code: function(file) {
        var sections = file.contents.toString().split(END_REG);
  
        var blocks = [],
          files = [];
  
        var self = this;
  
        sections.forEach(function(s) {
          if (s.match(START_REG)) {
            // s[0] html code
            // s[1] string 'css' or 'js'
            // s[2] string dest url
            // s[3] tags of link or script
            s = s.split(START_REG);
            blocks.push(s[0]);
            switch (s[1]) {
              case 'css':
                blocks.push('<link rel="stylesheet" href="' + s[2] + '">');
                break;
              case 'js':
                blocks.push('<script src="' + s[2] + '"></script>');
                break;
              default:
                throw new gutil.PluginError('gulp-htmlbuild', 'only build:css build:js accept\n');
            }
            var paths = self.matchContentPaths(s[1] === 'css' ? CSSFILE_REG : JSFILE_REG, s[3]);
            var source = concatSource(paths);
            files.push({
              type: s[1],
              dest: resolveSrc(s[2], self.filedir),
              source: source
            });
          } else {
            blocks.push(s);
          }
        });
  
        return {
          blocks: blocks,
          files: files
        }
      }
docs: /*
  分析 html 代码
  return {blocks: ['html代码块'], files: [{type: 'css', paths: ['static file path']}]}