Attempting to remove newline/spaces from a HTTP:payload without sucess

I have an irule that parses http payload that contain xml using the findstr function; the problem is some vendors xml requests have spaces and/or newline characters which getting difficult to account for. I am attempting to perform a string map - replacing spaces and newline chars with empty space. I keep getting errors and I cannot seem to get to save without errors.

 

 

Here is the actual line - attempting to replace all newline & spaces with empty from the HTTP:payload - while capturing string into the variable

 

 

set tmp [findstr [string map [" " "" "\n" ""][HTTP::payload]] "<" 16 ":"]

 

 

Here are the errors for the above line

 

line 32: [wrong args] [string map [" " "" "\n" ""][HTTP::payload]]

 

line 32: [undefined procedure: ] [" " "" "\n" ""]

 

 

 

I tried this variation - no joy

 

set tmp [findstr [string map [list " " "" "\n" ""][HTTP::payload]] "<" 16 ":"]

 

 

Got this error

 

line 32: [wrong args] [string map [list " " "" "\n" ""][HTTP::payload]]

 

 

Any suggestions?