# Wiki Links

With the flag `MD_FLAG_WIKILINKS`, MD4C recognizes wiki links.

The simple wiki-link is a wiki-link destination enclosed in `[[` followed with
`]]`.

```````````````````````````````` example
[[foo]]
.
<p><x-wikilink data-target="foo">foo</x-wikilink></p>
````````````````````````````````

However wiki-link may contain an explicit label, delimited from the destination
with `|`.

```````````````````````````````` example
[[foo|bar]]
.
<p><x-wikilink data-target="foo">bar</x-wikilink></p>
````````````````````````````````

A wiki-link destination cannot be empty.

```````````````````````````````` example
[[]]
.
<p>[[]]</p>
````````````````````````````````

```````````````````````````````` example
[[|foo]]
.
<p>[[|foo]]</p>
````````````````````````````````


The wiki-link destination cannot contain a new line.

```````````````````````````````` example
[[foo
bar]]
.
<p>[[foo
bar]]</p>
````````````````````````````````

```````````````````````````````` example
[[foo
bar|baz]]
.
<p>[[foo
bar|baz]]</p>
````````````````````````````````

The wiki-link destination is rendered verbatim; inline markup in it is not
recognized.

```````````````````````````````` example
[[*foo*]]
.
<p><x-wikilink data-target="*foo*">*foo*</x-wikilink></p>
````````````````````````````````

```````````````````````````````` example
[[foo|![bar](bar.jpg)]]
.
<p><x-wikilink data-target="foo"><img src="bar.jpg" alt="bar"></x-wikilink></p>
````````````````````````````````

With multiple `|` delimiters, only the first one is recognized and the other
ones are part of the label.

```````````````````````````````` example
[[foo|bar|baz]]
.
<p><x-wikilink data-target="foo">bar|baz</x-wikilink></p>
````````````````````````````````

However the delimiter `|` can be escaped with `/`.

```````````````````````````````` example
[[foo\|bar|baz]]
.
<p><x-wikilink data-target="foo|bar">baz</x-wikilink></p>
````````````````````````````````

The label can contain inline elements.

```````````````````````````````` example
[[foo|*bar*]]
.
<p><x-wikilink data-target="foo"><em>bar</em></x-wikilink></p>
````````````````````````````````

Empty explicit label is the same as using the implicit label; i.e. the verbatim
destination string is used as the label.

```````````````````````````````` example
[[foo|]]
.
<p><x-wikilink data-target="foo">foo</x-wikilink></p>
````````````````````````````````

The label can span multiple lines.

```````````````````````````````` example
[[foo|foo
bar
baz]]
.
<p><x-wikilink data-target="foo">foo
bar
baz</x-wikilink></p>
````````````````````````````````

Wiki-links have higher priority than links.

```````````````````````````````` example
[[foo]](foo.jpg)
.
<p><x-wikilink data-target="foo">foo</x-wikilink>(foo.jpg)</p>
````````````````````````````````

```````````````````````````````` example
[foo]: /url

[[foo]]
.
<p><x-wikilink data-target="foo">foo</x-wikilink></p>
````````````````````````````````

Wiki links can be inlined in tables.

```````````````````````````````` example
| A                | B   |
|------------------|-----|
| [[foo|*bar*]]    | baz |
.
<table>
<thead>
<tr>
<th>A</th>
<th>B</th>
</tr>
</thead>
<tbody>
<tr>
<td><x-wikilink data-target="foo"><em>bar</em></x-wikilink></td>
<td>baz</td>
</tr>
</tbody>
</table>
````````````````````````````````

Wiki-links are not prioritized over images.

```````````````````````````````` example
![[foo]](foo.jpg)
.
<p><img src="foo.jpg" alt="[foo]"></p>
````````````````````````````````

Something that may look like a wiki-link at first, but turns out not to be,
is recognized as a normal link.

```````````````````````````````` example
[[foo]

[foo]: /url
.
<p>[<a href="/url">foo</a></p>
````````````````````````````````

Escaping the opening `[` escapes only that one character, not the whole `[[`
opener:

```````````````````````````````` example
\[[foo]]

[foo]: /url
.
<p>[<a href="/url">foo</a>]</p>
````````````````````````````````

Like with other inline links, the innermost wiki-link is preferred.

```````````````````````````````` example
[[foo[[bar]]]]
.
<p>[[foo<x-wikilink data-target="bar">bar</x-wikilink>]]</p>
````````````````````````````````

There is limit of 100 characters for the wiki-link destination.

```````````````````````````````` example
[[12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901]]
[[12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901|foo]]
.
<p>[[12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901]]
[[12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901|foo]]</p>
````````````````````````````````

100 characters inside a wiki link target works.

```````````````````````````````` example
[[1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890]]
[[1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890|foo]]
.
<p><x-wikilink data-target="1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890">1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890</x-wikilink>
<x-wikilink data-target="1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890">foo</x-wikilink></p>
````````````````````````````````

The limit on link content does not include any characters belonging to a block
quote, if the label spans multiple lines contained in a block quote.

```````````````````````````````` example
> [[12345678901234567890123456789012345678901234567890|1234567890
> 1234567890
> 1234567890
> 1234567890
> 123456789]]
.
<blockquote>
<p><x-wikilink data-target="12345678901234567890123456789012345678901234567890">1234567890
1234567890
1234567890
1234567890
123456789</x-wikilink></p>
</blockquote>
````````````````````````````````