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Tech Tip: Assure to declare parameter $1 in 4DAction method to avoid web server error 500
PRODUCT: 4D | VERSION: 19 | PLATFORM: Mac & Win
Published On: September 12, 2022

When working with web server and 4DAction methods, make sure to explicitly declare the $1 parameter using C_TEXT($1) in order for the method to work properly when running in compiled mode as 4D requires this parameter internally. Otherwise, the 4DAction method may cause a "500 - Internal Server Error" when accessing the method via web server. Note the C_TEXT($1) declaration is only required in compiled mode and not interpreted.

Take the 4DAction method below when running web server in interpreted vs compiled:

WEB SEND TEXT("Hello world")


Interpreted (works properly):


Compiled (does not work without $1 declaration):


As mentioned before, this issue is fixed by simply adding the C_TEXT($1) declaration.

C_TEXT($1)
WEB SEND TEXT("Hello world")