Move default language to its own file

Author: jakezatecky

README.md

@@ -163,7 +163,7 @@ Returns:
 | `icons`              | object   | An object containing the mappings for the various icons and their components. See **Changing the Default Icons**.      | `{ ... }`        |
 | `iconsClass`         | string   | A string that specifies which icons class to utilize. Currently, `'fa4'` and `'fa5'` are supported.                    | `'fa5'`          |
 | `id`                 | string   | A string to be used for the HTML ID of the rendered tree and its nodes.                                                | `null`           |
-| `lang`               | object   | An object containing the language mappings for the various text elements.                                              | `{ ... }`        |
+| `lang`               | object   | A key-value pairing of localized text. See [`src/js/lang/default.js`][lang-file] for a list of keys.                   | `{ ... }`        |
 | `name`               | string   | Optional name for the hidden `<input>` element.                                                                        | `undefined`      |
 | `nameAsArray`        | bool     | If true, the hidden `<input>` will encode its values as an array rather than a joined string.                          | `false`          |
 | `nativeCheckboxes`   | bool     | If true, native browser checkboxes will be used instead of pseudo-checkbox icons.                                      | `false`          |
@@ -197,5 +197,6 @@ Individual nodes within the `nodes` property can have the following structure:
 [docs-controlled]: https://facebook.github.io/react/docs/forms.html#controlled-components
 [docs-state-hooks]: https://reactjs.org/docs/hooks-state.html
 [font-awesome]: https://fontawesome.com
+[lang-file]: https://github.com/jakezatecky/react-dual-listbox/blob/master/src/js/lang/default.js
 [mdn-key]: https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/key
 [react-fontawesome]: https://github.com/FortAwesome/react-fontawesome

src/js/CheckboxTree.jsx

@@ -6,13 +6,14 @@ import PropTypes from 'prop-types';
 import React from 'react';
 
 import Button from './Button';
-import { CHECK_MODEL, KEYS } from './constants';
 import NodeModel from './NodeModel';
 import TreeNode from './TreeNode';
+import defaultLang from './lang/default';
 import iconsShape from './shapes/iconsShape';
 import languageShape from './shapes/languageShape';
 import listShape from './shapes/listShape';
 import nodeShape from './shapes/nodeShape';
+import { CHECK_MODEL, KEYS } from './constants';
 
 class CheckboxTree extends React.Component {
     static propTypes = {
@@ -67,11 +68,7 @@ class CheckboxTree extends React.Component {
         },
         iconsClass: 'fa5',
         id: null,
-        lang: {
-            collapseAll: 'Collapse all',
-            expandAll: 'Expand all',
-            toggle: 'Toggle',
-        },
+        lang: defaultLang,
         name: undefined,
         nameAsArray: false,
         nativeCheckboxes: false,

src/js/lang/default.js

@@ -0,0 +1,5 @@
+export default {
+    collapseAll: 'Collapse all',
+    expandAll: 'Expand all',
+    toggle: 'Toggle',
+};