Technical Articles
CL_DEMO_OUTPUT invigorated
Some time ago, we introduced CL_DEMO_OUTPUT for simple examples and demonstrations.
CL_DEMO_OUTPUT, Part 1 of 2 – Usage | SAP Blogs
The functionality up to now was already nice and useful, but somehow it was not complete.
Writing a simple piece of code such as
DATA:
BEGIN OF super,
col1 TYPE i VALUE 1,
BEGIN OF sub,
col2 TYPE i VALUE 2,
col3 TYPE i VALUE 3,
END OF sub,
END OF super.
cl_demo_output=>display( super ).
results in
Duh!
We are happy to announce that from ABAP release 7.56, SP01 on, this output will look as follows:
In fact, you can output (nearly?) everything now:
CLASS demo_class DEFINITION.
PUBLIC SECTION.
TYPES:
BEGIN OF spfli_line,
carrid TYPE spfli-carrid,
connid TYPE spfli-connid,
cityfrom TYPE spfli-cityfrom,
cityto TYPE spfli-cityto,
END OF spfli_line,
spfli_tab TYPE HASHED TABLE OF spfli_line
WITH UNIQUE KEY carrid connid,
BEGIN OF struct,
carrname TYPE scarr-carrname,
spfli TYPE REF TO spfli_tab,
END OF struct.
DATA result TYPE SORTED TABLE OF struct WITH UNIQUE KEY carrname.
METHODS constructor.
ENDCLASS.
CLASS demo_class IMPLEMENTATION.
METHOD constructor.
SELECT s~carrname, p~carrid, p~connid, p~cityfrom, p~cityto
FROM scarr AS s
INNER JOIN spfli AS p
ON s~carrid = p~carrid
ORDER BY s~carrname
INTO TABLE @DATA(itab).
LOOP AT itab ASSIGNING FIELD-SYMBOL(<fs>) GROUP BY <fs>-carrname.
INSERT VALUE #( carrname = <fs>-carrname ) INTO TABLE result
ASSIGNING FIELD-SYMBOL(<line>).
<line>-spfli = NEW #(
FOR <wa> IN GROUP <fs> ( CORRESPONDING #( <wa> ) ) ).
ENDLOOP.
ENDMETHOD.
ENDCLASS.
START-OF-SELECTION.
DATA(oref) = NEW demo_class( ).
cl_demo_output=>display( oref ).
gives
Note, that simply the name of the reference variable oref is passed to the display method.
This has been achieved by introducing some recursions in CL_DEMO_OUTPUT_STREAM. That means that the intermediate XML coming from CL_DEMO_OUTPUT_STREAM supports nested stuff now and that the conversion capabilities of CL_DEMO_OUTPUT_HTML were enhanced accordingly.
And just for fun, we can also write self-explaining demos now:
DATA(o) = cl_demo_output=>new(
)->write_doc( cl_demo_output_helper=>get_infobox_html(
`This output is produced by program ` && sy-repid )
)->next_section( 'ABAP CDS View Entity'
)->write_doc( cl_demo_output_helper=>get_ddls_source_code_html(
source = 'DEMO_CDS_SPFLI_ENTITY' )
)->next_section( `ABAP SQL SELECT`
)->write_doc(
`The following code snippet demonstrates a ` &&
`<code>SELECT</code> statement accessing ` &&
`the CDS view entity without ` &&
`<code>ORDER BY</code> clause:`
)->begin_code( `select1` ).
SELECT *
FROM demo_cds_spfli_entity
INTO TABLE @DATA(itab). "#EC CI_NOWHERE
o->end_code( `select1`
)->write_doc( `The result in <code>itab</code> is:`
)->write( itab
)->write_doc( `Adding`
)->write_doc(
cl_demo_output_helper=>get_abap_source_code_html(
code = `ORDER BY cityfrom, cityto` )
)->write_doc( `as follows`
)->begin_code( `select2` ).
SELECT *
FROM demo_cds_spfli_entity
ORDER BY cityfrom, cityto
INTO TABLE @itab. "#EC CI_NOWHERE
o->end_code( `select2`
)->write_doc( `gives:`
)->write( itab
)->display( ).
gives
As before, you can retrieve the HTML file with method GET instead of DISPLAY in order to become independent from SAP GUI.
Caveats
- You have to wait for 7.56, SP01
- The new complex outputs are not fully supported by the text mode (but who wants to reprogram a browser in CL_DEMO_OUTPUT_TEXT?)
- ADT console supports only text but not HTML mode
- It is for demonstration purposes only …
Thanks for an update, Horst! This is great news. Too many times I've run into "data type not yet supported" and was wondering when that "yet" might be coming. I guess we're there now. 🙂
Thanks for sharing!
Wow. This looks cool.
Amazing,
though still for demonstration purposes only…
Hi Horst,
Cl_DEMO_OUTPUT is only for developer testing since we cannot move these classes to production systems, Could you please the let me know the possibilities where I could use this except testing?
Thanks & Regards
It is only for testing and demonstration purposes.
It's great to see that the good old cl_demo_output is still being developed. It makes me happy. 🙂
I won't ask about planned downport, because I think I know the answer 🙂
Nice blog, I got some issues earlier while using Cl_DEMO_OUTPUT (data type not yet supported)
https://answers.sap.com/questions/12655529/using-cldemooutput-to-display-internal-table.html
Thanks for sharing it is very helpful.
It is really amazing!
But, is it possible SAP release this tool, stop spelling it as "demo"? This is so usefull.
Personnaly I used it in productive program.
There are good reasons for keeping it as "Demo". First of all, it was developed for demo programs only (for a never finished follow-up of the ABAP Objects Book, later for the ABAP Keyword Documentation). If iit s useful for you in your demos, that's fine, but productive usage is at your own risk. For example, CL_DEMO_OUTPUT and CL_DEMO_OUTPT_STREAM are not suitable for large amounts of data. If we would publish it for productive usage, shortly we would be swamped with demands for improvement,
Furthermore, keeping it as "Demo" allows incompatible improvements. The change discussed under https://blogs.sap.com/2016/05/10/cldemooutput-part-1-of-2-usage/#comment-387632 was in fact incompatible and we received a customer incident regarding this change just recently! Of course we reacted by improving the respective behavior (method GET delivers HTML in background processing again, only DISPLAY switches to text mode), but we are not forced to backport that.
All in all, the classes might serve as patterns for your own (productive) classes but then it is your own responsibility. Please be aware, that it is not "SAP" that is shirking responsibility here. The classes are just the product of ABAP documentation writers playing around for their own purposes.
It is the problem of the tool coming realy usefull. But I understand the reasons you exposed.
As you set-it as FINAL class, we could not use inheritance to encapsulate in specific class.
Is it allowed to create a public version on GitHub of this tool ? if we want to propose a new version.
Removing the FINAL would cause the same compatibility problems. We couldn't change or even remove components of the class any more. In fact, that problem already occurred internally.
Since we promote it as a demo, you can copy it to your own (GIT) repositories.