How to make a field required for a post request in an API? - flask

Question

I'm making an API route that returns a random number in Flask. When sending a post request to the end-point, I want it to return an error(s) if a certain field(s) is not in the post request (for example, if there is no "name" in the request, it should return an error).
I've tried doing this with a dictionary, try, and catch. If a field is missing, I add a key: value to the dictionary and if the dictionary isn't empty, to return that. First problem is if there is more than one field missing, it only adds one of them to the error dictionary. Second problem is, I'm also trying to make sure some fields also have a certain value (for example, color needs to be red or blue). If I check for one thing, it works - if I do
if color != "red" or color != "blue":
it will always show an error. Even if I split it up into multiple if statements, it will still be an error. I've searched Google, rephrasing my question at least 30 different times, and most answers I've gotten are about SalesForce (which I'm assuming is some company/software etc).
So...is there a way to make a certain field(s) required? Or am I on the right track with try and catch? If it is through try and catch, how do I make it show more than one error/have a variable a certain thing?
#app.route('/api/get-num', methods=["POST"])
def num():
errors = {}
try:
name = request.json['name']
except:
errors["errors"] = {"name" : "This field is required."}
try:
color = request.json['color']
if color != "red" or color != "blue":
errors["errors"] = {"color" : "Invalid value, must be red or blue."}
except:
errors["errors"] = {"color" : "Invalid value, must be red or blue."}
if len(errors) != 0:
return errors
create_dict = {
'name' : request.json['name'],
'email ': request.json['email'],
'year': request.json['year'],
'color' : request.json['color']
}
return jsonify(create_dict)
Examples:
If name is missing and color is wrong, it should show:
{
"errors": {
"color": [
"Invalid value, must be red or blue."
],
"name": [
"This field is required."
]
}
}
With name missing and color being "red", it's currently showing:
{
"errors": {
"color": "Invalid value, must be red or blue."
}
}

Answer 1

Create a dict with expected errors, in this case it would be all the required fields
errorsDict = {"errors":{"color":[],"name":[]}}
In your try except block append to the nested as items as necessary, example:
errorsDict = {"errors":{"color":[],"name":[]}}
try:
name = request.json['name']
except:
errorsDict["errors"]["name"].append("This field is required.")
try:
color = request.json['color']
except:
errorsDict["errors"]["color"].append( "COLORS MISSING!")