indexedDB bootstrap angularjs之 MVC DOMO (应用示例)

2019-11-20 09:39:59

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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：

复制代码代码如下:

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(); //promisegetDb(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();//promisegetDb(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();//promisevar 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 = $q.defer();//promisegetDb(myDB.db).then(function(db) {var transaction = db.transaction(storeName, 'readonly');var store = transaction.objectStore(storeName);var result = store.openCursor();var results = [];result.onsuccess = function (event) {var cursor = event.target.result;if (cursor) {results.push(cursor.value);cursor.continue();} else {d.resolve(results);}};result.onerror = function (e) {d.reject();};});return d.promise;};return _self;});}(window, window.angular)); myUsers.js (应用的controller层脚本)'use strict';angular.module('myApp', ['db']).controller("userCtrl", function($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！

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