CODEWITHSUNDEEP
javascriptphantomjs
Eldar
Eldar

Reputation: 5237

page.evaluate - how to write to file inside of it?

How I can write result inside page.evaluate to file? This code works fine when putting results into console.log, but writing to file, using ts raising errors.

page.evaluate(function(url) {
        function getHTTPResponseString(url, callback) {
            try {
                var xhr = new XMLHttpRequest();
                xhr.onload = function() {
                    if (this.status == 200) {
                        var u8 = new Uint8Array(this.response), bs = [];
                        for (var i = u8.length - 1; i >= 0; --i) {
                            bs[i] = String.fromCharCode(u8[i]);
                        }
                        callback(bs.join(''));
                    } else {
                        console.log(this.statusText);
                        callback('');
                    }
                }
                xhr.open('GET', url, true);
                xhr.responseType = 'arraybuffer';
                xhr.send();
            } catch (e) {
                console.log(JSON.stringify(e));
            }
        }
        getHTTPResponseString(url, function(result) {
            console.log(result);
        })
    }, url);

Upvotes: 2

Views: 968

Answers (2)

Eldar
Eldar

Reputation: 5237

I found that it's possible to pass data by calling window.callphantom() inside of page.evaluate and next handle passed data by page.onCallback event:

page.onCallback = function(result) {
    var fs = require('fs');
    fs.write('file.out', result, 'w');
};


getHTTPResponseString(url, function(result) {
     console.log(result);
     window.callPhantom(result);
})

Upvotes: 4

Vaviloff
Vaviloff

Reputation: 16856

One can't write to file from inside of page.evaluate() function, as it's working in browser context where there is no access to local filesystem.

However you can return data you want to analyze and then deal with it on PhantomJS side.

var error = page.evaluate(function(url) {
    // ...
    return xhr.statusText;
  }, url);

fs.write(filename, error, 'a');

Perhaps a simpler way to log data is to subscribe to console messages from browser context with page.onConsoleMessage function:

page.onConsoleMessage = function (msg) {
    console.log("Browser console: " + msg);    
};

There's also a page.onError function to listen for errors that happen inside page.evaluate: http://phantomjs.org/api/webpage/handler/on-error.html

Upvotes: 1

Related Questions