Blueprints

Imagine you have a route, let’s say /signup. That route requires 3 things username, email, and password. Now we assume you can save the user to the database by running the create_user(username, email, password). This may seem simple, but this is where complications arise. The problem is that you need to get their user input. Now, without any special tools, you would have to check if the user provided a username, email, and password. It’s common knowledge among developers to follow the Don’t Repeat Yourself(DRY) design pattern and all of these checks violate these rules.

What The Heck Is A Blueprint?

A blueprint will allow you always to get the request in the format you define, and handle all the checks for you.

How to create Blueprints

Below are the simple instructions to use the CLI wizard to make the template for a blueprint.

For Linux or Mac OS users:

python3 -m libsodium create blueprint signup

For Windows users:

python -m libsodium create blueprint signup

Note

The name of the blueprint doesn’t have to be the name of the route, though it’s best practice.

Now that we have created our blueprint, let’s take a peek inside:

file: /src/blueprints/signupBlueprint.py:

from libsodium import Rule

class signupBlueprint:
    name = Rule(str, "<regex>")

Note

Alternative syntax(Not Recommended):

from libsodium import Blueprint

signupBlueprint = Blueprint([
('example', str, "<regex>")
])

Long story short, the Rule object contains the datatype and the regex which we can put into class variables.

Example of using regex’s

from libsodium import Rule

class signupBlueprint:
     username = Rule(str)
     email = Rule(str, r"(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"+'"'+"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*"+'"'+")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])")
     password = Rule(str)

Note

Alternative syntax(Not Recommended):

from libsodium import Blueprint

signupBlueprint = Blueprint([
('username', str)
('email', str, r"(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"+'"'+"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*"+'"'+")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])")
('password', str)
])

Note

The regex used for the email can be found here

Using The Blueprint

Now let’s add the blueprint to our route. We can do this by using the useBlueprint decorator.

Note

libsodium.classes.useBlueprint(Blueprint blueprint, List[str,..] mimetypes)

Code:

from libsodium import Route, Response, useBlueprint
from src.blueprints.postBlueprint import postBlueprint

def route():
    @useBlueprint(postBlueprint, ["applicaiton/json"])
    class signup:
        def onRequest(self, request):
            create_user(request.json["username"], request.json["email"], request.json["password"])
            rsp = Response(f'{"code":"success"}')
            rsp.headers['Content-Type'] = 'applicaiton/json'
            return rsp
    return Route('POST', '/signup', signup)

And just like that, we have blueprints installed.