How to get list of all variables in jinja 2 templates

Question

I am trying to get list of all variables and blocks in a template. I don\'t want to create my own parser to find variables. I tried using following snippet.

Answer 1

Since no one has answered the question and I found the answer

from jinja2 import Environment, PackageLoader, meta
env = Environment(loader=PackageLoader('gummi', 'templates'))
template_source = env.loader.get_source(env, 'page_content.html')
parsed_content = env.parse(template_source)
meta.find_undeclared_variables(parsed_content)

This will yield list of undeclared variables since this is not executed at run time, it will yield list of all variables.

Note: This will yield html files which are included using include and extends.

Answer 2

For my pelican theme, i have created a tools for analyse all jinja variables in my templates files.

I share my code

This script generate a sample configuration from all variables exists in template files and get a variables from my official pelicanconf.py

The function that extract all variables from template file

def get_variables(filename):
    env = Environment(loader=FileSystemLoader('templates'))
    template_source = env.loader.get_source(env, filename)[0]
    parsed_content = env.parse(template_source)

The complete script

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# use:
# generate_pelicanconf-sample.py my_official_blog/pelicanconf.py

import sys
import imp
import os

from jinja2 import Environment, FileSystemLoader, meta


# Search all template files
def list_html_templates():
    dirList = os.listdir('templates')

    return dirList


# get all variable in template file
def get_variables(filename):
    env = Environment(loader=FileSystemLoader('templates'))
    template_source = env.loader.get_source(env, filename)[0]
    parsed_content = env.parse(template_source)

    return meta.find_undeclared_variables(parsed_content)


# Check if the pelicanconf.py is in param
if len(sys.argv) != 2:
    print("Please indicate the pelicanconf.py file")
    sys.exit()

# Get all vars from templates files
all_vars = set()
files = list_html_templates()
for fname in files:
    variables = get_variables(fname)
    for var in variables:
        if var.isupper():
            all_vars.add(var)

m = imp.load_source('pelicanconf', sys.argv[1])

# Show pelicanconf.py vars content
for var in all_vars:
    varname = 'm.%s' % var
    if var in m.__dict__:
        print ("%s = %s" % (var, repr(m.__dict__[var])))


    return meta.find_undeclared_variables(parsed_content)

The sample result of this program

LINKS = ((u'Home', u'/'), (u'archives', u'/archives.html'), (u'tags', u'/tags.html'), (u'A propos', u'http://bruno.adele.im'))
SITESUBTITLE = u'Une famille compl\xe8tement 633<'
DEFAULT_LANG = u'fr'
SITEURL = u'http://blog.jesuislibre.org'
AUTHOR = u'Bruno Adel\xe9'
SITENAME = u'Famille de geeks'
SOCIAL = ((u'adele', u'http://adele.im'), (u'feed', u'http://feeds.feedburner.com/FamilleDeGeek'), (u'twitter', u'http://twitter.com/jesuislibre.org'), (u'google+', u'https://plus.google.com/100723270029692582967'), (u'blog', u'http://blog.jesuislibre.org'), (u'facebook', u'http://www.facebook.com/bruno.adele'), (u'flickr', u'http://www.flickr.com/photos/b_adele'), (u'linkedin', u'http://fr.linkedin.com/in/brunoadele'))
FEED_DOMAIN = u'http://blog.jesuislibre.org'
FEED_ALL_ATOM = u'feed.atom'
DISQUS_SITENAME = u'blogdejesuislibreorg'
DEFAULT_PAGINATION = 10
GITHUB_BLOG_SITE = u'https://github.com/badele/blog.jesuislibre.org'

For more détail of this script see https://github.com/badele/pelican-theme-jesuislibre

Answer 3

Solution: https://gist.github.com/sxslex/822bd2405885294747b86aac187f1aa8

def template(html, **params):
    import jinja2
    env = jinja2.Environment(loader=FileSystemLoader(''))

    def tojson(s):                                       
        import json
        return json.dumps(s)
    env.filters['tojson'] = tojson
    template = env.from_string(html)
    return template.render(context=params, **params)

print(template('{{ context|tojson }}', name='slex', value=39 ))

Answer 4

I had the same need and I've written a tool called jinja2schema. It provides a heuristic algorithm for inferring types from Jinja2 templates and can also be used for getting a list of all template variables, including nested ones.

Here is a short example of doing that:

>>> import jinja2
>>> import jinja2schema
>>>
>>> template = '''
... {{ x }}
... {% for y in ys %}
...     {{ y.nested_field_1 }}
...     {{ y.nested_field_2 }}
... {% endfor %}
... '''
>>> variables = jinja2schema.infer(template)
>>>
>>> variables
{'x': <scalar>,
 'ys': [{'nested_field_1': <scalar>, 'nested_field_2': <scalar>}]}
>>>
>>> variables.keys()
['x', 'ys']
>>> variables['ys'].item.keys()
['nested_field_2', 'nested_field_1']