indexedDB bootstrap angularjs之 MVC DOMO (应用示例)
作者:gabin
1、indexedDB(Model) -- 前端浏览器对象型数据库,一般我们后台用的数据库都是关系型数据库。那么indexeddb有什么特点呢:
首先,从字义上它是索引型数据库,从实际使用中可以体现为,它需要为表创建索引才可以根据某个字段来获取数据,而在关系型数据库中,这明显是不需要的。
其次,我不需要行列数据的转化,我只需要通过类似于数组的处理方式:
objectStore.push(data);
有点像是把一个json对象塞入数据库,是不是很暴力?
2、bootstrap(View) -- bootstrap,老实说,我不是很熟悉这个东西,毕竟我是后端java开发出身。以我的理解,这就是一个以响应式布局为特点的前端框架,至于说比较特别的,应该就是它比较流行吧?!老实说,我这边只用到css,而我也认为,后现代的前端开发,将不会需要bootstrap的js部分,毕竟那还是以jquery为主的方式。
3、angularjs(Controller) -- 必须承认这个东西东西的诞生完全颠覆了我对前端开发的看法,以前和现在我们依然困在前后端无法彻底分离的窘境中,但我认为如果后期,前端人员普遍采用应用式的angularjs脚本来开发(还有一些类似的框架),我们将不再需要让后端开发工程师套用诸多的前端样式、结构等等。
这么说,很多后端人员可能还是不能体会得到,举个例子:angularjs的使用方式有点像是jsp、freemarker等渲染html的东西,只是一个在客户端渲染,另一个在后台服务器渲染。我们只要改变数据的结构和属性,对应渲染出来的页面就会不同,angularjs就是让我们更加关注数据的变化,而非DOM的变化,就是说:你将很少会去写到$("btnSave").click(function() {});这样需要获取到html节点的脚本代码,可以说,这完全脱离了jQuery的范畴。所以这可以算是一个跨时代的改变?
接下来就上例子吧(最终必须运行到服务器上):
user.html
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width"/> <!-- 新 Bootstrap 核心 CSS 文件 --> <link rel="stylesheet" href="//cdn.bootcss.com/bootstrap/3.3.5/css/bootstrap.min.css"> <script src="http://apps.bdimg.com/libs/angular.js/1.4.6/angular.min.js"></script> </head> <body ng-app="myApp" ng-controller="userCtrl"> <div class="container"> <h3>Users</h3> <table class="table table-striped"> <thead> <tr> <th>Edit</th> <th>First Name</th> <th>Last Name</th> </tr> </thead> <tbody> <tr ng-repeat="one in users"> <td> <button class="btn" ng-click="editUser(one)"> <span class="glyphicon glyphicon-pencil"></span> Edit </button> <button class="btn" ng-click="deleteUser(one.id)"> <span class="glyphicon glyphicon-remove"></span> Delete </button> </td> <td>{{ one.fName }}</td> <td>{{ one.lName }}</td> <td>{{ one.telephone }}</td> </tr> </tbody> </table> <hr> <button class="btn btn-success" ng-click="editUser()"> <span class="glyphicon glyphicon-user"></span> Create New User </button> <hr> <h3 ng-show="edit">Create New User:</h3> <h3 ng-hide="edit">Edit User:</h3> <form class="form-horizontal"> <div class="form-group"> <label class="col-sm-2 control-label">First Name:</label> <div class="col-sm-10"> <input type="text" ng-model="user.fName" ng-disabled="!edit" placeholder="First Name"> </div> </div> <div class="form-group"> <label class="col-sm-2 control-label">Last Name:</label> <div class="col-sm-10"> <input type="text" ng-model="user.lName" ng-disabled="!edit" placeholder="Last Name"> </div> </div> <div class="form-group"> <label class="col-sm-2 control-label">telephone:</label> <div class="col-sm-10"> <input type="tel" ng-model="user.telephone" placeholder="telephone"> </div> </div> </form> <hr> <button class="btn btn-success" ng-click="saveCustomer()"> <span class="glyphicon glyphicon-save"></span> Save Changes </button> </div> <script src="jdbc.js?v=2323"></script> <script src="myUsers.js"></script> </body> </html>
jdbc.js(作为一个数据访问的模块,可供各个应用加载调用)
'use strict'; !(function (w, angular) { angular.module('db', []).service('jdbc', function ($http, $q) { var _self = this; var myDB = { name: 'roma', version: 1, db: null, schema: { 2: function(db) { // 初始化 用户 var customer = db.createObjectStore('customer', {keyPath:"id", autoIncrement: true}); customer.createIndex("customer_fName_index", "fName", {unique: true}); } } }; // 用于处理跟回调函数相反的方式,当defer调用resolve方法之后,就会触发defer.promise.then(callback)传入的callback方法,并且resolve可以传入任意的变量 /** * * function test() { * var defer = $q.defer(); * setTimeout(2000, function() { * defer.resolve("hello"); * }); * return defer.promise; * } * * test().then(function(say) { * console.log(say); * }); * * 2秒之后将会打印出"hello" * * @type {Deferred|*} */ var defer = $q.defer(); _self.onload = function(cb) { return defer.promise.then(cb); }; var getDb = function(db) { var d = $q.defer(); if (db) { d.resolve(db); } // 打开数据库 var result = window.indexedDB.open(myDB.name); result.onerror = function (e) { console.log("Open DB Error!"); d.reject("error"); }; // 正确打开 result.onsuccess = function (e) { var db = e.target.result; myDB.db = db; d.resolve(db); }; return d.promise; }; _self.openDB = function (name, version, success, upgrade) { var d = $q.defer(); var name = name || myDB.name; var version = version || myDB.version; // 打开数据库 var result = window.indexedDB.open(name, version); // 错误 result.onerror = function (e) { console.log("Open DB Error!"); d.reject(e); }; // 正确打开 result.onsuccess = function (e) { myDB.db = e.target.result; if (success) success(myDB.db); d.resolve(e); }; // 数据库版本变更 result.onupgradeneeded = function (e) { myDB.db = e.target.result; if (upgrade) upgrade(myDB.db); d.resolve("upgradeneeded"); }; return d.promise; }; var schema = function (schema) { angular.forEach(schema, function(upgrade, version, o) { _self.openDB(myDB.name, version, function() { defer.resolve(); }, function(db) { upgrade(db); }); }) }; schema(myDB.schema); _self.get = function (storeName, key) { var d = $q.defer(); //promise getDb(myDB.db).then(function (db) { var transaction = db.transaction(storeName, 'readonly'); var store = transaction.objectStore(storeName); var result = store.get(key); result.onsuccess = function (e) { _self.result = e.target.result; d.resolve(); }; result.onerror = function (e) { d.reject(); }; }); return d.promise; }; _self.find = function (storeName, key, value) { var d = $q.defer();//promise getDb(myDB.db).then(function(db) { var transaction = db.transaction(storeName, 'readonly'); var store = transaction.objectStore(storeName); var keyRange = IDBKeyRange.only(value); var result = store.index(key).openCursor(keyRange, "next"); var results = []; result.onsuccess = function(event) { var cursor = event.target.result; if (cursor) { results.push(cursor.value); cursor.continue(); } else { d.resolve(results); } }; result.onerror = function (e) { d.reject(); }; }); return d.promise; }; _self.put = function (storeName, value) { var d = $q.defer(); var db = myDB.db || getDb(); var transaction = db.transaction(storeName, 'readwrite'); var store = transaction.objectStore(storeName); if (value !== null && value !== undefined) { store.put(value); d.resolve(); } else { d.reject(); } return d.promise; }; _self.remove = function (storeName, value) { var d = $q.defer();//promise var db = myDB.db || getDb(); var transaction = db.transaction(storeName, 'readwrite'); var store = transaction.objectStore(storeName); var result = store.delete(value); result.onsuccess = function (e) { d.resolve(); }; result.onerror = function (e) { d.reject(); }; return d.promise; }; _self.findAll = function (storeName) { var d = $q.defer();//promise getDb(myDB.db).then(function(db) { var transaction = db.transaction(storeName, 'readonly'); var store = transaction.objectStore(storeName); var result = store.openCursor(); var results = []; result.onsuccess = function (event) { var cursor = event.target.result; if (cursor) { results.push(cursor.value); cursor.continue(); } else { d.resolve(results); } }; result.onerror = function (e) { d.reject(); }; }); return d.promise; }; return _self; }); }(window, window.angular)); myUsers.js (应用的controller层脚本) 'use strict'; angular.module('myApp', ['db']).controller("userCtrl", function($scope, $http, jdbc) { // 刷新数据结构,angularjs的双向绑定会自动帮我们渲染界面 function reload() { jdbc.findAll("customer").then(function(response) { if (!response) { $http.get("data.json").success(function(response) { $scope.users = response; }); return; } $scope.users = response; }); } // 数据结构完成之后刷新界面 jdbc.onload(reload); $scope.edit = true; var _user = $scope.user = {}; $scope.editUser = function(user) { if (user) { _user.id = user.id; _user.fName = user.fName; _user.lName = user.lName; _user.telephone = user.telephone; } else { _user.fName = ""; _user.lName = ""; _user.telephone = ""; _user.id = ""; } }; $scope.deleteUser = function(id) { // 从数据库删除记录之后刷新表格数据 jdbc.remove("customer", id).then(reload); }; $scope.saveCustomer = function() { // 从数据库添加或更新记录之后刷新表格数据 jdbc.put("customer", _user).then(reload); }; jdbc.find("customer", "customer_fName_index", "林").then(function(data) { console.log(data); }); }); data.json(当indexedDB无法正常获取的时候用来显示数据用) [ { "id": 1, "fName": "林", "lName": "嘉斌", "telephone": "13514087953" }, { "id": 2, "fName": "陈", "lName": "晓", "telephone": "13509890786" } ]
以上所述是小编给大家带来的indexedDB bootstrap angularjs之 MVC DOMO (应用示例)的全部叙述,希望对大家有所帮助!