How to export data to excel in a grid with more than 50 columns?

Hello  ,

I would suggest you to use OOTB of appian to achieve this. We created xlsx file using below approach to create more than 50 columns to be exportable.

Create Web API:
Parse request using  a!fromJson( http!request.body)  and retrieve information to query data for which identifier.
Retrieves data using queryEntity from your database using request identifier.
Encodes the generated Excel data in Base64 format using exportDataSubsetToBase64 function.
Sends the Base64 encoded data as the response body in the HTTP response with appropriate headers.

a!localVariables(
    /*Create Helper CDT of Request Type*/
  local!request: a!fromJson( http!request.body),/*Parse Request Here and cast to helper cdt*/
  local!entities: /*Retrive Data Here from DB using local!request parameters*/
  local!export:exportdatasubsettobase64(
    datasubset:todatasubset(  local!entities),
    fieldLabels:{} /*The labels of header to set in Excel*/,
    fieldNames: {} /*The names of the datasubset fields to add to Excel*/,
  ),
  a!httpResponse(
    statusCode: 200,
    headers: 
      a!httpHeader(name: "Content-Type", value: "application/xlsx"),
   
      body: a!toJson(value: local!export)
  ),
  a!httpResponse(
    statusCode: 400,
    headers: 
    a!httpHeader(name: "Content-Type", value: "application/xlsx"),

    body: {}
  )
)

Create Integration:
Calls the Web API using a POST method.
Send request as for which identifier you want data(Create Request).
Parses the JSON response from the Web API.
Extracts the Base64 encoded data from the response body (likely from fv!result.body.base64Document).
Decodes the Base64 data back into its original Excel format.
Saves the decoded Excel data as an Appian document in the specified directory.




Let me know if you have any questions.

Please share the configuration

a!httpResponse(
/*
* Set an HTTP header that tells the client that the body of the response
* will be a CSV attachment.
*/
headers: {
a!httpHeader(
name: "Content-Disposition",
value: "attachment; filename=" & char(
34
) & "agniwesh" & now() & ".csv" & char(
34
)
)
},
/*
* Create a CSV value of 'local!user' and place it in the response body.
*/
body: {
"Id,name,age,comment" & char(
10
) & joinarray(
a!forEach(
items: local!details,
expression: {
joinarray(
merge(
{
char(
34
) & fv!item.id & char(
34
)
},
{
char(
34
) & fv!item.name & char(
34
)
}
),
","
)
}
),
char(
10
)
)
}
)

a!httpResponse(
/*
* Set an HTTP header that tells the client that the body of the response
* will be a CSV attachment.
*/
headers: {
a!httpHeader(
name: "Content-Disposition",
value: "attachment; filename=" & char(
34
) & "agniwesh" & now() & ".csv" & char(
34
)
)
},
/*
* Create a CSV value of 'local!user' and place it in the response body.
*/
body: {
"Id,name,age,comment" & char(
10
) & joinarray(
a!forEach(
items: local!details,
expression: {
joinarray(
merge(
{
char(
34
) & fv!item.id & char(
34
)
},
{
char(
34
) & fv!item.name & char(
34
)
}
),
","
)
}
),
char(
10
)
)
}
)

I've used this pattern in the past to export more than 50 columns by first building the data in an expression and then passing formatted data to the api.