Assert key is not in Dynamic Attributes

[jridgewell]

A changing key attribute (but not passed as the key parameter) could cause havoc. Force key to always be static.

This is of particular interest to compile to iDOM build steps, since a runtime attr(name, value) would be impossible to catch:

var attrs = { key: 'key' };

elementOpenStart('div');
for (var name in attrs) {
    attr(name, attrs[name]);
}
elementOpenEnd('div');
elementClose('div');

[sparhami]

It doesn't seem like we should even allow a static attribute named 'key' or (better) for a pre-rendering flow use some attribute other than 'key'.

[jridgewell]

It doesn't seem like we should even allow a static attribute named 'key'

I was planning on using $('[key="key"]') to hook into my own code, though I'm exploring other ideas.

(better) for a pre-rendering flow use some attribute other than 'key'

That might tie in nicely with #50?

[jridgewell]

Also worth noting, if the statics and key are properly done, the attribute and the NodeData#key will always be in sync:

var key = 'key';
var statics = ['id', 'id', 'key', key];

function render() {
  statics[3] = key;
  elementVoid('div', key, statics);
}

patch(container, render);
key = 'other';
patch(container, render);

That's because the new key param will force a new div to be created, and it'll have the proper attribute.

[jridgewell]

Closing due to certain situations where a key cannot be in the statics array:

function render(items) {
  items = items.map((el, i) => {
    return <div id="id" key={i} />;
  });
  return <div>{items}</div>;
}

// - - -

var _statics13 = ["id", "id"];

function render(items) {
  items = items.map(function (el, i) {
    return _jsxWrapper(function () {
      return elementVoid("div", i, _statics13, "key", i);
    });
  });
  elementOpen("div");
    items.forEach((item) => item());
  return elementClose("div");
}

In this case, to properly hoist the statics, I cannot include key.