20.发送http请求服务 ($http)

转自：https://www.cnblogs.com/best/tag/Angular/  

服务从代码直接与服务器进行交互，底层是通过实现，与中http服务从AngularJS代码直接与Web服务器进行交互，底层是通过AJAX实现，与jQuery中.ajax类似

通过$http封装后的方法：

delete(url,[config]) 发送谓词为delete的异步请求

get(url,[config]) 发送谓词为get的异步请求

head(url,[config])  发送谓词为head的异步请求

jsonp(url,[config]) 发送通过jsonp实现跨域的同步请求的请求

post(url,data,[config]) 发送谓词为post的异步请求

put(url,data[config]) 发送谓词为put的异步请求
基本用法：
$http({method: 'GET', url: '/someUrl'}).
success(function(data, status, headers, config) {
}).
error(function(data, status, headers, config) {
});

详细的配置如下：

这里使用NodeJS+Express作为后台服务，完成一个简单的汽车管理功能：

cars.js

var express = require('express');
var router = express.Router();
var _= require('lodash');

var cars=[];
cars.push({id:201701,name:"BMW",price:190,speed:"210km/h",color:"白色"});
cars.push({id:201702,name:"BYD",price:25,speed:"160km/h",color:"红色"});
cars.push({id:201703,name:"Benz",price:300,speed:"215km/h",color:"蓝色"});
cars.push({id:201704,name:"Honda",price:190,speed:"170km/h",color:"黑色"});
cars.push({id:201705,name:"QQ",price:130,speed:"210km/h",color:"白色"});

/* Get */
/*获得所有汽车*/
/*url /cars/*/
router.get('/', function(req, res, next) {
    res.json(cars);
});

/*Get*/
/*获得汽车通过id*/
/*url：/cars/:id  */
router.get('/:id', function(req, res, next) {
     //从路径中映射参数，转换成数字
      var id=parseInt(req.params.id);
      var car=_.find(cars,{id:id});
      res.json(car);
});

/*Post*/
/*添加汽车*/
/*url：/cars/car  */
router.post('/car', function(req, res, next) {
      console.log("收到请求");
      var car=req.body;  //从请求正文中获得json对象
      car.id=_.last(cars).id+1;  //将编号修改为最后一辆车的编号+1
      cars.push(car);  //将汽车对象添加到集合中
      res.json(car);  //将添加成功的车以json的形式返回
});

/*Put*/
/*修改汽车*/
/*url：/cars/car  */
router.put('/car', function(req, res, next) {
      var car=req.body;  //从请求正文中获得json对象
      console.log(req.body);
      var index=_.findIndex(cars,{id:parseInt(car.id)});  //根据id获得车在集合中的下标
      
      cars[index]=car;  //替换原对象
      //res.json(car);  //将修改后的车以json的形式返回
      res.send({status:"success", message:"更新成功!"});  
});

/*Delete*/
/*删除汽车*/
/*url：/cars/:id  */
router.delete('/id/:id', function(req, res, next) {
      //获得url中的编号参数
      var id=parseInt(req.params.id);
      var index=_.findIndex(cars,{id:id});  //根据id获得车在集合中的下标
      cars.splice(index,1);   //在cars数组中删除下标从index开始的1条数据
      res.json(cars);  
});

module.exports = router;

app.js

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var index = require('./routes/index');
var users = require('./routes/users');
var pdts = require('./routes/product');
var task = require('./routes/task');
var cars = require('./routes/cars');

var app = express();

//指定视图引擎为ejs
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');

// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.all('*', function(req, res, next) { 
    res.header("Access-Control-Allow-Origin", "*");  
    res.header("Access-Control-Allow-Headers", "content-type");  
    res.header("Access-Control-Allow-Methods","PUT,POST,GET,DELETE,OPTIONS");  
    res.header("X-Powered-By",' 3.2.1')  
    res.header("Content-Type", "application/json;charset=utf-8");  
    next();  
});  

app.use('/', index);
app.use('/users', users);
app.use('/pdt', pdts);
app.use("/task",task);
app.use("/cars",cars);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;

www

#!/usr/bin/env node

/**
 * 依赖模块，导入
 */

var app = require('../app');
var debug = require('debug')('nodejsexpress:server');
var http = require('http');

/**
 * 从上下文环境中获得监听端口，如果空则3000
 */

var port = normalizePort(process.env.PORT || '3000');
app.set('port', port);

/**
 * 创建Web服务器
 */

var server = http.createServer(app);

/**
 * 开始监听
 */

server.listen(port);
server.on('error', onError);  //指定发生错误时的事件
server.on('listening', onListening);  //当监听成功时的回调

/**
 * 规范化端口
 */

function normalizePort(val) {
  var port = parseInt(val, 10);

  if (isNaN(port)) {
    // named pipe
    return val;
  }

  if (port >= 0) {
    // port number
    return port;
  }

  return false;
}

/**
 *错误事件监听
 */

function onError(error) {
  if (error.syscall !== 'listen') {
    throw error;
  }

  var bind = typeof port === 'string'
    ? 'Pipe ' + port
    : 'Port ' + port;

  //错误处理
  switch (error.code) {
    case 'EACCES':
      console.error(bind + ' requires elevated privileges');
      process.exit(1);  //结束程序
      break;
    case 'EADDRINUSE':
      console.error(bind + ' is already in use');
      process.exit(1);
      break;
    default:
      throw error;
  }
}

/**
 * 当用户访问服务器成功时的回调
 */

function onListening() {
  var addr = server.address();
  var bind = typeof addr === 'string'
    ? 'pipe ' + addr
    : 'port ' + addr.port;
  debug('Listening on ' + bind);
}

示例代码：

<!DOCTYPE html>
<!--指定angular管理的范围-->
<html ng-app="carApp">

    <head>
        <meta charset="UTF-8">
        <title>服务</title>
        <style>
            * {
                margin: 0;
                padding: 0;
                font-family: microsoft yahei;
                font-size: 14px;
            }
            
            body {
                padding-top: 20px;
            }
            
            .main {
                 90%;
                margin: 0 auto;
                border: 1px solid #777;
                padding: 20px;
            }
            
            .main .title {
                font-size: 20px;
                font-weight: normal;
                border-bottom: 1px solid #ccc;
                margin-bottom: 15px;
                padding-bottom: 5px;
                color: blue;
            }
            
            .main .title span {
                display: inline-block;
                font-size: 20px;
                background: blue;
                color: #fff;
                padding: 0 8px;
                background: blue;
            }
            
            a {
                color: blue;
                text-decoration: none;
            }
            
            a:hover {
                color: orangered;
            }
            
            .tab td,
            .tab,
            .tab th {
                border: 1px solid #777;
                border-collapse: collapse;
            }
            
            .tab td,
            .tab th {
                line-height: 26px;
                height: 26px;
                padding-left: 5px;
            }
            
            .abtn {
                display: inline-block;
                height: 20px;
                line-height: 20px;
                background: blue;
                color: #fff;
                padding: 0 5px;
            }
            
            .btn {
                height: 20px;
                line-height: 20px;
                background: blue;
                color: #fff;
                padding: 0 8px;
                border: 0;
            }
            
            .abtn:hover,
            .btn:hover {
                background: orangered;
                color: #fff;
            }
            
            p {
                padding: 5px 0;
            }
            
            fieldset {
                margin-top: 10px;
                border: 1px solid #ccc;
                padding: 5px 10px;
            }
            
            fieldset legend {
                margin-left: 10px;
                font-size: 16px;
            }
        </style>
    </head>

    <body>
        <!--指定控制器的作用范围-->
        <form ng-controller="CarController" class="main">
            <h2 class="title"><span>汽车管理</span></h2>
            <table border="1" width="100%" class="tab">
                <tr>
                    <th>序列</th>
                    <th>编号</th>
                    <th>名称</th>
                    <th>价格</th>
                    <th>颜色</th>
                    <th>速度</th>
                    <th>操作</th>
                </tr>
                <tr ng-repeat="c in cars">
                    <td>{{$index+1}}</td>
                    <td>{{c.id}}</td>
                    <td>{{c.name}}</td>
                    <td>{{c.price}}</td>
                    <td>{{c.color}}</td>
                    <td>{{c.speed}}</td>
                    <td>
                        <a href="#" ng-click="del(c.id)">删除</a>
                        <a href="#" ng-click="edit(c)">编辑</a>
                    </td>
                </tr>
            </table>
            <fieldset>
                <legend>汽车详细</legend>
                <p>
                    <label for="id">编号</label>
                    <input ng-model="car.id" id="id" ng-readonly="true" />
                </p>
                <p>
                    <label for="name">名称</label>
                    <input ng-model="car.name" id="name" />
                </p>
                <p>
                    <label for="price">价格</label>
                    <input ng-model="car.price" id="price" />
                </p>
                <p>
                    <label for="color">颜色</label>
                    <input ng-model="car.color" id="color" />
                </p>
                <p>
                    <label for="color">速度</label>
                    <input ng-model="car.speed" id="speed" />
                </p>
                <button ng-click="save()" class="btn">保存</button>
                <button ng-click="clear()" class="btn">清空</button>
            </fieldset>
        </form>

        <!--引入angularjs框架-->
        <script src="js/angular146/angular.min.js" type="text/javascript" charset="utf-8"></script>
        <script type="text/javascript">
            //定义模块，指定依赖项为空
            var carApp = angular.module("carApp", []);

            //定义控制器，指定控制器的名称，$scope是全局对象
            carApp.controller("CarController", ['$scope', '$http', function($scope, $http) {
                $scope.cars = [];
                $scope.save = function() {
                    $http({
                        url:"http://127.0.0.1:3000/cars/car",
                        data:$scope.car,
                        method: $scope.car.id?"PUT":"POST"
                        })
                        .success(function(data, status, headers, config) {
                            if($scope.car.id){
                               alert("修改成功");
                             }else{
                                 $scope.cars.push(data);
                             }
                        })
                        .error(function(data, status, headers, config) {
                            alert(status);
                        });
                }
                
                $scope.edit=function(c){
                    $scope.car=c;
                }
                $scope.clear=function(){
                    $scope.car={};
                }
            
                $http.get("http://127.0.0.1:3000/cars")
                    .success(function(data, status, headers, config) {
                        $scope.cars = data;
                    })
                    .error(function(data, status, headers, config) {
                        alert(status);
                    });

                $scope.del = function(id) {
                    $http.delete("http://127.0.0.1:3000/cars/id/" + id)
                        .success(function(data, status, headers, config) {
                            $scope.cars = data;
                        })
                        .error(function(data, status, headers, config) {
                            alert(status);
                        });
                }
            }]);
        </script>
    </body>

</html>

运行结果：

问题：如果后台服务不是Restful，不接收application/json的参数，则需要修改。Angular的post和put请求Content-Type: application/json默认情况下，jQuery传输数据使用Content-Type: x-www-form-urlencodedand和类似于"foo=bar&baz=moe"的序列，然而AngularJS，传输数据使用Content-Type: application/json和{ "foo": "bar", "baz": "moe" }这样的json序列。请求时修改请求头部内容：

headers: { 'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8' }

$httpParamSerializerJQLike 序列化参数，这个服务需要单独依赖。

示例：

结果：