The function new_fieldtype creates a new field type usable
for data validation. You supply it with field_check, a
predicate to check the validity of an entered data string
@@ -112,24 +113,31 @@
REQ_PREV_CHOICE assume that the possible values of a field
form an ordered set, and provide the forms user with a way
to move through the set. The set_fieldtype_choice func-
- tion allows forms programmers to define successor and
- predecessor functions for the field type. These functions
+ tion allows forms programmers to define successor and pre-
+ decessor functions for the field type. These functions
take the field pointer and an argument-block structure as
arguments.
-
RETURN VALUE
- The pointer-valued routines return NULL on error.
+
+ The pointer-valued routines return NULL on error. They
+ set errno according to their success:
+
+ E_OK The routine succeeded.
+
+ E_BAD_ARGUMENT
+ Routine detected an incorrect or out-of-range argu-
+ ment.
+
+ E_SYSTEM_ERROR
+ System error occurred, e.g., malloc failure.
The integer-valued routines return one of the following
codes on error:
E_OK The routine succeeded.
- E_SYSTEM_ERROR
- System error occurred (see errno).
-
E_BAD_ARGUMENT
Routine detected an incorrect or out-of-range argu-
ment.
@@ -137,14 +145,20 @@
E_CONNECTED
The field is already connected to a form.
+ E_CURRENT
+ The field is the current field.
+
+ E_SYSTEM_ERROR
+ System error occurred (see errno).
+