Tip! - Building a valid JSON array from a PowerApps collection (to pass to Flow as an example)

[JamesM]

I struggled with this a little bit myself, and I know it's one of those questions that people come up against often. The desire to take Collection data and pass it to Flow as a fully formed JSON array that can be easily worked with in Flow. I came up with the below solution which works really well for me, so I thought I'd provide it in case anyone else needs it 🙂 

I have a Gallery collection which has checkboxes. I want to add each checked item to a JSON array prior to passing it to FLOW. Below is my formula for this: 

"{" & Mid(Concat(groupStores, ",""" & store_id & """"),2,5000) & "}"

Which produces the following: 

{
  "228",
  "721",
  "328",
  "658",
  "655",
  "415",
  "427"
}

Adding or removing from the string correctly re-builds the string with the right quotes and commas etc. Hopefully this helps someone else who needs to do this 🙂 

[timl]

Thanks for sharing this @JamesM!

[Mike8]

Hello,

We also use it 🙂
To avoid the mid function you can use the following instead
"{"&Concat(groupStores,""""&store_id&"""",",")&"}"

Also you can set the column names
"{"&Concat(groupStores,"""store_id"":"&""""&store_id&"""",",")&"}"

You can send a table with as many columns as you want from powerapps to flow 🙂
"["&Concat(groupStores,"{""store_id"":"&""""&store_id&"""}",",")&"]"

[TopShelf-MSFT · Accepted solution]

Thanks for sharing @JamesM! This a great tip that help out future users. Have a great day. 

@TopShelf-MSFT

[johnnyshield]

Just in case anyone is searching through this forum, this solution has been superseded by the JSON function

https://docs.microsoft.com/en-gb/powerapps/maker/canvas-apps/functions/function-json

[DavesTechTips]

Correct @johnnyshield , the new JSON function works like a charm.

See below video if anyone hasn't used it yet.

https://youtu.be/HLdOO4JPZ2I

Dawid van Heerden
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