Change the way banners are handled

[brandonStell]

We have received this report from a user:

Hi,

The article here;
https://www.pnas.org/content/108/31/12937

Has a pop-up from your Firefox plugin claiming that this article is
retracted.

This is not the case, and clicking on the link take me to this pubpeer
post;
https://pubpeer.com/publications/44C82071DAEF19BAE1A4092E3A5D45?utm_source=Firefox&utm_medium=BrowserExtension&utm_campaign=Firefox

The correct article that is retracted is this one;
https://www.cell.com/cell-metabolism/supplemental/S1550-4131(08)00238-6

There must be a error in the database that your plugin uses, which would
severely limit it's usability.

I think that this occurs because one of the articles in the reference list at the bottom has been retracted. (see here: https://www.pnas.org/content/108/31/12937#ref-39). A potential solution is the following:

• If there is only one DOI found on the page then no changes necessary.
• If there are multiple DOIs found on the page and only one of them has information from PubPeer, then change the banner to: "An article on this page...".
• Make sure that the PubPeer tag is inserted into the page appropriately. (not the case here: https://www.pnas.org/content/108/31/12937#ref-39)
• If multiple DOIs are found on the page and more than one of them has PubPeer information, then no changes are necessary.

I guess that these changes will apply to retractions/ expressions of concern, and also regular green pubpeer banners.