Adobe 38040334 Extending Dreamweaver - Page 235

AP element, element

Page 235 highlights

DREAMWEAVER CS3 229 Extending Dreamweaver To help avoid performance penalties, use the setTimeout() function. As in the browsers, the setTimeout() function takes two arguments: the JavaScript to be called and the amount of time in milliseconds to wait before calling it. The setTimeout() method lets you build pauses into your processing. These pauses let the user continue interacting with the application. You must build in these pauses explicitly because the screen freezes while scripts process, which prevents the user from performing further edits. The pauses also prevent you from updating the interface or the floating panel. The following example is from a floating panel that displays information about every AP element in the document. It uses the setTimeout() method to pause for a half second after processing each AP element. /* create a flag that specifies whether an edit is being processed, and set it to false.*/ document.running = false; /* this function called when document is edited */ function documentEdited(){ /* create a list of all the AP elements to be processed */ var dom = dw.getDocumentDOM(); document.layers = dom.getElementsByTagName("layer"); document.numLayers = document.layers.length; document.numProcessed = 0; /* set a timer to call processLayer(); if we didn't get * to finish processing the previous edit, then the timer * is already set. */ if (document.running = false){ setTimeout("processLayer()", 500); } /* set the processing flag to true */ document.running = true; } /* process one AP element*/ function processLayer(){ /* display information for the next unprocessed AP element. displayLayer() is a function you would write to perform the "magic".0*/ displayLayer(document.layers[document.numProcessed]); /* if there's more work to do, set a timeout to process * the next layer.0.If we're finished, set the document.running * flag to false. */ document.numProcessed = document.numProcessed + 1; if (document.numProcessed < document.numLayers){ setTimeout("processLayer()", 500); }else{ document.running = false; } }

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DREAMWEAVER CS3
Extending Dreamweaver
229
To help avoid performance penalties, use the
setTimeout()
function. As in the browsers, the
setTimeout()
function takes two arguments: the JavaScript to be called and the amount of time in milliseconds to wait before
calling it.
The
setTimeout()
method lets you build pauses into your processing. These pauses let the user continue inter-
acting with the application. You must build in these pauses explicitly because the screen freezes while scripts process,
which prevents the user from performing further edits. The pauses also prevent you from updating the interface or
the floating panel.
The following example is from a floating panel that displays information about every
AP element
in the document.
It uses the
setTimeout()
method to pause for a half second after processing each AP
element
.
/* create a flag that specifies whether an edit is being processed, and set it to false.*/
document.running = false;
/* this function called when document is edited */
function documentEdited(){
/* create a list of all the AP elements to be processed */
var dom = dw.getDocumentDOM();
document.layers = dom.getElementsByTagName("layer");
document.numLayers = document.layers.length;
document.numProcessed = 0;
/* set a timer to call processLayer(); if we didn't get
* to finish processing the previous edit, then the timer
* is already set. */
if (document.running = false){
setTimeout("processLayer()", 500);
}
/* set the processing flag to true */
document.running = true;
}
/* process one AP element*/
function processLayer(){
/* display information for the next unprocessed AP element.
displayLayer() is a function you would write to
perform the "magic".0*/
displayLayer(document.layers[document.numProcessed]);
/* if there's more work to do, set a timeout to process
* the next layer.0.If we're finished, set the document.running
* flag to false. */
document.numProcessed = document.numProcessed + 1;
if (document.numProcessed < document.numLayers){
setTimeout("processLayer()", 500);
}else{
document.running = false;
}
}