`setAttribute` converts all attribute names to lowercase before setting

[webcomponents]

`setAttribute` converts all attribute names to lowercase before setting

[aaronshaf]

This bit me today with SVG's viewBox :-(

[aaronshaf]

This basically makes SVG unusable in some browsers in custom elements.

[chiefcll]

I was looking into this as well - I don't see why setAttribute is being patched as the mutation observer is handling the changing of attributes.

Seems like this can be fixed by removing:

custom-elements/src/custom-elements.js

Lines 759 to 785 in 36451e1

	const _nativeSetAttribute = Element.prototype.setAttribute;
	Element.prototype['setAttribute'] = function(name, value) {
	changeAttribute(this, name, value, _nativeSetAttribute);
	};
	const _nativeRemoveAttribute = Element.prototype.removeAttribute;
	Element.prototype['removeAttribute'] = function(name) {
	changeAttribute(this, name, null, _nativeRemoveAttribute);
	};
	function changeAttribute(element, name, value, operation) {
	name = name.toLowerCase();
	const oldValue = element.getAttribute(name);
	operation.call(element, name, value);
	// Bail if this wasn't a fully upgraded custom element
	if (element[_upgradedProp] == true) {
	const definition = _customElements()._definitions.get(element.localName);
	const observedAttributes = definition.observedAttributes;
	const attributeChangedCallback = definition.attributeChangedCallback;
	if (attributeChangedCallback && observedAttributes.indexOf(name) >= 0) {
	const newValue = element.getAttribute(name);
	if (newValue !== oldValue) {
	attributeChangedCallback.call(element, name, oldValue, newValue, null);
	}
	}
	}
	}

I have and everything still works in FF + Safari 10 - need to check IE11

[bicknellr]

This should be fixed (v1.0.0-alpha.4): http://jsbin.com/yayibu/edit?html,output

[bicknellr]

BTW, this is were the new patches to attribute methods of the Element prototype start:

custom-elements/src/Patch/Element.js

Line 119 in f4b6f1f

Utilities.setPropertyUnchecked(Element.prototype, 'setAttribute',