No Ouput to DOM Tree
In the following code, my attempts at creating the preparePlaceholder on the the fly has failed, and the only error is "parent is not defined" from the error console.
I'm modifying this example for use with a JS object literal and could use the sage wisdom of StackOverflow.
TIA
imageGallery={
// IDs
placeHolderID:'placeholder',
imageNavListID:'imagegallerylist',
// CSS Classes
init:function(){
if(!document.getElementById || !document.createTextNode){return;}
imageGallery.preparePlaceholder();// Call to preparePlacholder
// Prepare Gallery:
imageGallery.navList = document.getElementById(imageGallery.imageNavListID);
if(!imageGallery.navList){return;}
var links = imageGallery.navList.getElementsByTagName('a');
for(var i = 0; i<links.length;i++){
links[i].onclick = function(){
// Call to showPic function:
return imageGallery.showPic(this) ? false : true;
}
}
},
showPic:function(whichpic){
imageGallery.pHolder=document.getElementById(imageGallery.placeHolderID);
if(!imageGallery.pHolder || imageGallery.pHolder.nodeName != "IMG"){return;}
var source = whichpic.getAttribute("href");
imageGallery.pHolder.setAttribute("src",source);
if(document.getElementById("description")){
// var text = whichpic.getAttribute("title");
var text = whichpic.getAttribute("title") ? whichpic.getAttribute("title") : "";
var description = document.getElementById("description");
if(description.firstChild.nodeType == 3){
description.firstChild.nodeValue = text;
}
}
return true;
},
preparePlaceholder:function(){
var placeholder = document.createElement("img");
placeholder.setAttribute("id", "placeholder");
placeholder.setAttribute("src","images/placeholder.gif");
placeholder.setAttribute("alt","My Image Gallery");
// alert(placeholder);
var description = document.createElement("p");
description.setAttribute("id","description");
var desctext = document.createTextNode("Choose an Image");
descripti开发者_运维技巧on.appendChild(desctext);
var gallery = document.getElementById("imageGallery");
imageGallery.insertAfter(placeholder,imageGallery);
imageGallery.insertAfter(description,imageGallery.placeholder);
// alert("Function Called");
},
// Utility Functions
insertAfter:function(newElement,targetElement){
var parent = targetElement.parentNode;
if(parent.lastChild == targetElement){
parent.appendChild(newElement);
} else {
parent.insertBefore(newElement,targetElement.nextSibling);
}
},
addLoadEvent:function(func){
var oldonload = window.onload;
if(typeof window.onload != 'function'){
window.onload = func;
}else{
window.onload = function(){
oldonload();
func();
}
}
}
}
// End Utility Functions
imageGallery.addLoadEvent(imageGallery.init);
// window.onload=imageGallery.init;
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="uft-8" />
<title>Image Gallery</title>
<link rel="stylesheet" href="styles/layout.css" type="text/css" media="screen" title="layout" charset="utf-8" />
</head>
<body>
<h1>Snapshots</h1>
<ul id="imagegallerylist">
<!--Links Here-->
</ul>
<script src="scripts/imageGallery.js"></script>
</body>
</html>
Have an example here which doesn't produce errors. I have removed your comments and put in comments where I have changed the code.
JavaScript:
var gallery = document.getElementById("imageGallery");
// Changed from imageGallery to gallery
imageGallery.insertAfter(placeholder, gallery);
// Changed from imageGallery.placeholder to placeholder
imageGallery.insertAfter(description, placeholder);
HTML:
<div id="imageGallery"></div> <!-- Added this div -->
加载中,请稍侯......
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