aaac7fed
 liuqimichale
add
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
/**
* Module dependencies.
*/
var reduceCSSCalc = require("reduce-css-calc")
var helpers = require("postcss-message-helpers")
var postcss = require("postcss")
var CONTAINS_CALC = /\bcalc\([\s\S]*?\)/
/**
* PostCSS plugin to reduce calc() function calls.
*/
module.exports = postcss.plugin("postcss-calc", function(options) {
options = options || {}
var precision = options.precision
var preserve = options.preserve
var warnWhenCannotResolve = options.warnWhenCannotResolve
var mediaQueries = options.mediaQueries
var selectors = options.selectors
return function(style, result) {
function transformValue(node, property) {
var value = node[property]
if (!value || !CONTAINS_CALC.test(value)) {
return
}
helpers.try(function transformCSSCalc() {
var reducedValue = reduceCSSCalc(value, precision)
if (warnWhenCannotResolve && CONTAINS_CALC.test(reducedValue)) {
result.warn("Could not reduce expression: " + value,
{plugin: "postcss-calc", node: node})
}
if (!preserve) {
node[property] = reducedValue
return
}
if (reducedValue != value) {
var clone = node.clone()
clone[property] = reducedValue
node.parent.insertBefore(node, clone)
}
}, node.source)
}
style.walk(function(rule) {
if (mediaQueries && rule.type === "atrule") {
return transformValue(rule, "params")
}
else if (rule.type === "decl") {
return transformValue(rule, "value")
}
else if (selectors && rule.type === "rule") {
return transformValue(rule, "selector")
}
})
}
})
|
