We introduced runtime validation of tag names because we used to generate
HTML that was supposed to be inserted into a HTML string which could've
been an XSS attack.
However, these days we use document.createElement in most cases. That
already does its internal validation in the browser which throws. We're now
double validating it. Stack still has a path where innerHTML is used and
we still need it there. However in Fiber we can remove it completely.
In #2756 we ended up using toLowerCase to allow case insensitive HTML tags.
However, this requires extra processing every time we access the tag or
at least we need to process it for mount and store it in an extra field
which wastes memory.
So instead, we can just enforce case sensitivity for HTML since this might
matter for the XML namespaces like SVG anyway.
From D4296244:
> Each [...] had a component with innerHTML = '', causing us to go into HTML parsing code in the browser. Doing this takes 0.03ms per parse call which was 10x slower than skipping it.
We've already been warning for mutating styles so now we'll freeze them
in DEV instead. This isn't as good because we don't have more specific
warnings than the generic error that doesn't even fire in sloppy mode.
This lets Fiber pass the same tests.
* Reapply Check for event listener in props instead of bank (#8192)
This reverts the previous revert.
* Don't throw on falsy event listeners
Some code relies on passing null. This restores the earlier behavior.
This reverts commit a878c3056d.
The previous stuff that this builds on didn't successfully land fully. Since I
want to measure this in isolation, I'll revert this for now.
This just reads events from the props instead of storing them in a
listener back.
I had to rewrite a bunch of tests to cover this model.
I removed the tests that just test the adding and removing over listeners
since there is no equivalent behavior anymore.
When there is no onChange event handler, we should still listen to it to
ensure controlled values get reset.
There is warning associated with this but the prod behavior should still be
respected.
* Use explicit pass for restoring controlled state instead of asap
This gets rid of the first class ReactUpdates.asap scheduling. Instead of
scheduling a first class function to invoke later, I introduce an explicit
phase for restoring controlled state after dispatching events.
We assume that the deepest event target is the thing that needs its state
restored.
* Drop special cases for onChange in wrappers
We're now not using anything special about onChange handling in the
wrappers. Yay!
* Check if textContent should be set for textarea
shouldSetNodeTextContent returns whether a node.textContent should be
updated. Currently it only covers one case, which is to avoid setting
the textContent if the text is empty and a placeholder exists.
* Only set node.value if it's equal to initialValue
In IE11 textContent is populated when the placeholder attribute is set.
Without this check, we end up setting node.value equal to the
placeholder text, causing the textarea to actually render with the text
inside.
This check makes sure that textContent is equal to our expected
initialValue, which should be the case when using defaultValue.
* Remove placeholder/textarea check, use contentToUse instead
This is already where we trap non-bubbling events. We also already branch
on the tag type so we know if it is interactive or not.
This will let us get rid of the didPutListener and willDeleteListener
abstractions.
I use a simple onclick = emptyFunction to avoid the need for a bookkeeping
map.
This is just moving a bunch of DOM files.
It moves things into dom/stack and dom/fiber respectively. The
dom/stack folder remains split into client/server.
Mainly the shared folder is now my best guess for files that
we can reuse in fiber. Everything else will get forked or
reimplemented.
Also moved the event system out of renderers/shared/stack and
into renderers/shared/shared.
