onerror Event

  

Fires when an error occurs during object loading.

Syntax

Inline HTML

<ELEMENT onerror = "handler" ... >

All platforms

Event property

object.onerror = handler

JScript only

object.onerror = GetRef("handler")

Visual Basic Scripting Edition (VBScript) 5.0 or later only

Named script

<SCRIPT FOR = object EVENT = onerror>

Internet Explorer only

Event Information

Bubbles

No

Cancels

Yes

To invoke

Cause one of the following errors to occur:

• Run-time script error, such as an invalid object reference or security violation.
• Error while downloading an object, such as an image.

Default action

Displays the browser error message when a problem occurs and executes any error handling routine associated with the event.

Event Object Properties

Although event handlers in the DHTML Object Model do not receive parameters directly, a handler can query an event object for data.

Show Available Properties

altKey

Sets or retrieves a value that indicates the state of the ALT key.

altLeft

Sets or retrieves a value that indicates the state of the left ALT key.

ctrlLeft

Sets or retrieves the state of the left CTRL key.

returnValue

Sets or retrieves the return value from the event.

shiftLeft

Retrieves the state of the left SHIFT key.

srcElement

Sets or retrieves the object that fired the event.

type

Sets or retrieves the event name from the event object.

Remarks

To suppress the default Microsoft® Internet Explorer error message for the window event, set the returnValue property of the event object to true or simply return true in Microsoft JScript®.

The onerror event fires for run-time errors, but not for compilation errors. In addition, error dialog boxes raised by script debuggers are not suppressed by returning true. To turn off script debuggers, disable script debugging in Internet Explorer by choosing Internet Options from the Tools menu. Click the Advanced tab and select the appropriate check box(es).

Examples

The following examples use the onerror event to handle run-time script errors and object load errors.

This example specifies an invalid script entry. The script in the text field is evaluated when the Throw Error button is clicked. The onerror event fires because the script is invalid. The error results are inserted at the bottom of the sample page instead of in a dialog box.

HideExample

<SCRIPT>

window.onerror=fnErrorTrap;

function fnErrorTrap(sMsg,sUrl,sLine){

oErrorLog.innerHTML="<b>An error was thrown and caught.</b><p>";

oErrorLog.innerHTML+="Error: " + sMsg + "<br>";

oErrorLog.innerHTML+="Line: " + sLine + "<br>";

oErrorLog.innerHTML+="URL: " + sUrl + "<br>";

return false;

}

function fnThrow(){

eval(oErrorCode.value);

}

</SCRIPT>

<INPUT TYPE="text" ID=oErrorCode VALUE="someObject.someProperty=true;">

<INPUT TYPE="button" VALUE="Throw Error" onclick="fnThrow()">

<P>

<DIV ID="oErrorLog">

</DIV>

Show Me

This example shows how to set the handler for the onerror event in script before an image source is specified. When the invalid source is set on the img element, the event fires.

HideExample

<SCRIPT>

var sImg='<IMG STYLE="display: none;" ID=oStub ALT="Default Text">';

function fnLoadFirst(){

oContainer.innerHTML=sImg;

oStub.onerror=fnLoadFail1;

oStub.src="";

oStub.style.display="block";

}

function fnLoadFail1(){

oStub.alt="Image failed to load.";

return true;

}

</SCRIPT>

<INPUT TYPE=button VALUE="Load First Image" onclick="fnLoadFirst()">

<DIV ID=oContainer></DIV>

Show Me

Standards Information

There is no public standard that applies to this event.

Applies To

OBJECT

Platform

Version

Win16:

4.0

Win32:

4.0

Windows CE:

4.0

Unix:

4.0

Mac:

4.0

Version data is listed when the mouse hovers over a link, or the link has focus.

IMG, OBJECT, STYLE, window

Move the mouse pointer over an element in the Applies To list to display availability information for the listed platforms.

See Also

onerrorupdate