See LICENSE for this software's licensing terms.

SelectAllCheckbox is a JavaScript library which makes it easy to create "select all" checkboxes for checkbox groups.

This library is a vanilla JavaScript port of my jQuery SelectAllCheckbox plugin.

• This library is incompatible with all versions of IE. I do projects like this to learn, and I wanted to use ES6 features. (I tested in Chromium, Firefox and legacy Edge, and those were OK).
• The use of indeterminate checkboxes can no longer be disabled via configuration
• Minor API differences, though conceptually it's the same (see the Using section)

• Grants a checkbox control over a group of checkboxes to select or deselect all of them
• When checkboxes are individually checked/unchecked, the select-all checkbox's state updates accordingly between not checked, indeterminate (partially checked) and checked
• Supports any number of checkbox groups
• Configuration accepts a callback which executes when one or more checkboxes changes state
• The callback receives the changed checkbox(es) as an array of DOM objects, plus the status of the checkbox group (all/some/none checked)
• Select-all checkboxes do not modify the state of disabled checkboxes. Disabled checkboxes do affect the state of the select-all checkbox.

The callback function receives two arguments:

1. The affected checkboxes as an array of DOM objects
2. A string representing how many checkboxes in the group are checked; see CheckboxGroup.GROUP_STATE_NONE, CheckboxGroup.GROUP_STATE_SOME and CheckboxGroup.GROUP_STATE_ALL.

let group1 = new CheckboxGroup(
   "selectAllButton",
   "checkboxGroup",
   function( checkboxes, checkedState ) { do stuff; }
);

See demo/demo.html file for a more thorough demo.

If you change a checkbox's state via script (for example, with document.getElementById("box1").checked = true, you must manually fire the change event on the checkbox to ensure that the select-all checkbox's state is updated.