How to add smart offline capabilities in embedded canvas apps

Introduction

If you read my previous post, you will know that there was an issue - the cached phone call details were showing up irrespective of which account I was looking at. We will see what needs to be done to prevent that from happening. So if you are creating a phone call record for Account A, and switch to Account B, the cached data will not show up. If you enter details for a phone call record for Account B and go back to Account A, you will see the cached data for the phone call that you were creating for Account A (and similarly for Account B).

The setup

To make this happen, we will change the properties that we had set in the previous post as following:

1. 1. OnVisible of the screen (or the OnEndTimer of a 1 second timer)

      LoadData(
          colPhoneCalls,
          "colPhoneCalls",
          true
      );
      ClearCollect(
          colPhoneCallsCurrentAccount,
          Filter(
              colPhoneCalls,
              Regarding.Account = [@ModelDrivenFormIntegration].Item.Account
          )
      );
      If(
          CountIf(colPhoneCallsCurrentAccount, true) = 0,
          UpdateContext({locCurrentAccountCount: 0}),
          UpdateContext({locCurrentAccountCount: 1})
      );

   2. In the OnChange and Value fields of each data card of the form that I want to load from cache, I am using the following code (using the Subject datacard as an example here)
      1. OnChange

         If(
             locCurrentAccountCount = 0,
             Collect(
                 colPhoneCalls,
                 {
                     Subject: Self.Value,
                     Regarding: [@ModelDrivenFormIntegration].Item
                 }
             );
             UpdateContext({locCurrentAccountCount: 1}),
             Patch(
                 colPhoneCalls,
                 LookUp(
                     colPhoneCalls,
                     Regarding.Account = [@ModelDrivenFormIntegration].Item.Account
                 ),
                 {
                     Subject: Self.Value,
                     Regarding: [@ModelDrivenFormIntegration].Item
                 }
             )
         );
         SaveData(
             colPhoneCalls,
             "colPhoneCalls"
         );
         

      2. Value

         If(
             locCurrentAccountCount = 1,
             LookUp(
                 colPhoneCalls,
                 Regarding.Account = [@ModelDrivenFormIntegration].Item.Account
             ).Subject,
             Parent.Default
         )
         
         

With this code, this is how the app behaves:

Conclusion

With a few simple changes, you can make the caching of data smarter to be associated with the account it was created for.

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