topic Re: Use expression for a property value in custom visual? in Developer

Use expression for a property value in custom visual?

jprmsn — Sun, 13 Jun 2021 00:44:31 GMT

Is there any way for me to allow an expression to be used for a property value?

ideally, this would be a singl text property that the user could set using a Dax expression, but I'm open to workarounds as well. Anything that could get the value of a Dax expression to my custom visual as a property as opposed to a data value.
Thanks.
John

Re: Use expression for a property value in custom visual?

dm-p — Sun, 13 Jun 2021 23:07:00 GMT

Hi @jprmsn,

If I understand correctly, you're looking to supply the results of a measure into the propertied pane, rather than a user manually specifying a value? If so, then enabling conditional formatting for a property supports measures that return text.

Regards,

Daniel

Re: Use expression for a property value in custom visual?

jprdynamicapps — Mon, 14 Jun 2021 17:48:25 GMT

Thanks, Daniel. Will get up to speed on that and try it out and then post back.

Re: Use expression for a property value in custom visual?

jprdynamicapps — Mon, 14 Jun 2021 18:26:04 GMT

Unfortunately, apparently not supported for table and matrix dataviews.

Re: Use expression for a property value in custom visual?

dm-p — Mon, 14 Jun 2021 22:59:50 GMT

For table and matrix mappings, it will work if you just want to populate a single property, which is how I've interpreted your original question - essentially like the way the Title text property works in the standard Title menu.

Although yes, it likely won't work if you want to do data bound mapping (e.g. rows to colors).

I've implemented this approach in the HTML Content visual, which uses a table mapping. It works perfectly fine for the "No Data" Message property:

Here's a link to the location in the code where it's implemented so that you can hopefully take this and use it, if it suits your use case.

There's also a second property in the source code beneath the linked one, and this should turn up in all reports shortly, once the visual has been fully approved through to AppSource, but both work fine.

Re: Use expression for a property value in custom visual?

jprdynamicapps — Tue, 15 Jun 2021 12:49:20 GMT

Thanks, Daniel.

I can confirm that all anyone needs to do to support a formula for a color, text, icon, or web URL property is to
- update to API at least 3.5
- add an the import of VisualEnumerationInstanceKinds
- add "propertyInstanceKind: {yourPropertyName: VisualEnumerationInstanceKinds.ConstantOrRule}" to enumerateObjectInstances.

Huge thanks also for the pending reincarnation of the HTML visual!

John