{"id": "plugin_hooks:plugin-hook-prepare-jinja2-environment", "page": "plugin_hooks", "ref": "plugin-hook-prepare-jinja2-environment", "title": "prepare_jinja2_environment(env, datasette)", "content": "env  - jinja2 Environment \n                     \n                         The template environment that is being prepared \n                     \n                 \n                 \n                     datasette  -  Datasette class \n                     \n                         You can use this to access plugin configuration options via  datasette.plugin_config(your_plugin_name) \n                     \n                 \n             \n             This hook is called with the Jinja2 environment that is used to evaluate\n                Datasette HTML templates. You can use it to do things like  register custom\n                    template filters , for\n                example: \n             from datasette import hookimpl\n\n\n@hookimpl\ndef prepare_jinja2_environment(env):\n    env.filters[\"uppercase\"] = lambda u: u.upper() \n             You can now use this filter in your custom templates like so: \n             Table name: {{ table|uppercase }} \n             This function can return an awaitable function if it needs to run any async code. \n             Examples:  datasette-edit-templates", "breadcrumbs": "[\"Plugin hooks\"]", "references": "[{\"href\": \"http://jinja.pocoo.org/docs/2.10/api/#custom-filters\", \"label\": \"register custom\\n                    template filters\"}, {\"href\": \"https://datasette.io/plugins/datasette-edit-templates\", \"label\": \"datasette-edit-templates\"}]"}