Merge pull request #43 from ai/function

Add common rework.function to clean function filter

Readme.md

@@ -480,6 +480,40 @@ h1 {
 }
 ```
 
+### .function(object)
+
+  Add user-defined CSS functions.
+
+  For example create `black(0.5)` shortcut, to replace
+  long `rgba(0, 0, 0, 0.5)`.
+
+```js
+var css = rework(css)
+  .use(rework.function({ black: black }))
+  .toString()
+
+function black(opacity) {
+  return 'rgba(0, 0, 0, ' + opacity + ')';
+}
+```
+
+  User code will receive CSS arguments and replace user-defined function
+  by returned code.
+
+```css
+input {
+  box-shadow: 0 0 5px black(0.7);
+}
+```
+
+yields:
+
+```css
+input {
+  box-shadow: 0 0 5px rgba(0, 0, 0, 0.7);
+}
+```
+
 ### .references()
 
   Add property reference support.

examples/function.css

@@ -0,0 +1,3 @@
+input {
+  box-shadow: 0 0 5px black(0.7);
+}

examples/function.js

@@ -0,0 +1,15 @@
+
+var rework = require('..')
+  , read = require('fs').readFileSync;
+
+var css = rework(read('examples/function.css', 'utf8'))
+  .use(rework.function({
+    black: black
+  }))
+  .toString()
+
+function black(opacity) {
+  return 'rgba(0, 0, 0, ' + opacity + ')';
+}
+
+console.log(css);

lib/plugins/function.js

@@ -0,0 +1,49 @@
+
+/**
+ * Module dependencies.
+ */
+
+var visit = require('../visit');
+
+/**
+ * Define custom function.
+ */
+
+module.exports = function(functions) {
+  if (!functions) throw new Error('functions object required');
+  return function(style, rework){
+    visit.declarations(style, function(declarations){
+      for (var name in functions) {
+        func(declarations, name, functions[name]);
+      }
+    });
+  }
+};
+
+/**
+ * Escape regexp codes in string.
+ *
+ * @param {String} s
+ * @api private
+ */
+function escape(s) {
+  return s.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&');
+}
+
+/**
+ * Visit declarations and apply functions.
+ *
+ * @param {Array} declarations
+ * @param {Object} functions
+ * @api private
+ */
+function func(declarations, name, func) {
+  var regexp = new RegExp(escape(name) + '\\(([^\)]+)\\)', 'g');
+  declarations.forEach(function(decl){
+    if (!~decl.value.indexOf(name + '(')) return;
+    decl.value = decl.value.replace(regexp, function(_, args){
+      args = args.split(/,\s*/);
+      return func.apply(decl, args);
+    });
+  });
+}

lib/plugins/inline.js

@@ -3,7 +3,7 @@
  * Module dependencies.
  */
 
-var visit = require('../visit')
+var func = require('./function')
   , path = require('path')
   , mime = require('mime')
   , fs = require('fs')
@@ -29,25 +29,19 @@ module.exports = function(dirs) {
     dirs = Array.prototype.slice.call(arguments);
   }
 
-  return function(style, rework){
-    visit.declarations(style, function(declarations){
-      declarations.forEach(function(decl){
-        if (!~decl.value.indexOf('inline(')) return;
-        decl.value = decl.value.replace(/inline\(([^)]+)\)/g, function(_, name){
-
-          var file = dirs.map(function(dir) {
-            return path.join(dir, name);
-          }).filter(function(filePath){
-            return fs.existsSync(filePath)
-          })[0];
-
-          if (!file) throw new Error("Can't find `" + name + "` to inline");
-
-          var type = mime.lookup(file);
-          var base64 = new Buffer(read(file)).toString('base64');
-          return 'url("data:' + type + ';base64,' + base64 + '")';
-        });
-      });
-    });
+  return func({ inline: inline });
+
+  function inline(fileName){
+    var file = dirs.map(function(dir) {
+      return path.join(dir, fileName);
+    }).filter(function(filePath){
+      return fs.existsSync(filePath)
+    })[0];
+
+    if (!file) throw new Error("Can't find `" + fileName + "` to inline");
+
+    var type = mime.lookup(file);
+    var base64 = new Buffer(read(file)).toString('base64');
+    return 'url("data:' + type + ';base64,' + base64 + '")';
   }
 };

lib/plugins/url.js

@@ -4,7 +4,7 @@
  */
 
 var utils = require('../utils')
-  , visit = require('../visit');
+  , func = require('./function');
 
 /**
  * Map `url()` calls.
@@ -22,15 +22,10 @@ var utils = require('../utils')
  */
 
 module.exports = function(fn) {
-  return function(style, rework){
-    visit.declarations(style, function(declarations){
-      declarations.forEach(function(decl, i){
-        if (!~decl.value.indexOf('url(')) return;
-        decl.value = decl.value.replace(/url\(([^)]+)\)/g, function(_, url){
-          url = utils.stripQuotes(url);
-          return 'url("' + fn(url) + '")';
-        });
-      });
-    });
-  }
+  return func({ url: url });
+
+  function url(path){
+    path = utils.stripQuotes(path);
+    return 'url("' + fn(path) + '")';
+  };
 };

lib/rework.js

@@ -92,6 +92,7 @@ Rework.prototype.toString = function(options){
 
 exports.media = require('./plugins/media');
 exports.mixin = exports.mixins = require('./plugins/mixin');
+exports.function = exports.functions = require('./plugins/function');
 exports.prefix = require('./plugins/prefix');
 exports.colors = require('./plugins/colors');
 exports.extend = require('./plugins/extend');

test/fixtures/function.css

@@ -0,0 +1,4 @@
+@font-face {
+  scr: fonts(a.woff,a.ttf, a.otf);
+  font-family: A
+}

test/fixtures/function.out.css

@@ -0,0 +1,4 @@
+@font-face {
+  scr: url(a.woff) format("woff"), url(a.ttf) format("truetype"), url(a.otf) format("opentype");
+  font-family: A
+}

test/rework.js

@@ -112,6 +112,24 @@ describe('rework', function(){
     })
   })
 
+  describe('.function()', function(){
+    it('should add custom function', function(){
+      rework(fixture('function'))
+        .use(rework.function({ fonts: fonts }))
+        .toString()
+        .should.equal(fixture('function.out'));
+
+      function fonts() {
+        var files = Array.prototype.slice.call(arguments);
+        var types = { woff: 'woff', ttf: 'truetype', otf: 'opentype' };
+        return files.map(function(file){
+          var ext = file.replace(/^.*\./, '');
+          return 'url(' + file + ') format("' + types[ext] + '")';
+        }).join(', ');
+      }
+    })
+  })
+
   describe('.references()', function(){
     it('should substitute @<word> with property values', function(){
       rework(fixture('references'))