util.js

/**
* Utility functions for $rdf and the $rdf object itself
 */

if (typeof tabulator != 'undefined' && typeof tabulator.isExtension == 'undefined') tabulator.isExtension = false; // stand-alone library

if( typeof $rdf == 'undefined' ) {
    var $rdf = {};
} else {
    //dump("Internal error: RDF libray has already been loaded\n");
    //dump("Internal error: $rdf type is "+typeof $rdf+"\n");
    //dump("Internal error: $rdf.log type is "+typeof $rdf.log+"\n");
    //dump("Internal error: $rdf.log.error type is "+typeof $rdf.log.error+"\n");
    return $rdf;

    throw "Internal error: RDF libray has already been loaded: $rdf already exists";
};

/**
 * @class a dummy logger
 
 Note to implement this using the Firefox error console see
  https://developer.mozilla.org/en/nsIConsoleService
 */

//dump("@@ rdf/util.js test RESET RDF LOGGER  $rdf.log.error)\n");
if($rdf.log != undefined) {
    //dump("WTF util.js:" + $rdf.log);
    throw "Internal Error: $rdf.log already defined,  util.js: " + $rdf.log;
}

$rdf.log = {    
    'debug':function(x) {return;},
    'warn':function(x) {return;},
    'info':function(x) {return;},
    'error':function(x) {return;},
    'success':function(x) {return;},
    'msg':function(x) {return;}
}

 
/**
* @class A utility class
 */


$rdf.Util = {
    /** A simple debugging function */         
    'output': function (o) {
	    var k = document.createElement('div')
	    k.textContent = o
	    document.body.appendChild(k)
	},
    /**
    * A standard way to add callback functionality to an object
     **
     ** Callback functions are indexed by a 'hook' string.
     **
     ** They return true if they want to be called again.
     **
     */
    'callbackify': function (obj,callbacks) {
        obj.callbacks = {}
        for (var x=callbacks.length-1; x>=0; x--) {
            obj.callbacks[callbacks[x]] = [];
        }

        obj.addHook = function (hook) {
            if (!obj.callbacks[hook])
                obj.callbacks[hook] = [];
        }

        obj.addCallback = function (hook, func) {
            obj.callbacks[hook].push(func);
        }

        obj.removeCallback = function (hook, funcName) {
            for (var i=0;i<obj.callbacks[hook].length;i++){
                if (obj.callbacks[hook][i].name==funcName){
                    obj.callbacks[hook].splice(i,1);
                    return true;
                }
            }
            return false; 
        }

        obj.insertCallback=function (hook,func){
            obj.callbacks[hook].unshift(func);
        }

        obj.fireCallbacks = function (hook, args) {
            var newCallbacks = []
            var replaceCallbacks = []
            var len = obj.callbacks[hook].length
            //	    $rdf.log.info('!@$ Firing '+hook+' call back with length'+len);
            for (var x=len-1; x>=0; x--) {
                //		    $rdf.log.info('@@ Firing '+hook+' callback '+ obj.callbacks[hook][x])
                if (obj.callbacks[hook][x].apply(obj,args)) {
                    newCallbacks.push(obj.callbacks[hook][x])
                }
            }

            for (var x=newCallbacks.length-1; x>=0; x--) {
                replaceCallbacks.push(newCallbacks[x])
            }

            for (var x=len; x<obj.callbacks[hook].length; x++) {
                replaceCallbacks.push(obj.callbacks[hook][x])
            }

            obj.callbacks[hook] = replaceCallbacks
        }

    },
    
    /**
    * A standard way to create XMLHttpRequest objects
     */
	'XMLHTTPFactory': function () {
        if (typeof module != 'undefined' && module && module.exports) { //Node.js
            var XMLHttpRequest = require("XMLHttpRequest").XMLHttpRequest;
            return new XMLHttpRequest()
        }
        if (typeof tabulator != 'undefined' && tabulator.isExtension) {
            return Components.
            classes["@mozilla.org/xmlextras/xmlhttprequest;1"].
            createInstance().QueryInterface(Components.interfaces.nsIXMLHttpRequest);
        } else if (window.XMLHttpRequest) {
                return new window.XMLHttpRequest()
	    }
	    else if (window.ActiveXObject) {
                try {
                    return new ActiveXObject("Msxml2.XMLHTTP")
                } catch (e) {
                    return new ActiveXObject("Microsoft.XMLHTTP")
                }
	    }
	    else {
                return false
	    }
	},

	'DOMParserFactory': function () {
        if(tabulator && tabulator.isExtension) {
            return Components.classes["@mozilla.org/xmlextras/domparser;1"]
            .getService(Components.interfaces.nsIDOMParser);
        } else if ( window.DOMParser ){
		    return new DOMParser();
        } else if ( window.ActiveXObject ) {
            return new ActiveXObject( "Microsoft.XMLDOM" );
        } else {
            return false;
	    }
	},

    /**
    * Returns a hash of headers and values
    **
    ** @@ Bug: Assumes that each header only occurs once
    ** Also note that a , in a header value is just the same as having two headers.
     */
	'getHTTPHeaders': function (xhr) {
	    var lines = xhr.getAllResponseHeaders().split("\n")
	    var headers = {}
	    var last = undefined
	    for (var x=0; x<lines.length; x++) {
            if (lines[x].length > 0) {
                var pair = lines[x].split(': ')
                if (typeof pair[1] == "undefined") { // continuation
                    headers[last] += "\n"+pair[0]
                } else {
                    last = pair[0].toLowerCase()
                    headers[last] = pair[1]
                }
            }
	    }
	    return headers
	},
    
    'dtstamp': function () {
	    var now = new Date();
	    var year  = now.getYear() + 1900;
	    var month = now.getMonth() + 1;
	    var day  = now.getDate();
	    var hour = now.getUTCHours();
	    var minute = now.getUTCMinutes();
	    var second = now.getSeconds();
	    if (month < 10) month = "0" + month;
	    if (day < 10) day = "0" + day;
	    if (hour < 10) hour = "0" + hour;
	    if (minute < 10) minute = "0" + minute;
	    if (second < 10) second = "0" + second;
	    return year + "-" + month + "-" + day + "T"
            + hour + ":" + minute + ":" + second + "Z";
	},
    
    'enablePrivilege': ((typeof netscape != 'undefined') && (typeof netscape.security.PrivilegeManager != 'undefined') && netscape.security.PrivilegeManager.enablePrivilege) || function() { return; },
    'disablePrivilege': ((typeof netscape != 'undefined') && (typeof netscape.security.PrivilegeManager != 'undefined') && netscape.security.PrivilegeManager.disablePrivilege) || function() { return; },



    'RDFArrayRemove': function(a, x) {  //removes all statements equal to x from a
        for(var i=0; i<a.length; i++) {
            //TODO: This used to be the following, which didnt always work..why
            //if(a[i] == x)
            if (a[i].subject.sameTerm( x.subject ) && 
                a[i].predicate.sameTerm( x.predicate ) && 
                a[i].object.sameTerm( x.object ) &&
                a[i].why.sameTerm( x.why )) {
                a.splice(i,1);
                return;
            }
        }
        throw "RDFArrayRemove: Array did not contain " + x;
    },

    'string_startswith': function(str, pref) { // missing library routines
        return (str.slice(0, pref.length) == pref);
    },

    // This is the callback from the kb to the fetcher which is used to 
    // load ontologies of the data we load.
    'AJAR_handleNewTerm': function(kb, p, requestedBy) {
        var sf = null;
        if( typeof kb.sf != 'undefined' ) {
            sf = kb.sf;
        } else {
            return;
        }
        if (p.termType != 'symbol') return;
        var docuri = $rdf.Util.uri.docpart(p.uri);
        var fixuri;
        if (p.uri.indexOf('#') < 0) { // No hash
            
            // @@ major hack for dbpedia Categories, which spread indefinitely
            if ($rdf.Util.string_startswith(p.uri, 'http://dbpedia.org/resource/Category:')) return;  
            
            /*
              if (string_startswith(p.uri, 'http://xmlns.com/foaf/0.1/')) {
              fixuri = "http://dig.csail.mit.edu/2005/ajar/ajaw/test/foaf"
              // should give HTTP 303 to ontology -- now is :-)
              } else
            */
            if ($rdf.Util.string_startswith(p.uri, 'http://purl.org/dc/elements/1.1/')
                || $rdf.Util.string_startswith(p.uri, 'http://purl.org/dc/terms/')) {
                fixuri = "http://dublincore.org/2005/06/13/dcq";
                //dc fetched multiple times
            } else if ($rdf.Util.string_startswith(p.uri, 'http://xmlns.com/wot/0.1/')) {
            fixuri = "http://xmlns.com/wot/0.1/index.rdf";
            } else if ($rdf.Util.string_startswith(p.uri, 'http://web.resource.org/cc/')) {
                //            $rdf.log.warn("creative commons links to html instead of rdf. doesn't seem to content-negotiate.");
                fixuri = "http://web.resource.org/cc/schema.rdf";
            }
        }
        if (fixuri) {
            docuri = fixuri
        }
        if (sf && sf.getState(docuri) != 'unrequested') return;
        
        if (fixuri) {   // only give warning once: else happens too often
            $rdf.log.warn("Assuming server still broken, faking redirect of <" + p.uri +
                               "> to <" + docuri + ">")	
                }
        sf.requestURI(docuri, requestedBy);
    }, //AJAR_handleNewTerm
    'ArrayIndexOf': function(arr, item, i) {
        i || (i = 0);
        var length = arr.length;
        if (i < 0) i = length + i;
        for (; i < length; i++)
            if (arr[i] === item) return i;
        return -1;
    }
    
};

///////////////////// Parse XML
//
// Returns: A DOM
//

$rdf.Util.parseXML = function(str) {
    var dparser;
    if ((typeof tabulator != 'undefined' && tabulator.isExtension)) {
        dparser = Components.classes["@mozilla.org/xmlextras/domparser;1"].getService(
                    Components.interfaces.nsIDOMParser);
    } else if (typeof module != 'undefined' ){ // Node.js
        //var libxmljs = require('libxmljs'); // Was jsdom before 2012-01 then libxmljs but that nonstandard
        //return libxmljs.parseXmlString(str);
        var jsdom = require('jsdom');
        var dom = jsdom.jsdom(str, undefined, {} );// html, level, options
        return dom
    } else {
        dparser = new DOMParser();
    }
    return dparser.parseFromString(str, 'application/xml');
};


//////////////////////String Utility
// substitutes given terms for occurrnces of %s
// not well named. Used??? - tim
//
$rdf.Util.string = {
    //C++, python style %s -> subs
    'template': function(base, subs){
        var baseA = base.split("%s");
        var result = "";
        for (var i=0;i<subs.length;i++){
            subs[i] += '';
            result += baseA[i] + subs[i];
        }
        return result + baseA.slice(subs.length).join(); 
    }
};

// from http://dev.jquery.com/browser/trunk/jquery/src/core.js
// Overlap with JQuery -- we try to keep the rdflib.js and jquery libraries separate at the moment.
$rdf.Util.extend = function () {
    // copy reference to target object
    var target = arguments[0] || {},
        i = 1,
        length = arguments.length,
        deep = false,
        options, name, src, copy;

    // Handle a deep copy situation
    if (typeof target === "boolean") {
        deep = target;
        target = arguments[1] || {};
        // skip the boolean and the target
        i = 2;
    }

    // Handle case when target is a string or something (possible in deep copy)
    if (typeof target !== "object" && !jQuery.isFunction(target)) {
        target = {};
    }

    // extend jQuery itself if only one argument is passed
    if (length === i) {
        target = this;
        --i;
    }

    for (; i < length; i++) {
        // Only deal with non-null/undefined values
        if ((options = arguments[i]) != null) {
            // Extend the base object
            for (name in options) {
                src = target[name];
                copy = options[name];

                // Prevent never-ending loop
                if (target === copy) {
                    continue;
                }

                // Recurse if we're merging object values
                if (deep && copy && typeof copy === "object" && !copy.nodeType) {
                    var clone;

                    if (src) {
                        clone = src;
                    } else if (jQuery.isArray(copy)) {
                        clone = [];
                    } else if (jQuery.isObject(copy)) {
                        clone = {};
                    } else {
                        clone = copy;
                    }

                    // Never move original objects, clone them
                    target[name] = jQuery.extend(deep, clone, copy);

                    // Don't bring in undefined values
                } else if (copy !== undefined) {
                    target[name] = copy;
                }
            }
        }
    }

    // Return the modified object
    return target;
};