Generate download link when clicking on button

Hello manjit.1486,

Does this button trigger a Start process? If so I would recommend you to use a Record/Related actions to perform this and try using a User Input task where the user has a summary of what kind of document and what data is there and so on, add a document download link using a!documentDownloadLink() pass your generated document as the value here. 

I guess this would help and this is what you were asking for. If not please ignore.

I am using rich text and startprocess link. Want to generate a file document link.

a!buttonArrayLayout(
buttons: {
a!buttonWidget_23r3(
label: "Generate File",
value: cons!IPA_VAL_DATA,
saveInto: {
ri!buttonValue,
a!save(
ri!assign.preparedby,
local!loggedInUser
),
a!startProcess(
processModel: cons!IPA_DATA_PROCESS_MODEL,
processParameters: {
employee:ri!employee,
address:ri!address,
tax:ri!tax,
assigne:ri!assigne
buttonValue:ri!buttonValue
},
 onSuccess: {
                a!save(local!docId,fv!processInfo),
                )
              },
              onError: a!save(
                local!errorMessage,
                "Error Exporting File to Excel"
              )
)
},

submit: false(),
validate: false(),
style: "SECONDARY",

)
},
align: "START",
marginAbove: "STANDARD"
),

You need to read the details in the rule description for a!startProcess - granted it's not SUPER well explained at a surface level, but it's also not that hard.  The highlighted snippet is what you're missing in the above iteration:

Thanks for the information. I am following the above highlighted snippet. But when I used that local variable in documentdownload link. It gives an error.

a!buttonArrayLayout(
buttons: {
a!buttonWidget_23r3(
label: "Generate File",
value: cons!IPA_VAL_DATA,
saveInto: {
ri!buttonValue,
a!save(
ri!assign.preparedby,
local!loggedInUser
),
a!startProcess(
processModel: cons!IPA_DATA_PROCESS_MODEL,
processParameters: {
employee:ri!employee,
address:ri!address,
tax:ri!tax,
assigne:ri!assigne
buttonValue:ri!buttonValue
},
 onSuccess: {
                a!save(local!docId,fv!processInfo.pv.docId),
                )
              },
              onError: a!save(
                local!errorMessage,
                "Error Exporting File to Excel"
              )
)
},

submit: false(),
validate: false(),
style: "SECONDARY",

)
},
align: "START",
marginAbove: "STANDARD"
),
  a!linkField(
            label: "Download document",
            labelPosition: "ABOVE",
            links: {
              a!documentDownloadLink(
                label: document(
                  documentId: local!docId,
                  property: "name"
                ),
                document: local!docId
              )
            }
          )

Could not display interface. Please check definition and inputs. Interface Definition: Expression evaluation error at function 'document' [line 945]: The passed parameter(s) are of the wrong type. Received the type Text.

What I am missing? I tried change the type - still gets an error. 
pv.docId is integer type.

Make sure you account for the fact that the Doc ID will be blank at first.  It will be easier if you use a!richTextDisplayField() (i recommend nobody EVER use a!linkField() at this point, it is essentially deprecated by the existence of the Rich Text field) - the benefit here is you can either hide the field entirely and/or disable the link while the local variable containing the document ID is still blank.

I got it. I used this a!richTextDisplayField(). But still why it's giving me an errror.
Could not display interface. Please check definition and inputs. Interface Definition: Expression evaluation error at function 'document' [line 949]: Document Does Not Exist or has been Deleted

You should display that link only if the document is not null.

I really don't know what's happening.

      a!richTextDisplayField(
        value: a!richTextItem(
          text:"Dowload Document",
          link: a!documentDownloadLink(
            label: document(
              documentId: if(rule!GLB_isBlank(local!docId),null(),local!docId),
              property: "name"
            ),
            document: if(rule!GLB_isBlank(local!docId),null(),local!docId)
          ),
          showWhen: not(rule!GLB_isBlank(local!docId))
          )
        ),

That depends on what this GLB_isBlank is doing. Why not use a!isNotNullOrEmpty()?

      a!richTextDisplayField(
        value: a!richTextItem(
          text:"Dowload Document",
          link: a!documentDownloadLink(
            label: document(
              documentId: if(a!isNotNullOrEmpty(local!docId),null(),local!docId),
              property: "name"
            ),
            document: if(a!isNotNullOrEmpty(local!docId),null(),local!docId)
          ),
          showWhen: not(a!isNotNullOrEmpty(local!docId))
          )
        ),

Could not display interface. Please check definition and inputs. Interface Definition: Expression evaluation error at function 'document' [line 949]: The passed parameter(s) are of the wrong type. Received the type Text.

You need to check the value of local!docId.

This should not be much of a challenge for a senior developer !?!?!?

You need to check the value of local!docId.

This should not be much of a challenge for a senior developer !?!?!?

Yeah.. let me check