Merge pull request #1657 from gnestor/build-css-watch

Add `npm run build:css:watch` script

package.json

@@ -16,7 +16,7 @@
     "build:css": "concurrent \"npm run build:css:ipython\" \"npm run build:css:style\"",
     "build:css:ipython": "lessc --include-path=notebook/static notebook/static/style/ipython.less notebook/static/style/ipython.min.css",
     "build:css:style": "lessc --include-path=notebook/static notebook/static/style/style.less notebook/static/style/style.min.css",
-    "build:css:watch": "echo Not implemented yet...",
+    "build:css:watch": "./scripts/less-watch ./notebook/static",
     "build:js": "webpack",
     "build:js:watch": "npm run build:js -- --watch"
   },

scripts/less-watch

@@ -0,0 +1,39 @@
+#!/usr/bin/env node
+
+/**
+
+Usage:
+./scripts/less-watch [watchPath]
+
+Example:
+./scripts/less-watch ./notebook/static/notebook/less
+
+**/
+
+var less = require('less');
+var fs = require('fs');
+var path = require('path');
+var child_process = require('child_process');
+
+function watchDir(dir) {
+  var rootPath = path.join(__dirname, '..');
+  var watchPath = path.resolve(dir);
+  console.log('less-watch:', 'watching:', path.relative(rootPath, watchPath));
+  fs.watch(watchPath, {recursive: true}, function(event, file) {
+    if (file && /.+\.less$/.test(file)) {
+      console.log('less-watch:', 'modified:', file);
+      child_process.exec('lessc --include-path=notebook/static --verbose notebook/static/style/style.less notebook/static/style/style.min.css', function(err, stdout, stderr) {
+        if (err) return console.log(err);
+        if (stdout) console.log(stdout);
+        if (stderr) console.log(stderr);
+      });
+      child_process.exec('lessc --include-path=notebook/static notebook/static/style/ipython.less notebook/static/style/ipython.min.css', function(err, stdout, stderr) {
+        if (err) return console.log(err);
+        if (stdout) console.log(stdout);
+        if (stderr) console.log(stderr);
+      });
+    }
+  });
+}
+
+watchDir(process.argv[2]);