I have several custom exception classes that were created "With Message Class". Since I can't directly get a message from them, I want to create a utility method that returns a BAPIRET2 from a given exception based on the values in IF_T100_MESSAGE~T100KEY. However, I can't provide that method with a generic CX_ROOT importing parameter as this class is not message-enabled. I also can't create a generic message-enabled exception class as new classes have to inherit from one of CX_STATIC_CHECK, CX_DYNAMIC_CHECK, or CX_NOCHECK.
How can I then retrieve the message details from an unspecified exception? Should I create a method that receives a CX_ROOT and then does up to three calls to methods with an import typed to each of the three possible subclasses? Or are there better alternatives?
You could prepare a type descriptor of the interface (once):
DATA: lr_t100_descr TYPE REF TO cl_abap_intfdescr.
lr_t100_descr ?= cl_abap_typedescr=>describe_by_name( 'IF_T100_MESSAGE' ).
and then examine each exception as it comes your way:
DATA: lr_t100_exception TYPE REF TO if_t100_message.
IF lr_t100_descr->applies_to( ir_any_exception ) = abap_true.
lr_t100_exception ?= ir_any_exception.
" ...
ENDIF.
You could use the message collector object, so for example
DATA:
excp type ref to CX_ROOT,
bapi_messages type BAPIRETTAB,
message_collector type ref to IF_RECA_MESSAGE_LIST.
FIELD_SYMBOLS:
<bapi_message> TYPE BAPIRET2.
message_collector = cf_reca_message_list=>create( ).
TRY.
" some code which may cause and exception
CATCH cx_root into excp.
message_collector->add_from_exxeption( io_exception = excp).
ENDTRY.
bapi_messages = message_collector->get_list_as_bapiret( ).
LOOP AT bapi_messages ASSIGNING <bapi_message>.
" write out message
ENDLOOP.
It is well worth checking out the message collector object.
For example
http://wiki.scn.sap.com/wiki/display/profile/2007/07/09/Message+Handling+-+Finding+the+Needle+in+the+Haystack
For a logging class I use something like this:
METHOD add_message_exception.
DATA:
lr_type TYPE REF TO cl_abap_typedescr,
lr_class TYPE REF TO cl_abap_classdescr,
lr_intf TYPE REF TO cl_abap_intfdescr,
l_bapiret2 TYPE bapiret2,
lr_msg TYPE REF TO if_t100_message.
CHECK ir_exception IS NOT INITIAL.
l_bapiret2-type = i_type.
"Test for T100KEY interface
cl_abap_classdescr=>describe_by_object_ref(
EXPORTING
p_object_ref = ir_exception
RECEIVING
p_descr_ref = lr_type
EXCEPTIONS
reference_is_initial = 1
OTHERS = 2 ).
TRY.
lr_class ?= lr_type.
IF sy-subrc = 0.
lr_class->get_interface_type(
EXPORTING
p_name = 'IF_T100_MESSAGE'
RECEIVING
p_descr_ref = lr_intf
EXCEPTIONS
interface_not_found = 1
OTHERS = 2 ).
IF sy-subrc = 0.
lr_msg ?= ir_exception. "Cast to interface
l_bapiret2-id = lr_msg->t100key-msgid.
l_bapiret2-number = lr_msg->t100key-msgno.
cl_message_helper=>set_msg_vars_for_if_t100_msg( text = lr_msg ).
l_bapiret2-message_v1 = sy-msgv1.
l_bapiret2-message_v2 = sy-msgv2.
l_bapiret2-message_v3 = sy-msgv3.
l_bapiret2-message_v4 = sy-msgv4.
l_bapiret2-message = me->get_msg(
i_msgid = l_bapiret2-id
i_msgno = l_bapiret2-number ).
ENDIF.
ENDIF.
CATCH cx_root.
"Pokémon exception handling
ENDTRY.
"No T100KEY Interface available
IF lr_msg IS INITIAL.
l_bapiret2-message = ir_exception->if_message~get_text( ).
l_bapiret2-message_v1 = sy-msgv1.
l_bapiret2-message_v2 = sy-msgv2.
l_bapiret2-message_v3 = sy-msgv3.
l_bapiret2-message_v4 = sy-msgv4.
ENDIF.
ENDMETHOD.
Hope this helps as I struggled with the same problem. Maybe there is some adjustment needed, but I think you get the basic idea. This method can handle
I might be missing something, but can't you just use IF_MESSAGE~GET_TEXT which is present on CX_ROOT ?
Otherwise, I would make it the responsibility of the custom exception class to have a method that can return a proper message ( it might rely on the utility method you are planning on ).
Related
I was parsing some string input from a file when I came across this error. Normally it should not make a difference if you chain a series of methods on a single line or separate them into multiple operations. Yet here, it does not compile when the method chain is in a single line.
I do not get an error when split to multiple statements like so (link to playground)
let input = std::fs::read_to_string("tst_input.txt").expect("Failed to read input");
let input = input
.lines()
.map(|l| {
let mut iter = l.split(" | ");
(
iter.next()
.unwrap()
.split_whitespace()
.collect::<Vec<&str>>(),
iter.next()
.unwrap()
.split_whitespace()
.collect::<Vec<&str>>(),
)
})
.collect::<Vec<_>>();
I get a lifetime error when it is in a single statement like so (link to playground)
let input = std::fs::read_to_string("tst_input.txt")
.expect("Failed to read input")
.lines()
.map(|l| {
let mut iter = l.split(" | ");
(
iter.next()
.unwrap()
.split_whitespace()
.collect::<Vec<&str>>(),
iter.next()
.unwrap()
.split_whitespace()
.collect::<Vec<&str>>(),
)
})
.collect::<Vec<_>>()
error[E0716]: temporary value dropped while borrowed
--> src/main.rs:2:17
|
2 | let input = std::fs::read_to_string("tst_input.txt")
| _________________^
3 | | .expect("Failed to read input")
| |_______________________________________^ creates a temporary which is freed while still in use
...
18 | .collect::<Vec<_>>();
| - temporary value is freed at the end of this statement
19 | println!("{:?}", input);
| ----- borrow later used here
|
= note: consider using a `let` binding to create a longer lived value
Should these 2 cases be effectively identical? why is the compiler treating them differently? Could this possibly be a compiler error?
These two cases are not identical, since the stored information differs.
In Rust, variables have semantic meaning: they act as a place where the information is stored, and, what's more important, they define when this information is destroyed - this is handled by Drop trait. By default, drop method is called for every variable which goes out of scope; this can be overridden with mem::forget and some other functions like Box::into_raw, but these are rather niche cases.
In the first case, the data being read is stored into the input variable of type String. This type wraps Vec<u8>, which implements Drop, so this data is deallocated when input goes out of scope. Then, the second input variable is of type Vec<(Vec<&str>, Vec<&str>)> - you can see that it contains a reference, so it is borrowing from the first input, so it must live no longer then the source string. Here, this is satisfied - of course, as long as you don't try to return this value up the stack, in which case the source string is dropped, and the references would dangle.
In the one-line version, however, the string is not stored anywhere - it is a temporary, which is destroyed right at the end of statement. That's why you're not allowed to hold any references to it. You can, however, make an owned version of the split data, by inserting an extra mapping operation:
let _: Vec<(Vec<String>, Vec<String>)> = std::fs::read_to_string("tst_input.txt")
.expect("Failed to read input")
// This iterator borrows from the temporary...
.lines()
.map(|l| {
// ...this iterator reborrows that borrow...
let mut iter = l.split(" | ");
(
iter.next()
.unwrap()
.split_whitespace()
// ...and this operation clones the source data,
// so they are copied to the new owned location,
// and not referenced anymore, so can be freely dropped
.map(str::to_owned)
.collect::<Vec<_>>(),
iter.next()
.unwrap()
.split_whitespace()
.map(str::to_owned)
.collect::<Vec<_>>(),
)
})
.collect::<Vec<_>>();
A minimal recreation of the issue might help
let split_value = String::from("example")// <- string owned value
.split("x");
// string has no owner, so its lifetime ends
println!("{:?}", split_value); //error
A reference must not outlive the lifetime of the value it is referencing. Because the string is not being stored anywhere, and therefore has no owner, the value's lifetime ends.
And because split returns data that references that string value, its lifetime is linked to that string so it also ends.
By storing the result in a variable, the string now has a lifetime that lives past the expression.
let str_result = String::from("example"); //str_result owns the string value
let split_value = s.split("x");
println!("{:?}", r);
split_value can be printed because str_result's lifetime ends at the end of the function, therefore references to str_result are valid too.
I want to pass an error local object in a class method which will display a detail error to the user.
This is the current code:
CATCH cx_root INTO lcx_general_error.
DATA(lv_longtext) = lcx_general_error->get_longtext( ).
lcx_general_error->get_source_position(
IMPORTING
program_name = lv_program_name
include_name = lv_include_name
source_line = lv_program_line
).
DATA(lv_program_include) = |{ lv_program_name }/ { lv_include_name }|.
DATA(lv_length_message) = strlen( lv_longtext ).
DATA(lv_error_message1) = lv_longtext(50).
IF lv_length_message > 50.
DATA(lv_remaining) = lv_length_message - 50.
DATA(lv_error_message2) = lv_longtext+50(lv_remaining).
ENDIF.
MESSAGE e001 WITH lv_error_message1 lv_error_message2
lv_program_include
lv_program_line.
Instead, I want to create a class method and pass any local object that refers to any error and display the error detail message:
CATCH cx_root INTO lcx_general_error.
lo_fi_uploads->display_error( lcx_general_error ).
How to create and use this parameter in the local class?
Exceptions are regular classes with regular object instances, so declare them like any other object parameter:
METHODS display_error
IMPORTING
exception TYPE REF TO cx_root.
In the method’s implementation you can then paste the code you already have:
METHOD display_error.
DATA(lv_longtext) = exception->get_longtext( ).
exception->get_source_position(
IMPORTING
program_name = DATA(lv_program_name)
include_name = DATA(lv_include_name)
source_line = DATA(lv_program_line)
).
DATA(lv_program_include) = |{ lv_program_name }/ { lv_include_name }|.
DATA(lv_length_message) = strlen( lv_longtext ).
DATA(lv_error_message1) = lv_longtext(50).
IF lv_length_message > 50.
DATA(lv_remaining) = lv_length_message - 50.
DATA(lv_error_message2) = lv_longtext+50(lv_remaining).
ENDIF.
MESSAGE e001 WITH lv_error_message1 lv_error_message2
lv_program_include
lv_program_line.
ENDMETHOD.
People often fear that working with exceptions might accidentally trigger them. That won’t happen. As long as you do not invoke the RAISE statement, exceptions are really quite ordinary objects. You can even instantiate them with NEW without triggering them.
I want to catch and handle SAPSQL_DATA_LOSS in my ABAP code.
I tried this:
try.
SELECT *
FROM (rtab_name) AS rtab
WHERE (sub_condition)
into table #<sub_result>
.
catch SAPSQL_DATA_LOSS into error.
...
endtry.
But above code is not valid. I get this message:
Type "SAPSQL_DATA_LOSS" is not valid
And I tried this:
catch SYSTEM-EXCEPTIONS SAPSQL_DATA_LOSS = 123.
SELECT *
...
.
endcatch.
if sy-subrc = 123.
...
endif.
But above code gives me:
Instead of "SAPSQL_DATA_LOSS" expected "system-exception" (translated from german to english by me)
How to catch SAPSQL_DATA_LOSS?
This question is not about "why does this exception happen?". This is already solved. My code should handle the exception.
SAPSQL_DATA_LOSS is a runtime error.
As SAPSQL_DATA_LOSS is not a class-based exception, it is not possible to catch it using try catch.
As SAPSQL_DATA_LOSS is not a catchable runtime error, it is not possible to catch it using try catch SYSTEM-EXCEPTIONS.
see the below catchable runtime errors.
https://help.sap.com/doc/abapdocu_751_index_htm/7.51/en-US/abenueb-abfb-sysexc.htm
After some tries I can propose you a possible solution.
This is a workaround:
I don't know if it can be applied to your case, since it needs the select statement to be wrapped into an RFC function module !
The main point is that a short dump (message type X) CAN be handled in RFC calls.
So using an RFC (CALL FUNCTION 'xxxxx' destination 'NONE' for example) and using special exception SYSTEM_FAILURE, the system does not terminate the caller program, but instead it returns a SY-SUBRC > 0 with the Short dump informations in system message fields (SY-MSGxx).
STEPS
Create a Function module (RFC enabled) with your select statement input + the row type of the result table. (All parameters passed by value)
You need this last parameter since generic tables can't be passed in RFC (no "TYPE ANY TABLE" allowed)
FUNCTION Z_DYN_SEL .
*"----------------------------------------------------------------------
*"*"Local interface:
*" IMPORTING
*" VALUE(RTAB_NAME) TYPE TABNAME16
*" VALUE(SUB_CONDITION) TYPE STRING
*" VALUE(RESULT_TYPE) TYPE STRING
*"----------------------------------------------------------------------
* RTAB_NAME: DB Table
* SUB_CONDITION: WHERE Condition
* RESULT_TYPE: The ROW type of the internal table
field-symbols <sub_result> type any table.
* DEFINE LOCAL DYNAMIC TABLE TO STORE THE RESULT
data: lr_res type ref to data.
create data lr_res type standard table of (result_type).
assign lr_res->* to <sub_result>.
* DYNAMIC SELECT
select *
from (rtab_name) as rtab
where (sub_condition)
into table #<sub_result>.
* EXPORT RESULT TO A MEMORY ID, SO IT CAN BE RETRIEVED BY CALLER
export res = <sub_result> to memory id 'RES'.
Main program:
In this caller example some parameters are passed to the RFC.
KTOKD field (should be 4 chars long) is passed with a char10 value (producing your short dump).
If ANY Dump is triggered inside the function, we can now handle it.
If everything went fine, IMPORT result from the EXPORT statement inside the RFC
field-symbols <sub_result> type any table.
data: lr_res type ref to data.
create data lr_res type standard table of KNA1.
assign lr_res->* to <sub_result>.
data lv_msg type char255.
call function 'Z_DYN_SEL' destination 'NONE'
exporting
rtab_name = 'KNA1'
sub_condition = `KTOKD = 'D001xxxxxx'`
result_type = 'KNA1'
exceptions
system_failure = 1 message lv_msg.
if sy-subrc = 0.
import res = <sub_result> from memory id 'RES'.
else.
write: / lv_msg.
write : / sy-msgid, sy-msgno, sy-msgty, sy-msgv1, sy-msgv2, sy-msgv3, sy-msgv4.
endif.
RESULTS
After the RFC call in case of a short dump in the select statement, the program is not terminated and the following pieces of information are available
SY-SUBRC = 1
lv_msg is the error text (Data was lost while copying a value.)
Sy-msgid = 00
Sy-msgno = '341'
Sy-msgty = 'X'
Sy-msgv1 = 'SAPSQL_DATA_LOSS'
I know that I can use LIST_TO_ASCI to convert a report to ASCII, but I would like to have a more high level data format like JSON, XML, CSV.
Is there a way to get something that is easier to handle then ASCII?
Here is the report I'd like to convert:
The conversion needs to be executed in ABAP on a result which was executed like this:
SUBMIT <REPORT_NAME> ... EXPORTING LIST TO MEMORY AND RETURN.
You can get access to SUBMIT list in memory like this:
call function 'LIST_FROM_MEMORY'
TABLES
listobject = t_list
EXCEPTIONS
not_found = 1
others = 2.
if sy-subrc <> 0.
message 'Unable to get list from memory' type 'E'.
endif.
call function 'WRITE_LIST'
TABLES
listobject = t_list
EXCEPTIONS
EMPTY_LIST = 1
OTHERS = 2
.
if sy-subrc <> 0.
message 'Unable to write list' type 'E'.
endif.
And the final step of the solution (conversion of result table to JSON) was already answered to you in your question.
I found a solution here: http://zevolving.com/2015/07/salv-table-22-get-data-directly-after-submit/
This is the code:
DATA: lt_outtab TYPE STANDARD TABLE OF alv_t_t2.
FIELD-SYMBOLS: <lt_outtab> like lt_outtab.
DATA lo_data TYPE REF TO data.
" Let know the model
cl_salv_bs_runtime_info=>set(
EXPORTING
display = abap_false
metadata = abap_false
data = abap_true
).
SUBMIT salv_demo_table_simple
AND RETURN.
TRY.
" get data from SALV model
cl_salv_bs_runtime_info=>get_data_ref(
IMPORTING
r_data = lo_data
).
ASSIGN lo_data->* to <lt_outtab>.
BREAK-POINT.
CATCH cx_salv_bs_sc_runtime_info.
ENDTRY.
Big thanks to Sandra Rossi, she gave me the hint to cx_salv_bs_sc_runtime_info.
Related answer: https://stackoverflow.com/a/52834118/633961
With SQLAlchemy, I'm finding that sometimes I mis-type a name of an attribute which is mapped to a column, which results in rather difficult to catch errors:
class Thing(Base):
foo = Column(String)
thing = Thing()
thing.bar = "Hello" # a typo, I actually meant thing.foo
assert thing.bar == "Hello" # works here, as thing.bar is a transient attribute created by the assignment above
session.add(thing)
session.commit() # thing.bar is not saved in the database, obviously
...
# much later
thing = session.query(Thing)...one()
assert thing.foo == "Hello" # fails
assert thing.bar == "Hello" # fails, there's no even such attribute
Is there a way to configure the mapped class so assigning to anything which is not mapped to an SQLAlchemy column would raise an exception?
Ok, the solution seems to be to override __setattr__ method of the base class, which allows us to check if the atribute already exists before setting it.
class BaseBase(object):
"""
This class is a superclass of SA-generated Base class,
which in turn is the superclass of all db-aware classes
so we can define common functions here
"""
def __setattr__(self, name, value):
"""
Raise an exception if attempting to assign to an atribute which does not exist in the model.
We're not checking if the attribute is an SQLAlchemy-mapped column because we also want it to work with properties etc.
See http://stackoverflow.com/questions/12032260/ for more details.
"""
if name != "_sa_instance_state" and not hasattr(self, name):
raise AttributeError("Attribute %s is not a mapped column of object %s" % (name, self))
super(BaseBase, self).__setattr__(name, value)
Base = declarative_base(cls=BaseBase)
Sort of "strict mode" for SQLAlchemy...
Override the __get__ method of objects, and check to see if it is in the column (by storing it with the class definition or runtime search)
More information here from SO.