PUMA

tagCloud.js

/** limits for different font-sizes */
var lim1;
var lim2;

var limit = 0;
var order;

/** 
* Retrieves tags from BibSonomy 

* param url: the url of the JSON feed
* param limit: tag limitation
* param order: order of the tags (tagname or tagcount)
*/
function getTags(url, lim, ord) {
    limit = lim;
    order = ord;

    var headID = document.getElementsByTagName("head")[0];         
    var newScript = document.createElement("script");
    newScript.type = "text/javascript";
    newScript.src = url + "?callback=jsonBibSonomyFeed";
    headID.appendChild(newScript);
}

/** 
* Handler function 
*/
function jsonBibSonomyFeed(feed) {
    var div = document.getElementById("tags");
    var ultag = document.getElementById("tagbox");
    var maxCount = -1000;
    var minCount = 1000;

    for(x=0; x < feed.items.length; x++){
            var tagCount = feed.items[x].count;
            if (tagCount < minCount)
                    minCount = tagCount;
            if (tagCount > maxCount)
                    maxCount = tagCount;                    
    }               
    var diff = maxCount - minCount;
    var part = diff / 3;    
    lim2 = maxCount - part;
    lim1 = lim2 - part;

    // remove old tags      
    var lilength = ultag.getElementsByTagName("LI").length;
    while (lilength > 0) {
            ultag.removeChild(ultag.firstChild);
            lilength = ultag.getElementsByTagName("LI").length;
    }

    // limitation
    if (limit == 0 || limit > feed.items.length)
            limit = feed.items.length;

    // sort to frequency and cut after limit
    feed.items = feed.items.sort(softFreq);
    feed.items = feed.items.slice(0,limit);         

    // sort 
    feed.items = feed.items.sort(comparator);

    // insert new tags
    var space = document.createTextNode(" ");
    for(var x=0; x < feed.items.length; x++){
            var tagname  = feed.items[x].label;
            var tagcount = feed.items[x].count;
            var clazz = getClazz(tagcount);

            var newli = document.createElement("LI");

            var newa = document.createElement("A");
            newa.href = "http://www.bibsonomy.org/tag/" + tagname;
            newa.innerHTML = tagname;
            newa.className = clazz;

            newli.appendChild(newa);
            newli.appendChild(space.cloneNode(true));
            ultag.appendChild(newli);
    }               
}

/**
* compartor function for array sort
**/
function comparator(x,y) {
    if (order == "frequency") {
            var count1 = x.count;   
            var count2 = y.count;   

            return count2 - count1; 
    } else {
            var name1 = x.label.toLowerCase();      
            var name2 = y.label.toLowerCase();

            return (name1 == name2) ? 0 : (name1 < name2) ? -1 : 1                  
    }
}

/**
* sorts array to frequency
**/
function softFreq(x,y) {
    var count1 = x.count;   
    var count2 = y.count;   

    return count2 - count1; 
}

/** 
* Computes the style class for a tag 
*/
function getClazz(count) {
    if (count > lim2)
            return "big";
    if (count < lim1)
            return "small";
    return "normal";
}