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How to pass data between Django module/app functions without using database in asynchronous web service

I've got a web service under development that uses Django and Django Channels to send data across websockets to a remote application. The arrangement is asynchronous and I pass information between the 2 by sending JSON formatted commands across websockets and then receive replies back on the same websocket.
The problem I'm having is figuring out how to get the replies back to a Javascript call from a Django template that invokes a Python function to initiate the JSON websocket question. Since the command question & data reply happen in different Django areas and the originating Javascript/Python functions call does not have a blocking statement, the Q&A are basically disconnected and I can't figure out how to get the results back to the browser.
Right now, my idea is to use Django global variables or store the results in the Django models. I can get either to work, but I beleive the Django global variables would not scale beyond multiple workers from runserver or if the system was eventually spread across multiple servers.
But since the reply data is for different purposes (for example, list of users waiting in a remote lobby, current debugging levels in remote system, etc), the database option seems unworkable because the reply data is varying structure. That, plus the replies are temporal and don't need to be permanently stored in the database.
Here's some code showing the flow. I'm open to different implementation recommendations or a direct answer to the question of how to share information between the 2 Django functions.
In the template, for testing, I just have a button defined like this:
<button id="request_lobby">Request Lobby</button>
With a Javascript function. This function is incomplete as I've yet to do anything about the response (because I can't figure out how to connect it):
$("#request_lobby").click(function(){
$.ajax({
type: "POST",
url: "{% url 'test_panel_function' %}",
data: { csrfmiddlewaretoken: '{{ csrf_token }}', button:"request_lobby" },
success: function(response){
}
});
});
This is the Django/Python function in views.py . The return channel for the remote application is pre-stored in the database as srv.server_channel when the websocket is initially connected (not shown):
#login_required
def test_panel_function(request):
button = request.POST.get('button', '')
if button == "request_lobby" :
srv = Server.objects.get(server_key="1234567890")
json_res = []
json_res.append({"COMMAND": "REQUESTLOBBY"})
message = ({
"text": json.dumps(json_res)
})
Channel(srv.server_channel).send(message)
return HttpResponse(button)
Later, the remote application sends the reply back on the websocket and it's received by a Django Channels demultiplexer in routing.py :
class RemoteDemultiplexer(WebsocketDemultiplexer):
mapping = {
"gLOBBY" : "gLOBBY.receive",
}
http_user = True
slight_ordering = True
channel_routing = [
route_class(RemoteDemultiplexer, path=r"^/server/(?P<server_key>[a-zA-Z0-9]+)$"),
route("gLOBBY.receive" , command_LOBBY),
]
And the consumer.py :
#channel_session
def command_LOBBY(message):
skey = message.channel_session["server_key"]
for x in range(int(message.content['LOBBY'])):
logger.info("USERNAME: " + message.content[str(x)]["USERNAME"])
logger.info("LOBBY_ID: " + message.content[str(x)]["LOBBY_ID"])
logger.info("OWNER_ID: " + message.content[str(x)]["IPADDRESS"])
logger.info("DATETIME: " + message.content[str(x)]["DATETIME"])
So I need to figure out how to get the reply data in command_LOBBY to the Javascript/Python function call in test_panel_function
Current ideas, both of which seem bad and why I think I need to ask this question for SO:
1) Use Django global variables:
Define in globals.py:
global_async_result = {}
And include in all relevant Django modules:
from test.globals import global_async_result
In order to make this work, when I originate the initial command in test_panel_function to send to the remote application (the REQUESTLOBBY), I'll include a randomized key in the JSON message which would be round-tripped back to command_LOBBY and then global_async_result dictionary would be indexed with the randomized key.
In test_panel_function , I would wait in a loop checking a flag for the results to be ready in global_async_result and then retrieve them from the randomized key and delete the entry in global_async_result.
Then the reply can be given back to the Javascript in the Django template.
That all makes sense to me, but uses global variables (bad), and seems that it wouldn't scale as the web service is spread across servers.
2) Store replies in Django mySQL model.py table
I could create a table in models.py to hold the replies temporarily. Since Django doesn't allow for dynamic or temporary table creations on the fly, this would have to be a pre-defined table.
Also, because the websocket replies would be different formats for different questions, I could not know in advance all the fields ever needed and even if so, most fields would not be used for differing replies.
My workable idea here is to create the reply tables using a field for the randomized key (which is still routed back round-trip through the websocket) and another large field to just store the JSON reply entirely.
Then in test_panel_function which is blocking in a loop waiting for the results, pull the JSON from the table, delete the row, and decode. Then the reply can be given back to the Javascript in the Django template.
3) Use Django signals
Django has a signals capability, but the response function doesn't seem to be able to be embedded (like inside test_panel_function) and there seems to be no wait() function available for an arbitrary function to just wait for the signal. If this were available, it would be very helpful

How do i save model data when creating a Backbone driven theme in Wordpress?

Ok so im messing around with Backbone for the first time. I think I've pretty much covered all the basics of frontend logic, but i have never really been any good at backend logic and coding.
I'm working with wordpress and creating a theme using backbone. My understanding is as long as i set up a template page that has the correct containers that my backbone code will render views in, the fact that it's a wordpress theme instead of it's own app shouldn't really change anything on the frontend side.
I'm at the stage where i want to save a model so that i can fetch it in my routes to link to my view to render.
I'm unsure about the whole process of saving data. I know i need to give the model attribute 'urlRoot' a string but i don't know what that string should be, and what happens after that.
Can someone explain the whole process, especially in terms of how to do it with Wordpress. (i did stumble upon the WP REST API plugin that i think helps, although i don't exactly know how.)
EDIT
OK so in the end i presume my problem was something to do with authentication when trying to access the database as the textResponse was just returning the entire HTML for the current page i was on, probably due to the fact it wasn't getting through to the database and being redirected back to the page.
After googling around for a while i came across this. Rather than reinventing the wheel I installed this plugin and followed the setup instructions and low and behold it worked pretty much out of the box. If your trying to build a Backbone theme i suggest using the WP-API Client JS plugin with the WP REST API plugin. Seems to cover everything.

How to expose a WordPress blog's content through an API?
WP REST API seems like a good way to start. There are a lot of options and it exposes everything you need.
Note that it is named WordPress REST API (Version 2) in the wordpress.org plugin directory.
You can test that the plugin works by navigating to:
http://www.example.com/wp-json/wp/v2/
It should output all the information on the blog as a big JSON dump.
You can also test that it works for other endpoints, like post:
http://www.example.com/wp-json/wp/v2/posts
There's a Backbone plugin for the WP REST API that works out of the box.
How to communicate with the API?
This is a simple example using Backbone without any plugin. If you want to know how to use the plugin, see the documentation for it.
Since it offers a lot of arguments that can be passed in the URL, I made a small collection and an example of how it could be used.
var API_ROOT = '/wp-json/wp/v2/',
DEFAULT_API_ARGS = ['context' /* etc. */ ];
var WordPressCollection = Backbone.Collection.extend({
constructor: function(models, options) {
options = options || {};
this.apiArgs = _.union(DEFAULT_API_ARGS, this.apiArgs, options.apiArgs);
this.args = _.extend({}, this.args, this.getApiArgs(options));
WordPressCollection.__super__.constructor.apply(this, arguments);
},
getApiArgs: function(obj) {
return _.pick(obj, this.apiArgs);
},
fetch: function(options) {
options = options || {};
options.data = _.extend({}, this.args, this.getApiArgs(options), options.data);
return WordPressCollection.__super__.fetch.call(this, options);
},
});
And to use it:
var CommentCollection = WordPressCollection.extend({
url: API_ROOT + 'comments',
// all the arguments to look for in the passed options
apiArgs: ['page', 'per_page', 'post' /* etc. */ ],
});
var myPostComments = new CommentCollection(null, {
post: 23 // id
});
console.log(myPostComments.url());
myPostComments.fetch({ page: 2 });
The fetch should make a GET request to:
/wp-json/wp/v2/comments?post=23&page=2
And from that point, the WP REST API plugin takes control. It returns a new JSON encoded array of comment objects in the body of the response.
It should looks something like this:
Backbone automatically parses the JSON received, so you don't need to worry about that and you just have to go on and use it:
myPostComments.each(function(comment) {
console.log(comment.get('author_name'));
});
Then, saving a new comment is a matter of calling:
// check the doc for the comment object details
myPostComments.create({
post: 23,
content: "my new comment",
/* etc. */
});
And this would make a POST request to /wp-json/wp/v2/comments.

Returning a value from Javascript to C++

I have tried searching for answers but nothing seems to have worked thus far. I have a GUI application that I am building for WinAPI, and I want to use a Javascript function that will check on the Youtube API for certain videos and such, but I haven't been able to call on any of the functions in Javascript.
The farthest I've seemed to be able to get is to add an HTML file to the external dependencies(.rc), and then the Javasctipt file from there, but I can't seem to be able to just call on the function.
Is there a better way of doing this than trying to interop Javasctipt and C++, or am I just going about calling the function wrong?
/* Pseudocode */
Javascript.js
void callAPI()
{
... Call on the Youtube API, check if there are new videos i'd like...
return boolIfUpdatedOrNot;
}
Source.cpp
... Some includes and such ...
WindowProc and such
{
Case Something:
... Call on the Javascript function ...
... Do something if returned true ...
... or return 0 if false ...
}

Do you really need Javascript to get the videos? If you don't need to authenticate, there is a simple data API that will return up to 50 videos specified by certain parameters such as playlist ID or search term. You can get the results in JSON or XML by using a simple HTTP GET request. I'm not familiar with doing this in WINAPI, but you could probably start here: http://msdn.microsoft.com/en-us/library/aa384110(v=vs.85).aspx
A simple example that will get the 10 most recent uploads from a channel with CHANNEL_NAME:
https://gdata.youtube.com/feeds/api/users/CHANNEL_NAME/uploads?max-results=10
To get this in JSON:
https://gdata.youtube.com/feeds/api/users/CHANNEL_NAME/uploads?v=2&max-results=10&alt=jsonc
You have to use the second version of the API to get it in JSON (hence the v=2 parameter). XML will probably be easier to parse in native C++ though, depending on whether you want to work with another library.
For more: https://gdata.youtube.com/demo/index.html

Postponing search until template load

I want to make a request to a server to get a bunch of news articles based off of what the user clicks on (recent, trending, etc). I'd like to be able to load the page first and show a loading bar while I wait for the response from the API. What I have, and although it works and returns the JSON data I need, will wait until the response comes back from the server before loading anything. This is all it is so far:
What I want to achieve is the following: Load up an empty array of objects, and then make API calls to articles incrementally (let's say grab all the articles from this hour, then last hour, then the hour before, and so on) and whenever I retrive articles populate the view (I'm assuming I can just inject them into a controller somehow) however I'm getting lost on the Emberisms on how to add to that array of objects. I think I need to make an ArrayController and then create a model in said array, then call a function to add to it, but as I said I'm lost as to how to add items into that controller on the fly
App = Ember.Application.create();
App.Router.map(function() {
this.resource('today');
});
App.TodayRoute = Ember.Route.extend({
model: function() {
return $.getJSON('/today');
}
});
To elaborate a bit on the reasoning for my question - I'm confused on how to approach this with ember. I'm familiar on how to do something like this using jquery, however I'm trying to learn the framework and am having a little bit of trouble originally knowing what the division of labor is between the two. I know the actual AJAX requests should be jquery, but I want to do as much as possible in Ember. If this however is something that should be done by jquery though, then that is fine as well!

The getJSON method looks to have a callback function on success you could use, something like this maybe?
App.TodayRoute = Ember.Route.extend({
model: function() {
$.getJSON('/today', function(data) {
// hide loading here
/ data is the JSON returned
});
}
});
Check out this link http://api.jquery.com/jQuery.getJSON/

I found the solution - and like everything with ember, it was very simple. I used some blank fixture data, then defined my controller as below.
App.ArticleRoute = Ember.Route.extend({
model: function() {
return App.Article.find();
}
})
Then upon pageload I call a method focused around
App.Article.createRecord({
// Attributes, pulling from the returned JSON
})
Simple! :)

Sending extra, non-model data in a save request with backbone.js?

I'm looking for a solution for dealing with an issue of state between models using backbone.js.
I have a time tracking app where a user can start/stops jobs and it will record the time the job was worked on. I have a job model which holds the job's data and whether it is currently 'on'.
Only 1 job can be worked on at a time. So if a user starts a job the currently running job must be stopped. I'm wondering what the best solution to do this is. I mean I could simply toggle each job's 'on' parameter accordingly and then call save on each but that results in 2 requests to the server each with a complete representation of each job.
Ideally it would be great if I could piggyback additional data in the save request similarly to how it's possible to send extra data in a fetch request. I only need to send the id of the currently running job and since this really is unrelated to the model it needs to be sent alongside the model, not part of it.
Is there a good way to do this? I guess I could find a way to maintain a reference to the current job server side if need be :\

when you call a save function, the first parameter is an object of the data that's going to be saved. Instead of just calling model.save(), create an object that has the model data and your extra stuff.
inside of your method that fires off the save:
...
var data = this.model.toJSON();
data.extras = { myParam : someData };
this.model.save(data, {success: function( model, response ) {
console.log('hooray it saved: ', model, response);
});
...