How to extract filename from HTTP response headers

[Daniel-Kendall]

I have the following outputs of a HTTP block

{
    "statusCode": 200,
    "headers": {
        "Pragma": "no-cache",
        "Strict-Transport-Security": "max-age=35136000; includeSubDomains",
        "Access-Control-Allow-Origin": "*",
        "X-Server-Time": "2022-02-22T16:04:08.614Z",
        "Access-Control-Expose-Headers": "X-SessionToken,X-Server-Time",
        "X-Role-Instance": "Cognito.Services_IN_20",
        "X-Request-Time": "51ms",
        "Content-Security-Policy": "default-src 'self' https://*; img-src * data:; script-src https://* 'unsafe-inline' 'unsafe-eval'; style-src https://* 'unsafe-inline'; frame-src 'self' https://* mailto:; worker-src blob:;",
        "X-Content-Type-Options": "nosniff",
        "Referrer-Policy": "origin-when-cross-origin",
        "Request-Context": "appId=cid-v1:bac45fa9-8f8e-4ddb-8e70-d648fe57a27a",
        "Cache-Control": "no-store, must-revalidate, no-cache",
        "Date": "Tue, 22 Feb 2022 16:04:08 GMT",
        "P3P": "CP=\"Cognito does not have a P3P policy.  Visit https://cognitoforms.com/privacy for details.\"",
        "Server": "Microsoft-IIS/10.0",
        "Content-Length": "6602",
        "Content-Disposition": "attachment; filename=\"New Microsoft Excel Worksheet.xlsx\"",
        "Content-Type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
        "Expires": "-1"
    },
    "body": {
        "$content-type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
        "$content": "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"
    }
}

I would like to extract the header value between filename=// i.e. here it is just a new excel document (New Microsoft Excel Worksheet.xlsx)

How would I do this for usage here

[Expiscornovus]

Hi @Daniel-Kendall,

Try an expression like below:

split(outputs('HTTP')['Headers']['Content-Disposition'], '\"')[1]

The example assumes that the action which outputs the block has a name which is HTTP.

[Daniel-Kendall]

Thanks for your response here is my debugging steps

split(outputs('HTTP')['Headers']['Content-Disposition'], '\"')[1]

Led to the following output

Unable to process template language expressions in action 'Create_file' inputs at line '0' and column '0': 'The template language expression 'split(outputs('HTTP')['Headers']['Content-Disposition'], '\"')[1] ' cannot be evaluated because array index '1' is outside bounds (0, 0) of array. Please see https://aka.ms/logicexpressions for usage details.'.

So removing the index to check the full array

[
  "attachment; filename=\"jimmy.xlsx\""
]

became the file name

I then applied the following Regex to the string

(?<=\\)(.*?)(?=\\)

Which extracted

["jimmy.xlsx"]

I then used the follwing substring to clear the front/back 2 characters 

substring(variables('fileName'),2,sub(length(variables('fileName')),4))

Leading to the correct

jimmy.xlsx

However, this is sent to power automate as

_jimmy.xlsx_

 
==

To clarify this is very hacky/janky for example if the file name isn't escaped then there are no \'s for the regex to find.

Ideal solution:One clean expression to extract the file name for correct sending to power automate wheter sent as

[
  "attachment; filename=\"jimmy.xlsx\""
]

or

[
  "attachment; filename="jimmy.xlsx""
]

[Daniel-Kendall · Accepted solution]

For context for this solution see:

Re: How to extract filename from HTTP response hea... - Power Platform Community (microsoft.com)

==

Solved using the following regex thanks to:

https://www.reddit.com/user/CryptoOTC_creator/

[\w\s]+\.[\.\w\d]+

[Character set. Match any character in the set.
\w Word. Matches any word character (alphanumeric & underscore).
\s Whitespace. Matches any whitespace character (spaces, tabs, line breaks).
] 
+Quantifier. Match 1 or more of the preceding token.
\.Escaped character. Matches a "." character (char code 46).
[Character set. Match any character in the set.
\.Escaped character. Matches a "." character (char code 46).
\w Word. Matches any word character (alphanumeric & underscore).
\d Digit. Matches any digit character (0-9).
] 
+Quantifier. Match 1 or more of the preceding token.

[v-xiaochen-msft]

Hi @Daniel-Kendall ,

Glad to see you solved it.

You could mark your own reply to close the case.

Best Regards,

Wearsky