# Jinja2 Content

This plugin allows the use of Jinja2 directives inside your pelican articles and pages.

In this approach, your content is *first* rendered by the Jinja template engine. The result
is then passed to the normal pelican reader as usual. There are two consequences for usage.
First, this means the Pelican context and jinja variables [usually
visible](http://docs.getpelican.com/en/stable/themes.html#templates-and-variables) to your
article or page template are _not_ available at rendering time. Second, it means that if any
of your input content could be parsed as Jinja directives, they will be rendered as such.
This is unlikely to happen accidentally, but it's good to be aware of.

All input that needs Pelican variables such as `article`, `category`, etc., should be put
inside your *theme's* templating.  As such, the main use of this plugin is to automatically
generate parts of your articles or pages.

Markdown, reStructured Text, and HTML input are all supported. Note that by enabling this
plugin, all input files of these file types will be preprocessed with the Jinja renderer.
It is not currently supported to selectively enable or disable `jinja2content` for only some of
these input sources.


## Example

One usage is to embed repetitive HTML in Markdown articles. Since Markdown doesn't allow
customization of layout, if anything more sophisticated than just displaying an image is
necessary, one is forced to embed HTML in Markdown articles (i.e. hardcode `<div>` tags and
then select them from the theme's CSS).  However, with `jinja2content`, one can do the
following.

File `my-cool-article.md`
```
# My cool title

My cool content.

{% from 'img_desc.html' import img_desc %}
{{ img_desc("/images/my-cool-image.png",
    "This is a cool tooltip",
    "This is a very cool image.") }}
```

Where file `img_desc.html` contains:
```
{% macro img_desc(src, title='', desc='') -%}
<div class="img-desc">
  <p><img src="{{ src }}" title="{{ title }}"></p>
  {% if desc %}
  <p><em>{{ desc }}</em></p>
  {% endif %}
</div>
{%- endmacro %}
```

The result will be:
```
# My cool title

My cool content.

<div class="img-desc">
  <p><img src="/images/my-cool-image.png" title="This is a cool tooltip"></p>
  <p><em>This is a very cool image.</em></p>
</div>
```

After this, the Markdown will be rendered into HTML and only then the
theme's templates will be applied.

In this way, Markdown articles have more control over the content that is
passed to the theme's `article.html` template, without the need to pollute
the Markdown with HTML.  Another added benefit is that now `img_desc` is
reusable across articles.

Note that templates rendered with `jinja2content` can contain Markdown as
well as HTML, since they are added before the Markdown content is converted
to html.


## Usage

Enable the `jinja2content` plugin in your project in [the usual
manner](http://docs.getpelican.com/en/stable/plugins.html#how-to-use-plugins).

```
PLUGINS = [
    # ...
    "jinja2content",
]
```


## Configuration

This plugin accepts the setting `JINJA2CONTENT_TEMPLATES` which should be set to a list of
paths relative to `PATH` (the main content directory, usually `"content"`).  `jinja2content`
will look for templates inside these directories, in order.  If they are not found in any,
the theme's templates folder is used.


## Extension

This plugin is structured such that it should be quite easy to extend readers for other file
types to also render Jinja template logic. It should be sufficient to create a new reader
class that inherents from the `JinjaContentMixin` and then your desired reader class. See
class definitions in the source for examples.


## Acknowledgements

- Created by @Leonardo.
- Updated to support rst and HTML input by @micahjsmith.
- Replaces [pelican-jinj2content](https://github.com/joachimneu/pelican-jinja2content/tree/f73ef9b1ef1ee1f56c80757b4190b53f8cd607d1),
which had become unmaintained.