Add isSupported method #355

dist/clipboard.js

@@ -728,6 +728,20 @@ module.exports = E;
                     this.clipboardAction = null;
                 }
             }
+        }], [{
+            key: 'isSupported',
+            value: function isSupported() {
+                var action = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : ['copy', 'cut'];
+
+                var actions = typeof action === 'string' ? [action] : action;
+                var support = !!document.queryCommandSupported;
+
+                actions.forEach(function (action) {
+                    support = support && !!document.queryCommandSupported(action);
+                });
+
+                return support;
+            }
         }]);
 
         return Clipboard;

src/clipboard.js

@@ -77,6 +77,22 @@ class Clipboard extends Emitter {
         }
     }
 
+    /**
+     * Returns the support of the given action, or all actions if no action is
+     * given.
+     * @param {String} [action]
+     */
+    static isSupported(action = ['copy', 'cut']) {
+        const actions = (typeof action === 'string') ? [action] : action;
+        let support = !!document.queryCommandSupported;
+
+        actions.forEach((action) => {
+            support = support && !!document.queryCommandSupported(action);
+        });
+
+        return support;
+    }
+
     /**
      * Default `text` lookup function.
      * @param {Element} trigger

test/clipboard.js

@@ -94,6 +94,17 @@ describe('Clipboard', () => {
         });
     });
 
+    describe('#static isSupported', () => {
+        it('should return the support of the given action', () => {
+            assert.equal(Clipboard.isSupported('copy'), false);
+            assert.equal(Clipboard.isSupported('cut'), false);
+        });
+
+        it('should return the support of the cut and copy actions', () => {
+            assert.equal(Clipboard.isSupported(), false);
+        });
+    });
+
     describe('#destroy', () => {
         it('should destroy an existing instance of ClipboardAction', () => {
             let clipboard = new Clipboard('.btn');