Re: Creating a REST API with RPGLE

I would suggest outputting JSON as it's more generic and most applications
can read it.

Here's a simple program and HTTP config that will do what you want using
RPG and YAJL.. you just need to change the $Data subroutine to run your SQL
statement, then build the JSON as it reads the results from the command:

https://fieldexit.com/forum/display?threadid=522

PS, passing in straight SQL can be very dangerous in the wrong hands, so I
would put some sort of checking so there's not something like delete from
lib.file passed in.

On Fri, Oct 7, 2022 at 8:09 PM <[email protected]> wrote:

> First, let me say I am trying to do something here that I have zilch
> experience with from the IBM i perspective.  I have done this type of stuff
> using C#.Net on Windows but nothing on the IBM i.  Yesterday was my first
> voyage into IBM Web Administration for i.
>
> That said, I am trying to create a REST API written in RPGLE that will
> return JSON data.  I have looked at a lot of examples but just can't find
> what I am after.
>
> This needs to be modeled after some existing C#.Net REST APIs so the
> following requirements are not negotiable.
>
> The request needs to be a POST type.
> The body of the POST request needs to have two "fields".
>   1) Input - An SQL statement that will be used to retrieve the data.
>   2) Output - The results of the SQL.  These results can be anything so the
> fields can't be predefined in the RPGLE program's parameters like they are
> in all of the examples that I find.  There can also be multiple records so
> it would end up having an array in the results.  I think I need a single
> "results" field that is pretty big and I will need to manually build the
> JSON for it.
>
> I tried creating a new HTTP server and deploying a service to it.  I have
> been successful using Scott's customer lookup as a model and I have been
> able to do a few different things to experiment.  However, I can't figure
> out how to handle the POST body for input or the array results in the
> output.
>
> One attempt was to create the following:
>        dcl-pi *n;
>          sql char(5000);
>          resultSet char(50000);
>        end-pi;
> The problem was that I got back a value in the resultSet that was really
> junked up JSON because it escaped all of the " as \".  I considered trying
> to make the resultSet value return as plain text instead of JSON (I'm
> assuming I can do that somehow) but I decided before I went too far down
> the
> wrong rabbit hole, I would ask for help.
>
> Can someone help point me in a good direction?  I don't mind doing a lot of
> web digging, I just don't really know what I need to search for to do the
> digging.
>
> Thanks.
>
>
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