notification resource-file causing source path error

[rolinger]

I followed all the steps here : https://github.com/dpa99c/cordova-plugin-firebasex#android-default-notification-icon

Created the icons, then added the <resource-file ...> lines to the config.xml file (and the <edit-config ...and finally added the files to the /app/res/src/main/res/drawable-XYpi` folders and when I did my first build I got the following error:

Source path does not exist: resources/android/drawable-hdpi/notification_icon.png

To fix this, I had to add all the icon files to the /project/resources/android/drawable-XYpifolders. In fact, for my Ionic project, I had to create the drawable folders as this did not exist. My assumption was if those files and config.xml resource-files were defined thecordova build androidwould auto create/add the folders and files to the/project/resources` directory for me.

In the documentation, you might want to reflect what I had to do to get those files added to the project - it took me a few minutes to realize the source path does not exist was because it wasn't being auto created.