$filter array is return undefined in logs - flow.fileContents or payload.arrayEntry not accessible?

[dubnemo]

I am trying $filter a subset of json based an email address in the JSON payload which I copied to flow.fileContents context data (attached), trying many variations of the function syntax. I get a $distinct list of emailAddress copied to msg.arrayEntry, and then I use the Rollun Common foreach successfully iterate on that list.

This JSONata is return undefined. I also tried flow.fileContents without the $. msg.arrayEntry and $msg.arrayEntry were previously attempted (legacy message disappeared when I switched to payload.arrayEntry).

Why am I missing? Is flow not accessible inside JSONata?

$filter(
  $flow.fileContents,
   function($v) {
       $v.farmerEmailAddress = payload.arrayEntry 
   }
)

tstCSV.json (1.9 KB)

[bakman2]

@dubnemo

Why am I missing? Is flow not accessible inside JSONata?

It is but in a different manner

[dubnemo]

Thank you that was helpful in checking the flow reference while debugging (yes, the data is still in the flow context), but I still get undefined in the $filter statement:

$filter(
  $flowContext("fileContents"),
   function($v) {
       $v.farmerEmailAddress = payload.arrayEntry 
   }
)

[E1cid]

Do you have more than one context store?
What is the value of payload.arrayEntry ?
Is the flow context saved in same flow tab?

[dubnemo]

1. One context store
2. Context is in the same flow tab, of course (thanks for asking). Data is there as per debug:
   
   

Debug config:

2. payload.arrayEntry:
   On the first iteration of the for-each

node: emailAddress in the loop
c:\\temp\\reportingTail : msg.arrayEntry : string[23]
"steve.cropper@gmail.com"

On the second iteration of the for-each

node: emailAddress in the loop
c:\\temp\\reportingTail : msg.arrayEntry : string[15]
"paddy@gmail.com"

This should be a similar filter to this JSON PATH which IMHO is what JSONata should leverage (just saying):

$[?(@.farmerEmailAddress=="paddy@gmail.com")]

You can see in my screen shot I also tried the jsonpath node that is out there, but it is not ready for prime-time.

[E1cid]

@dubnemo

: msg.arrayEntry : string[15]
"paddy@gmail.com"

msg.arrayEntry, but the jsonata references msg.payload.arrayEntry.

But I sse we are at cross purposes, as i am asking about the payload going into the change node, not the iterations of the $filter

[dubnemo]

$v is the payload? Or is it the full $flowContext("fileContents") set prior to the function()?
The documentation does not explicitly clarify that.

[E1cid]

$v is the the object iterations of the flow context

[dubnemo]

@E1cid thank you! That was it.
I reassigned my emailAddressList to msg.emailAddressList and the for-each on output to emailAddress instead of payload.

The $filter function is now:

  $flowContext("fileContents"),
   function($v) {
       $v.farmerEmailAddress = msg.emailAddress 
   }
)

And the results are perfect!

[dubnemo]

its as if $flowContext("fileContents") has no 'value' in the $filter. Its all about payload (again) -- so much store and restoring back to payload.

[E1cid]

@dubnemo

 $flowContext("fileContents"),
   function($v) {
       $v.farmerEmailAddress = msg.emailAddress 
   }
)

To note, if theere is only one match the output will be an object not an array with a single object, this maybe OK for you, but if you require an array of object/s then enclose the expression in square brackets to force an array output.

 [$flowContext("fileContents"),
   function($v) {
       $v.farmerEmailAddress = msg.emailAddress 
   }
)]

[dubnemo]

Thanks, that is a good preventative measure.

I will test for that now.

[dubnemo]

That didn't quite work:

$filter(
   [
       $flowContext("fileContents"),
       function($v) {
           $v.farmerEmailAddress = msg.emailAddress 
   }
   ]
)

I will play around more.

Creating more test data.

[dubnemo]

Tested this.

[
   $filter(
       $flowContext("fileContents"),
       function($v) {
           $v.farmerEmailAddress = msg.emailAddress 
   }
   
)
]

Worked

versus without wrapper: