Forms

Mojito provides a simple interface for validating form inputs against Pydantic models for CRUD application.

Using form processing

The Form and FormManager functions provide a layer on top of Starlettes request.form(). That layer on top helps to clean up normal headaches associated with form entries. To describe it, let's start with an example.

Basic form procsesing

First define your form inputs as a Pydantic model and validate the form data against it using the Form function.

from pydantic import BaseModel
from mojito import Mojito, Request, forms

app = Mojito()

class UserCreateForm(BaseModel):
    name: str
    email: str
    permissions: list[str]

@app.route('/create_user', methods=["GET", "POST"])
async def create_user(request: Request):
    if request.method == "POST":
        form = await forms.Form(request, UserCreateForm)
        print(form.model_dump())
    return """
    <form method="post">
        <div>
            <label for="name">Name</label>
            <input name="name" id="name" type="text">
        </div>
        <div>
            <label for="name">Name</label>
            <input name="name" id="name" type="text">
        </div>
        <div id="permissions">
            <div>
                <label for="readPermission">Read</label>
                <input type="checkbox" name="permissions" value="read" id="readPermission">
            </div>
            <div>
                <label for="writePermission">Write</label>
                <input type="checkbox" name="permissions" value="write" id="writePermission">
            </div>
        </div>
        <button type="submit">Submit</button>
    </form>
    """

When this form is submitted the Form function will first preprocess the form data to combine fields with the same name, like the checkboxes above, into a list and remove fields submitted as empty strings before sending them to be validated by Pydantic.

Forms with files

The FormManager is an asynccontextmanager providing the same functionality as form except it can be used within a context manager to maintain the open form data, alllowing for reading and working with uploaded files. This can also be used when you want to keep working with Starlettes request.form() data directly after data validation.

The form module provides UploadFile as a Pydantic compatible alternaitive to Starlettes UploadFile to type files in your Pydantic models.