Where should validation logic go in this DJANGO project - django

I have an existing python program which verifies coordinates are correct - by that I mean they are in the correct place, not a simple range check.
In my Django project I want someone to be able to send these coordinates in, and use my existing code to verify they are correct before saving them to the model.
My question is, where does this logic go?
Do I put it in the view and reject the HTTP request, if the coordinates are invalid? - this seems simplest to me?
Or does this go in the model somewhere, and I prevent invalid coordinates from being saved to the database?
I'm new to Django, so not sure what is a good practice / idea.
An issue I see with writing a custom validator(?) is these coordinates come in pairs.

Related

Decide which model to retrieve data on Django Rest Framework

I'm trying to build a simple API which should do the following:
A user makes a request on /getContent endpoint, with the geographical coordinates for this user. By content, it means audio files.
Every time they send a request, we should just get a random object from a Model and return the URL field from it, to be consumed by the front end. For this, it can be a random one, it doesn't matter much which one.
Also, we should keep tracking about the requests each user makes. This way, we can check how many requests the user has made, and when they were made.
Every 5 requests or so, the idea is to send the user a customized content based on their location. My idea is to store this content in another model, since it would have many more fields in comparison from the standard content.
Basically, at every request, I'd check if it's time to send a special content. If not, just send the random one. Otherwise, I'd check if the time is appropriate, and the user is within a valid location based on the special content's data in the model. If this validation passes, we send the URL of the special content, otherwise, we just send the random one.
I'm having a hard time figuring out the best way to design this. My initial idea is to have two different models:
Model 1: Standard content. It has some fields to its meta data, such as duration, title and other stuff like this.
Model 2: Custom content. Besides the meta data, it should contain the geographical data, and the datetime range. This will allow the checking to be made if the content should be played or not.
Now it's the part I'm pretty much clueless. How to make it all work together?
QUESTIONS
Maybe storing every single request data from every user, and checking this data might not be very effective. It would require some writing at every request instead of just reading.
Since I'd be using two different models, how can I make the decision to happen in the view? I mean, the final output would be the same, an URL. But I'd have to make the decision process to happen in the view on which model to use.
I appreciate the help!

backend design:What should I store in system-push-message model?

I'am a green hands in web backend and recently I have a problem about designing system-message module in my django project.
Consideration of expansibility, I don't store indexes using ForeignKey or concrete fields of exact object because it's difficult to predict what messages will carry. Then I can only make it in a easy way. I add four fields:receiver_id, time,readflag and content(str). But content is text/html type and it's inflexible to modify in frontend.
Thus I wanner see the common way to solve this problem.
Sincere thanks!

Display uploaded gpx points and lines on map

I want to create simple upload form on my django site where users could upload their gpx files but I want to give them possibility to preview their points and lines on map before they proceed with submiting it.
I have some basic knowledge of working with django forms but I'm not sure how to convert that gpx data and display it on map.
I hope you can tell me at least where to start because I'm completely out of ideas.
Thanks
Well, if you use Django then you could probably extend it with Geodjango which provides you easy and nice way to create geometry fields for your models (points,lines, poligons).
In case you decide to use Geodjango for this purpose then please check my blog post http://ipasic.com/article/uploading-parsing-and-saving-gpx-data-postgis-geodjango/
I've described there process of uploading,parsing and saving gpx file to spatial database (like Postgis).It could help you to get an idea.
I didn't describe how to display it on map but it shouldn't be problem. I would recommend you to use Leaflet or some other javascript mapping library for it.
However, that's to much for writing right now.
I hope that helps.

Connecting two views in Django

I want to make sure that my visitors (not authenticated users), are unable to visit a particular view without coming directly from a "previous view". I've kind of had to manually create a form preview and confirmation state. It's the step between submission and preview, and preview and confirm I'd like to "secure".
form submission-view -> preview-view -> confirm-view.
Is there some way that I can create a unique hash, POST it, and check if it's correct, or somewhat generate a cookie, session — or anything else that feels clever?
I'm a Django beginner (programming beginner in general) and any snippets' or pointing me in a right direction would be very much appreciated!
Thanks.
There are at least two ways you can accomplish this that I can think of:
One would be to include a hidden field in your form or querystring value that contains your hash/unique that you want to pick up in the next view. If it's not there, or incorrect, redirect.
Another would be to check the referring url from the request.META to see if they've come from the view you want them to come in on first, and save a session value from the form submission to carry through the rest of the views. If it's not there, redirect. If the referring URL isn't what you expect, redirect.
Whether you use a cookie, session, querystring parameter or hidden form post, it's all doing the same thing - validating a value exists. Whatever method works best, is what makes the most sense for you as the developer and most likely maintainer of said app.

How can I prevent automatic form submission by bots?

I am running ColdFusion MX, so I don't have the possibility of using the built-in cfimage Captcha functionality in my application, before form submitting.
But the problem is without captcha the bots submit the forms.
What will be best way to prevent automatic submitting?
Captchas don't have to be images!
Try one of the following solutions:
Most bots don't understand CSS. Create two submit buttons, the first with a value that will be rejected by the server, the second with a value that will be accepted by the server. Hide the first one using CSS.
Ask the user to answer a simple math problem. This will require you to create the math problem and store the expected solution somewhere (like the user's session), then compare the user's submitted answer with the stored answer. For extra protection, you can create simple addition, subtraction and multiplication questions. Avoid division, remainders are a pain for some users.
Bots read the names of form elements, and tend to ignore text labels. Try creating a checkbox named "optout" (like a newsletter), checked by default. Next to the checkbox, ask the user to uncheck the checkbox if they are a human. The opposite technique also works (unchecked checkbox that you ask the user to check).
All of these solutions can be done without third party code or API calls.
That being said, reCAPTCHA is pretty good and easy to integrate into almost any environment.
Take a look at cfformprotect - it will work with CFMX 6 and all later engines.
It aims to be fully accessible - and invisible to most users - with an assortment of methods to stop bots and spammers.
Also you might want to look at a CF wrapper for reCaptcha, which is compatible with CFMX 7.
A technique I used with a different technology was to use image buttons. Your POST handler gets the x,y co-ordinates where the images were clicked. I found the bots (which are just generating post requests) were passing 0,0 and by dropping those requests on the floor I brought the spam posts down to less than the real ones. Sorry that I don't know how to do that in CF but I hope the technique is useful to you.
Its always a good idea to do data validation on the server side before processing no matter which solution you use.
This post may help: http://www.bennadel.com/blog/405-Fully-Accessible-Spam-Form-Submission-Blocking-Using-ColdFusion-And-X-HTML-Version-III-.htm
How about using calculation method? Just like 8 + 5 = ?
OR
how about using ColdFusion.Ajax.submitForm?