the client-side DataWindow Clicked event:
|
1 2 3 4 |
#IF Defined PBDOTNET THEN dw_1.JavaScriptFile = �D:ScriptsMyScriptFile.js� dw_1.OnClientClicked = �MyDWClickedEventHandler� #END IF |
The script for the MyDwClickedEventHandler
event handler must use the syntax for the client-side Clicked
event described in Clicked.
Client-side CommandButton property
The OnClientClick CommandButton property specifies a snippet
of JavaScript code that executes when a command button is clicked.
AutoPostBack
postbacks and increase performance by setting the AutoPostBack property
for CheckBox and RadioButton controls to false:
|
1 2 3 |
#IF DEFINED PBWEBFORM THEN cbx_1.AutoPostBack = false #END IF |
For more information on the built-in Web Forms control properties,
see Web Forms Properties.