Need explanation of the following code

[Former Member]

HI All,

I need your help on explanation of the following code :

what I don't understand is how it route the request (all the benefit of the replace statement )

If the input is /scarr/LH/SPFLI/402

how he know to route it and

what is the benefit for using the wild card and the concatenate CONCATENATE '^' lv_verif_pattern '$'

Edited by: James Herb on Apr 13, 2010 9:53 AM

Edited by: James Herb on Apr 13, 2010 9:53 AM

[Former Member]

DATA: lt_routing_tab TYPE z_resource_routing_tab,
      
  CONSTANTS: param_wildcard TYPE string VALUE '([^/])*'.

  FIELD-SYMBOLS: <ls_routing> LIKE LINE OF lt_routing_tab.

  CALL METHOD get_routing
    RECEIVING
      rt_routing_tab = lt_routing_tab.

  LOOP AT lt_routing_tab ASSIGNING <ls_routing>.
*   replace all parameters placeholders by regex
    lv_verif_pattern = <ls_routing>-url_info.
    lv_signature = <ls_routing>-url_info.
    REPLACE ALL OCCURRENCES OF REGEX '\{([A-Z]*[_]*[a-z]*[0-9]*)*\}'
    IN lv_verif_pattern WITH param_wildcard.

    CONCATENATE '^' lv_verif_pattern '$'  INTO lv_verif_pattern.

*   check if pattern matches current entry
    FIND ALL OCCURRENCES OF REGEX lv_verif_pattern
    IN url_info MATCH COUNT lv_count.

*   pattern matched
    IF lv_count > 0.
*     get controller class name
      lv_controller_name = <ls_routing>-handler_class.
      ls_class-clsname = lv_controller_name.
*     check if class exists
 
*     class found
      IF sy-subrc = 0.
*       create controller
        CREATE OBJECT eo_controller TYPE (lv_controller_name).
*       create parameter table
        SHIFT lv_verif_pattern RIGHT DELETING TRAILING '$'.
        SHIFT lv_verif_pattern LEFT DELETING LEADING ' ^'.

        SPLIT lv_verif_pattern AT param_wildcard INTO TABLE lt_url_parts.
        lv_url_info = url_info.

        LOOP AT lt_url_parts INTO lv_url_part.
          SHIFT lv_signature LEFT DELETING LEADING lv_url_part.
          SHIFT lv_signature LEFT DELETING LEADING '{'.
          SHIFT lv_url_info LEFT DELETING LEADING lv_url_part.

Edited by: James Herb on Apr 13, 2010 9:56 AM

[Former Member]

the get routing is

DATA ls_routing LIKE LINE OF rt_routing_tab.

  ls_routing-clnt = sy-mandt.
  ls_routing-guid = '123'.
  ls_routing-url_info = '/scarr/{PARAM_CARR_ID}'.
  ls_routing-handler_class = 'ZCL_RESOURCE_SCARR'.
  APPEND ls_routing TO rt_routing_tab.

  ls_routing-clnt = sy-mandt.
  ls_routing-guid = '456'.
  ls_routing-url_info = '/scarr/{PARAM_CARR_ID}/spfli/{PARAM_CONNID}'.
  ls_routing-handler_class = 'ZCL_RESOURCE_SPFLI'.
  APPEND ls_routing TO rt_routing_tab.

i take this code from the following link

/people/community.user/blog/2009/06/09/restful-webservices-in-abap-using-a-generic-controller

Regards

James

Edited by: James Herb on Apr 13, 2010 2:43 PM