Power platform is all built around data. Luckily, this data can reside anywhere, thanks to the Connections feature provided by the platform. If you want your Apps to interact with data from a local database hosted on a server somewhere then this is how you do it. This has a lot of potential from master data management to compliance to regulations and many more. I will go through a simple example starting from creating the database then to building a Canvas App around the data.

Step 1: Create the database and a table (if you don’t have one already). In your server, create a database or use an existing one. In this case, I created a DB called Master Accounts.

To simulate a CRUD operation later, I created a table called Accounts in this database using the following script. Make sure to specify a Primary Key or Canvas App will make your app read only without the ability to add/delete records.

Step 2: Create a user that can access this database. This is achieved by creating a “login” in the security database in your server and assigning this login the created database.

Step 3: To give the Power Platform the ability to interact with you local database, you need to install the On-Premises Data gateway. Notice that this gateway can be configured to work with all the Power Platform apps or only Power BI, of course we need the former option. After you are done, the gateway interface will look like the following image.

Step 4: Sign in with you Power Platform Admin Account:

When done, this is what you should get:

Step 5: Connect to the database from Power Platform. Visit make.powerapps.com and on the left pane, select Data and Connections. Select the New Connection from the command bar.

In the new Connection wizard, select the type of connection to be SQL Server and you should see a window similar to the following:

Of course, you can authenticate in different way, but I choose the SQL Server Authentication mechanism. Plug the values we created in the first two steps. Make sure that the correct gateway is selected.

If all is well, you should see a new connection in the list, mine looks like this:

Now let’s go and create a canvas app from data and see the magic!

Step 6: Create a Canvas App starting from SQL Server Data.

Select the “Accounts” table we created before and hit Connect:

And now you should end up with a Canvas app the can perform CRUD Operations on the local database. It will require some redesign though:)

The nice thing is that this connection is a Power Platform Connection now so you can use it with Flow!

This capability opens a lot of doors for the organizations that are hesitant to move their data up in the clouds, so go experiment with it and use it!

Let’s face it, switching users from using their Excel sheets or Access databases toward using one monolithic Dynamics 365 application can be a hard change management process if you have so many users to convince. Sometimes,even the upper management can’t force that change depending on what type of organization it is.

With the new Power platform capabilities , the change management seems to be getting easier and easier because now we have options that we didn’t have before (or we did have but the are currently improved). Once the organization decides that this is the platform to go with, then here are some options that will make it easier to convince the user base to switch.

The simple approach that can be used right away is using the model-driven apps capability of dividing your applications into verticals. If you have one huge application with so many entities, then create multiple apps that are used by different business units or group of users. Each business unit or group should only see what they need to see and in this way, the probability users getting lost in the application is reduced and the amount of training needed for the users is reduced. This also means that error rate will be reduced as well because their options are more limited to what they need only.

With Model-driven apps, and in addition to limiting what entities a user can see, you can also limit what forms, views, charts, dashboards and business process flows. So when you have an entity (like the Case) that is used by multiple groups then each group can see their own forms and views and charts without being overwhelmed with everything else. I won’t call this a security layer but a way of organizing components.

If model-driven apps are not enough, then the Canvas Apps are to the rescue. Canvas Apps are new and their concept is new. Unlike model-driven app that seem intuitive to someone who knows the previous versions of Dynamics, Canvas App require a shift in the design mentality. Now we are not talking about a single application that can do many things, but about an application and many other little helper separate applications around it that all feed the same data layer (Common Data Model). So when you create data using a Canvas App, it is possible to view it from Dynamics and vice versa.

The introduction of Canvas Apps adds a new question during to the design process: “Should we implement this module in Dynamics or using a Canvas App?“. This question is becoming an important one because it doesn’t only affect the application architecture but also the user on-boarding experience, training time, error rate and user confidence.

Canvas apps are great when there is a user or group of users who do a limited set of functionalities that can be separated away. Take an example of a service call center agent who just answers the calls, log a ticket and try to solve it or escalate it. You don’t need to train this agent on the whole almighty Dynamics for customer service but only on a screen or two of the Canvas App that she and her team has access to. Keep in mind that Canvas Apps can have more complicated use cases.

So to make the change management process easier, you don’t need to take the users away from their Excel sheet into an application that is a 100 times the size of their Excel sheet but to an application that is almost the same size as their Excel sheet. Success is almost guaranteed in this case.

Often, we get asked to show records in a calendar view. I personally used the JavaScript-based Full Calendar many times in the past to do that. If your requirement is just showing the records on a calendar with basic functionality then the Calendar control in the unified interface might be your answer.

In the classic interface, we used to have a calendar control on the entity that only works in the Phone and Tablet Layouts. This control basically allows us to view the records on a calendar instead of just showing them in a list.

Moving to the unified interface, the “Web” option is now available. To test that, I created a dummy event entity with Start date, End date and Description fields.

Then from the controls section on the new entity (use the classical interface designer as this is not available yet on the new designer), add a calendar view, enable it for web and bind the start,end and description fields to the fields we just created above. Note that the description field will show on the calendar, you either can bind it to the name of the record or a custom description field if you want to show more information. Save and Publish your changes.

Now when you go to view the events, instead of the classical view, you will see a nice calendar view.

If you like to go back to the normal View list, you can do that from the top right corner.

Not long ago, I was involved in submitting a really complex application built on top of Dynamics 365 to Microsoft AppSource. The application contains a lot of plugins and code activities that perform some complex tasks and automation. The team faced some issues that I think are worth sharing with others to save your time if you you are working on such a submission.

Microsoft, provides us with tools such as the Solution Checker that validates your solution including your plugin and web resource code. The problem is, that’s not all. When you submit an application to the AppSource team, it goes through a rigorous manual and automatic checks using tools that are not publicly available to us, developers. If there are issues in your code, your submission will be rejected with explanation on what to fix and with the list of issues ordered based on their priorities. To pass the submission, all critical and high priority issues need to be fixed (if you can convince the AppSource team that somethings needs to be done a certain way and can’t be done another way, they will mostly make an exception).

After the first submission, the app got rejected with tons of things to modify/fix (even after running the solution checker on all the solutions). To be honest, the documents they sent were scary (1000+) pages with explanations on the issues. After looking at the issue list, it turned out that 90% of the critical/high priority issues are related to writing thread safe plugins. Luckily, the fix was very easy for those issues but it cost us around 2 weeks of time to do another submission and get it verified again. The following are the most common critical issues.

Variables May Cause Threading Issues

A plugin in Dynamics, is a simple class that implements the IPlugin interface, and thus, has a single Execute method as a minimum. Almost always, you need to create the organization service, the tracing service, the context and maybe other object. A bare bone plugin that builds, will look something like this:

public class SomePlugin : IPlugin
{
    public void Execute(IServiceProvider serviceProvider)
    {
        throw new NotImplementedException();
    }
}

A useful plugin, will have extra objects created so that we can communicate with the Dynamics organization,

public class SomePlugin: IPlugin {
 // Obtain the tracing service
 ITracingService tracingService = null;
 IPluginExecutionContext context = null;
 // Obtain the execution context from the service provider.  

 public void Execute(IServiceProvider serviceProvider) {
  tracingService =
   (ITracingService) serviceProvider.GetService(typeof(ITracingService));

  context = (IPluginExecutionContext)
  serviceProvider.GetService(typeof(IPluginExecutionContext));
 }
}

Now what’s wrong with the above plugin code? In a normal .NET application, this is a normal thing to do, but in a Dynamics plugin, it is not. To understand why, we need to understand how plugins get executed on our behalf behind he scenes. When a plugin runs for the first time (because of some trigger), most of the plugin global variables get cached, this happens when the constructor of the plugin is first executed. This means, in the next run, the same tracing service and context “may” be shared with the next run. This applies on any variable you define outside your function as a global variable in your plugin class. Ultimately, this causes threading issues (multiple runs of the same plugin instance compete for the same cached variable) and you may end up with extremely difficult-to-debug errors and unexplained deadlocks. The fix for the above, is very simple, just create your variables locally in the execute function, so each run of the plugin executes its own set of local variables.

public class SomePlugin: IPlugin {
 public void Execute(IServiceProvider serviceProvider) {
 ITracingService  tracingService =
   (ITracingService) serviceProvider.GetService(typeof(ITracingService));

  IPluginExecutionContext context = (IPluginExecutionContext)
  serviceProvider.GetService(typeof(IPluginExecutionContext));
 }
}

This by default means, that any helper function in your plugin should get what it needs from its parameters and not from global variables. Assume you have a function that needs the tracing service, and this function get’s called from the Execute method, pass the tracing service that was created in the execute method to that function and don’t make it a global object.

public class SomePlugin: IPlugin {
 public void Execute(IServiceProvider serviceProvider) {
 ITracingService  tracingService =
   (ITracingService) serviceProvider.GetService(typeof(ITracingService));

  IPluginExecutionContext context = (IPluginExecutionContext)
  serviceProvider.GetService(typeof(IPluginExecutionContext));
// do work here
HelperFunction(tracingService,1,2,"string");
 }

private void HelperFunction(ITracingService tracingService, int param1, int param2, string param3)
{
//use tracing service here
}
}

On the other hand, anything that is read only (config string, some constant number) is safe to stay as a global class member.

Plugins That Trigger on Any Change

This problem is more common. The filtering attributes of a plugin, are a way to limit when that plugin executes. Try to have as few as possible of those filtering attributes, don’t specify all of them. At that time I was involved in that submission, the solution checker wasn’t able to detect such problem but it may have improved now.

Plugins That Update the Record Or Retrieve Attributes Again

This is also a common issue, when a plugin is triggered on an update of an entity record, it is really a bad idea to issue another update request to the same record again. An example of this can be the need to update fieldX based on the value of fieldY. When the plugin triggers on fieldY change, you issue an service.Update(entity) with the new value of fieldX. This implicates the performance of the whole organization and even worse, it can cause an infinite loop if the filtering attributes are not set properly. Another, bad use case is to issue a retrieve attributes query for the same record when pre-images and post images can be used to remedy that.

To be clear, sometimes, there is no way around issuing another retrieve inside the plugin or sending a self-update request, we had some of those cases and we were able to convince the AppSource team that our way was the only way.

Slow Plugins

As a general rule of thumb, your plugin should be slim and does a very small thing and does it fast. Plugins have some upper limit on the time they can run within and your plugin should never exceed that time (or not even half of it). When your plugin does exceed the time allocated for it, it is time for redesigning it.

Conclusion

While those issues have simple fixes in general, they can cause slowness and unexplained errors and a rejection from AppSource. Even if you are not submitting anything to AppSource, make sure that you set some ground rules for the developers working on the same code base on how to write good plugins. More on plugins best practices can be found here.