javascript - 解析 CSS 背景图像

Question

如何解析 CSS background-image，它支持多个值，可以是 none 和函数(例如 url() 和linear-gradient()) 有多个逗号分隔的参数？我似乎无法用正则表达式正确地做到这一点。一个好的测试用例如下:

  linear-gradient(top left, red, rgba(255,0,0,0))
, url(a)
, image(url(b.svg), 'b.png' 150dpi, 'b.gif', rgba(0,0,255,0.5))
, none

我想将其转换为以下数组:

[
      "linear-gradient(top left, red, rgba(255,0,0,0))"
    , "url(a)"
    , "image(url(b.svg), 'b.png' 150dpi, 'b.gif', rgba(0,0,255,0.5))"
    , "none"
]

Answer 1

function split (string) {
    var token = /((?:[^"']|".*?"|'.*?')*?)([(,)]|$)/g;
    return (function recurse () {
        for (var array = [];;) {
            var result = token.exec(string);
            if (result[2] == '(') {
                array.push(result[1].trim() + '(' + recurse().join(',') + ')');
                result = token.exec(string);
            } else array.push(result[1].trim());
            if (result[2] != ',') return array
        }
    })()
}

split("linear-gradient(top left, red, rgba(255,0,0,0)), url(a), image(url" +
      "(b.svg), 'b.png' 150dpi, 'b.gif', rgba(0,0,255,0.5)), none").toSource()

["linear-gradient(top left,red,rgba(255,0,0,0))", "url(a)",
 "image(url(b.svg),'b.png' 150dpi,'b.gif',rgba(0,0,255,0.5))", "none"]