plotly#189 categorymode defaults

src/plots/cartesian/category_mode_defaults.js

@@ -0,0 +1,39 @@
+/**
+* Copyright 2012-2016, Plotly, Inc.
+* All rights reserved.
+*
+* This source code is licensed under the MIT license found in the
+* LICENSE file in the root directory of this source tree.
+*/
+
+'use strict';
+
+var layoutAttributes = require('./layout_attributes');
+
+module.exports = function handleCategoryModeDefaults(containerIn, containerOut, coerce) {
+
+    if(containerIn.type !== 'category') return;
+
+    var validCategories = layoutAttributes.categorymode.values;
+
+    var properCategoryList = Array.isArray(containerIn.categorylist) && containerIn.categorylist.length > 0;
+
+    if(validCategories.indexOf(containerIn.categorymode) === -1 && properCategoryList) {
+
+        // when unspecified or invalid, use the default, unless categorylist implies 'array'
+        coerce('categorymode', 'array'); // promote to 'array'
+
+    } else if(containerIn.categorymode === 'array' && !properCategoryList) {
+
+        // when mode is 'array' but no list is given, revert to default
+
+        containerIn.categorymode = 'trace'; // revert to default
+        coerce('categorymode');
+
+    } else {
+
+        // otherwise use the supplied mode, or the default one if unsupplied or invalid
+        coerce('categorymode');
+
+    }
+};