Why do links from custom link / image fields not appear in the link database?

Question

I am using the following custom fields on our instance of Sitecore 9.0.2:

Advance Image Field

https://github.com/saadahmedkhan/sitecore-fields

Sitecore Field Suite

https://github.com/Velir/SitecoreFieldSuite

When doing some testing, I found that custom link type fields were not showing relationships between items. For example, if an Advance Image Field linked to a media library item, we were able to delete that media library item without any warnings about broken links.

How do we ensure these fields correctly register links?

Answer 1

I found that the custom field must patch /App_Config/FieldTypes.config:

<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
    <sitecore>
        <fieldTypes>
          <!-- Register field so that image references will appear in the link database -->
          <fieldType name="Advance Image" type="SitecoreFramework.Fields.Fields.AdvanceImageField,SitecoreFramework.Fields" />
        </fieldTypes>
    </sitecore>
</configuration>

Once we confirmed showconfig.aspx was picking up this patch, I rebuilt the link database and the links were added to the database.

EDIT:

Another requirement is that the field must inherit from base Sitecore fields. In the case of FieldSuite, as of this date the module is not built in this manner.