Node.js 教程第五篇——request

摘要：一个第三方的模块，可用于发起或请求，可理解成服务端的请求。可用于代简单的服务器代理，用法和类似。在使用前需要先安装请求多参数设置请求支持和实现表单上传。常用多参数设置流

一个第三方的模块，可用于发起 http 或 https 请求，可理解成服务端的 ajax 请求。可用于代简单的服务器代理，用法和 ajax 类似。

在使用前需要先安装 npm install request --save

request.get("https://cnodejs.org/api/v1/topics?page=1&limit=10", (error, response, body) => {
    console.log(body)
})
//or
request("https://cnodejs.org/api/v1/topics?page=1&limit=10", (error, response, body) => {
    console.log(body)
})

exports.get = function(url, options) {
    options = options || {};
    var httpOptions = {
        url: url,
        method: "get",
        timeout: options.timeout || 10000,
        headers: options.headers || default_post_headers,
        proxy: options.proxy || "",
        agentOptions: agentOptions,
        params: options.params || {}
    }
    if(options.userAgent){
        httpOptions.headers = {
            "User-Agent": userAgents[options.userAgent],
        }
    }

    try{
        request.get(httpOptions, function(err, res, body) {
            if (err) {
                options.callback({status: false, error: err})
            } else {
                options.callback({status: res.statusCode == 200, error: res, data: body})
            }
        }).on("error", logger.error);
    } catch(err){
        console.log("http error");
    }
}

request支持application/x-www-form-urlencoded和multipart/form-data实现表单上传。

request.post("http://service.com/upload", {form:{key:"value"}})
// or
request.post("http://service.com/upload").form({key:"value"})
// or
request.post({url:"http://service.com/upload", form: {key:"value"}}, function(err,httpResponse,body){ /* ... */ })

var formData = {
  // Pass a simple key-value pair
  my_field: "my_value",
  // Pass data via Buffers
  my_buffer: new Buffer([1, 2, 3]),
  // Pass data via Streams
  my_file: fs.createReadStream(__dirname + "/unicycle.jpg"),
  // Pass multiple values /w an Array
  attachments: [
    fs.createReadStream(__dirname + "/attachment1.jpg"),
    fs.createReadStream(__dirname + "/attachment2.jpg")
  ],
  // Pass optional meta-data with an "options" object with style: {value: DATA, options: OPTIONS}
  // Use case: for some types of streams, you"ll need to provide "file"-related information manually.
  // See the `form-data` README for more information about options: https://github.com/form-data/form-data
  custom_file: {
    value:  fs.createReadStream("/dev/urandom"),
    options: {
      filename: "topsecret.jpg",
      contentType: "image/jpeg"
    }
  }
};
request.post({url:"http://service.com/upload", formData: formData}, function optionalCallback(err, httpResponse, body) {
  if (err) {
    return console.error("upload failed:", err);
  }
  console.log("Upload successful!  Server responded with:", body);
});

exports.form_post = function(url, postdata, options) {
    // console.log(`${moment().format()} HttpFormPost: ${url}`)
    return new Promise((resolve, reject) => {
        options = options || {};
        var httpOptions = {
            url: url,
            form: postdata,
            method: "post",
            timeout: options.timeout || 3000,
            headers: options.headers || default_post_headers,
            proxy: options.proxy || "",
            agentOptions: agentOptions
        };
        request(httpOptions, function(err, res, body) {
            if (err) {
                reject(err);
            } else {
                if (res.statusCode == 200) {
                    resolve(body);
                } else {
                    reject(res.statusCode);
                }
            }
        }).on("error", logger.error);
    });
};

request("http://img.zcool.cn/community/018d4e554967920000019ae9df1533.jpg@900w_1l_2o_100sh.jpg").pipe(fs.createWriteStream("test.png"))
request("https://cnodejs.org/api/v1/topics?page=1&limit=10").pipe(fs.createWriteStream("cnodejs.json"))