Triggering Flow from NFC cards

I recently came back from Sydney and I now have 4 new Opal cards. Opal card is used in public transport across Sydney and these cards use NFC technology. Since I no longer have any use for these cards in Melbourne, I wanted to do some thing productive with these cards. I also wanted to try a low cost alternative for triggering Flow from a hardware that is not flic (Opal cards are free).

Reading NFC card is not a native functionality of Flow, so I decide to use something that is capable of reading NFC card and also can call a HTTP endpoint. Since I am using Android, there is an app that meets this need perfectly. It is called Automate. This app has been around for a while, and you can develop Automate Flows that can use native hardware capability of Android.

Here is how my Flow looks in Automate.

Automate Flow

The are start important blocks to get this Automate Flow working:

  1. Read NFC Tag
  2. HTTP Request
  3. Flow Start

Read NFC block is used to read the NFC card. I map the NFC tag id to the variable called “TagId”. You can use the “Read tag” button in this to identify the NFC tagid and then use it in the switch/case statements in Microsoft Flow.

Read NFC

 

The next step in the one where I call Microsoft Flow, which is triggered by HTTP Request.

HTTP Request

The same Automate Flow has to be triggered again after Microsoft Flow is called using HTTP Request, so that a new fiber is started to continue reading the NFC card.

Start Flow

This is the Microsoft Flow that is triggered by HTTP request.

NFC HTTP Flow

The HTTP trigger accepts the tagId in the URL parameter of the HTTP Request.

HTTP Trigger

Based on what tag has been scanned, I can then perform the appropriate action. I use the switch statement for this purpose.

Flow Switch.png

Here is a quick demo of Automate and Flow working together in harmony.

Automate Flow.gif

Here are somethings that are now possible with the NFC capability:

  1. Deploy solution from DEV to TEST, using Azure Function, PowerShell and Xrm.Data.PowerShell module. I experimented with this and it works nicely even though PowerShell support in Azure Function is only experimental
  2. Call a RunBook in Azure Automate using HTTP Webhook

I hope this is useful in scenarios where you need alternate ways to trigger Microsoft Flow.

 

 

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Quick Tip: CDS Base URL in Flow

I have a Flow that sends out email at 8 a.m everyday that lists the solutions that were imported in the past 24 hours. In the initial version of the Flow, the email was missing an link to the actual solution. But, after making some changes, the email now includes a clickable link to the solution that was imported.

Flow Email.png

As you can see there is a link in the last column. This link is not hardcoded. The base URL changes, based on the CDS environment the Flow is deployed to. The trick is to grab this URL from the “List records” action which includes the full URL to each record in the result. You just need the first record in the result set to use in the expression in the next step.

RetrieveMultiple.png

As you can see the @odata.id key contains the full URL to the record, from which you just need the base URL. Once you grab the base URL, you can easily compose the full URLs to the areas that you want the link to navigate to e.g. open the record, open solution, new record, open list etc.

Below is the expression that I use to get the base URL only.

first(split(first(body(‘[ACTION_NAME]’)?[‘value’])?[‘@odata.id’],’/api/’))
If you use this expression and assign it to a variable, you can set the variable with the base URL.
Variable.png
This technique is quite useful if you are sending emails with clickable links that navigate to a CDS record or area.