This prevents feature tests like:
var ReactElement = React.createElement(...).constructor;
if (element.constructor === ReactElement)
This is intentional so that we have the option to make these plain objects.
E.g. for direct inlining or replacing them with value types.
Because the JS community's polyfilling infrastructure sucks and we'll
have to fix it for them before we require this.
JSX spread uses React.__spread
(which might get special behavior for key/ref, not sure yet)
This never uses the native implementation and throws for prototype chains.
Once the native implementations are faster, we'll start using them.
People may have a bad time if they're depending on these but we can
delay that a little bit. Unless they're using directly and not
polyfilling Object.assign.
Because we're using innerHTML to generate DOM Elements, we need to make
sure that the tag is sane and doesn't try to do injection.
This wouldn't be an issue if we used document.createElement instead.
* ReactComponents aren't really the thing we need, ReactElements are
* Remove the deprecation notice that we've had in there for a long time
Test Plan: build, jest
This makes it easier to contribute without having to learn a bunch of
slightly different helpers and remember their slightly different
signatures and semantics.
We'll probably start using ES7 spread properties instead of merge in the
future when at least one more transpiler supports it.
React.DOM is becoming helper factories to generate ReactElements. They're not
classes. It will be ok to call them directly as functions, but not to use them
where a class is expected.
I grepped for uses of React.DOM. This is going to be a set of helper functions
to generate ReactElements without JSX.
They're not classes so they cannot be used where a React class is expected.
Since we always use JSX, we should have no internal use for these helpers.
We can use strings instead.
We're trying to move to a convention where lower-case variables on JSX are always HTML/SVG tags rather than variables in scope. See:
http://fb.me/react-jsx-lower-case
Therefore, this diff renames existing uses to upper case variables.
This throws an error on all these files, so I manually go rename all the variables. I then run lint to ensure that the rename doesn't leave any undeclared variables.
This makes ReactDOM a simple helper for creating ReactElements with the string tag as the type. The actual class is internal and created by instantiateReactComponent. Configurable using injection.
There's not a separate class for each tag. There's just a generic ReactDOMComponent which could take any tag name.
Invididual tags can be wrapped. When wrapping happens you can return the same tag again. If the wrapper returns the same string, then we fall back to the generic component. This avoids recursion in a single level wrapper.