I am working on a GAE (python) and JINJA based application. I have created a JINJA template from a text string using from_string method. i.e.
template = JINJA.from_string(text)
The result template looks like this:
Template(body=[Scope(body=[ScopedEvalContextModifier(options=[Keyword(key='autoescape', value=Name(name='on', ctx='load'))], body=[Output(nodes=[TemplateData(data=u'Dear '), Filter(node=Name(name='customer_name', ctx='load'), name='safe', args=[], kwargs=[], dyn_args=None, dyn_kwargs=None), TemplateData(data=u',\n\n'), Filter(node=Name(name='customer_name_new', ctx='load'), name='extra', args=[], kwargs=[], dyn_args=None, dyn_kwargs=None), TemplateData(data=u'\n \nThank you for choosing '), Name(name='company_name', ctx='load'), TemplateData(data=u'.\n\n')]), If(test=Name(name='start_datetime', ctx='load'), body=[Output(nodes=[TemplateData(data=u'Your '), Name(name='order_type', ctx='load'), TemplateData(data=u' is scheduled for:\n'), Filter(node=Name(name='start_datetime_block', ctx='load'), name='safe', args=[], kwargs=[], dyn_args=None, dyn_kwargs=None), TemplateData(data=u'\nYou can check out the estimated time of arrival for your '), Name(name='order_type', ctx='load'), TemplateData(data=u' using the button below\n'), Filter(node=Name(name='live_link_button', ctx='load'), name='safe', args=[], kwargs=[], dyn_args=None, dyn_kwargs=None), TemplateData(data=u'\n')])], else_=[Output(nodes=[TemplateData(data=u'Your '), Name(name='order_type', ctx='load'), TemplateData(data=u' is now placed.\n')])]), If(test=And(left=Name(name='start_datetime', ctx='load'), right=Name(name='confirmation_required', ctx='load')), body=[Output(nodes=[TemplateData(data=u'Please confirm your availability for this appointment:\n'), Filter(node=Name(name='confirmation_buttons', ctx='load'), name='safe', args=[], kwargs=[], dyn_args=None, dyn_kwargs=None), TemplateData(data=u'\n')])], else_=[]), If(test=Name(name='custom_text', ctx='load'), body=[Output(nodes=[Filter(node=Name(name='custom_text', ctx='load'), name='safe', args=[], kwargs=[], dyn_args=None, dyn_kwargs=None), TemplateData(data=u'\n')])], else_=[]), Output(nodes=[TemplateData(data=u'We look forward to seeing you. In case you have any questions please reach us at '), Name(name='company_email', ctx='load'), TemplateData(data=u'. '), Name(name='company_name', ctx='load'), TemplateData(data=u' '), Name(name='company_address', ctx='load'), TemplateData(data=u' '), Name(name='company_phone', ctx='load')])])])])
Now, what I want to do is that I want to get all the variables from this template and especially I am concerned with such variables which have some filters like in above template expected filters are safe and extra. Please note that extra is my custom filter.
Calling meta.find_undeclared_variables method only gives me list of keywords but, not their filters. i.e.
parsed_content = JINJA.parse(text)
keywords = meta.find_undeclared_variables(parsed_content)
Is there any way I can get keywords along with filter names as well?
Here is a simple solution that might help. It gives variable name with filters (only variables that have filters):
from jinja2 import Environment, PackageLoader, meta, nodes
def find_filters(ast):
"""Find all the nodes of a given type. If the type is a tuple,
the check is performed for any of the tuple items.
"""
for child in ast.iter_child_nodes():
if isinstance(child, nodes.Filter):
yield child
else:
for result in find_filters(child):
yield result
def filtered_variables(ast):
"""Return variables that have filters, along with their filters. might
return duplicate variable names with different filters
"""
results = []
for i, node in enumerate(find_filters(ast)):
filters = []
f = node
filters.append(f.name)
while isinstance(f.node, nodes.Filter):
f = f.node
filters.append(f.name)
filters.reverse()
results.append((f.node.name, filters))
return results
env = Environment(loader=PackageLoader('templates'))
template = '{% extends "layout.html" %}'\
'{% from "test.html" import a, b as c %}{{ some_variable | a | x}} {{ some_other }}'\
'{% import "meh.html" as meh %}{{ some_variable | b | c | d}}'\
'{% include "muh.html" %}'
ast = env.parse(template)
print(filtered_variables(ast))
The output will be:
[('some_variable', ['a', 'x']), ('some_variable', ['b', 'c', 'd'])]
You can include variables that has no filter like this:
f_vars = filtered_variables(ast)
filtered = []
for var in f_vars:
filtered.append(var[0])
f = [(x, []) for x in keywords if x not in filtered]
f_vars.extend(f)
print(f_vars)
Output:
[('some_variable', ['a', 'x']), ('some_variable', ['b', 'c', 'd']), ('some_other', [])]
Note that result might have duplicate values. This can be more useful as different filters might be present on each occurrence of variable.