Marked this as blocking #5979.

We need something better specified than 'use metadata'.

1. If the 'native' clauses are removed from the dart2js DOM implementation, the resulting program would be malformed. E.g. native methods would look abstract, even though they exist.
2. It would impact dart2js throughput if we had to resolve all the metadata annotations just to see if the interesting ones are there. dart2js goes to great lengths to avoid parsing each class.

We do have an 'external' keyword, but that currently tied up with the 'patch' mechanism which is unsuited to the DOM libraries.

This is a related issue: Issue #9: Remove native keyword, replace with @­native annotation
I suggest we keep two issues - this one to properly specify how we should do these things, and the existing one as a work item for dart2js.

BTW the editor team did not know about "native" either, but when it was described to them, they had a CL to handle native classes and methods within the hour. It might be more efficient in the short term to simply educate the tool vendors how to work around the native 'keyword'.

Thanks Stephen. My point is, if our tool ecosystem has to deal with native and patch, we should either put it into the language or use language constructs. Having these "shadow" features seems weird to be, and are barriers to a richer tool ecosystem.

This comment was originally written by Hannes.R...@gmail.com

Hi :),

currently I use the native keyword.
what would be the correct way to code it then? Is there an example for the metadata way, or should I wait and stick with native till there is a proper implementation for it?

Thanks

Hannes, for the foreseeable future the native keyword is the way to interact with native extensions to the Dart code from the VM.

This comment was originally written by Hannes.R...@gmail.com

Cool, thanks!

Is the "native" keyword used in any place except the VM patch files?

If so, could we change those other places to use "external" instead. If they need a string, that can be added as metadata, like

    @­NativeCode("whattamagonnacall")
    external foo();

?
(The VM could do that too, but patch files are not really public, so the need is very small).

If it's only the VM using it now, we can close this issue.

It seems that, at least, the _blink/dartium, dart2js html, js/js_dart2js and tools/dom libraries use "native" notation.

Added Library-Html label.

Duplicate of #11606.