Enable alternative text field for attachments added via ArcGIS Pro

[EricaNova]

I created a feature class in ArcGIS Pro and added attachments in Pro so I could bulk-upload them. Currently, AGOL does not support this functionality (ArcGIS Online currently does not allow batch-add for attachments).

When I manually add an image to a record in AGOL, I can add alternative text; there is a custom field here. See:  https://www.esri.com/arcgis-blog/products/arcgis-online/mapping/configure-pop-ups-tips-photos/

However, there is no alternative text field for the attachments I added in Pro. This is an important accessibility feature that is missing. Ideally, an alternative text field would also show up in my configure pop-up window, and I could use an expression or field to fill it. 

[MappyIan]

We've hit the exact same problem in a project we're working on.  We've loaded images as attachments on a polygon layer and published the layer to AGOL to expose in a web app.  But as mentioned by Erica, there's no functionality in AGOL to add alternative text to the Attachment block when configuring popups in Map Viewer.  Alternative text is a WCAG requirement, so it's surprising that suitable functionality isn't built in to Map Viewer.

The alternative approach is to upload all the images separately to AGOL as individual items, and then add them to the popup in Map Viewer using the Image block.  This allows us to specify fields to use as the URL and alternative text.

Really this functionality should be added to the Attachment block as having images as attachments against features is a really easy way of managing them rather than having to load them all in to AGOL as separate items that have to be managed individually for permissions, updates etc. etc.