[FIXED] Flask - use jinja macros without a template

Issue

I have a Flask app that looks as follows:

@app.route('/')
def index():
    headline = render_template('headline.html', headline = 'xyz') #-> return <h1>xyz</h1>
    return render_template('page.html', headline = headline) # insert headline html into a page

headline.html is a template which imports a jinja macro from a macro file (macros.html). The macro generates the headline.

headline.html:

{% import 'macros.html' as macros %}
{{ macros.get_headline(headline) }}

macros.html:

{% macro get_headline(headline) %}
<h1>{{ healine }}</h1>
{% endmacro %}

My question is - is it possible to call the macro to get headline without the need to call the template headline.html?

Ideally, I'd like to see

@app.route('/')
def index():
    headline = # somehow call get_headline('xyz') from macros.html
    return render_template('page.html', headline = headline) # insert headline html into a page

Solution

Instead of rendering the template from a file, you can render a template from a string. So you can call your macro from a string.

from flask.templating import render_template_string

@app.route('/')
def index():
    headline = render_template_string(
        "{% import 'macros.html' as macros %}"
        "{{ macros.get_headline(headline) }}",
        headline='xyz'
    )
    return render_template('page.html', headline=headline)

_{(ignoring the typo healine instead of headline in macros.html)}

Answered By - Sven Eberth