module.js
var Promise = require('bluebird');
var XMLHttpRequest = require('xhr2');
function fetchdata(id) {
var url = 'http://www.youtube.com/watch?v=' + id;
return new Promise(function (fulfill, reject) {
var xhr = new XMLHttpRequest();
xhr.open('GET', url);
xhr.onload = function() {
var jsonStr;
try {
fulfill(xhr.response);
} catch (e) {
reject(jsonStr);
}
};
xhr.onerror = function(e) {
reject(e);
};
xhr.send('');
});
}
module.exports = {
getdata: function (videoID) {
return new Promise(function (fulfill, reject) {
if (!videoID) {
reject(new Error('Unable to get video id.'));
return;
}
fetchdata(videoID).then(
function (d) {
console.log( d);
}
);
});
}
};
index.js
var parser = require('./module.js');
parser.getdata("ZI4tRn4dOGg", function (data) {
console.log(data);
}
)
I tried to get youtube view page source code with xmlhttprequest.
BUT above code does not finish. I guess it is waiting for something.
Is problem from bluebird? or xhr2? and why does this code never finish?
Your xhr instance had a memory leak, might be a problem with the library, last publish was a year ago. Bluebird was ok. You can fix the hangup by using node-fetch and dropping in this replacement for fetchdata
const fetch = require('node-fetch')
function fetchdata(id) {
var url = 'http://www.youtube.com/watch?v=' + id;
return fetch(url).then(res => res.text())
}
Related
controller on localhost:8000
const fs = require("fs");
exports.install = function () {
ROUTE("GET /", indexPage);
};
function indexPage() {
var self = this;
console.log(" In GET ROUTE");
RESTBuilder.GET("http://127.0.0.1:8500/getFile/").stream(function (
err,
response
) {
if (err) {
console.log(err);
return;
}
var writer = fs.createWriteStream("./public/testBuilder.txt");
// console.log("Writing to file");
response.pipe(writer);
self.json({ thankyou: "ok" });
});
}
controller on localhost:8500
exports.install = function () {
ROUTE("GET /getFile/", test);
};
function test() {
var self = this;
console.log("#################");
console.log(self.body);
self.file("~trimSail/restBuilder.txt");
// });
}
above code works in totaljs 3 but failing in total4.
sending a file in response to RestBuilder.GET and streaming the response to file.
error response.pipe is not a function.
First of all, please clean your code.
Total.js guidelines https://docs.totaljs.com/welcome/67b47001ty51c/
Optimized for Total.js:
const Fs = require('fs');
exports.install = function () {
ROUTE('GET /', index);
};
function index() {
var $ = this;
console.log('In GET ROUTE');
RESTBuilder.GET('http://127.0.0.1:8500/getFile/').stream($.successful(function(response) {
var writer = Fs.createWriteStream('./public/testBuilder.txt');
response.stream.pipe(writer);
$.json({ thankyou: 'ok' });
}));
}
Can someone please explain to me why i'm getting this warning Warning: a promise was created in a handler but was not returned from it when I execute the following code:
cache['deviceSlave'].getBySystemId(systemId).then(function(slavesMapping) {
// do other stuff
}).catch(function(err) {
// throw error
});
Here is the rest of the code:
var Promise = require('bluebird');
var _ = require('lodash');
var Redis = require('ioredis');
var config = require('/libs/config');
var redis = new Redis({
port: config.get('redis:port'),
host: config.get('redis:host'),
password: config.get('redis:key'),
db: 0
});
var self = this;
module.exports.getBySystemId = function(systemId) {
return new Promise(function(resolve, reject) {
var systemIds = [systemId];
self.getBySystemIds(systemIds).then(function(result) {
return resolve(_.values(result)[0]);
}).catch(function(err) {
return reject(err);
});
});
};
module.exports.getBySystemIds = function(systemIds) {
return new Promise(function(resolve, reject) {
var pipeline = redis.pipeline();
_.each(systemIds, function(systemId) {
var cacheKey = 'device_slaves:' + systemId.replace(/:/g, '');
// get through pipeline for fast retrieval
pipeline.get(cacheKey);
});
pipeline.exec(function(err, results) {
if (err) return reject(err);
else {
var mapping = {};
_.each(systemIds, function(systemId, index) {
var key = systemId;
var slaves = JSON.parse(results[index][1]);
mapping[key] = slaves;
});
return resolve(mapping);
}
});
});
};
I'm using the following libraries: ioredis & bluebird.
The code executes fine and everything just works good! I just dont like the fact I get an warning which I can not solve!
Bluebird is warning you against explicit construction here. Here is how you should write the above code:
module.exports.getBySystemId = function(systemId) {
return self.getBySystemIds([systemId]).then(result => _.values(result)[0]);
};
There is no need to wrap the promise - as promises chain :)
I have updated my server solution to work with MVC 5 and latest version of signalr and have two major issues:
I have overriden the OnConnected function and it is not being invoked.
Messages to client are not being received , calls from the client are being received
this is the client code
define(['jquery', 'toastr', 'Q'], function($, toastr, Q) {
var incidentHubProxy;
var deferred = Q.defer();
var connect = function() {
var connection = $.hubConnection(localStorage.url);
$.connection.hub.logging = true;
incidentHubProxy = connection.createHubProxy('notification');
connection.start()
.done(function () {
toastr.success('Now connected, connection ID=' + connection.id);
setInterval(function () {
incidentHubProxy.invoke('ping');
}, 3000);
deferred.resolve();
})
.fail(function () { toastr.error('Could not connect'); });
incidentHubProxy.on('notify', function (data) {
toastr.info(data.topic);
toastr.info(data.data);
});
incidentHubProxy.on('pong', function (data) {
toastr.info('got pong');
});
return deferred.promise;
};
var joinGroup = function (groupName) {
incidentHubProxy.invoke('joinGroup', groupName);
};
return {
connect: connect,
joinGroup: joinGroup
};
});
i have updated the code to that and still dont work
define(['jquery', 'toastr', 'Q'], function($, toastr, Q) {
var incidentHubProxy;
var deferred = Q.defer();
var connect = function() {
var connection = $.hubConnection(localStorage.url);
$.connection.hub.logging = true;
incidentHubProxy = connection.createHubProxy('notification');
incidentHubProxy.notify = function(data) {
toastr.info(data.topic);
toastr.info(data.data);
};
incidentHubProxy.pong = function(data) {
toastr.info('got pong');
};
connection.start()
.done(function () {
toastr.success('Now connected, connection ID=' + connection.id);
setInterval(function () {
incidentHubProxy.invoke('ping');
}, 3000);
deferred.resolve();
})
.fail(function () { toastr.error('Could not connect'); });
return deferred.promise;
};
var joinGroup = function (groupName) {
incidentHubProxy.invoke('joinGroup', groupName);
};
return {
connect: connect,
joinGroup: joinGroup
};
});
I'm wrapping a simple jQuery promise with RSVP and noticed that when I cause an error on purpose the failure callback is never invoked. I assume it's because when you use vanilla jQuery and the callback throws an error, the returned promise will not be moved to failed state (the opposite of the spec).
If I need to use jQuery $.ajax but I want to get true resolve/reject callbacks with RSVP what (if anything) can I do to the example below?
var peoplePromise = new Ember.RSVP.Promise(function(resolve, reject) {
$.getJSON('/api/people/', resolve).fail(reject).error(reject);
});
var catPromise = new Ember.RSVP.Promise(function(resolve, reject) {
$.getJSON('/api/cats/', resolve).fail(reject).error(reject);
});
Ember.RSVP.all([peoplePromise, catPromise]).then(function(things) {
things[0].forEach(function(hash) {
var thing = App.Person.create(hash);
Ember.run(self.people, self.people.pushObject, thing);
});
things[1].forEach(function(hash) {
var wat = hash.toJSON(); //this blows up
var thing = App.Person.create(hash);
Ember.run(self.people, self.people.pushObject, thing);
});
}, function(value) {
alert(value.status + ": promise failed " + value.responseText);
});
Example here: http://www.youtube.com/watch?feature=player_detailpage&v=g5CSaK3HqVA#t=1080
var ajaxPromise = function(url, options){
return Ember.RSVP.Promise(function(resolve, reject) {
var options = options || {};
options.success = function(data){
resolve(data);
};
options.error = function(jqXHR, status, error){
reject([jqXHR, status, error]);
};
$.ajax(url, options);
});
};
var peoplePromise = ajaxPromise('/api/people/',{
dataType: "json"
});
var catPromise = ajaxPromise('/api/cats/',{
dataType: "json"
});
Ember.RSVP.all([peoplePromise, catPromise]).then(function(things) {
things[0].forEach(function(hash) {
var thing = App.Person.create(hash);
Ember.run(self.people, self.people.pushObject, thing);
});
things[1].forEach(function(hash) {
var wat = hash.toJSON(); //this blows up
var thing = App.Person.create(hash);
Ember.run(self.people, self.people.pushObject, thing);
});
}, function(args) {
var jqXHR = args[0];
alert(jqXHR.status + ": promise failed " + jqXHR.responseText);
});
http://emberjs.jsbin.com/aREDaJa/1/
As I want to implement a chat in AngularJS, I want to use the promise/deferred principle. My ChatService looks like the following:
factory('ChatService', ['$q', '$resource', function($q, $resource) {
var Service = {};
var connected = false;
var connection;
var chatResource = $resource('/guitars/chat/:action', {action: '#action'}, {
requestChatroomId: {
params: {
action: 'requestChatroomId'
},
method: 'GET'
},
sendMessage: {
params: {
action: 'sendMessage'
},
method: 'POST'
}
});
Service.connect = function(cb) {
var deferred = $q.defer();
chatResource.requestChatroomId(function(data) {
connection = new WebSocket('ws://127.0.0.1:8888/realtime/' + data.chatroomId);
connection.onerror = function (error) {
deferred.reject('Error: ' + error);
};
connection.onmessage = function (e) {
cb.call(this, e.data);
deferred.notify(e.data);
};
connected = true;
});
return deferred.promise;
};
Service.sendMessage = function(msg) {
if(!connected) {
return;
}
chatResource.sendMessage({message: msg});
}
return Service;
}])
My controller using the ChatService is:
app.controller('ChatCtrl', ['$scope', 'ChatService', function($scope, ChatService) {
$scope.chat = {};
$scope.chat.conversation = [];
var $messages = ChatService.connect(function(message) {
$scope.$apply(function() {
// #1 THIS FIRES EVERY TIME
$scope.chat.conversation.push(message);
});
});
$messages.then(function(message) {
console.log('Finishes - should never occur!')
}, function(error) {
console.log('An error occurred!')
}, function(message) {
// #2 THIS FIRES ONLY IF THERE IS AN INTERACTION WITH THE ANGULAR MODEL
console.log(message);
});
$scope.sendMessage = function(event) {
ChatService.sendMessage($scope.chat.message);
$scope.chat.message = '';
};
}]);
If something is pushed from the server, callback #1 is called, but callback #2 wont be called until there is some interaction with the angular-model, i.e. start writing something in the input-Box. What is the reason for that behaviour?
Okay the reason was, that AngularJS was not aware of a change. So I injected the $rootScope to my ChatService:
factory('ChatService', ['$q', '$resource', '$rootScope', function($q, $resource, $rootScope) {
and in connection.onmessage I called $apply() on $rootScope:
connection.onmessage = function (e) {
deferred.notify(e.data);
$rootScope.$apply();
};