Web Panel Breaking Change Deprecation for Confluence 9

The way you can add a provider class/script for web panels is different after upgrading to Confluence 9.0.

Tip: Most simple scripts, like writer.write("some HTML"), will continue to work correctly.

This breaking change only impacts users who used class implementations of the Atlassian WebPanel interface for the Provider class/script

We recommend you fix/update the Show a web panelprovider class/scripts, as described below.

Fix/Update the Show a web panel provider class/scripts

The following is an example of an outdated provider class/script:

import com.atlassian.plugin.web.model.WebPanel
 
class MyWebPanel implements WebPanel {
    @Override
    String getHtml(Map<String, Object> context) {
        ""
    }
    
    @Override
    void writeHtml(Writer writer, Map<String, Object> context) throws IOException {
        writer.write("<div>Hello World!</div>")
    }
}

In this script the writeHtml method will be ignored with Confluence 9.0 and the import has been deprecated. You can update these as follows:

Update the getHtml/writeHtml methods:
- Problem: The writeHtml method will be ignored, so any content generated using this method alone will not be rendered.
- Solution: From now on, only use the getHtml method to return the HTML content that you want the panel to render.
Update the WebPanel interface:
- Problem: If you're using Atlassian's com.atlassian.plugin.web.api.model.WebPanel interface, this has now been deprecated. Using the deprecated interface will still compile until Atlassian fully removes it in a later release. However, we recommend you update to the new interface now if you were using it in your script to avoid this breaking in the future.
- Solution: Replace the `com.atlassian.plugin.web.model.WebPanel` Import with `com.atlassian.plugin.web.api.model.WebPanel` instead.

The fixed/updated script would look something like this:

import com.atlassian.plugin.web.api.model.WebPanel
 
class MyWebPanel implements WebPanel {
    @Override
    String getHtml(Map<String, Object> context) {
        "<div>Hello World!</div>"
    }
    
    @Override
    void writeHtml(Writer writer, Map<String, Object> context) throws IOException {
        // not used
    }
}