4.11. Templates

The need to render templates on the server side is used in some projects. External template engines that support async can be used for this purpose. You can also use the framework helper layer for this, which is a layer for using the Jinja2 template engine package. The Backendpy framework facilitates the use of templates with this template engine and adapts it to its architecture with things like template files async reading from predefined application template paths.

An example of rendering a web page template and returning it as a response is as follows.

First we need to specify the application template dirs inside the application main.py module with the template_dirs parameter of the App class:

project/apps/hello/main.py

from backendpy.app import App

app = App(
    ...
    template_dirs=['templates'],
    ...)

Then we create the desired templates in the defined path:

project/apps/hello/templates/home.html

<!DOCTYPE html>
<html>
<head>
    <title>Backendpy</title>
</head>
<body>
  <h1>{{ message }}</h1>
</body>
</html>

Refer to the Jinja2 package documentation to learn the templates syntax.

Finally, we use these template inside a handler:

project/apps/hello/controllers/handlers.py

from backendpy.router import Routes
from backendpy.response import HTML
from backendpy.templating import Template

routes = Routes()

@routes.get('/home')
async def home(request):
    context = {'message': 'Hello World!'}
    return HTML(await Template('home.html').render(context))

In this example code, we first initialize Template class with the template name and then with the render method we render the context values in it (note that this method must also be called async) and then we return the final content with HTML response.

Also here you just need to enter the template name and the framework will automatically search for this name in the application template dirs.

Details of the Template class are as follows: