Merge pull request #11 from meszaros-lajos-gyorgy/master

Added onImport config key for compatibility with postcss-import

Author: matthew-dean

README.md

@@ -147,3 +147,20 @@ grunt.initConfig({
 	}
 });
 ```
+
+#### Misc
+
+Similarly to `postcss-import`, the list of imported files can be viewed by
+assigning a function to the `onImport` key among the options:
+
+```javascript
+less({
+	/* other Less.js options */
+	onImport: function(sources){
+		console.log(sources)
+	}
+})
+```
+
+The received sources will be an array of strings, containing the absolute path
+to the files, which were imported, including the source file.

index.js

@@ -6,6 +6,10 @@ var postcss = require('postcss')
 
 var render = require("./lib/render")(less.ParseTree, less.transformTree);
 
+function isFunction(f){
+	return typeof f === 'function';
+}
+
 function LessPlugin() {
 	var cacheInput;
 
@@ -272,16 +276,19 @@ function LessPlugin() {
 		    	}
 	    	}
 
-	        return new Promise(function (resolve, reject) {
-
-	        	cacheInput = cacheInput.toString();
-	        	if(!cacheInput) {
-	        		// TODO: explain the error
-	        		reject(new CssSyntaxError(
-	        			"No input is present"
-	        		));
-	        	}
-	            render(cacheInput, opts, function(err, tree, evaldRoot, imports) {
+			return new Promise(function (resolve, reject) {
+				var onImport = opts.onImport;
+				
+				delete opts.onImport
+				
+				cacheInput = cacheInput.toString();
+				if(!cacheInput) {
+					// TODO: explain the error
+					reject(new CssSyntaxError(
+						"No input is present"
+					));
+				}
+				render(cacheInput, opts, function(err, tree, evaldRoot, imports) {
 					if(err) {
 						// Build PostCSS error
 						return reject(new CssSyntaxError(
@@ -299,7 +306,11 @@ function LessPlugin() {
 						context = {};
 						// Convert Less AST to PostCSS AST
 						convertImports(imports.contents);
-
+						
+						if(isFunction(onImport)){
+							onImport(Object.keys(postCssInputs))
+						}
+						
 						processRules(css, evaldRoot.rules);
 						resolve();
 					}