Overview

Jinja2 extension to enable the use of any filter as a custom autoescape filter.

This package allows you to define rules to determine when your custom autoescaping filter will be enabled using the same 'select_autoescape' method you already use to determine when the built-in autoescaping filter is enabled.

Usage

from jinja2_ext_custom_autoescaping import CustomAutoescapeExtension, enable_custom_autoescaping
from jinja2 import Environment, select_autoescape, FileSystemLoader

# Your custom filter...        
def my_filter(val):
    print(val)
    if isinstance(val, str):
        return val.replace(r"\\", r"\\\\")
    return val

    
# Here you set the rules for when the built-in autoescaping will be enabled
built_in_select_autoescape = select_autoescape(enabled_extensions=['html', 'htm', 'xml'],
                                               disabled_extensions=['txt', 'tex'],
                                               default_for_string=True,
                                               default=True)

# - select_autoescape is a closure
# - enabled_extensions takes precedence over disabled_extensions, so an extension in both lists will be enabled
# - You most likely do not want to have custom autoescaping on while built-in autoescaping is also on

# Here you set the rules for when your custom autoescaping will be enabled
custom_select_autoescape = select_autoescape(enabled_extensions=['tex', 'txt'],
                                             disabled_extensions=[],
                                             default_for_string=False,
                                             default=False)

# Just focusing on the important parts of your Environment construction.
env = Environment(extensions=[CustomAutoescapeExtension],
                  loader=FileSystemLoader(['.']),
                  autoescape=built_in_select_autoescape)

opts = {'custom_select_autoescape': custom_select_autoescape,
        'custom_autoescape_filter_name': 'my_filter',
        'custom_autoescape_filter_func': my_filter}

# Register the filter and enables autoescaping
enable_custom_autoescaping(env, **opts)

# Now you are ready to go...
template = env.get_template('test_template.txt')
print(template.render(var={'entry 1': 'value 1', 'entry2': r'val\\ue 2'}))