[[!template id=plugin name=sidebar2 author="[[Louis|spalax]]"]]
[[!tag type/chrome]]

*Claim:* The [[sidebar|plugins/sidebar]] plugin has nothing
to do with sidebars. This plugin renders some page (which happens to be named
`sidebar`) and put the result in template variable `SIDEBAR`, in template
`page.tmpl`. But the fact that it is a sidebar, i.e. a bar appearing on the
side on the screen, is done by CSS.

What if I want a sidebar, and a [[navigation bar|plugins/contrib/navbar]], and
a footer a bit more elaborated than the one in the template, etc.? This plugin
allows this.

# Configuration

If no option is given, or if option `global_sidebars` is a boolean, this plugin
is identical to the [[sidebar plugin|plugins/sidebar/]] (if not, please [report
a bug](https://atelier.gresille.org/projects/gresille-ikiwiki/issues)).
Otherwise, `global_sidebars` is a list of sidebars to include. The list is as
follow:

    global_sidebars => [
      "var1", "page1", "pagespec1",
      "var2", "page2", "pagespec2",
      ]

The meaning is: if available, render `page1` in pages matching `pagespec1`, and
put it in variable `var1` of the page template, and so on for `var2`, `page2`,
etc.

The default, which gives the behaviour of the sidebar plugin, is
`global_sidebars => ["sidebar", "sidebar", "*"]`.

*Remark: It would be more sensible to have a list of lists, as the following example, but I did not manage to do so because of [[this bug|bugs/structured_config_data_is_mangled]].*

    global_sidebars => [
      ["var1", "page1", "pagespec1"],
      ["var2", "page2", "pagespec2"],
      ]

# Improvements over sidebar plugin

* You can add several "sidebars" to your wiki. For example, to have a sidebar, a submeno that appear only in pages documentations, and a footer, your `global_sidebars` would be:

      global_sidebars => [
        "sidebar", "sidebar", "*",
        "menu", "/doc/menu", "doc/*",
        "footer", "/footer", "*"
        ]

* You can enable sidebars only in certain pages matching the pagespec. If, for
  the same template variable, several pagespec match the current page, the
  first page in the list is taken into account.

  For example, the following configuration says: render `menu` as the sidebar
  for every page, excepted subpages of `doc`, for which the `doc_menu` page
  should be rendered.

      global_sidebars => [
        "sidebar", "doc_menu", "doc/*",
        "sidebar", "menu", "*",
        ]

# Directive

The behaviour of the `sidebar` directive is similar to the directive of the
original [[sidebar|plugins/sidebar]], excepted that a new `var` argument is
available.

If this `var` argument is set, instead of applying to the default `sidebar`
template variable, the directive applies to the value given in the argument.

For example, the following command forces the `footer` sidebar to appear on the
current page.

    \[[!sidebar var=footer]]

The following command forces the `footer` sidebar to appaer, containing the
content given in argument.

    \[[!sidebar var=footer content="TEST"]]

# Which pages to render?

Here is the decision process to decide what is rendered in a template variable
handled by this plugin.

1. If the page contains the [[sidebar|ikiwiki/directive/sidebar]] directive, with a `content` argument, this content is rendered.
2. If the page contains the [[sidebar|ikiwiki/directive/sidebar]] directive with no `content` argument, the first rule for the considered template variable is applied, disregarding the pagespec.
3. If none of the above, the first rule having its pagespec patching the current page is applied.
4. If none of the above, the variable is left empty.

# Download and install

Code and documentation: [[https://atelier.gresille.org/projects/gresille-ikiwiki/wiki/Sidebar2]].
