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/*jshint eqeqeq:false */
'use strict';
let uniqueID = 1;
/**
* Creates a new client side storage object and will create an empty
* collection if no collection already exists.
*
* @param {string} name The name of our DB we want to use
* @param {function} callback Our fake DB uses callbacks because in
* real life you probably would be making AJAX calls
*/
class Store {
constructor(name, callback) {
this._dbName = name;
this.memoryStorage = this.memoryStorage || {};
if (!this.memoryStorage[name]) {
let data = {
todos: []
};
this.memoryStorage[name] = JSON.stringify(data);
}
if (callback) {
callback.call(this, JSON.parse(this.memoryStorage[name]));
}
}
/**
* Finds items based on a query given as a JS object
*
* @param {object} query The query to match against (i.e. {foo: 'bar'})
* @param {function} callback The callback to fire when the query has
* completed running
*
* @example
* db.find({foo: 'bar', hello: 'world'}, function (data) {
* // data will return any items that have foo: bar and
* // hello: world in their properties
* })
*/
find(query, callback){
if (!callback) {
return;
}
let todos = JSON.parse(this.memoryStorage[this._dbName]).todos;
callback.call(this, todos.filter(todo => {
for (let q in query) {
if (query[q] !== todo[q]) {
return false;
}
}
return true;
}));
}
/**
* Will retrieve all data from the collection
*
* @param {function} callback The callback to fire upon retrieving data
*/
findAll(callback){
if (callback) {
callback.call(this, JSON.parse(this.memoryStorage[this._dbName]).todos);
}
}
/**
* Will save the given data to the DB. If no item exists it will create a new
* item, otherwise it'll simply update an existing item's properties
*
* @param {object} updateData The data to save back into the DB
* @param {function} callback The callback to fire after saving
* @param {number} id An optional param to enter an ID of an item to update
*/
save(updateData, callback, id){
const data = JSON.parse(this.memoryStorage[this._dbName]);
let todos = data.todos;
const len = todos.length;
// If an ID was actually given, find the item and update each property
if (id) {
for (let i = 0; i < len; i++) {
if (todos[i].id === id) {
for (let key in updateData) {
todos[i][key] = updateData[key];
}
break;
}
}
this.memoryStorage[this._dbName] = JSON.stringify(data);
if (callback) {
callback.call(this, JSON.parse(this.memoryStorage[this._dbName]).todos);
}
} else {
// Generate an ID
updateData.id = uniqueID++;
todos.push(updateData);
this.memoryStorage[this._dbName] = JSON.stringify(data);
if (callback) {
callback.call(this, [updateData]);
}
}
}
/**
* Will remove an item from the Store based on its ID
*
* @param {number} id The ID of the item you want to remove
* @param {function} callback The callback to fire after saving
*/
remove(id, callback){
const data = JSON.parse(this.memoryStorage[this._dbName]);
let todos = data.todos;
const len = todos.length;
for (let i = 0; i < todos.length; i++) {
if (todos[i].id == id) {
todos.splice(i, 1);
break;
}
}
this.memoryStorage[this._dbName] = JSON.stringify(data);
if (callback) {
callback.call(this, JSON.parse(this.memoryStorage[this._dbName]).todos);
}
}
/**
* Will drop all storage and start fresh
*
* @param {function} callback The callback to fire after dropping the data
*/
drop(callback){
this.memoryStorage[this._dbName] = JSON.stringify({todos: []});
if (callback) {
callback.call(this, JSON.parse(this.memoryStorage[this._dbName]).todos);
}
}
}
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