data factory - check if result of pipeline task contains a specific string or value? - azure-data-factory

Question

I have a web task in a pipeline.
The result of the api call can be one of 3:
An item exists in a database.
an item does not exist in a database.
the body sent to the call was invalid.
If the record exists, I want to take further action.
As the resulting JSON from the API call is entirely different when an entity exists vs does not exists, how can I check for if a specific value is returned, if there is a chance it wont be returned at all?
Below is the output from a successful call. I'd like to check for the "Tag" attribute, but also cover a case where this does not exist.
How is this done using a dynamic content expression, seeing as there is no exists function?
{
"Data": [
{
"Data": {
"RowNumber": 0,
"Tag": "GLT-GM-45",
"GMStatus": 0,
"CustomValues": [
{
"CSLabel": "Asset Status",
"CSType": 0,
"CSValue": "Assigned"
},
{
"CSLabel": "Usage Status",
"CSType": 0,
"CSValue": "Permanent"
}
],
"AttachmentsToAdd": [],
"AttachmentsToDelete": []
},
"Messages": [
{
"ResultCode": 0,
"Message": "Success",
"HttpStatusCode": 200,
"FieldName": "GLT-GM-45"
}
],
"HasError": false,
"HasHttpError": false,
"HasMessage": true,
"HasSuccessWithMoreDataRemaining": false
}
],
"Messages": [
{
"ResultCode": 0,
"Message": "Success.",
"HttpStatusCode": 200,
"FieldName": ""
}
],
"TotalRecordsLongCount": 1,
"HasSuccessWithMoreDataRemaining": false,
"HasError": false,
"HasMessage": true,
"HasHttpError": false,
"ADFWebActivityResponseHeaders": {
"Connection": "keep-alive",
"Pragma": "no-cache",
"WaspResult": "WaspResult",
"X-UA-Compatible": "IE=edge;IE=edge",
"Cache-Control": "no-store, no-cache",
"Date": "Tue, 02 Aug 2022 11:58:31 GMT",
"Server": "Microsoft-IIS/10.0;Microsoft-IIS/8.5",
"X-AspNet-Version": "4.0.30319",
"X-Powered-By": "ASP.NET;ASP.NET",
"Content-Length": "2364",
"Content-Type": "application/json",
"Expires": "-1"
},
"effectiveIntegrationRuntime": "AutoResolveIntegrationRuntime (North Europe)",
"executionDuration": 0,
"durationInQueue": {
"integrationRuntimeQueue": 1
},
"billingReference": {
"activityType": "ExternalActivity",
"billableDuration": [
{
"meterType": "AzureIR",
"duration": 0.016666666666666666,
"unit": "Hours"
}
]
}
}

Answer 1

Wouldn't you be able to use an IF Condition that uses a contains function? Obviously I do not have a way to recreate your output, but I did the following to simulate something.
Added an If Condition to a pipeline
Added dynamic content that uses a contains function. The first part was a string containing part of your output from above (copy/paste). The part behind the comma (i.e. the search string) being 'Tag'
Added False activity causing the component to fail
Added a True activity to set a variable to be equal to "Found"!.
The full If Condition:
#contains('{
"Data": [
{
"Data": {
"RowNumber": 0,
"Tag": "GLT-GM-45",
"GMStatus": 0
}
}', 'Tag')
Seeing the 'Tag' should be found in the string, it produces the result of setting the variable:
Changing the search word to NotATag which does not exist in the string produces this instead:
My guess would be that you can substitute the hard-coded string with something like the following:
#contains(activity('Web1').output, 'Tag')
Obviously, change 'Web1' to the name of your web component.

Answer 2

Might not be an ideal way but you can do something like below to check the existence of Tag attribute in output (the reason i am trying to check the string size is the pipeline exp expected the return type to be boolean, hence using condition to achieve it), you can map the other actions based on If activity status. If the property doesn't exist if condition fails with error.
Condition
Mapping