从Node.js中的请求中提取POST参数

Question

I am trying to get parameters from a POST in the variable postData by using the request by - ( i used this because it was suggested here - How do I get the post request with express js? )

and here - How to retrieve POST query parameters?

var express = require('express');
var app = express();
var fs = require('fs');
var json = require('json');
app.use(express.json());       // to support JSON-encoded bodies
app.use(express.urlencoded()); // to support URL-encoded bodies

app.post('/shrib/:file/:data',function(req,res){
    var fileName = req.params.file;
    var data = req.params.data;
    req.on('data',function(data){ body+=data; } );
    req.on('end' ,function(){
        var postData = qs.parse(body);
        var writeStream = fs.createWriteStream(fileName);
        var postData = req.body.text;
        if(postData)
            console.log(postData);
        else    
            console.log("failed miserably");
        res.write(200);
        res.end();
    });
});
app.get('/shrib/:file',function(req,res){   
    var fileName = req.params.file;
    if(fileName != ''){
        var readStream = fs.createReadStream(fileName);
        var content;
        readStream.on('data',function(chunk){
            content+=chunk.toString();
            console.log(content);
        });
        readStream.on('end',function(){
            res.writeHead(200,{"Content-Type":"text/html"});
            res.write("<form id=\"submitForm\" method=\"POST\">");
            res.write("<textarea id=\"text\"rows=50 cols=50 >");
            console.log(content);
            if(content)
                res.write(content.toString());
            res.write("</textarea>");
            res.write("<input type=\"submit\" value=\"submit\" />");
            res.write("</form>");
            res.write("<script>");
            res.write("var windowLocation = location.href;");
            res.write("document.getElementById(\"submitForm\").action=windowLocation + \'/data\';");
            res.write("</script>");
            res.end();
        });
    }else{
        res.writeHead(200);
        res.write("invalid/empty path name"); 
    }
});
app.listen(8080);

and got this error -

Error: Most middleware (like json) is no longer bundled with Express and must be installed separately. Please see https://github.com/senchalabs/connect#middleware.
    at Function.Object.defineProperty.get (/home/unknown/public_html/node/node_modules/express/lib/express.js:89:13)

I was using body parser before which i read in some solutions here and it gave me the same error middleware missing, i installed it globally then also got the same error and after that i read about json , so i installed it globally using

npm install -g json

did not work, then too. then i tried adding the dependancies -

{
  "name": "express_shrib.js",
  "version": "0.0.1",
  "description": "Creating Shrib Using Express",
  "main": "express_shrib.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "https://github.com/iamdeadman/nodejs.git"
  },
  "author": "",
  "license": "ISC",
  "bugs": {
    "url": "https://github.com/iamdeadman/nodejs/issues"
  },
  "homepage": "https://github.com/iamdeadman/nodejs",
  "dependencies": {
    "express": ">= 1.2.0",
    "json": ">= 9.0.0"
  }
}

and ran npm install still the same error -

Error: Most middleware (like json) is no longer bundled with Express and must be installed separately. Please see https://github.com/senchalabs/connect#middleware.
    at Function.Object.defineProperty.get (/home/unknown/public_html/node/node_modules/express/lib/express.js:89:13)

Edit** - Code with the new body-parser module

var express = require('express');
var app = express();
var fs = require('fs');
var bodyParser = require('body-parser');
app.use(bodyParser());
app.post('/shrib/:file/:data',function(req,res){
    var fileName = req.params.file;
    var data = req.params.data;
    req.on('data',function(data){ body+=data; } );
    req.on('end' ,function(){
        var postData = req.body;
        var writeStream = fs.createWriteStream(fileName);
        if(postData)
            console.log(postData);
        else{   
            console.log("failed miserably");
            console.log(postData);
        }
        res.writeHead(200);
        res.end();
    });
});
app.get('/shrib/:file',function(req,res){   
    var fileName = req.params.file;
    if(fileName != ''){
        var readStream = fs.createReadStream(fileName);
        var content;
        readStream.on('data',function(chunk){
            content+=chunk.toString();
            console.log(content);
        });
        readStream.on('end',function(){
            res.writeHead(200,{"Content-Type":"text/html"});
            res.write("<form id=\"submitForm\" method=\"POST\">");
            res.write("<textarea id=\"text\"rows=50 cols=50 >");
            console.log(content);
            if(content)
                res.write(content.toString());
            res.write("</textarea>");
            res.write("<input type=\"submit\" value=\"submit\" />");
            res.write("</form>");
            res.write("<script>");
            res.write("var windowLocation = location.href;");
            res.write("document.getElementById(\"submitForm\").action=windowLocation + \'/data\';");
            res.write("</script>");
            res.end();
        });
    }else{
        res.writeHead(200);
        res.write("invalid/empty path name"); 
    }
});
app.listen(8080);

and here i get

{}

in the console which means that the body object is empty for some reason.

Answer 1

With Express 4, the body parsing middleware (like other previously built-in middleware) was extracted out into the 'body-parser' module. However, this new module only handles JSON and urlencoded form submissions, not multipart.

If you need multipart support, you'd need to use something like connect-busboy or multer or connect-multiparty (connect-multiparty is essentially the old Express bodyParser middleware).

EDIT: Also, the name attribute is missing for the textarea input field. This is required, otherwise the field will not be sent with the form.

Answer 2

When using express 4 use body-parser middleware to get parameters. Multipart has issue that it creates loads of temp files. So its better to avoid it whenever possible and use upload services directly.

app.use(function (req, res, next) {
        var urlParser = require('url');
        var url = urlParser.parse(req.url, true);
        if (url.pathname == "/rest/file/upload") {
            next();
        } else {
            var contentType = req.header("content-type");
            if (contentType && contentType.indexOf("application/json") != -1) {
                bodyParser.json({limit: 1024 * 1024 * 10})(req, res, next);
            } else {
                bodyParser.urlencoded({ extended: true, limit: 1024 * 1024 * 10})(req, res, next);
            }
        }
    });

then just get your request parameter as :

console.log(req.param("parameter-name"));