I am very new to node-webkit. I am using the following code to download a file. How would I go about running the file automatically when the file has finished?
var https = require('https');
var fs = require('fs');
var file = fs.createWriteStream("update_setup.exe");
var request = https.get(url + "/appdata/update_setup.exe", function (response) {
response.pipe(file);
});
Just use the writable stream's close event and spawn a child process. The event will fire once the response has completed piping to the stream.
var https = require('https');
var fs = require('fs');
var exec = require('child_process').exec;
var file = fs.createWriteStream('update_setup.exe');
var request = https.get(path, function(res) {
res.pipe(file);
});
file.on('close', function() {
exec('update_setup.exe', function(err, stdout, stderr) {
// output from starting
});
});
Related
I have code where I can download the file form URL but I need the file to have the same name as per original file name where it was uploaded
const downloadImage = () => {
var http = require("http"),
Stream = require("stream").Transform,
fs = require("fs");
var url = "http://cutt.ly/0JCQfSh";
http
.request(url, function (response) {
var data = new Stream();
response.on("data", function (chunk) {
data.push(chunk);
});
response.on("end", function () {
fs.writeFileSync('image.png', data.read());
});
})
.end();
};
Open the URL Link on the browser and check the file name its Asset0.png. I want to download a file with the same name
This question is about a crawler in node.js.
A start_url is given where he crawls for URLs, and "pushes" them to a .json-file (output.json).
At the moment, he runs the request function only with the start_url, and saves the collected URLs in output.json. I want that he uses the saved URLs by replacing the start_url with the first collected URL and collect links again ... and so on ...
var fs = require('fs');
var request = require('request');
var cheerio = require('cheerio');
var start_url = ["http://stackoverflow.com/"]
var req = function(url){
request(url, function(error, response, html){
var $ = cheerio.load(html);
var data = [];
$("a").each(function() {
var link = $(this);
var exurls = {exurl: new Array(link.attr("href"))}
data.push(exurls);
// Queue "exurls" for "start_url" and call the same function with the new URL (endless loop)
// save to "output.json" from time to time, so you can stop it anytime
});
fs.writeFile("output.json", JSON.stringify(data, null, 4), function(err){
if(err){
console.log(err);
} else {
console.log("File successfully written!");
}
});
});
}
for (var i = 0; i < start_url.length; i++){
req(start_url[i]);
}
So what you can do is make the function call recursively. The below example should work:
var fs = require('fs');
var request = require('request');
var cheerio = require('cheerio');
var start_url = ["http://stackoverflow.com/"]
var req = function(url){
var count = 0;
request(url, function(error, response, html){
var $ = cheerio.load(html);
$("a").each(function() {
var link = $(this);
var exurls = {exurl: new Array(link.attr("href"))}
start_url.push(exurls);
// Queue "exurls" for "start_url" and call the same function with the new URL (endless loop)
// save to "output.json" from time to time, so you can stop it anytime
});
try {
fs.writeFileSync("output.json");
console.log("File successfully written!");
}catch(err){
console.log(err);
}
++count;
if(start_url.length > count) {
req(start_url[count]);
}
});
}
return req(start_url[0]);
The problem with this is that you are completely rewriting the file each time. If this goes on for awhile you are going to run out of memory. Another option is to create a write stream
var fs = require('fs');
var request = require('request');
var cheerio = require('cheerio');
var start_url = ["http://stackoverflow.com/"]
var wstream = fs.createWriteStream("output.json");
var req = function(url){
request(url, function(error, response, html){
var $ = cheerio.load(html);
$("a").each(function() {
var link = $(this);
var exurls = {exurl: new Array(link.attr("href"))}
start_url.push(exurls);
// Queue "exurls" for "start_url" and call the same function with the new URL (endless loop)
// save to "output.json" from time to time, so you can stop it anytime
wstream.write('"'+ exurls + '",');
});
start_url.shift();
if(start_url.length > 0) {
return req(start_url[0]);
}
wstream.end();
});
}
req(start_url[0]);
Edit: switched to a basic queue so combat memory problems
I am trying to download a mp3 file from the remote url using node js. For that I am using the following code. But It doesn't work (File that downloading having 0 bytes only its not playing once it downloaded).
var http = require('http');
var fs = require('fs');
var url = "http://play.publicradio.org/rivet/d/podcast/marketplace/segments/2015/09/28/mp_20150928_seg_01_64.mp3";
var dest = "2.mp3";
var file = fs.createWriteStream(dest);
var request = http.get(url, function(response) {
console.log("res "+response);
response.pipe(file);
file.on('finish', function() {
console.log("File download Completed");
});
}).on('error', function(err) { // Handle errors
});
The problem here is that http doesn't follow redirects.
You can use the request npm module that does it by default to avoid handling headers yourself.
var fs = require('fs'),
request = require('request');
request
.get('http://foo.com/bar.mp3')
.on('error', function(err) {
// handle error
})
.pipe(fs.createWriteStream('2.mp3'));
I am using node-webkit to automate some common tasks.
I have an iframe which goes to a site address, then clicks save and I have a file save dialog pop out.
Is there any way I can catch the event to save the file witout requiring an external action (like setting the save folder and clicking on save)?
You may not be able to do it that way, but have you thought about just doing an HTTP GET request from node's http module? That's really the beauty of using node-webkit, you get to use node.js!
var http = require('http');
var fs = require('fs');
var path = require('path');
var saveLocation = path.join(__dirname, "/cache", "file.txt");
//The url we want is: 'www.random.org/integers/file.txt'
var options = {
host: 'www.random.org',
path: '/integers/file.txt'
};
callback = function(response) {
var str = '';
//another chunk of data has been recieved, so append it to `str`
response.on('data', function (chunk) {
str += chunk;
});
//the whole response has been recieved, so we just print it out here
response.on('end', function () {
console.log(str);
fs.writeFile(saveLocation, str, function (err) {
if (err) console.log("Problem Saving File.");
});
});
}
// Send the request.
http.request(options, callback).end();
I have a file called node.js:
var net = require('net');
var crypto = require('crypto');
//sjcl
var sjcl = require('./sjcl');
//retrive fb profile
var loadFb = require('./loadFb.js');
var loadFeed = require('./loadFeed.js');
//read json user file
var fs = require('fs');
var text = fs.readFileSync(__dirname + '/users','utf8');
var HOST = 'localhost';
var PORT = 7000;
net.createServer(function(sock) {
// We have a connection - a socket object
console.log('CONNECTED: ' + sock.remoteAddress +':'+ sock.remotePort);
// Add a 'data' event handler to this instance of socket
sock.on('data', function(data) {
console.log('User request profile of: ' + data);
//var date = (data.toString()).split("***");
//var from = date[1];
loadFb(extendetPath, function(pageData)
{
loadFeed(extendetPath2, function(pageData2)
{
var fs = require('fs');
var profileText = fs.readFileSync('/tmp/profile','utf8');
console.log(profileText);
sock.write(profileText);
});
});
});
// Add a 'close' event handler to this instance of socket
sock.on('close', function(data) {
console.log('CLOSED: ' + sock.remoteAddress +' '+ sock.remotePort);
});
}).listen(PORT);
console.log('Server listening on ' + HOST +':'+ PORT);
function returnKeyFromUser(id)
{
//text
var trovata = false;
var dati = JSON.parse(text);
for(var i=0; i<dati.friendlist.friend.length && trovata==false; i++)
{
var user = (dati.friendlist.friend[i].username).replace("\n","");
var userID = (id).replace("\n","");
if(user==userID)
{
trovata=true;
return ((dati.friendlist.friend[i].publicKey).toString()).replace("\n","");
}
}
if(trovata==false)
return null;
}
There is a small http server that receives a facebook username and what he have to do is retrieve 2 page:
a graphapi with the profile information, and a graphapi with the feed informations of a facebook profile
I copy the other two files:
var https = require('https');
module.exports = function(path, callback) {
var options = {
host: 'graph.facebook.com',
port: 443,
path: (path.toString()).replace("\n",""),
method: 'GET'
};
var req = https.get(options, function(res) {
var pageData = "";
if((path.toString()).indexOf("/")==0 && (path.toString()).indexOf("/GET /`HTTP/")!=0)
//for load only (I hope facebook profile)
{
console.log(options);
res.setEncoding('utf8');
res.on('data', function (chunk) {
pageData += chunk;
});
res.on('end', function()
{
var fs = require('fs');
fs.writeFile("/tmp/profile", pageData, function(err) {
if(err) {
console.log(err);
} else {
console.log("The file was saved!");
}
});
//callback(pageData);
return;
});
}
});
};
3° file
var https = require('https');
module.exports = function(path, callback) {
var options = {
host: 'graph.facebook.com',
port: 443,
path: (path.toString()).replace("\n",""),
method: 'GET'
};
var req = https.get(options, function(res) {
var pageData = "";
if((path.toString()).indexOf("/")==0 && (path.toString()).indexOf("/GET / HTTP/")!=0) //for load only (I hope facebook profile)
{
console.log(options);
res.setEncoding('utf8');
res.on('data', function (chunk) {
pageData += chunk;
});
res.on('end', function()
{
var fs = require('fs');
fs.appendFile('/tmp/profile', "***"+pageData, function (err) {
if (err) throw err;
console.log('It\'s saved!');
});
callback(pageData);
});
}
});
};
I don't know If there is a way to call the two file in the first file node.js but what I done is this: (to call from node.js the fist file, and from the second file call the third)
in node.js file I call the first file loadFb.js with this command:
loadFb(extendetPath, function(pageData)
{
This call saves a file on my tmp profile directory and inside I call the other file loadFeed that appends some text.
After that I have to send the entire information to the client but I have a mistake.
In order the nodejs correctly call loadFb and he write tmp - profile, than he call loadFeed
but before appending the information the node call back to the client only the half of informations that I need.
I'm not a good nodejs programmer, this is a work for my thesis.
Can someone help me?
Let's look at the following code:
res.on('end', function()
{
var fs = require('fs');
fs.appendFile('/tmp/profile', "***"+pageData, function (err) {
if (err) throw err;
console.log('It\'s saved!');
});
callback(pageData);
});
What it does it runs the asynchronous method appendFile and immediately after that calls callback. So when the code in the callback is executed, the file is not updated yet. You need to move the callback(pageData); to the appendFile's callback. And you need to review you code keeping this in mind because I see that the same fix should be made in another file so maybe there are some similar places as well.