import { postcss } from "https://deno.land/x/bundler@0.6.5/deps.ts";
const { Node } = postcss;
All node classes inherit the following common methods.
You should not extend this classes to create AST for selector or value parser.
Properties
The nodeās parent node.
root.nodes[0].parent === root
Information to generate byte-to-byte equal node string as it was in the origin input.
Every parser saves its own properties, but the default CSS parser uses:
before
: the space symbols before the node. It also stores*
and_
symbols before the declaration (IE hack).after
: the space symbols after the last child of the node to the end of the node.between
: the symbols between the property and value for declarations, selector and{
for rules, or last parameter and{
for at-rules.semicolon
: contains true if the last child has an (optional) semicolon.afterName
: the space between the at-rule name and its parameters.left
: the space symbols between/*
and the commentās text.right
: the space symbols between the commentās text and */.important
: the content of the important statement, if it is not just!important
.
PostCSS cleans selectors, declaration values and at-rule parameters from comments and extra spaces, but it stores origin content in raws properties. As such, if you donāt change a declarationās value, PostCSS will use the raw value with comments.
const root = postcss.parse('a {\n color:black\n}')
root.first.first.raws //=> { before: '\n ', between: ':' }
The input source of the node.
The property is used in source map generation.
If you create a node manually (e.g., with postcss.decl()
),
that node will not have a source
property and will be absent
from the source map. For this reason, the plugin developer should
consider cloning nodes to create new ones (in which case the new nodeās
source will reference the original, cloned node) or setting
the source
property manually.
decl.source.input.from //=> '/home/ai/a.sass'
decl.source.start //=> { line: 10, column: 2 }
decl.source.end //=> { line: 10, column: 12 }
// Bad
const prefixed = postcss.decl({
prop: '-moz-' + decl.prop,
value: decl.value
})
// Good
const prefixed = decl.clone({ prop: '-moz-' + decl.prop })
if (atrule.name === 'add-link') {
const rule = postcss.rule({ selector: 'a', source: atrule.source })
atrule.parent.insertBefore(atrule, rule)
}
Methods
Insert new node after current node to current nodeās parent.
Just alias for node.parent.insertAfter(node, add)
.
decl.after('color: black')
Insert new node before current node to current nodeās parent.
Just alias for node.parent.insertBefore(node, add)
.
decl.before('content: ""')
Clear the code style properties for the node and its children.
node.raws.before //=> ' '
node.cleanRaws()
node.raws.before //=> undefined
Returns an exact clone of the node.
The resulting cloned node and its (cloned) children will retain code style properties.
decl.raws.before //=> "\n "
const cloned = decl.clone({ prop: '-moz-' + decl.prop })
cloned.raws.before //=> "\n "
cloned.toString() //=> -moz-transform: scale(0)
Shortcut to clone the node and insert the resulting cloned node after the current node.
Shortcut to clone the node and insert the resulting cloned node before the current node.
decl.cloneBefore({ prop: '-moz-' + decl.prop })
Returns a CssSyntaxError
instance containing the original position
of the node in the source, showing line and column numbers and also
a small excerpt to facilitate debugging.
If present, an input source map will be used to get the original position of the source, even from a previous compilation step (e.g., from Sass compilation).
This method produces very useful error messages.
if (!variables[name]) {
throw decl.error(`Unknown variable ${name}`, { word: name })
// CssSyntaxError: postcss-vars:a.sass:4:3: Unknown variable $black
// color: $black
// a
// ^
// background: white
}
Returns the next child of the nodeās parent.
Returns undefined
if the current node is the last child.
if (comment.text === 'delete next') {
const next = comment.next()
if (next) {
next.remove()
}
}
Convert string index to line/column.
Returns the previous child of the nodeās parent.
Returns undefined
if the current node is the first child.
const annotation = decl.prev()
if (annotation.type === 'comment') {
readAnnotation(annotation.text)
}
Returns a Node#raws
value. If the node is missing
the code style property (because the node was manually built or cloned),
PostCSS will try to autodetect the code style property by looking
at other nodes in the tree.
const root = postcss.parse('a { background: white }')
root.nodes[0].append({ prop: 'color', value: 'black' })
root.nodes[0].nodes[1].raws.before //=> undefined
root.nodes[0].nodes[1].raw('before') //=> ' '
Removes the node from its parent and cleans the parent properties from the node and its children.
if (decl.prop.match(/^-webkit-/)) {
decl.remove()
}
Inserts node(s) before the current node and removes the current node.
AtRule: {
mixin: atrule => {
atrule.replaceWith(mixinRules[atrule.params])
}
}
Fix circular links on JSON.stringify()
.
Returns a CSS string representing the node.
new Rule({ selector: 'a' }).toString() //=> "a {}"
This method is provided as a convenience wrapper for Result#warn
.
Declaration: {
bad: (decl, { result }) => {
decl.warn(result, 'Deprecated property bad')
}
}