warc2zim's service worker captures all requests and then decides what to do based on
availability of the URL in the ZIM or not.
To allow the external URL blocking mechanism, it needs to known whether this was
enabled or not (as those in-iframe links won't be caught).
It detects this by looking for the `window.block_path` variable that is set in the
`block_external.js` script.
As this is fragile, we're adding a comment so that a future maintainer knows that
a third party tools relies on it.
if a link contains nested elements like `<a href="http://somewhere"><strong>goto</strong></a>`
then the link is trigger by the `<strong />` element which has no `href` attribute.
We were thus releasing the event in this case, resulting in legitimate external links
not blocked.
We are now looking for the closest `<a />` parent (might be self) to retrieve the `href`
attribute and capture if necessary.
- `setBlockExternalLinks()` on server
- zero-dependency JS code
- JS script added in `inject_externallinks_blocker()`
- changed URL to `/catch/external?source=<source>`
renaud gaudin