EZP-27572: Markdown specs for the selection buttons.

doc/spec/selection-button.md

@@ -0,0 +1,21 @@
+## Provides the suggested markup for the selection buttons
+
+
+```html
+  <table class="ez-selection-table" data-selection-buttons=".mybutton">
+  <tr class="ez-selection-table-row">
+      <td>
+          <input type="checkbox" class="ez-selection-table-checkbox">
+      </td>
+  </tr>
+  <!-- ... -->
+  </table>
+  <button class="mybutton" data-can-multiple-selection="true" disabled="disabled">Do!</button>
+```
+
+
+
+This is a very similar markup from what we had in PlatformUI (see https://github.com/ezsystems/PlatformUIBundle/blob/master/Resources/public/js/extensions/ez-selection-table.js#L27) :
+
+When a `ez-selection-table-checkbox` checkbox is checked, its `ez-selection-table-row` ancestor gets the `is-row-selected` class and if there's one checked checkbox, the buttons that match the selector in the `data-selection-buttons` attribute are enabled.
+If others checkboxes are checked the button will still stay enabled if it has its `data-can-multiple-selection` to `true`. If it's not it will get disabled back.