Welcome to pydantic-forms’s documentation!¶
Table of Contents
About¶
Pydantic Forms takes a very simplistic approach to form validation. Create a Pydantic Model to represent your form data, and utilize Pydantic’s own strong validation logic at your disposal.
Some libraries require you to define custom classes for forms and work to auto-generate HTML for you. This library is NOT one of those.
Pydantic Models are just Plain Old Pydantic Models. No extra logic from this library needs to be injected into it. Use your existing models.
HTML generation is up to the user. Create your templates as simple or as complex as you would like. Utilize macros for complex error display.
Examples¶
FastAPI example
from fastapi import FastAPI
from fastapi.requests import Request
from fastapi.responses import HTMLResponse
from fastapi.templating import Jinja2Templates
from pydantic import BaseModel, validator, constr, ValidationError
from pydantic_forms import PydanticForm
# Needed to access FastAPI Request Session data
from starsessions import SessionMiddleware
templates = Jinja2Templates(directory="templates")
app = FastAPI()
app.add_middleware(SessionMiddleware, secret_key="secret", autoload=True)
class MyForm(BaseModel):
name: constr(min_length=1) # Supported Pydantic constrained types
age: int
# pydantic validators work too
@validator('age')
def age_must_be_over_30(cls, value, values):
if value <= 30:
raise ValueError("30's are your new 20's")
return value
@app.get('/myform', response_class=HTMLResponse)
async def get_my_form(request: Request):
form = await PydanticForm.create(request, MyForm)
return templates.TemplateResponse("myform.html", {"request": request, 'form': form})
@app.post('/myform', response_class=HTMLResponse)
async def handle_my_form(request: Request):
form = await PydanticForm.validate_request(request, MyForm)
if form.is_valid:
model = form.model
return f"Hello {model.name} you are {model.age} years old"
else:
return templates.TemplateResponse("myform.html", {"request": request, 'form': form})
Using Jinja2 (myform.html)
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>My Form</title>
</head>
<body>
<form method="POST">
<input type="hidden" name="csrf" value="{{form.csrf}}" />
<label for="name">Name</label>
<input type="text" name="name" id="name" value="{{form.fields.name.value}}" />
<div>{{form.fields.name.error}}</div>
<label for="age">Age</label>
<input type="text" name="age" id="age" value="{{form.fields.age.value}}" />
<div>{{form.fields.age.error}}</div>
<input type="submit" />
</form>
</body>
</html>
For complex forms that require a lot of validation, utilize Macros in your template library.
Installing¶
Install Pydantic Forms using poetry from Github
Note
The Default Strategy described in the table of contents uses the request session for validation. FastAPI requires starsessions to be installed for this to work