How to control a CasperJS automation script from a

问题:

I have an automation script in CasperJS controlling a PhantomJS headless browser that logs into a site, enters data over multiple pages / form.

From the same physical server, I have PHP/MySQL serving up a CRM client website. On the CRM site, I want to have the ability to:

1. Trigger the remote CasperJS script to go browse a remote site and log in and fill out forms
2. Read the output stream (i.e. "Page 1 complete, page 2 complete" ,etc)
3. Display the status updates to the client user as the CasperJS script is executing

I am thinking that socket.io is the ticket here. But, I am I going about this all wrong? I am trying to avoid having a selenium server running. I checked this answer on SO but I am not looking for screenshots, I'm looking for the console output from CasperJS to be displayed in the client website.

回答1:

I had a similar task once and concocted a solution using local Express.js server with Socket.io.

You would launch this server with node.js and then pass tasks to it from PHP by making POST requests to http://127.0.0.1:9000 (I used the excellent Requests library).

Here's a simplified version of my script:

var fs = require("fs");
var express = require("express");
var app = express();
var server = require("http").Server(app);
var io = require("socket.io")(server);
var iosocket;

// Express middleware to get variables from POST request
var bodyParser = require('body-parser');
app.use(bodyParser.urlencoded({ extended: true })); 


// Create websocket connection
io.on("connection", function(socket){

    console.log('io.js connection');
    iosocket = socket;
});

// Receieve task from external POST request
app.post("/scrape", function(req, res){

    res.send("Request accepted");

    // Url to parse
    var url = req.body.url;

    // Variable to collect data from scraper
    var data = [];

    // Launch scraping script
    var spawn = require('child_process').spawn,
        child = spawn('/path/to/casperjs', ['/path/to/scrape/script.js', url]);

    console.log("Spawned parser");

    // Receieve data from script
    child.stdout.on('data', function (data) {

        var message = data.toString();

        data.push(message);

        // Send data to the web client
        iosocket.emit("message", message);
    });

    // On error
    child.stderr.on('data', function (data) {
        console.log('stderr: ' + data.toString());
    });

    // On scraper exit
    child.on('close', function (code) {
        console.log("Scraper exited with code: " + code);
        // 
        // Put data into a file or a database, for example
        // 
        fs.writeFileSync("path/to/file/results_" + (new Date()).getTime() + ".json", JSON.stringify(data));
    });      

});

// Bind app to port @ localhost
server.listen(9000, "127.0.0.1");

Solution with CasperJS/Phantomjs server is interesting, however people pointed out that it leaks memory, which probably won't be happening if you run short-lived CasperJS scripts.