dynamically identify layers? 1

[ClulessChris]

I'm brand new to JavaScript so please excuse my ignorance.

Using an external script file I have the following function:

Function hideAll(){
	hideLayer('layer1');
	hideLayer('layer2');
	hideLayer('layer3');
	hideLayer('layer4');
	}

Is there a method (such as a loop) where I can dynamically identify and hide all layer rather than implicitly naming each?
I would like to use this external Script file for all pages, but not all pages will have all layers.

Never knock on Death's door: ring the bell and run away! Death really hates that!

 

[trollacious]

You can use documents.getElementsByTagName('div') (or whatever container you want to work with).

Lee

 

[nickdel]

Chris, you can use the getElementsByTagName method which basically takes all tags of a certain type and sticks them into an array however lets say your "layers" are made from divs then this will hide all your divs when implemented into a function.

Another way would be to use the getElementsById like do

function hideAll()

for (i=0;i<=4;i++){
hideLayer(document.getElementsByTagName('Layer'+i).id)
}
}

So if you know how many "layers" you have then you could use a loop like the one above.

Cheers

Nick

 

[ClulessChris]

Both thanks for your responces.
However I'm not quite following.
I can see how this will loop (1 to 4) but can I dynamicly determine howmany layers are in a given sheet?
i.e. page 1 has 4 layers but page 2 has 2.
If I loop 4 times the code will crash when looking for layer3.

Sorry for being dim, I'm well out of my waters here.

Never knock on Death's door: ring the bell and run away! Death really hates that!

 

[tsuji]

I guess it should mean this.
[tt]
function hideAll() { //f in lower case
var clayer=document.getElementsByTagName("layer");
for (var i=0;i<clayer.length;i++) {
hideLayer(clayer.name);
//.name or .id just can't be sure
//clayer[0].name or clayer[0].id should reproduce "layer1", for instance
}
}[/tt]

 

[BillyRayPreachersSon]

If your layers are DIV elements, you can use the following for "n" DIVs:

function hideAll() {
	var divNum = 1;
	while (divEl = document.getElementById('layer' + divNum)) {
		hideLayer(divEl.id);
		divNum++;
	}
}

This assumes the DIVs have an ID of "layer1", "layer2", etc.

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[ClulessChris]

fantastic, many thanks too all for your input.

Never knock on Death's door: ring the bell and run away! Death really hates that!