Clipboard bugfix (#70)

Brings over bug fix for table clipboard issue that was fixed
on the internal repo.

packages/table/src/common/clipboard.ts

@@ -30,7 +30,7 @@ export const Clipboard = {
      * See `Clipboard.copy`
      */
     copyCells(cells: string[][]) {
-        const table = document.createElement("tbody");
+        const table = document.createElement("table");
         Clipboard.applySelectableStyles(table);
         for (const row of cells) {
             const tr = table.appendChild(document.createElement("tr"));
@@ -40,7 +40,8 @@ export const Clipboard = {
             }
         }
 
-        return Clipboard.copyElement(table);
+        const tsv = cells.map((row) => row.join("\t")).join("\n");
+        return Clipboard.copyElement(table, tsv);
     },
 
     /**
@@ -54,13 +55,19 @@ export const Clipboard = {
         Clipboard.applySelectableStyles(text);
         text.value = value;
 
-        return Clipboard.copyElement(text);
+        return Clipboard.copyElement(text, value);
     },
 
     /**
      * Copies the element and its children to the clipboard. Returns a boolean
      * indicating whether the copy succeeded.
      *
+     * If a plaintext argument is supplied, we add both the text/html and
+     * text/plain mime types to the clipboard. This preserves the built in
+     * semantics of copying elements to the clipboard while allowing custom
+     * plaintext output for programs that can't cope with HTML data in the
+     * clipboard.
+     *
      * Verified on Firefox 47, Chrome 51.
      *
      * Note: Sometimes the copy does not succeed. Presumably, in order to
@@ -69,7 +76,7 @@ export const Clipboard = {
      * inconsistent limit at about 300KB or 40,000 cells. Depending on the on
      * the content of cells, your limits may vary.
      */
-    copyElement(elem: HTMLElement) {
+    copyElement(elem: HTMLElement, plaintext?: string) {
         if (!Clipboard.isCopySupported()) {
             return false;
         }
@@ -78,6 +85,20 @@ export const Clipboard = {
         document.body.appendChild(elem);
         try {
             window.getSelection().selectAllChildren(elem);
+
+            if (plaintext != null) {
+                // add plaintext fallback
+                // http://stackoverflow.com/questions/23211018/copy-to-clipboard-with-jquery-js-in-chrome
+                elem.addEventListener("copy", (e: UIEvent) => {
+                    e.preventDefault();
+                    const clipboardData = (e as any).clipboardData || (window as any).clipboardData;
+                    if (clipboardData != null) {
+                        clipboardData.setData("text/html", elem.outerHTML);
+                        clipboardData.setData("text/plain", plaintext);
+                    }
+                });
+            }
+
             return document.execCommand("copy");
         } catch (err) {
             return false;