/**
* TOC.js: create a table of contents for a document.
*
* This module registers an anonymous function that runs automatically
* when the document finishes loading. When it runs, the function first
* looks for a document element with an id of "TOC". If there is no
* such element it creates one at the start of the document.
*
* Next, the function finds all <h1> through <h6> tags, treats them as
* section titles, and creates a table of contents within the TOC
* element. The function adds section numbers to each section heading
* and wraps the headings in named anchors so that the TOC can link to
* them. The generated anchors have names that begin with "TOC", so
* you should avoid this prefix in your own HTML.
*
* The entries in the generated TOC can be styled with CSS. All entries have
* a class "TOCEntry". Entries also have a class that corresponds to the level
* of the section heading. <h1> tags generate entries of class "TOCLevel1",
* <h2> tags generate entries of class "TOCLevel2", and so on. Section numbers
* inserted into headings have class "TOCSectNum".
*
* You might use this module with a stylesheet like this:
*
* #TOC { border: solid black 1px; margin: 10px; padding: 10px; }
* .TOCEntry { font-family: sans-serif; }
* .TOCEntry a { text-decoration: none; }
* .TOCLevel1 { font-size: 16pt; font-weight: bold; }
* .TOCLevel2 { font-size: 12pt; margin-left: .5in; }
* .TOCSectNum:after { content: ": "; }
*
* That final line generates a colon and space after section numbers. To hide
* the section numbers, use this:
*
* .TOCSectNum { display: none }
*
* This module requires the onLoad() utility function.
**/
onLoad(function() { // Anonymous function defines a local scope
// Find the TOC container element.
// If there isn't one, create one at the start of the document.
var toc = document.getElementById("TOC");
if (!toc) {
toc = document.createElement("div");
toc.id = "TOC";
document.body.insertBefore(toc, document.body.firstChild);
}
// Find all section heading elements
var headings;
if (document.querySelectorAll) // Can we do it the easy way?
headings = document.querySelectorAll("h1,h2,h3,h4,h5,h6");
else // Otherwise, find the headings the hard way
headings = findHeadings(document.body, []);
// Recursively traverse the document body looking for headings
function findHeadings(root, sects) {
for(var c = root.firstChild; c != null; c = c.nextSibling) {
if (c.nodeType !== 1) continue;
if (c.tagName.length == 2 && c.tagName.charAt(0) == "H")
sects.push(c);
else
findHeadings(c, sects);
}
return sects;
}
// Initialize an array that keeps track of section numbers.
var sectionNumbers = [0,0,0,0,0,0];
// Now loop through the section header elements we found.
for(var h = 0; h < headings.length; h++) {
var heading = headings[h];
// Skip the section heading if it is inside the TOC container.
if (heading.parentNode == toc) continue;
// Figure out what level heading it is.
var level = parseInt(heading.tagName.charAt(1));
if (isNaN(level) || level < 1 || level > 6) continue;
// Increment the section number for this heading level
// and reset all lower heading level numbers to zero.
sectionNumbers[level-1]++;
for(var i = level; i < 6; i++) sectionNumbers[i] = 0;
// Now combine section numbers for all heading levels
// to produce a section number like 2.3.1.
var sectionNumber = sectionNumbers.slice(0,level).join(".")
// Add the section number to the section header title.
// We place the number in a <span> to make it styleable.
var span = document.createElement("span");
span.className = "TOCSectNum";
span.innerHTML = sectionNumber;
heading.insertBefore(span, heading.firstChild);
// Wrap the heading in a named anchor so we can link to it.
var anchor = document.createElement("a");
anchor.name = "TOC"+sectionNumber;
heading.parentNode.insertBefore(anchor, heading);
anchor.appendChild(heading);
// Now create a link to this section.
var link = document.createElement("a");
link.href = "#TOC" + sectionNumber; // Link destination
link.innerHTML = heading.innerHTML; // Link text is same as heading
// Place the link in a div that is styleable based on the level.
var entry = document.createElement("div");
entry.className = "TOCEntry TOCLevel" + level;
entry.appendChild(link);
// And add the div to the TOC container.
toc.appendChild(entry);
}
});
An automatically generated table of contents Create a table of contents for a document
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You can use [html][/html], [css][/css], [php][/php] and more to embed the code. Urls are automatically hyperlinked. Line breaks and paragraphs are automatically generated.