feat: add onClick event to PDFDownloadLink

[adamduncan]

Based on request #975 and our own experience, having an onClick handler to invoke for PDFDownloadLink would be benficial. E.g. We'd like to send a custom event to our analytics on download. (We're finding other means to lazily load the heavier components, so wouldn't need to resort to the workaround for this feature proposed there.)

This implementation refactors the existing onClick handler slightly, to also allow consumer's to provide a function via props. We conditionally call this function after existing handleDownloadIE. (We'd generally opt for onClick?.(), but as this package targets Node v12, we'll check typeof before invoking.)

I've included the event as the first function argument, should the consumer need to use native event properties. That seems like the expected behaviour. Secondly, we pass along the instance, which might be helpful in certain circumstances. If that's not a beneficial use-case, would gladly omit.

Added types. Not sure that this component has unit tests, but happy to add if need be.

Fixes #975

[diegomura]

Thanks so much!

[aclec]

Hi, I have an issue with your Type in TS:

node_modules/@react-pdf/renderer/index.d.ts:451:15 - error TS2552: Cannot find name 'function'. Did you mean 'Function'?

451     onClick?: function;
                  ~~~~~~~~

  node_modules/typescript/lib/lib.es5.d.ts:324:13
    324 declare var Function: FunctionConstructor;
                    ~~~~~~~~
    'Function' is declared here.


Found 1 error in node_modules/@react-pdf/renderer/index.d.ts:451

[adamduncan]

@aclec My mistake. Rushed that one through. PR here #1924

[miladehghani]

@adamduncan I still can see the issue @aclec mentioned on @react-pdf/renderer@2.3.0 have you fixed it on that version?

[adamduncan]

@miladehghani I believe the PR has been merged into master but a fixed 2.3.1 patch version of that package hasn't yet been released