Utilizing some advanced Jinja2 features

Chapter 1 introduced the Jinja2 engine and templating, and some of these Jinja constructs were applied to render HTML contents:

• {{ variable }}: The placeholder expression that renders a single-valued object from view functions.
• {% statement %}: The expression that implements if-else-conditions, for-loops, block-expressions for calling layout fragments, with-blocks for managing context, and macro calls.

But some Jinja2 features, such as applying the with-statement, macros, filters, and comments, can help generate better views for our routes.

Applying with-blocks and macros

In the Applying flash messages section, templates used the {% with %} statement to extract the flash messages from the view functions and {% macro %} in optimizing our Jinja2 transactions. The {% with %} statement sets a context to limit the access or scope of some variables within the with-block. Access outside the block produces a Jinja2 error.

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