Media Picker Configured to Pick one AND ONLY one Image and not a pixel more gives you a UI to allow you to pick billions

[marcemarc]

Which Umbraco version are you using?

v16.3 RC3

Bug summary

With the popular incarnation of the Media Picker AKA Umbraco.MediaPicker.3 There is a weird UI quirk, that when you want to configure it to ONLY pick ONE image and not a pixel more... it seems to ignore the configuration, and allow the editor to pick as many images as they want, 'one at a time'... I'll add a video, once they've added an extra ijmage it immediately tells them 'This field exceeds the allowed amount of images'. Back in the olden days of V13, well it just didn't let you pick multiple images if you had configured the picker to only pick ONE image and not a pixel more.

Specifics

So this is on a Media Picker on a Block. For context, I've spun up the latest Umbraco version I can find V16 RC3 and installed Paul Seals clean starter kit...

The Media Picker is configured thus:

'Pick Multiple items IS NOT TICKED
The Amount is set to be in a range between 0 AND 1

This picker is configured as the Media Picker for Pauls simply named Image Row.

Now lets see it in action - so the restriction of 'one' only applies to the number of items that can be selected when the library is open to pick from, the defect appears to be to have a + choose option next to the image...

2025-10-07_16-56-48.mp4

WAIT - is this by design? is the thinking here that if an editor has picked an image, they might want to choose another first, and then remove the first one?? after they've picked the replacement... or is it it a bug?

Steps to reproduce

Install Umbraco
Install Paul Seal's Clean Starter Kit
Go to the About page, click on the Image Row - look you can choose multiple images, even though it's configured to only allow ONE and only ONE and not a pixel more.

Expected result / actual result

Previous versions of Umbraco wouldn't show the Choose + option to allow you to pick another media item if the Media Picker was configured to only allow one image to be picked!

---

This item has been added to our backlog AB#57549

[github-actions]

Hi there @marcemarc!

Firstly, a big thank you for raising this issue. Every piece of feedback we receive helps us to make Umbraco better.

We really appreciate your patience while we wait for our team to have a look at this but we wanted to let you know that we see this and share with you the plan for what comes next.

• We'll assess whether this issue relates to something that has already been fixed in a later version of the release that it has been raised for.
• If it's a bug, is it related to a release that we are actively supporting or is it related to a release that's in the end-of-life or security-only phase?
• We'll replicate the issue to ensure that the problem is as described.
• We'll decide whether the behavior is an issue or if the behavior is intended.

We wish we could work with everyone directly and assess your issue immediately but we're in the fortunate position of having lots of contributions to work with and only a few humans who are able to do it. We are making progress though and in the meantime, we will keep you in the loop and let you know when we have any questions.

Thanks, from your friendly Umbraco GitHub bot 🤖 🙂

[bjarnef]

It has also been reported in #20225

I see the challenge regarding ModelsBuilder and if the property previously was a multiple picker.

However I think it initially should indicate a single item can be picked as (although it may return as collection in ModelsBuilder).

In case previously e.g. 3 images were selected, I guess it can show a validation error based on min/max in configuration of datatype.

When the extra images are removed I imagine it shows as a single picker.

Perhaps the add button only need to be shown when maximum is not equal to 1.

In my opinion it is okay to show validation errors, but better to be proactive and avoid them to happen in first place when possible.
E.g. when it is expected to be a single picker, I don't see a reason content should be two or three images just to get validation error afterwards.

Unfortunately I also think the "single mode" in block list has a side-effect on how we used to work with single blocks causing validation errors, where it previously was optional to fill:
#18115

[iOvergaard]

The problem here really is that the property editor can change its output based on configuration. Imagine setting up a media picker that picks 3 images, and an editor does just that.

Later, the developer changes it to allow only one image.

Next, the editor publishes the document again, none the wiser, and all of a sudden loses two out of three images without having made a conscious decision.

The media picker, as of V16, now allows you to pick multiple images (even though it is configured to pick only one following #19900) and controls that with the validation system instead. That way, the user can choose what to keep. You are, after all, not allowed to publish a page that exceeds the boundaries of the picker.

That all being said, I could imagine us landing on a compromise, where we don't allow the user to pick more images on a freshly configured media picker, but only allow it if there is already picked more than the allowed number of images.

Would that sound like a suitable solution?

P.S. We are going to tackle single/multiple modes at some point with the introduction of a "single-mode block list", and the media picker will possibly, at some point, be forced to return a collection. It is too dangerous to have the Models Builder change depending on a data type configuration.

[bjarnef]

@iOvergaard I wouldn't say it need to change output (as it has done previously based on single/multi picker), more a UI/UX question.

If changing configuration back to max 1 and previously 3 images were selected, I imagine in only show add button if no images were selected - and the number of images/medias exceeding the maximum limit were marked as invalid + validation error on publish, but it still save document (as it currently does for e.g. missing mandatory properties).

If previously 3 images and changing to maximum 1 image, I guess output from converter would still be 3 images (as they were originally published), until the 2 extra images are removed - but it doesn't allow a new publish until the validation errors are handled.

[iOvergaard]

Let's not confuse the two things at play. The Models Builder changes the strongly typed models as soon as you set the media picker to pick a single image. That doesn't mean that the data doesn't hold more images. But that's a problem for the frontend.

In the Backoffice, we would like the user to make a conscious decision about which images to keep, hence why it displays the original dataset regardless of configuration.

I think what @marcemarc is saying is that it is confusing to let the user pick more than one (additional) image if they aren't allowed to do so. Let's address that - I'll bring it up with the team.

[bjarnef]

Yes, I am not talking about how the converter and Models Builder handle the data - more a visual indication in UI/UX indication that only a single image is expected.

In the past in general pickers removed add button, when selected items reached the limit. IIRC the behavior started to change when Block List was introduces, where add button still was shown when reaching maximum and instead validation errors are shown.

I think this is okay for a multi picker (2 or more - or not maximum). However for especially for a single picker, I think content editors will be frustrated to allow selecting another image - just to discover it fails :)

[iOvergaard]

Good input, @bjarnef. We could specifically check if the media picker is configured to be "single mode" and not show the Add button in that case.

[bjarnef]

I don't recall if media cards have a invalid/error state, but if changed to a single picker, it can possible highlight images previously selected beside the first?
https://uui.umbraco.com/?path=/story/uui-card--error

Maybe sorting is still enabled, so it can re-arrange items. Ideally a single picker probably shouldn't be sortable - not sure if it can be handled dynamically based on single picker and when editor is updated to contain none or one item.

[marcemarc]

@iOvergaard Yes I think that's how it worked in V13, the configuration of the Media Picker dictated the UI that was displayed to the editor, leaving a clear UX for when an editor only has to pick a single image. (and not a pixel more)