Advanced Jinja2¶

What It Will Cover¶

• {% macro %} for reusable template snippets across multiple .j2 files, with {% import %}
• Whitespace control ({%- / -%}) to stop generated config files from accumulating blank lines
• Writing a custom Jinja2 filter plugin and referencing it from a collection — cross-referenced from Build a Collection From Zero
• vars()/{% set %} for computing an intermediate value inside a template

Common Mistakes¶

• Overusing macros for logic that would be clearer as a set_fact computed before the template renders at all.
• Not using whitespace control, producing config files with irregular blank lines that make diffs noisy in review.

Interview Questions¶

• When would you write a custom Jinja2 filter instead of chaining built-in ones?
• What does whitespace control ({%-/-%}) actually change in rendered output?

Next¶

Continue to Modules.