Hashtag Links

This page explains how MDViewer turns #tag in the text into links, along with the matching rules and limits.

Enabling

new MDViewer({
    id: "viewer",
    sync: { editor: editor },
    hashtag: { path: "/search?tag=", target: "_blank" }
});

Condition	Result
`hashtag.path` is a non-empty string	Conversion enabled
`hashtag.path` empty or unset	No conversion; `#tag` is output as-is
Using `MDParser`	No conversion: `MDParser` passes `null` as the path

Output

Today's topics #JavaScript and #前端

Today's topics <a class="tag" href="/search?tag=JavaScript" target="_blank">JavaScript</a> and <a class="tag" href="/search?tag=前端" target="_blank">前端</a>

Item	Rule
`href`	`hashtag.path` concatenated with the tag text, without URL encoding
Link text	Without the `#`
`class`	`tag`, styled by `NanoMD.css`
`target`	`_blank` when `hashtag.target` is `"_blank"`, otherwise `_self`

Matching Rules

Rule	Detail
Prefix	Half-width `#` or full-width `＃`
Preceded by	A whitespace character (newline included), so a `#` glued to preceding text (`a#b`) is not converted; a `#` at the start of a line counts as preceded by a newline
Tag characters	CJK unified ideographs, hiragana/katakana, Hangul syllables, ASCII letters, digits and underscore
End	Stops at the first character outside that set (punctuation, space, `-`)
Escape	`\#tag` is not converted and outputs the literal `#tag`

setHashtag runs last in the pipeline; code blocks and inline code are already placeholders by then, so a # inside them is untouched. A # followed by a space is heading syntax and is handled earlier by setHeading.