cssify-to-json/src/index.js

CSS pseudo-rules parser, to be used as a transform for Browserify

/**
 * the CSSify-to-json transform matches all occurences of the following string in the *.js source files :
 * "@CSSify exports : .aClassName foregroundColor/stdTextColor/emphasizeTextColor/borderColor/bevelColor/roundedCorner/bigRoundedCorner/etc."
 * and writes the formatted result in a json file for the server templating engine to compile 
 * "ad-hoc" CSS with the exactly-needed number of rules.
 * 
 * Benefit : avoids the need to decompose styles and selectively add mini-classes 
 * 			when a component uses a generic combination of styling rules 
 */

var themableCSSselectors = {}
module.exports = function(file, options) {
	var through = require('through');
	var fs = require('fs');

	var content = '';
	var componentExportedClassNames;
	var className, sep = ', ';
	
	return through(write, end);
	// callback (cb) function is not used here
	
	function write(buf) {
		componentExportedClassNames = buf.toString().matchAll(/@CSSify\sexports\s?:\s*(\.[^\s]+)\s([\w\/]+)/g);
		if (null !== componentExportedClassNames) {
			for(var matches of componentExportedClassNames) {
				className = matches[1];
				matches[2].split('/').forEach(function(prop) {
					sep = ', ';
					if (typeof themableCSSselectors[prop] === 'undefined') {
						themableCSSselectors[prop] = '';
						sep = '';
					}
					themableCSSselectors[prop] += sep + className;
				});
			};
		}
		return content += buf;
	}
	
	function end() {
		fs.writeFileSync((options.pathToProject|| '') + 'css/jsComponents_css_compile.json.html', JSON.stringify(themableCSSselectors));
		this.queue(content);
		this.queue(null);
	}
}