ST22: OBJECTS_OBJREF_NOT_ASSIGNED

Question

Hi SDN, can somebody give me a clue about this ST22 dump:
Coding OnInputProcessing:
DATA: event TYPE REF TO cl_htmlb_event.
DATA: data_t TYPE REF TO cl_htmlb_inputfield.
event = cl_htmlb_manager=>get_event( runtime->server->request ).
IF event->id = 'BZUR' AND event->event_type = 'click'.
Coding im Layout:
      <htmlb:form method="post" >
        <htmlb:button id      = "BZUR"
                      onClick = "clicked"
                      text    = "zurück"></htmlb:button>
I thought this is the way to make things work safely - still sometimes I get this short dump:
     1 method _ONINPUTPROCESSING.                                        
     2 * event handler for checking and processing user input and        
     3 * for defining navigation                                         
     4                                                                   
     5 DATA: event TYPE REF TO cl_htmlb_event.                           
     6 DATA: data_t TYPE REF TO cl_htmlb_inputfield.                     
     7                                                                   
     8 event = cl_htmlb_manager=>get_event( runtime->server->request ).  
     9                                                                   
>>>>> IF event->id = 'BZUR' AND event->event_type = 'click'.            
    11                                                                   
    12 * HOOK_URL ist befüllt und muss nicht erst neu geholt werden      
    13   data_t ?= cl_htmlb_manager=>get_data(                           
    14                               request = runtime->server->request  
    15                               name     = 'inputField'             
    16                               id       = 'I01'                    
    17                               ).                                  
    18   IF NOT data_t IS INITIAL.                                       
    19     hook_url = data_t->value.                                     
    20   ENDIF.                                                          
    21                                                                   
    22   navigation->set_parameter( name = 'HOOK_URL' value = hook_url ).
    23   navigation->goto_page( url = 'start.htm' ).                     
    24 ENDIF.                                                            
The dump does not occur regularly only seldom randomly.
regards, matthias
ps: this is WAS 700
SAP_ABA      700     0010     SAPKA70010
SAP_BASI 700     0010     SAPKB70010
pps: I did some more testing and noticed taht this dump occurs when hitting the submit Button, which is not htmlb but mere html with some css formats:
<input type="submit" name="onInputProcessing(go)"
                       value="an EVI senden" style="border: solid 1px black;
                       background-color: #C1D3E0; color: #000000; font-size: 11px;">
Message was edited by:
        Matthias Kasig
Message was edited by:
        Matthias Kasig

Answer 1

Hi Matthias,
I guess as in your case the form is not submitted by the respective JavaScript libraries of HTMLB that some hidden inputfields that contain more information about the type of the event are not filled and therefor the event-manager cannot create the event. To circumvent the dump you can just check whether the event is bound.
if event is bound and .....
In case the event is not bound (could not been instantiated) the rest of the if-clause will not be checked.
The better option from my point of view is to proceed as follows:
Use the bsp-tag htmlbEvent on the layout to get the javascript for executing an event generated:
<bsp:htmlbEvent  event_code = "<%=lv_event%>"
                 event_type = "MyEventType"
                 id         = "SubmitMyEvent"
                 name       = "SubmitMyEvent"/>
If you place this within your layout the variable lv_event contains the javascript that is required to trigger the event. If you put this coding into you Button as onClick:
<input type="BUTTON" value="Submit" onClick="<%=lv_event%>">
Then you should be able to handle the event in the onInputprocessing by:
DATA: event TYPE REF TO IF_HTMLB_DATA.
event = cl_htmlb_manager=>get_event_ex( runtime->server->request ).
Now you can find your Id's in the attributes of the interface reference. In case you use standard htmlb-elements to trigger the form submit (e.g. checkbox or dropdown) you can use the following to distinguish what element has fired the event:
CASE event->event_name.
  WHEN htmlb_events=>checkbox.
  "Checkbox was clicked
  WHEN .......
  "Some other events
ENDCASE.
The constants for the htlmb-events are available in class htmlb_events, the ones for phtmlb in phtmlb_events and the ones for xhtmlb in xhtmlb_events.
Hope that helps.
Best Regards
Michael