source: Dev/trunk/src/client/util/build/transforms/read.js

define([
        "../buildControl",
        "../fileUtils", 
        "../fs",
        "../replace"
], function(bc, fileUtils, fs, replace){
        var
                getFiletype = fileUtils.getFiletype,

                encodingMap=
                        // map from file type to encoding
                        (bc.transformConfig.read && bc.transformConfig.read.encoding) || {
                                css:"utf8",
                                html:"utf8",
                                htm:"utf8",
                                js:"utf8",
                                json:"utf8",
                                asc:"utf8",
                                c:"utf8",
                                cpp:"utf8",
                                log:"utf8",
                                conf:"utf8",
                                text:"utf8",
                                txt:"utf8",
                                dtd:"utf8",
                                xml:"utf8",
                                png:undefined,
                                jpg:undefined,
                                jpeg:undefined,
                                gif:undefined
                        };

        return function(resource, callback){
                resource.getText = function(){
                        if(!this.replacementsApplied){
                                this.replacementsApplied = true;
                                if(bc.replacements[this.src]){
                                        this.text = replace(this.text, bc.replacements[this.src]);
                                }
                        }
                        return this.text;
                };

                resource.setText = function(text){
                        resource.text = text;
                        resource.getText = function(){ return this.text; };
                        return text;
                };

                var filetype = getFiletype(resource.src, 1);
                // the expression is a little odd since undefined is a legitimate encodingMap value
                resource.encoding = resource.encoding ||(!(filetype in encodingMap) && "utf8") || encodingMap[filetype];
                fs.readFile(resource.src, resource.encoding, function(err, data){
                        if(!err){
                                resource.text = data;
                        }
                        callback(resource, err);
                });
                return callback;
        };
});