Please explain DOI hyperlinking

Katie, I’ve gotten to the bottom of this, and I would like to suggest a change to shortcode.request.php, the section // Hyperlink DOIs, beginning line 664. The change is shorter than the original, covers more cases, and causes ZP to behave more like Zotero. When the style presents a DOI variable, there are really just two basic cases: a) we create a hyperlink that only shows the DOI itself (for styles that use ‘doi:’, ‘doi: ‘, or only the bare DOI), or b) a hyperlink that shows the link text as well (https://doi.org/). In the latter case, if the style presents http://doi.org/, I see no reason why ZP shouldn’t output https anyway, but maybe there is a reason.

Here is the suggested code:

				// Hyperlink DOIs
				if ( isset($item->data->DOI)
						// && $item->data->DOI !== null
						&& strlen($item->data->DOI) > 0 )
				{
					// Styles without link text +
					if ( strpos( $item->bib, "doi.org" ) == false )
					{
         				$item->bib = str_ireplace(
   								$item->data->DOI,
   								"<a class='zp-DOIURL' ".$zp_target_output."href='https://doi.org/".$item->data->DOI."'>".$item->data->DOI."</a>",
   								$item->bib
   							);
     				}
					// Styles with http or https
					elseif ( strpos( $item->bib, "doi.org/" ) !== false
                            && strpos( $item->bib, "</a>" ) == false )
					{
         				$item->bib = preg_replace(
   								"#https?://doi.org/\S+#i",
   								"<a class='zp-DOIURL' ".$zp_target_output."href='https://doi.org/".$item->data->DOI."'>https://doi.org/".$item->data->DOI."</a>",
   								$item->bib
   							);
					}
				}