определить типы полей проверки (define validation-field types)
Имя (Name)
form_fieldtype - define validation-field types
Синопсис (Synopsis)
#include <form.h>
FIELDTYPE *new_fieldtype(
bool (* const field_check)(FIELD *, const void *),
bool (* const char_check)(int, const void *));
int free_fieldtype(FIELDTYPE *fieldtype);
int set_fieldtype_arg(
FIELDTYPE *fieldtype,
void *(* const make_arg)(va_list *),
void *(* const copy_arg)(const void *),
void (* const free_arg)(void *));
int set_fieldtype_choice(
FIELDTYPE *fieldtype,
bool (* const next_choice)(FIELD *, const void *),
bool (* const prev_choice)(FIELD *, const void *));
FIELDTYPE *link_fieldtype(FIELDTYPE *type1,
FIELDTYPE *type2);
Описание (Description)
new_fieldtype
The function new_fieldtype creates a new field type usable for
data validation. Its parameters are function pointers:
field_check
This function checks the validity of an entered data string
whenever the user attempts to leave a field. It has two
arguments:
• The (FIELD *) argument is passed in so the validation
predicate can see the field's buffer, sizes and other
attributes.
• The second argument is an argument-block structure,
about which more below.
char_check
This function validates input characters as they are
entered. The form library passes it the character to be
checked and a pointer to an argument-block structure.
free_fieldtype
The free_fieldtype function frees the space allocated for a given
validation type by new_fieldtype.
set_fieldtype_arg
The function set_fieldtype_arg associates three storage-
management functions with a field type:
make_arg
This function is automatically applied to the list of
arguments you give set_field_type when attaching validation
to a field. It stores the arguments in an allocated
argument-block object which is used when validating input.
copy_arg
This function may be used by applications to copy argument-
blocks.
free_arg
Frees an argument-block structure.
You must supply the make_arg function. The other two are
optional: you may supply NULL for them. In this case, the form
library assumes that make_arg does not allocate memory but simply
loads the argument into a single scalar value.
set_fieldtype_choice
The form driver requests REQ_NEXT_CHOICE and 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 function allows forms programmers to
define successor and predecessor functions for the field type.
These functions take the field pointer and an argument-block
structure as arguments.
link_fieldtype
The function link_fieldtype creates a new field type from the two
given types. They are connected by an logical 'OR'.
Возвращаемое значение (Return value)
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 argument.
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_BAD_ARGUMENT
Routine detected an incorrect or out-of-range argument.
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(3)).
Смотри также (See also)
curses(3X), form(3X), form_field_validation(3X).
Примечание (Note)
The header file <form.h> automatically includes the header file
<curses.h>.
Портативность (Portability)
These routines emulate the System V forms library. They were not
supported on Version 7 or BSD versions.
