One of the first lessons when getting to grips with Canvas Apps was that you should always use Collections where possible to reduce the number of calls to the original data source, and with any luck, you may see a performance increase as a result too. However, I often find that the data source I’m using always collects a number of columns that I am never going to use in the Canvas App itself.
Let’s take the example of listing Account records from Dataverse using a simple Power Fx statement:
As you can see below, there are a significant number of columns that I don’t plan to use relating to various relationships across the Dataverse database.
These columns are extremely important for the database and we shouldn’t underestimate their criticality, but these are not necessarily important for me when building a Canvas App as I just want to retrieve the Account Name and the Account ID.
We can make a small change to the original Power Fx statement, by expressing exactly which columns to use, such as:
One of the technical challenges we have in the UK is that for half of the year we are in the UTC time zone that we’re all familiar with, and the other half we’re in British Summer Time (BST). Those lucky few that keep the same time zone all year don’t know how easy they have it!
It can be quite confusing, as some digital solutions (including Dynamics 365) host UTC and our local time as separate time zones but call both UTC, but others don’t always make this distinction, and you may have seen data that you just submitted appear with a date stamp of ‘1 hour ago’. This is easily done if you’re non-technical. Why would you ever consider having to change your time zone if you can already see ‘UTC’ in the dropdown?
This doesn’t have a major material impact until you’re working with date values without times, particularly if the solution you’re using only allows you to control the date entry from the front end, and not the time entry. The difficulty we face in this scenario is that an application could even show yesterday’s date!
Yesterday’s date? Are you sure?
Well submitting data at 2pm during your workday doesn’t cause too much of an issue, you might see data entry from 1pm instead. But what if you submit a ‘date only’ value, or, (hopefully you’re not working at this time) but at some time between 00:00 and 00:59?! In this instance, the application can often confuse the user and present the data back as yesterday’s date instead!
How do I prevent this?
Fortunately we don’t have any problems submitting data as these will always be submitted in UTC and convert appropriately.
The issue we face occurs when we are trying to retrieve data from a data source, where (for example) the database stores the date as 30/07/22 00:00:00, but our Canvas App reads this from the data source as 29/07/22 23:00:00 due to the database storing our submitted date in UTC.
I discovered this when using the Outlook Tasks Connector to pull in today’s To Do items into a Collection, rather than using the Today() function to compare dates.
“Add the negative of my local timezone offset in minutes to the local date, and then show me all of the To Do Items where the DueDateTime.DateTime value is equal to the newly calculated date.”
Note: For this particular connector I needed to explicitly specify DateTimeValue as the format, but you don’t need to do this for all Connectors.
That’s all. Fortunately Power Fx allows us to grab the time zone offset for the time zone I am currently in, but we must be aware that this value is a negative, and therefore we need to negate the negative in order to add the correct number of minutes. I’ll be using this in every Canvas App I build now, particularly as I work in an organisation that spans multiple time zones!
A couple of weeks ago I found an empty slot in my diary, and I (dangerously) thought “I know, I’ll brush up on my Canvas app skills!”.
In my role I find myself looking across multiple Dynamics 365 apps, Excel spreadsheets, and Power BI reports daily, and I set myself the task of bringing all of this together into one place so that I could access all of the data I need with one or two clicks instead of manually transforming data and keeping several browser tabs permanently open.
This was going great, until I saw the dreaded ‘delegation’ warning that all Canvas app novices will see very quickly in their career.
“Delegation warning. The Filter part of this formula might not work on large data sets.”
When you expand the warning, you get the following detail:
What is Delegation?
Simply put, delegation is an instruction from the target application to the data source, to carry out a query before returning the subset of results that are wanted by the target application itself.
This means that we only ever receive the desired data in the target application, and in turn, performance is increased as a result.
When you compare the processing required in this scenario compared to retrieving every piece of data and then filtering it in the target application, you see a measurable performance increase by using delegation, and you’re also increasing technical debt by pulling back data into the target environment that you want to throw away immediately.
The wording for this warning can be considered a little misleading. The warning is actually telling us that there will be a lack of delegation in the data source. In this instance, the data source does not have the ability to carry out the condition logic with its capabilities, and therefore it needs request that the Canvas app carries out the query instead.
For example, Power Fx provides the ability to retrieve a day, month, or year value from a Date field, but Dataverse cannot do this! Dataverse can only query date ranges such as ‘on or before [Date]’! When querying a ‘month’ in this scenario, you would receive the delegation warning as the delegation cannot happen.
As a result, the full data set from the data source has to be retrieved by the target application, only for the target application to filter the data once it has all been received. This lowers the performance of the app, but it could be worse than that – if you exceed the definition of ‘large data set’, the data set may not return at all, leaving you with incomplete results with no error and a low quality solution.
The biggest lesson learned whilst working on delegation recently was from a colleague – there is always a workaround.
Whilst you can’t “fix” the warning with the same piece of code, you can use combinations of delegated conditional logic in order to achieve the same results.
A classic example steps back into using dates in Canvas Apps. In Power Fx I can express “Month = 1”, but Dataverse only allows date ranges so the Canvas App needs to bring back the full data set to work out whether “Month = 1”. As a result, I can’t quite express “in January this year” using delegated logic, so instead I need to combine two ranges using something that Dataverse can recognise. In this example I would combine “Created On must be on or after 1st January 2021”, and “Created On must be on or before 31st January 2021” to obtain the right data at source.
Some examples can be more complicated than this, but a top tip for Dataverse specifically is that if you can achieve it using Advanced Find, then you can be certain that the logic can be delegated!
Have you worked in this space before and found any cool workarounds? Leave a comment below!
Earlier this week I found myself trying to embed an existing Canvas app into a Model-Driven app to better present information relating to the record using the flexible UI controls, but as an infrequent user of such a feature, I struggled to understand how I could reference the current Model-Driven app record’s data within the Canvas app!
All over the web I could find resources pointing towards a special type of control called ModelDrivenFormIntegration and how it works, but I simply couldn’t see it within my solution. This is where it should be:
The new Power Platform interface has improved so many of the existing controls and added fantastic new features, but unfortunately at the time of writing, embedding a Canvas app via the new user interface needs a little more work, and it doesn’t quite complete the job in all circumstances. There are two reasons for this:
You have to associate the control with a field on the Form, and when adding the Canvas app via the new User Interface, it doesn’t configure the field control automatically leading to errors when loading.
The functionality available via the ‘Customize’ button is not available in the new User Interface, which is partly the reason for this blog post!
As some of you will be aware, sometimes it’s just better to head over to the classic user interface to complete your configuration, and although I’m finding myself using this user interface less these days. In this post I attempt to bridge the gap and I’ll explain how to get things working.
What is ModelDrivenFormIntegration?
As Microsoft have explained in detail here, this control allows us to bring contextual data from the Model-Driven app that the Canvas app is utilised in.
There are a significant number of benefits to doing this, primarily because it provides you with the ability to dynamically change your Canvas app content based upon the record you’re currently viewing in the Model-Driven app.
Step 1: From https://make.powerapps.com, navigate to the correct environment and choose the relevant Table’s Form within your solution file. Use the ‘Switch to Classic‘ button from the navigation bar straight away.
Step 2: Navigate to the required field you’ve configured for your Canvas app control and double click. You’ll notice a pop up window which provides the ability to navigate to the Canvas app control configuration. Click on ‘Controls‘ and press the ‘Customize‘ button.
Step 3:Your Canvas app will now open, and you’ll notice that ModelDrivenFormIntegration is now available as the first control on the list for the first time! We’re not done yet though, we need to tell the control which Table we are using within the Model-Driven app by editing the ‘DataSource‘ Property.
And finally the ‘OnDataRefresh‘ Property.
We can use the plural label/friendly name of the Table here, instead of having to look up the logical name, which is a great touch in a lot of Power FX’s abilities.
And we’re done!
The configuration for this isn’t difficult, but finding out why the issue exists can often be challenging, especially if you’re an infrequent user of this functionality.
Remember to ‘Save‘ and ‘Publish‘ your Canvas app changes when you’re ready, but you don’t need to publish your Model-Driven app as this was simply a route into enabling the functionality with no configuration changes.
There are a few pointers to be aware of when generally configuring embedding Canvas Apps:
Microsoft advise that associating your embedded Canvas app control is tied to a mandatory field, so that you can guarantee the operation of the Canvas app.
Remember to share your Canvas app or make other users Co-Owners as appropriate before releasing the functionality to end users.
The classic user interface is due to be deprecated in an upcoming release nearer the end of the year. I suspect this feature will still work for a short period of time, but we will have to watch and wait until such a time, and I’ll update this post if/when this happens.