I have been trying to replicate typeracer which is an online platform to increase typing speed and also I am a beginner in django.
I have three models named, Players(is an abstraction of the default user model and holds info of all the registered users), Posts(contains all the passages that are available to practice typing), UserPost(contains id of all the posts which are used and the id of Account which used it).
My question is how can I implement multiple games. For example, suppose A and B are playing together on one game, and at the same time C,and D want to start a new game identified by another game url, also again at the same time E, F, G, H want to start another game identified by different game url to compete just amongst themselves at the same time.
If I am not able to make myself clear, please check
this and go on to race your friends, and just click on invite people to join! You will get what I mean.
How to do implement this.? Any ideas?
I think you will have to create a new model named games and make a slug field called url, it can act as pk too.
Related
I am new to Django and want to know deeper about the concept of signals.
I know how it works but really don't understand when should one really use it.
From the doc it says 'They’re especially useful when many pieces of code may be interested in the same events.'
What are some real applications that use signals for its advantage?
e.x. I'm trying to make a phone verification after user signup. Because it can be integrated inside the single app and the event that interested for the signal is only this 'verify' function, therefore I don't really need signal. I can just pass the information from one view to the other, rather than using pre_save signal from the registration.
I'm sorry if my question is kind of basic. But I really want to know some insight what is the real application, in which many codes interested in one particular event and what are some trade off in my application.
Thanks!!
Often signals is used when you need to do some database-specific low-level stuff. For example, if you use ElasticSearch for better searching documents on your site, you may want to automatically update search indexes, when new document is created or old one was edited.
Also you may have some complex logic of managing database objects. For example, you may need some specific logic of deleting object. For example, when user is deleted, you may want change all the links to his profile by some placeholder, or when new message is created or other action is performed by user, you want to update "last visited" field in user's profile and there's no direct relation between this action and updating the profile.
But when you're just implementing business-logic as in your example with verification, you don't need to use signals, because you don't need any universal logic related to deleting/creating/editing any object: you have a certain object with which you work and can do stuff directly.
TL;DR - How do I maintain a list of users in each room so that I can send that data to the front-end to display a list of participants in this room.
I'm designing a collaborative web application that uses django-channels for websocket communication between the browser and the server. A room can be joined by more than one user and every user should be aware of every other user in the room. How would I go about achieving this using django-channels (v2)?
I already went through the documentation and a few example projects available online but none of them have added a similar functionality. I also know about django-channels-presence but the project doesn't seem to be actively maintained so I didn't really bother looking into examples using that.
Here's what I've come up with so far:
- For every room, I create an object in the database and those objects can keep track of the users that are in the room. So for e.g in the WS consumer's connect() method I could do a get_or_create_room() call and room.add_participant(self.user_name) (or fetch this from the scope) and in the disconnect() method I could remove myself from the room. The problem with this, however, is that I might end up creating race conditions? I think? Also since I'm fetching objects from the ORM, I have to make sure that every time, before using this object I have to re-fetch it from the DB because it can (and will) become outdated quickly. This doesn't seem ideal at all.
- Another way I can think of is attaching data to self.channel_layer in the consumer where I can do something like setattr(self.channel_layer, f'users_{room_id}', {}) and maintain this dictionary for every user entering and leaving. This again doesn't sound very safe and I didn't see anyone using this so I'm unsure.
Any help regarding this would be appreciated. I'd also like to be able to see how existing applications do this if anyone can point me to one?
so in short there is no way to ask channels for the members in a group so you either need to:
Write some info into the db, with a timestamp so that you can see if it is old
or
send a message every (n seconds) over the channel group (machine readable item with the users id) then your consumers (or frontend) can maintain a list of users and filter this to those that have a resent timestamp. The disadvantage here is it might take a few seconds to detect all the users in a chat room.
You can't do anything like writing to a dict or global object since this is not shared over all the consumers.
I am currently building a simple site where users can login and write comments. Its somewhat similar to a forum but difference is that users will see image/an article and they get to comments on things based what they see. In addition they also get to rate what they see in 5 star scale or thumbs up thumbs down.
I have build this site using django now I want to add another application where I can control who gets to see the 5 star scale vs. thumbs up and thumbs down scale after they log in to the site. I want to randomly pic users as they come into the site and make sure half of the user population see one scale vs the other.
Here are my questions:
How should the random selection take place? Does django has inbuilt function or functionality to do such randomization?
Can someone provide simple example?
Here is my thought process on building such thing:
We create a model where we keep track of the userid, experimentGroup(5 Star or Thumbs up), Time
Then in each template we check if which group the user is in and based on that we adjust the users view?
I am new django so it would be great is someone provides a simple example so I can built upon that. After doing google search I found out a very heavy django application but I would rather user something simple that I can understand and control with my limited knowledge.
You can get objects in a random order by using (from django docs):
<YOUR_MODEL>.objects.order_by('?')
The exact queryset depends of how you define your models
Also django provide a template filter to random a list of items (see django docs)
Last, if above is not enough you can use python random module
Maybe this isn't the correct place to ask, but I asked this question on Joomla forums and did not get any answers. If someone can help me or at least point me in the right direction, I would really appreciate.
My question is: In a Joomla 2.5 website, I want to create two different kinds of forms for registering users. Maybe "registering" isn't the correct term. I want to create something like a very simple database which will hold records for two kinds of users:
- one which will be interested in working in projects, so in this case the form will have more fields and specific details to fill
- one which will be interested only in receiving newsletters from the site, and in this case only basic contact information will be required.
I did some research and found an extension named AcyMailing which can handle the newsletters for example, but I need to have all my potential users registered as Joomla users. I would like to avoid that if possible. If not, how can I differentiate the two kinds of users on registration, so the visitor can choose which option he wants and in this case, add more information to the registering process, if possible.
I'm not very experienced with Joomla, but since the site in question is already implemented using it, I don't have much choice.
Thanks in advance!
Chronoforms. Most definitely here would be a great use for their AWESOME free component. Your forms can work as registration forms (should you desire that); or can also just be free standing forms that log the information filled out on them to your database which you can later use however you would like (i.e. compiling a mailing list or something of that sort).
The form wizard makes it almost bullet proof, then you can have a form for 1 type of user to fill out, and a form for a different user build different ways.
That will get you the data - in order to mass mail those people you'll need a way to extract their emails out of the database (or find an email component that will let you email based on certain fields in the database or what have you); but it's totally possible and would be easily done I think with 1 simple mySQL query on your database table created by chronoforms.
In terms of something that will solve your issue quickly and get you the info you're looking for in two separate ways - chronoforms will do that exactly.
I'm going to be honest: this is a question I asked on the Django-Users mailinglist last week. Since I didn't get any replies there yet, I'm reposting it on Stack Overflow in the hope that it gets more attention here.
I want to create an app that makes it easy to do user friendly,
multiple / mass file upload in your own apps. With user friendly I
mean upload like Gmail, Flickr, ... where the user can select multiple
files at once in the browse file dialog. The files are then uploaded
sequentially or in parallel and a nice overview of the selected files
is shown on the page with a progress bar next to them. A 'Cancel'
upload button is also a possible option.
All that niceness is usually solved by using a Flash object. Complete
solutions are out there for the client side, like: SWFUpload
http://swfupload.org/ , FancyUpload http://digitarald.de/project/fancyupload/
, YUI 2 Uploader http://developer.yahoo.com/yui/uploader/ and probably
many more.
Ofcourse the trick is getting those solutions integrated in your
project. Especially in a framework like Django, double so if you want
it to be reusable.
So, I have a few ideas, but I'm neither an expert on Django nor on
Flash based upload solutions. I'll share my ideas here in the hope of
getting some feedback from more knowledgeable and experienced people.
(Or even just some 'I want this too!' replies :) )
You will notice that I make a few assumptions: this is to keep the
(initial) scope of the application under control. These assumptions
are of course debatable:
All right, my idea's so far:
If you want to mass upload multiple files, you are going to have a
model to contain each file in. I.e. the model will contain one
FileField or one ImageField.
Models with multiple (but ofcourse finite) amount of FileFields/
ImageFields are not in need of easy mass uploading imho: if you have a
model with 100 FileFields you are doing something wrong :)
Examples where you would want my envisioned kind of mass upload:
An app that has just one model 'Brochure' with a file field, a
title field (dynamically created from the filename) and a date_added
field.
A photo gallery app with models 'Gallery' and 'Photo'. You pick a
Gallery to add pictures to, upload the pictures and new Photo objects
are created and foreign keys set to the chosen Gallery.
It would be nice to be able to configure or extend the app for your
favorite Flash upload solution. We can pick one of the three above as
a default, but implement the app so that people can easily add
additional implementations (kinda like Django can use multiple
databases). Let it be agnostic to any particular client side solution.
If we need to pick one to start with, maybe pick the one with the
smallest footprint? (smallest download of client side stuff)
The Flash based solutions asynchronously (and either sequentially or
in parallel) POST the files to a url. I suggest that url to be local
to our generic app (so it's the same for every app where you use our
app in). That url will go to a view provided by our generic app.
The view will do the following: create a new model instance, add the
file, OPTIONALLY DO EXTRA STUFF and save the instance.
DO EXTRA STUFF is code that the app that uses our app wants to run.
It doesn't have to provide any extra code, if the model has just a
FileField/ImageField the standard view code will do the job.
But most app will want to do extra stuff I think, like filling in
the other fields: title, date_added, foreignkeys, manytomany, ...
I have not yet thought about a mechanism for DO EXTRA STUFF. Just
wrapping the generic app view came to mind, but that is not developer
friendly, since you would have to write your own url pattern and your
own view. Then you have to tell the Flash solutions to use a new url
etc...
I think something like signals could be used here?
Forms/Admin: I'm still very sketchy on how all this could best be
integrated in the Admin or generic Django forms/widgets/...
(and this is were my lack of Django experience shows):
In the case of the Gallery/Photo app:
You could provide a mass Photo upload widget on the Gallery detail
form. But what if the Gallery instance is not saved yet? The file
upload view won't be able to set the foreignkeys on the Photo
instances. I see that the auth app, when you create a user, first asks
for username and password and only then provides you with a bigger
form to fill in emailadres, pick roles etc. We could do something like
that.
In the case of an app with just one model:
How do you provide a form in the Django admin to do your mass
upload? You can't do it with the detail form of your model, that's
just for one model instance.
There's probably dozens more questions that need to be answered before
I can even start on this app. So please tell me what you think! Give
me input! What do you like? What not? What would you do different? Is
this idea solid? Where is it not?
Thank you!
I just released a simple app for this about a month ago: django-uploadify.
It's basically a Django template tag that acts as a wrapper for the very nifty Uploadify (requires jQuery). Using it is as simple as adding this to your template...
{% load uploadify_tags }{% multi_file_upload ‘/upload/complete/url/’ %}
The tag will fire events (1 per file) on both the client-side and server-side (Django signal) to indicate when an incoming file has been received.
For example, assuming you have a model 'Media' that handles all user-uploaded files...
def upload_received_handler(sender, data, **kwargs):
if file:
new_media = Media.objects.create(
file = data,
new_upload = True,
)
new_media.save()
upload_recieved.connect(upload_received_handler, dispatch_uid=‘whatever.upload_received’)
Check out the wiki for info on how to set it up and create the signal handlers (client/server).
About your conceptual implementation from above, here's a few points of consideration:
Having the app automatically create the "File Model" instance probably isn't as robust as people may already have their own models they're working with
If you want to implement any type of security or authentication, you need an open system and less of an 'auto-create' type
I really think signals/events are the way to handle this, and also handle the 'DO OTHER STUFF' part of what you mentioned.
My conclusion was that multi-upload can never really be a form widget in the sense that Django implements form widgets. 1 file will most likely be represented by 1 model instance (with some exceptions), which means that we end up with a situation where 1 widget can represent N model instances. However Django is setup so that a widget represents 1 value for 1 field in 1 instance. It just doesn't fit for the majority of use-cases to have it as a widget (hence why I went the template tag route).