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Problems using custom tag with javascript

Greenhorn

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posted 16 years ago

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Hey everyone.

I am trying to make a tree list to show a file directory standing on the server. As javascript is not really my area

I've chosen to use a pre-existent function (http://www.destroydrop.com/javascripts/tree/) - which is really good by the way.
To pass the arguments to the javascript code, I am using a custom tag.

This is a chunk of the JSP:

and this is the generated code:

everything as expected... however the function never runs, and the tree list is never showed.

I created a JSP without the custom tag, with just the code generated by the 'real' JSP, and it worked just fine. That made me very confused...

Is there any problem with generating dynamic code in the header of the page? Or using custom tags with javascript? I am a bit lost...

Ben Souther

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posted 16 years ago

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Custom tags (and any JSP code for that matter) and Javascript exist in two totally different times and places so... no, there is no problem with using custom tags to generate Javascript and there is no problem using them in the head of an HTML page.

Think of it this way, your JSP code creates your HTML and Javascript code.
To the JSP side of the world HTML and Javascript are nothing more strings of text.

I see your Javascript array,
Where is the function?

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Felipe Reis

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posted 16 years ago

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That's what I thought... But my question is: Why when I copy the generated code into a new 'static' jsp, and make a request to that page the function works perfectly? At the end of the day is the same code, so why different results? That's why I assumed that there was a problem when using tags and javascript.

The function is in an external file. I can't understand it entirely (javascript simply doesn't make sense to me), and I can't post it here because of special characteres or something like that.

Bear Bibeault

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posted 16 years ago

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How are you including the JS file? That may be suspect.

See the entry in the JSP FAQ regarding resource URLs.

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Ben Souther

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posted 16 years ago

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Also check to make sure you're not trying to call the function before the array is written to the page.

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Felipe Reis

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posted 16 years ago

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I've checked the FAQ about resources URL. As my page uses a static URL to include the js file I don't think that's the problem.

The elements are included in the array in the page <head> tag, so I think the function will be called just after that...

I'm stuck now. I'll do some more tests and see what I find out.

I've posted this question on a different forum, and a user suggested me to use scriptlets, because custom tags won't work. But that just doesn't make sense to me...

Thanks Bear and Ben.

Bear Bibeault

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posted 16 years ago

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Originally posted by Felipe Reis:
I've checked the FAQ about resources URL. As my page uses a static URL to include the js file I don't think that's the problem.

I'm not sure what you mean by "static" URL. Can you show us the URL? In fac t, how about showing us the code? (Please be sure to use UBB code tags).

The elements are included in the array in the page <head> tag, so I think the function will be called just after that...

Yeah, I definitely think that we need to see some code.

I've posted this question on a different forum, and a user suggested me to use scriptlets, because custom tags won't work. But that just doesn't make sense to me...

That is just about as flat out wrong as anything can be. Anything else this person says should be considered suspect.

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Felipe Reis

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posted 16 years ago

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Here is the code from the jsp:

This is the js file:

/**************************************************************************
Copyright (c) 2001-2003 Geir Landr� (drop@destroydrop.com)
JavaScript Tree - <a href="http://www.destroydrop.com/hjavascripts/tree/" target="_blank" rel="nofollow">www.destroydrop.com/hjavascripts/tree/</a>
Version 0.96
 
This script can be used freely as long as all copyright messages are
intact.
**************************************************************************/
 
// Arrays for nodes and icons
var nodes= new Array();;
var openNodes= new Array();
var icons= new Array(6);
 
// Loads all icons that are used in the tree
function preloadIcons() {
icons[0] = new Image();
icons[0].src = "img/plus.gif";
icons[1] = new Image();
icons[1].src = "img/plusbottom.gif";
icons[2] = new Image();
icons[2].src = "img/minus.gif";
icons[3] = new Image();
icons[3].src = "img/minusbottom.gif";
icons[4] = new Image();
icons[4].src = "img/folder.gif";
icons[5] = new Image();
icons[5].src = "img/folderopen.gif";
}
// Create the tree
function createTree(arrName, startNode, openNode) {
nodes = arrName;
if (nodes.length > 0) {
preloadIcons();
if (startNode == null) startNode = 0;
if (openNode != 0 || openNode != null) setOpenNodes(openNode);

if (startNode !=0) {
var nodeValues = nodes[getArrayId(startNode)].split("|");
document.write("<a href=\"" + nodeValues[3] + "\" onmouzeover=\"window.status='" + nodeValues[2] + "';return true;\" onmouzeout=\"window.status=' ';return true;\"><img src=\"img/folderopen.gif\" align=\"absbottom\" alt=\"\" />" + nodeValues[2] + "</a><br />");
} else document.write("<img src=\"img/base.gif\" align=\"absbottom\" alt=\"\" />Website<br />");

// Write out folder & page icons
if (hcn) {
document.write("<img id=\"icon" + nodeValues[0] + "\" src=\"img/folder")
if (ino) document.write("open");
document.write(".gif\" align=\"absbottom\" alt=\"Folder\" />");
} else document.write("<img id=\"icon" + nodeValues[0] + "\" src=\"img/page.gif\" align=\"absbottom\" alt=\"Page\" />");

// Write out node name
document.write(nodeValues[2]);
 
// End link
document.write("</a><br />");

// If node has children write out divs and go deeper
if (hcn) {
document.write("<div id=\"div" + nodeValues[0] + "\"");
if (!ino) document.write(" style=\"display: none;\"");
document.write(">");
addNode(nodeValues[0], recursedNodes);
document.write("</div>");
}

// remove last line or empty icon 
recursedNodes.pop();
}
}
}
// Opens or closes a node
function oc(node, bottom) {
var theDiv = document.getElementById("div" + node);
var theJoin= document.getElementById("join" + node);
var theIcon = document.getElementById("icon" + node);

if (theDiv.style.display == 'none') {
if (bottom==1) theJoin.src = icons[3].src;
else theJoin.src = icons[2].src;
theIcon.src = icons[5].src;
theDiv.style.display = '';
} else {
if (bottom==1) theJoin.src = icons[1].src;
else theJoin.src = icons[0].src;
theIcon.src = icons[4].src;
theDiv.style.display = 'none';
}
}
// Push and pop not implemented in IE
if(!Array.prototype.push) {
function array_push() {
for(var i=0;i<arguments.length;i++)
this[this.length]=arguments[i];
return this.length;
}
Array.prototype.push = array_push;
}
if(!Array.prototype.pop) {
function array_pop(){
lastElement = this[this.length-1];
this.length = Math.max(this.length-1,0);
return lastElement;
}
Array.prototype.pop = array_pop;
}

Ben Souther

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posted 16 years ago

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Are you naming your array "Tree" or "DivArray"?

Also, when you create an array with the 'new' keyword in Javascript 'Array' needs parenthesis after it:
Example:

The name discrepancy wasn't there in the first piece of code you posted so I'm not sure if this is a red herring or not.

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Felipe Reis

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posted 16 years ago

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Oops, sorry... I've got 2 functions in that page, one with an array called Tree, and another called DivArray. But i've only posted the code relevant to the createTree() function.

Felipe Reis

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posted 16 years ago

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Ben and Bear, thanks for the support.

I manage to solve the problem, and with the info that I provide, you guys could never have helped me. The problem was not in the code after all!

I have this habit of spending all my time looking for bugs in the code, and forgeting other issues like file location.

After some tests I found out that the function was not being called. The js file was in the same folder as my jsp, however, the jsp was called after a Servlet's forward(), so the URL in the browser bar was still from the first Servlet.

I spent days looking at the code, and the problem was solved after a glimpse on the browser bar...

Anyway, thanks again.

Ben Souther

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posted 16 years ago