RegisterEvent
PowerScript function
Description
Registers the PowerBuilder user event so they can be triggered in
JavaScript. For how to define and trigger the PowerBuilder user event,
refer to Triggering PowerBuilder events in
JavaScript.
Applies to
Syntax
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1 |
controlname.RegisterEvent (string eventname) |
|
Argument |
Description |
|---|---|
|
controlname |
The name of the WebBrowser control. |
|
eventName |
The name of the user-defined event to be |
Return value
Integer.
Returns 1 if the function succeeds and a negative value if an error occurs.
If any argument’s value is null, the method returns null.
Usage
The initialization of the WebBrowser control is run as a separate
process from the PowerBuilder application. Therefore, if the WebBrowser
control is being initialized while you register the event in PowerBuilder,
the registration will fail. To avoid such issue, it is recommended that
you trigger the NavigateStart event
first. If NavigateStart can be triggered
successfully, it indicates that WebBrowser is completely initialized. For
example, you can add the following code to the NavigateStart event:
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IF ib_RegisterEvent = FALSE THEN Int li_rc li_rc = wb_1.RegisterEvent ( "ue_getstring" ) IF li_rc =1 THEN ib_RegisterEvent =TRUE END IF END IF |
Example 1
The following example defines a PowerBuilder user event which is
then triggered in JavaScript in wb_1, and the result of the JavaScript
which is returned in a JSON string is parsed by the JSONParser
object.
Note that this user event should not call any other WebBrowser
function, otherwise the application may get stuck.
|
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//define a user event: ue_getstring in wb_1 //event type string ue_getstring(string as_arg); string ls_String ls_String = "This is PB Event!" + "~r~nFrom JavaScript:" + as_arg Return ls_String //end event |
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Integer li_Return String ls_JS, ls_Result, ls_Error JsonParser lnv_JsonParser Long ll_RootObject String ls_Type, ls_Value li_Return = wb_1.RegisterEvent("ue_getstring") If li_Return = 1 Then ls_JS = "function event1() { return window.webBrowser.ue_getstring('Hi,PB!');} event1();" li_Return = wb_1.EvaluateJavascriptSync(ls_JS, ls_Result, ls_Error) If li_Return = 1 Then lnv_JsonParser = Create JsonParser lnv_JsonParser.LoadString(ls_Result) ll_RootObject = lnv_JsonParser.GetRootItem() ls_Value = lnv_JsonParser.GetItemString( ll_RootObject, "value" ) End If End If //{"type":"string","value":"This is PB Event! From JavaScript:Hi,PB!"} MessageBox( "Tips", ls_Result ) //This is PB Event! //From JavaScript:Hi,PB! MessageBox( "Tips", ls_Value ) |
Example 2
The following example registers a PowerBuilder user event in the
WebBrowser NavigationProgressIndex event,
and then triggers the user event in JavaScript in an HTML file.
Step 1: Defines the user event: ue_getstring in
the WebBrowser control.
|
1 2 3 4 5 6 |
//event type string ue_getstring(string as_arg); string ls_String ls_String = "This is PB Event!" + "~r~nFrom JavaScript:" + as_arg sle_1.text = ls_String Return ls_String //end event |
Step 2: Registers the user event: ue_getstring
in the WebBrowser NavigationProgressIndex
event.
Note that the NavigationProgressIndex event will be triggered
multiple times when the HTML page is being loaded. It is recommended to
execute the next script after the NavigationProgressIndex event receives the value of
100 (which means the page is 100% loaded).
|
1 2 |
//Defines an instance variable ib_flag to determine whether the user event has been registered boolean ib_flag = true |
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//event navigationprogressindex; Integer li_Return If progressindex =100 Then If ib_flag Then li_Return = wb_1.RegisterEvent("ue_getstring") If li_Return = 1 Then ib_flag = False End If End If End If //end event |
Step 3: Triggers the user event in JavaScript in the HTML page:
page.html.
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<!DOCTYPE html> <html> <header> <meta charset="UTF-8"> </header> <body> <button type="button" onclick="window.webBrowser.ue_getstring('Hi,PB!')"> Call PB event </button> <button type="button" onclick="CallPBEvent()"> Call PB event with return </button> <script> function CallPBEvent(){ var ret = window.webBrowser.ue_getstring('Hi,PB!'); alert(ret); } </script> </body> </html> |
Step 4: Loads the HTML page in the WebBrowser control.
|
1 |
wb_1.Navigate("file:///page.html") |
Example 3
The following example defines a user event which is then triggered
in JavaScript in wb_1:
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//define a user event: ue_getstring in wb_1 //event type string ue_getstring(string as_arg); string ls_String ls_String = "This is PB Event!" + "~r~nFrom JavaScript:" + as_arg Return ls_String //end event Integer li_Return String ls_JS, ls_Result, ls_Error JsonParser lnv_JsonParser Long ll_RootObject String ls_Type, ls_Value li_Return = wb_1.RegisterEvent("ue_getstring") If li_Return = 1 Then ls_JS = "function event1() { return window.webBrowser.asyncfun.prototype.ue_getstring('Hi,PB!');} event1();" li_Return = wb_1. EvaluateJavascriptAsync (ls_JS) End If |
See also