source: main/trunk/greenstone3/web/client-side-xslt.js@ 36943

/*

Greenstone 3 'Client-side transformer'
Performs client-side transformations of XSLT, using HTML5 local storage (simulated if the browser doesn't support it).

Currently only supports Firefox 3 and greater, since it's the only browser (at the time of writing) that can do this properly.

@author     Steven McTainsh
@author     David Bainbridge
@date       2011-2016

*/

function isSupported()
{
    // The whole script currently assumes SaxonCE is used to provide XSLT
    // which means it is always supported => return true
    //
    // Could consider testing for native XSLT (using simple
    // hardwired XML + XSL Tranform?) and using that
    // if successful (presumably faster)
    //
    // Or even try to transform the given transform natively,
    // and store 'isNativelySupported' as true/false in cookie
    // accordingly

    return true; 
}

function notSupportedCookie() {
    document.cookie = 'supportsXSLT=false; expires=0; path=/';
}

function notSupported() {
    notSupportedCookie();

    // Remove the client-side XSLT output parameter
    var location_href = window.location.href.replace("o=xsltclient", "");

    // location_href = location_href.replace(/^(.*)\/(client-)?([^\?\#]+)(.*)$/,"$1/$3$4");
    console.log("Client-side XSLT not supported.  Redirecting to: " + location_href);
    
    window.location.href = location_href;
}

function getUrlParameterHashmap() {
    var sPageURL = decodeURIComponent(window.location.search.substring(1));
    var sURLVariables = sPageURL.split('&');

    var paramHashmap = {};
    
    for (var i = 0; i < sURLVariables.length; i++) {
        var sParameterName = sURLVariables[i].split('=');
        paramHashmap[sParameterName[0]] = sParameterName[1];
    }

    return paramHashmap;
}

// From:
//   http://stackoverflow.com/questions/298750/how-do-i-select-text-nodes-with-jquery
function getTextNodesIn(node, includeWhitespaceNodes) {
    var textNodes = [], nonWhitespaceMatcher = /\S/;

    function getTextNodes(node) {
        if (node.nodeType == 3) {
            if (includeWhitespaceNodes || nonWhitespaceMatcher.test(node.nodeValue)) {
                textNodes.push(node);
            }
        }
    else {
            for (var i = 0, len = node.childNodes.length; i < len; ++i) {
                getTextNodes(node.childNodes[i]);
            }
        }
    }

    getTextNodes(node);
    return textNodes;
}

function applyDisableEscapingToTextNodes(elem)
{
    var textNodes = getTextNodesIn(elem,false); // ignore whitespace

    for (var i=textNodes.length-1; i>=0; i--) {
        var text_node = textNodes[i];
        var text = text_node.nodeValue;
        var html = $.parseHTML(text);
        $(text_node).replaceWith(html);
    }
}

var onSaxonLoad = function() {
    try {
        var paramHashmap = getUrlParameterHashmap();
        var rooturl = window.location.pathname;
        var queryStr = window.location.search.substring(1);

        queryStr = queryStr.replace(/o=.*?(&|$)/g,"");
        if (queryStr != '') {
            queryStr += "&";
        }

        queryStr += "o=clientside";
        paramHashmap['o']="clientside";
        
        //console.log("*** rooturl = " + rooturl);
        //console.log("*** queryStr = " + queryStr);
        
        $.get(rooturl, paramHashmap, function(data) {
            var toplevel_children = $(data).children().eq(0).children();
            var skindoc = toplevel_children[0];
            var xmldoc = toplevel_children[1];
                
            var library_name = $('xsltparams>param[name=library_name]', xmldoc).text();
            var interface_name = $('xsltparams>param[name=interface_name]', xmldoc).text();
            var site_name = $('xsltparams>param[name=site_name]', xmldoc).text();
            var use_client_side_xslt = $('xsltparams>param[name=use_client_side_xslt]', xmldoc).text();
            
            // Convert temporarily to text so we can easily replace invalid values
            var xmlSerializer = new XMLSerializer();
            skindoc = xmlSerializer.serializeToString(skindoc);
            xmldoc = xmlSerializer.serializeToString(xmldoc);
            
            skindoc = skindoc.replace(/<xslt:stylesheet\s+/,"<xslt:stylesheet xmlns:ixsl=\"http://saxonica.com/ns/interactiveXSLT\" xmlns:js=\"http://saxonica.com/ns/globalJS\" ");
            skindoc = skindoc.replace(/extension-element-prefixes="(.*?)"/,"extension-element-prefixes=\"$1 ixsl\"");
            
            skindoc = skindoc.replace(/util\:exists\(\$meta, ''\)/g, "$meta!=''"); // For now - use regex instead
            skindoc = skindoc.replace(/util:replace\((.*?)\)/g, "replace($1)"); // 'replace()' exists in XSLT 2.0
            skindoc = skindoc.replace(/util:storeString\(\s*'(.+?)'\s*,\s*'(.*?)'\s*\)/g, "js:storeString(string($1),string($2))");
            skindoc = skindoc.replace(/util:getString\('(.+?)'\)/g, "js:getString(string($1))");
            skindoc = skindoc.replace(/util:escapeNewLinesAndQuotes\(([^)]+)\)/g, "js:escapeNewLinesAndQuotes(string($1))");
            skindoc = skindoc.replace(/util:escapeNewLinesQuotesAngleBracketsForJSString\(([^)]+)\)/g, "js:escapeNewLinesQuotesAngleBracketsForJSString(string($1))");
            
            skindoc = skindoc.replace(/util:getDetailFromDate\((.+?),.+?,.+?\)/g, "'getDetailFromDate $1'"); // ****

            skindoc = skindoc.replace(/util:oidIsMatchOrParent\(([^,]+),([^)]+)\)/g,"js:oidIsMatchOrParent(string($1),string($2))");
            skindoc = skindoc.replace(/util:hashToDepthClass\(([^)]+)\)/g,"js:hashToDepthClass(string($1))");
            skindoc = skindoc.replace(/util:hashToSectionId\(([^)]+)\)/g,"js:hashToSectionId(string($1))");

            skindoc = skindoc.replace(/java:.*?getNumberedItem\(([^,]+),([^)]+)\)/g, "js:getNumberedItem(string($1),string($2))");

            // The XMLSerializer converts some escaping, which we undo here
            // so that Saxon-CE can successfully parse the document.
            skindoc = skindoc.replace("\"'''\"", "\"'&amp;apos;'\"");

            // Convert back to XML
            xmldoc = parseFromString(xmldoc, "text/xml");           
            skindoc = parseFromString(skindoc, "text/xml");
            
            var proc = Saxon.newXSLT20Processor();
            proc.setParameter(null, 'library_name', library_name);
            proc.setParameter(null, 'interface_name', interface_name);
            proc.setParameter(null, 'site_name', site_name);
            proc.setParameter(null, 'use_client_side_xslt', use_client_side_xslt);
            
            console.log("Applying client-side XSLT");    
            proc.importStylesheet(skindoc);
            var result = proc.transformToDocument(xmldoc);

            var excerptid = paramHashmap['excerptid'];
            if (excerptid) {
                result = result.getElementById(excerptid);
            }
            
            applyDisableEscapingToTextNodes(result);
            var DOMString = xmlSerializer.serializeToString(result);
            
            if (excerptid) {
                var callback = paramHashmap['callback'];
                parent[callback](DOMString);
            }
            else
            {
                /**
                 * NOTE (Carl - cstephen):
                 * This is not an ideal solution. document.open() is a slow option
                 * and is limited in certain browsers, wherein scripts are prevented
                 * from running under certain networking conditions.
                 * 
                 * Ideally we'd directly replace the document with the constructed DOM.
                 * However, despite the replacement being successful, it wasn't being
                 * parsed successfully at the time of writing.
                 * 
                 * If you'd like to attempt this again, the following is a good starting point:
                 * var processor = Saxon.newXSLT20Processor();
                 * var documentFragment = processor.transformToFragment(xmldoc);
                 * document.replaceChild(documentFragment, document.documentElement);
                 */

                var newDocument = document.open("text/html");
                newDocument.write(DOMString);
                newDocument.close();

                document.cookie = 'supportsXSLT=true; expires=0; path=/';
            }
        }, 'xml');
    }
    catch (e) {
        alert("Error occured:" + e.message + "\n======\nSee web browser console for more details");
        notSupported();
    }
}

function parseFromString(content, contentType) {
    try {
        var retobj;
        
        if (typeof window.DOMParser != 'undefined') {
            // Firefox, Chrome
            retobj = (new DOMParser()).parseFromString(content, contentType);
        }
        else {
            // IE
            var retobj = new ActiveXObject("Microsoft.XMLDOM");
            retobj.async = "false";
            retobj.loadXML(content);
        }
        
        return retobj;
    }
    catch(e) {
        var obj = new ActiveXObject('MSXML.DomDocument');
        obj.async = false;
        obj.loadXML(content);

        return obj;
    }
}


/* Simulating web storage for browsers that don't support it */
/* Credit: http://www.thewojogroup.com/2010/01/simulating-html5-local-storage/ */
(function(){var k=this;if(!k.localStorage&&navigator.cookieEnabled){var x="storageData_",y="++",z="::",l=function(a,c,b){var e=new Date;e.setTime(e.getTime()+b);b="; expires="+e.toGMTString();document.cookie=a+"="+c+b+"; path=/"},h=function(a){a=a+"=";for(var c=document.cookie.split(";"),b=0,e=c.length;b<e;b++){for(var d=c[b];d.charAt(0)==" ";)d=d.substring(1,d.length);if(d.indexOf(a)===0)return d.substring(a.length,d.length)}return null},m=function(a){l(a,"",-1)},i=function(){for(var a="",c=0;h(y+c)!==null;)a+=h(y+
c++);return a==""?[]:a.split(y)},n=function(a){for(var c=Math.ceil(a.length/4E3),b=0;b<c||h(y+b)!==null;){b<c?l(y+b,a.substr(b*4E3,(b+1)*4E3>a.length?a.length-b*4E3:4E3),2592E3):m(y+b);b++}},f=k.localStorage={length:0,setItem:function(a,c){var b=i(),e=0,d=b.length,g=false;for(e=0;e<d;e++){var j=b[e].split(z);if(j[0]==a){j[1]=c;g=true;b[e]=j.join(z);e=d}}if(!g){b.push(a+z+c.replace(/::/g,": :").replace(/\+\+/g,"+ +"));this.a.push(a);this.length++}n(b.join(y))},
getItem:function(a){var c=i(),b=0,e=c.length;for(b=0;b<e;b++){var d=c[b].split(z);if(d[0]==a&&d[1])return d[1]}return null},removeItem:function(a){var c=i(),b=0,e=c.length,d=false,g=[];for(b=0;b<e;b++)if(c[b].split(z)[0]!=a)g.push(c[b]);else d=true;if(d){n(g.join(y));o()}},clear:function(){for(var a=0;h(y+a)!==null;)m(y+a++);this.a=[];this.length=0},key:function(a){return a<this.length?this.a[a]:null},a:[]},o=function(){f.a=i();for(var a=0;f.a[a];)f.a[a]=f.a[a++].split(z)[0];
f.length=f.a.length};o()}})();