4Geeks Coding Boilerplates for Junior Developers
API Validations
API Validations
Let's say a request is coming from the client and we need to make sure it contains the right information.
We have to use conditionals to make the validations, if we want to validate the request body we have to retrieve it first and then add the condition, like this:
body = request.get_json()if 'username' not in body: raise APIException('You need to specify the username', status_code=400)- It's a good practice to raise exceptions because it will stop the code execution.
- It's a good practice to return 400 because that way the client knows it was his mistake and not ours (the server).
Here is a full example of a POST request to add a new person into a database:
@app.route('/person', methods=['POST'])def handle_person():
# First we get the payload json body = request.get_json()
if body is None: raise APIException("You need to specify the request body as a json object", status_code=400) if 'username' not in body: raise APIException('You need to specify the username', status_code=400) if 'email' not in body: raise APIException('You need to specify the email', status_code=400)
# at this point, all data has been validated, we can proceed to insert into the database user1 = Person(username=body['username'], email=body['email']) db.session.add(user1) db.session.commit() return "ok", 200