cordova-fs-accessing.js

    styleSheetRaw = null;
    fileSystem = null;
    imgDataURIs = {};

    imgBgStyle = $('#img-bg-style');
    bgStyleUrl = imgBgStyle.attr('href');

    function useLocalImages(msg){
        console.log(msg);
        if(null === styleSheetRaw|| null == fileSystem){
            return;
        }

        var imgurls = [];

        // this is not really a replace, but just finding out all unique URLs
        var unique = {};
        styleSheetRaw.replace(/(url\()(.*?)(\))/gi, function(m, p1, p2, p3){
            if(p2.match(/https?:\/\//i)) return;
            p2 = p2.replace(/"/g, '').replace(/\.\./, '');
            if(unique.hasOwnProperty(p2)) return;
            unique[p2] = 1;
            imgurls.push(p2);
        });

        var counter = imgurls.length;

        // apply local images as data URI for all url() calls in the raw style
        // sheet
        var applyLocalImageAsDataURI = function(msg){
            //console.log(msg);
            counter--;

            // wait till all images are loaded
            if(counter > 0) return;
            alert("done all image to base 64 conversion");
            //return;
            //console.log("all done");
            var styleSheetConverted = styleSheetRaw.replace(
                /(url\()(.*?)(\))/gi, function(m, p1, p2, p3){
                if(p2.match(/https?:\/\//i)) return p1+p2+p3;
                var naked = p2.replace(/"/g, '').replace(/\.\./, '');
                if(imgDataURIs.hasOwnProperty(naked)){
                    return p1+imgDataURIs[naked]+p3;
                }
                return p1+p2+p3;
            });
            $('body').append(
                styleSheetConverted
            );
        };

        for(var i = 0, len = imgurls.length; i < len; i++){
            var url = imgurls[i];
            var imgPath = "file://" + fileSystem.root.fullPath + url;
            (function(){
                var fileUrl = url;
                window.resolveLocalFileSystemURI(imgPath, function(fileEntry){
                    fileEntry.file(function(file){
                        var reader = new FileReader();
                        reader.onloadend = function (evt) {
                            var base64content = evt.target.result;
                            if (!base64content) { return; }
                            imgDataURIs[fileUrl] = base64content;
                            applyLocalImageAsDataURI("found " + fileUrl);
                        };
                        reader.readAsDataURL(file);
                    });
                },
                function(e){ applyLocalImageAsDataURI("not found " + fileUrl); });
            })();
        }
    }

    // Wait for device API libraries to load
    //
    document.addEventListener("deviceready", function(){
        console.log(typeof window.requestFileSystem);
        $.get(bgStyleUrl, function(data){
            //join all lines into a single line string and consolidate whitespaces
            data = data.replace(/(\r\n|\n|\r)/gm, " ").replace(/\s+/g, " ");

            //remove comments
            data = data.replace(/\/\*.*?\*\//g, '');

            styleSheetRaw = data;

            useLocalImages("from ajax");
        });
        window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function(pFileSystem){
            console.log("got FS");
            fileSystem = pFileSystem;
        },
        function(){
            console.log('no can do.');
        });
    }, false);