util.setAttributesBySelector(el, attrs)

Set attributes on the DOM element (SVG or HTML) el and its descendants based on the selector in the attrs object. The attrs object is of the form: { [selector]: [attributes }. For example:

var myEl = document.querySelector('.mydiv');
joint.util.setAttributesBySelector(myEl, {
    '.myDiv': { 'data-foo': 'bar' },    // Note the reference to the myEl element itself.
    'input': { 'value': 'my value' }
});

The code above sets 'data-foo' attribute of the myEl element to the value 'bar' and 'value' attribute of all the descendant inputs to the value 'my value'. This is a convenient way of setting attributes on elements (including themselves) and their descendants. Note that 'class' attribute is treated as a special case and its value does not override the previous value of the 'class' attribute. Instead, it adds this new class to the list of classes for the element referenced in the selector.