Using render_template

In this lesson we introduce a shortcut to rendering Jinja2 templates, using Flask's render_template function. We will refactor the main.py in our hello-flask directory to use this shortcut. When you use render_template, you can eliminate a lot of the code that we have been using. You can use this shortcut function as long as all your templates are in the templates/ directory and you want a setting of autoescape=True (which is built into render_template).

Here are the steps to using render_template:

1. Import it:

   from flask import Flask, request, redirect, render_template

   This import of render_template replaces the need to import jinja2 and the need to construct the template_dir variable and create a template loader, as we did with the following code:

   template_dir = os.path.join(os.path.dirname(__file__),
       'templates')
   jinja_env = jinja2.Environment(
       loader = jinja2.FileSystemLoader(template_dir), autoescape=True)

   Note that using render_template requires you to put your templates in a directory named templates, while our initial, more hands-on approach allowed us to specify where our templates are located.

2. Call render_template:

   return render_template('hello_greeting.html', name=first_name)

   This call to render_template replaces the two calls below (using the hello function as an example):

   template = jinja_env.get_template('hello_greeting.html')
   return template.render(name=first_name)

References

• flask.render_template