Using render_template

In this lesson we introduce a shortcut to rendering Jinja2 templates, using Flask's render_template function. We will refactor the 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__),
    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)