For the last few days, I’ve been working on an app. Not just any app – it’s a canvas app! (It actually happens to be a COVID-19 related app, for local authorities to use to contact vulnerable people & check they’re OK etc).

Now, my background isn’t canvas apps – it’s the model-driven app approach. I’ve been doing this for years – after all, my experience goes back to Microsoft CRM 3.0! So that’s all really nice & easy for me (even with some of the more modern ‘tweaks’ that have been brought in). Canvas apps, on the other hand, are very different from what I’m used to, and are taking quite a bit of getting used to.

See, the following example is easy in a traditional model-driven app:

Create a contact, save various attributes to the contact record. Then create a task, and set the Task Regarding field to the contact that you’ve just created

Looking at that, my mind says ‘easy-peasy’!. I create the fields required for the contact entity (& task entity as well, if needed). I then add them to the entity form/s (creating or modifying the form view/s as well). Finally, I create a Business Process Flow for users on the contact entity, and append the task creation to it. Simple, and done – not much time needed to be spent.

But when needing to do this as a canvas app, things change around QUITE a bit. I can’t create that business process flow, and I have multiple screens to have all of the information on.

Now, if I could add the ‘Regarding’ field to the edit form grid, and apply formatting to it, I could hopefully then just submit & save the grid. However, that unfortunately doesn’t work. I can add the field, but when I do so, I get the following:

So that doesn’t work. Hmmm – how then should I go around doing it?

I did (obviously!!) take a look online. Here I came across this wonderful article all about polymorphic lookups (https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/working-with-references). Having read, & re-read through it, I’m STILL not understanding what exactly I should be doing by this!

So I was stumped. Thankfully we have an amazing community, and on reaching out to someone within it (thanks Eric!), I was helped out. I therefore thought to write this post up, so that it can help others as well.

There are two parts to this, for my specific scenario:

• Saving the contact record down. This is a matter of using (in my case) the command ‘SubmitForm.ContactInformation’ on my contact form screen. I can then also set a variable if I want to, to refer to the Contact record GUID (hey – I’m trying to be cool here & show that I can!)

• Finding a different way to save my task record. I accomplished this using the Patch statement – this thankfully wasn’t too difficult for me to grasp how it worked.

So, how did I go about using the Patch statement? Well, the function is referenced here – https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/functions/function-patch. With Eric’s help, I soon started to see how to do it.

What I did was add the following line in my Patch statement when I was wanting to save the task: ‘Regarding:ContactForm.LastSubmit’ (‘ContactForm was the name of the form for the contact information). What this did was write into the record the GUID for the contact record that I last saved.

An alternative to this would be to use a variable instead, and set it there.

Thankfully this all worked. I’m now able to create Task records and set their Regarding field value to the Contact that I set up before them – which is the exact thing that I was trying to do!

I hope that this has been helpful – leave a note in the comments if you’ve found another way of doing this.