dl/lib/dataprovider/FileListProvider.js

DreamLab Libs

var fs = require('fs');

var Core = require('core'),
    Class = Core.Class,
    Assertions = Core.common.Assertions,
    Types = Core.common.Types;

var AbstractDataProvider = require('./AbstractDataProvider.js').AbstractDataProvider;

var FileListProvider = function () {
    this.Extends = AbstractDataProvider;

    this.initialize = function (fileList) {
        Assertions.isArray(fileList, FileListProvider.Exception.BAD_FILE_NAME);
        this._fileList = fileList;
    };

    this._merge = function (data) {
        if (data.length < 2) {
            return data;
        }

        var i = 1,
            length = data.length,
            key,
            tmp = data[0];


        for (; i < length; i++) {
            for (key in data[i]) {
                if (data[i].hasOwnProperty(key)) {
                    tmp[key] = data[i][key];
                }
            }
        }

        return tmp;
    };

    this.init = function (callback) {
        var that = this,
            i = 0,
            length = this._fileList.length,
            tmp = length,
            error = {};
            success = function () {
                if (--tmp == 0) {
                    var keys = Object.keys(error);
                    if (keys.length) {
                        callback(error, null);
                    } else {
                        callback(null, true);
                    }
                }

        };

        for (; i < length; i++) {
            fs.stat(this._fileList[i], function (file) {
                return function (err, stats) {
                    if (err) {
                        if (err.code != "ENOENT") {
                            error[file] = err;
                            success();
                            return;
                        } else {
                            fs.writeFile(file, '', function (err) {
                                if (err) {
                                    error[file] = err;
                                    success()
                                    return;
                                }

                                success();
                            });
                        }
                        return;
                    }
                    success();
                };
            }(this._fileList[i]));
        }
    };

    this.destroy = function () {
        this.unwatch(null, function () {});
    };

    this.watch = function (key, callback) {
        var i = 0, length = this._fileList.length;

        for(; i < length; i++) {
            fs.watchFile(this._fileList[i], function (current, previous) {
                if (current.size == 0) {
                    /*
                     * pomijam event przy czyszczeniu pliku
                     * po CLOSE_WRITE zostanie wygenerowany nowy event
                     */
                } else {
                    callback(null, current);
                }
            });
        }
    };

    this.unwatch = function (key, callback) {
        var i = 0, length = this._fileList.length;

        for(; i < length; i++) {
            fs.unwatchFile(this._fileList[i]);
        }
        callback();
    };

    this.set = function (key, value, callback) {
        throw FileListProvider.Exception.SET_NOT_SUPPORTED;
    };

    this.get = function (key, callback) {
        var that = this,
            data = [],
            error = {},
            i = 0,
            length = this._fileList.length,
            tmp = length,
            success = function () {
                if (--tmp == 0) {
                    var keys = Object.keys(error);

                    if (keys.length) {
                        callback(error, null);
                    } else {
                        callback(null, that._merge(data));
                    }
                }
        };

        for (; i < length; i++) {
            fs.readFile(this._fileList[i], 'utf8', function (index, file) {
                return function (err, d) {
                    if (err) {
                        error[file] = err;
                        success();
                        return;
                    }

                    try {
                        d = JSON.parse(d);
                    } catch (e) {
                        d = {};
                    }

                    data[index] = d;
                    success();
                };
            }(i, this._fileList[i]));
        }
    };
};

FileListProvider = new Class(new FileListProvider());

FileListProvider.Exception = {};
FileListProvider.Exception.BAD_FILE_NAME = "Array of files has to be passed";
FileListProvider.Exception.SET_NOT_SUPPORTED = "Setting configuration is not supported";

exports.FileListProvider = FileListProvider;