Power Platform Community Forum Thread Details

Issue accessing property of an object with a dynamic value

I've run into a problem that's got me scratching my head and I can't seem to get past it - can someone help?

Trying to access a JSON property dynamically but it tells me that the property that clearly exists doesn't. ???????

Situation:

Trying to create a flow that is generic and uses an online spreadsheet to map fields. These fields are then used to help pull out values from a JSON object that has dynamic properties and values.

Sample JSON payload that I create and send to a handler flow:

{
 "formId": "somelongstingoflettersreferringtoaform", 
 "responder": "responder@abc.com", 
 "questions": [ 
 { 
 "id": "r78dbe3634ee567889a4c12be12345678", 
 "question_and_answer": { 
 "What do you need help with": "Something I can't figure out" 
 }
 } 
 ] 
}

Sample mapping values:

formId : somelongstingoflettersreferringtoaform
q_id : r78dbe3634ee567889a4c12be12345678 
question : What do you need help with 
field_type : Category

Steps in the flow

I use the filter array (f_arr_1) to retrieve the mapping values I need from the mapping spreadsheet:

#Filter array advanced mode:

@equals(item()?['field_type'], 'Category')

where Category refers to my mapping.

which returns:

# returned by f_arr_1 
[
 { 
 "@odata.etag": "", 
 "ItemInternalId": "0aaa00a0-aaa0-00a0-aaa0-00000de000aa", 
 "formId": "somelongstingoflettersreferringtoaform", 
 "question_hash": "r78dbe3634ee567889a4c12be12345678", 
 "question": "What do you need help with", 
 "field_type": "Category" 
 } 
]

Then I pass the questions array from the JSON payload accepted by the flow and use another filter array (f_arr_2) to select question_and_answer

#Filter array advanced mode:

@equals(item()?['id'], body('f_arr_1')[0]['q_id'])

# where q_id refers to my mapping and inserts r78dbe3634ee567889a4c12be12345678

which returns

# returned by f_arr_2
[
 { 
 "id": "r78dbe3634ee567889a4c12be12345678", 
 "question_and_answer": 
 { 
 "What do you need help with": "Something I can't figure out" 
 } 
 }
]

I assign

variables('question') = body('f_arr_2')[0]['question_and_answer']

so that variables('question') returns

{ 
 "What do you need help with": "Something I can't figure out" 
}

I also assign

variables('selectON') = body('f_arr_1')[0]['question']

so that variables('selectON') returns

What do you need help with

Problem:

The problem is when I try to dynamically access the property 'What do you need help with' from variables('question').

The expression I use is:

variables('question')[variables('selectON')]

The error is:

Unable to process template language expressions in action 'Initialize_variable' inputs at line '1' and column '16134': 'The template language expression 'variables('question')[variables('selectON')]' cannot be evaluated because property 'What do you need help with' doesn't exist, available properties are 'What do you need help with'. Please see https://aka.ms/logicexpressions for usage details.'.

Notice that the error message says

'What do you need help with' doesn't exist, available properties are 'What do you need help with'

HOWEVER....

When I specify the name of the property explicitly,

variables('question')['What do you need help with']

it resolves with no issue.

Only trouble is that I will have to hardcode the value. I do not want to do that....

Help please!!!

replace(replace(string(split(string(body('f_arr_2')[0]['question_and_answer']),':')[1]),'"',''),'}','') # # Cast Object to Sting, split it by the :, select the second token, replace all occurences of " with nothing, and replace the final instance of } with nothing. # { "What do you need help with": "Something I can't figure out" }

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