I rewrote most of tools/lib/pretty-printer.py, which
was fairly easy due to being able to crib some
important details from the previous implementation.
The main motivation for the rewrite was that we weren't
handling else/elif blocks correctly, and it was difficult
to modify the previous code. The else/elif shortcomings
were somewhat historical in nature--the original parser
didn't recognize them (since they weren't in any Zulip
templates at the time), and then the pretty printer was
mostly able to hack around that due to the "nudge"
strategy. Eventually the nudge strategy became too
brittle.
The "nudge" strategy was that we would mostly trust
the existing templates, and we would just nudge over
some lines in cases of obviously faulty indentation.
Now we are bit more opinionated and rigorous, and
we basically set the indentation explicitly for any
line that is not in a code/script block. This leads
to this diff touching several templates for mostly
minor fix-ups.
We aren't completely opinionated, as we respect the
author's line wrapping decisions in many cases, and
we also allow authors not to indent blocks within
the template language's block constructs.
This results in a substantial performance improvement for all of
Zulip's backend templates.
Changes in templates:
- Change `block.super` to `super()`.
- Remove `load` tag because Jinja2 doesn't support it.
- Use `minified_js()|safe` instead of `{% minified_js %}`.
- Use `compressed_css()|safe` instead of `{% compressed_css %}`.
- `forloop.first` -> `loop.first`.
- Use `{{ csrf_input }}` instead of `{% csrf_token %}`.
- Use `{# ... #}` instead of `{% comment %}`.
- Use `url()` instead of `{% url %}`.
- Use `_()` instead of `{% trans %}` because in Jinja `trans` is a block tag.
- Use `{% trans %}` instead of `{% blocktrans %}`.
- Use `{% raw %}` instead of `{% verbatim %}`.
Changes in tools:
- Check for `trans` block in `check-templates` instead of `blocktrans`
Changes in backend:
- Create custom `render_to_response` function which takes `request` objects
instead of `RequestContext` object. There are two reasons to do this:
1. `RequestContext` is not compatible with Jinja2
2. `RequestContext` in `render_to_response` is deprecated.
- Add Jinja2 related support files in zproject/jinja2 directory. It
includes a custom backend and a template renderer, compressors for js
and css and Jinja2 environment handler.
- Enable `slugify` and `pluralize` filters in Jinja2 environment.
Fixes#620.
In order to enable internationalization support in Zulip, and to use
Django internationalization tools, all strings in Zulip frontend needs
to be marked for translation.