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Libgnomedb Reference Manual | ![]() |
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GnomeDbParameterGnomeDbParameter — Represents a GdaValue with various attributes |
GnomeDbParameter; GType gnome_db_parameter_get_type (void); GObject* gnome_db_parameter_new (GnomeDbDict *dict, GnomeDbServerDataType *type); GObject* gnome_db_parameter_new_copy (GnomeDbParameter *orig); GObject* gnome_db_parameter_new_with_dest_field (GnomeDbField *field, GnomeDbServerDataType *type); void gnome_db_parameter_add_dest_field (GnomeDbParameter *param, GnomeDbField *field); GSList* gnome_db_parameter_get_dest_fields (GnomeDbParameter *param); GnomeDbServerDataType* gnome_db_parameter_get_data_type (GnomeDbParameter *param); const GdaValue* gnome_db_parameter_get_value (GnomeDbParameter *param); void gnome_db_parameter_set_value (GnomeDbParameter *param, const GdaValue *value); gboolean gnome_db_parameter_set_value_str (GnomeDbParameter *param, const gchar *value); void gnome_db_parameter_declare_invalid (GnomeDbParameter *param); gboolean gnome_db_parameter_is_valid (GnomeDbParameter *param); const GdaValue* gnome_db_parameter_get_default_value (GnomeDbParameter *param); void gnome_db_parameter_set_default_value (GnomeDbParameter *param, const GdaValue *value); void gnome_db_parameter_set_not_null (GnomeDbParameter *param, gboolean not_null); gboolean gnome_db_parameter_get_not_null (GnomeDbParameter *param); gboolean gnome_db_parameter_set_source_field (GnomeDbParameter *param, GnomeDbField *field, GError **error); GnomeDbField* gnome_db_parameter_get_source_field (GnomeDbParameter *param); void gnome_db_parameter_add_dependency (GnomeDbParameter *param, GnomeDbParameter *depend_on); void gnome_db_parameter_del_dependency (GnomeDbParameter *param, GnomeDbParameter *depend_on); GSList* gnome_db_parameter_get_dependencies (GnomeDbParameter *param); void gnome_db_parameter_replace_ref (GnomeDbParameter *param, GHashTable *replacements); void gnome_db_parameter_bind_to_param (GnomeDbParameter *param, GnomeDbParameter *bind_to); GnomeDbParameter* gnome_db_parameter_get_bind_param (GnomeDbParameter *param); gboolean gnome_db_parameter_requires_user_input (GnomeDbParameter *param); void gnome_db_parameter_set_user_input_required (GnomeDbParameter *param, gboolean input_required);
"full-bind" gpointer : Read / Write "handler-plugin" gchararray : Read / Write "simple-bind" gpointer : Read / Write "use-default-value" gboolean : Read / Write
A GnomeDbParameter object basically conveys a value (as a GdaValue) and several attributes specifying the value itself.
Parameters are usually used in conjunction with the GnomeDbDataModel interface and with queries which require parameters for their execution.
Also a parameter can be set to an alias of another parameter, in which case that parameter and the one of which it is an alias will always be synchronized regarding their value and attributes. This feature is usefull when a parameter required by a query needs to be synchronized to an already existing parameter.
GObject* gnome_db_parameter_new (GnomeDbDict *dict, GnomeDbServerDataType *type);
Creates a new parameter of type type
dict : |
a GnomeDbDict object |
type : |
the GnomeDbServerDataType requested |
Returns : | a new GnomeDbParameter object |
GObject* gnome_db_parameter_new_copy (GnomeDbParameter *orig);
Copy constructor.
orig : |
a GnomeDbParameter object to copy |
Returns : | a new GnomeDbParameter object |
GObject* gnome_db_parameter_new_with_dest_field (GnomeDbField *field, GnomeDbServerDataType *type);
Creates a new parameter to be passed to field
for the operations where a parameter is required;
other GnomeDbField can also be added by using the gnome_db_parameter_add_dest_field()
method.
field : |
the GnomeDbField object the parameter is for |
type : |
the GnomeDbServerDataType requested |
Returns : | a new GnomeDbParameter object |
void gnome_db_parameter_add_dest_field (GnomeDbParameter *param, GnomeDbField *field);
Adds a GnomeDbField object for which the parameter is for
param : |
a GnomeDbParameter object |
field : |
the GnomeDbField object the parameter is for |
GSList* gnome_db_parameter_get_dest_fields (GnomeDbParameter *param);
Get the GnomeDbField objects which created param
(and which will use its value)
param : |
a GnomeDbParameter object |
Returns : | the list of GnomeDbField object; it must not be changed or free'd |
GnomeDbServerDataType* gnome_db_parameter_get_data_type (GnomeDbParameter *param);
Get the requested data type for param
.
param : |
a GnomeDbParameter object |
Returns : | the data type |
const GdaValue* gnome_db_parameter_get_value (GnomeDbParameter *param);
Get the value held into the parameter
param : |
a GnomeDbParameter object |
Returns : | the value (a NULL value returns a GDA_VALUE_TYPE_NULL GdaValue) |
void gnome_db_parameter_set_value (GnomeDbParameter *param, const GdaValue *value);
param : |
|
value : |
gboolean gnome_db_parameter_set_value_str (GnomeDbParameter *param, const gchar *value);
Same function as gnome_db_parameter_set_value()
except that the value
is provided as a string, and may return FALSE if the string did not
represent a correct value for the data type of the parameter.
param : |
a GnomeDbParameter object |
value : |
a value to set the parameter to, as a string |
Returns : | TRUE if no error occured |
void gnome_db_parameter_declare_invalid (GnomeDbParameter *param);
Forces a parameter to be invalid; to set it valid again, a new value must be assigned
to it using gnome_db_parameter_set_value()
.
param : |
a GnomeDbParameter object |
gboolean gnome_db_parameter_is_valid (GnomeDbParameter *param);
Get the validity of param
(that is, of the value held by param
)
param : |
a GnomeDbParameter object |
Returns : | TRUE if param 's value can safely be used
|
const GdaValue* gnome_db_parameter_get_default_value (GnomeDbParameter *param);
Get the default value held into the parameter. WARNING: the default value does not need to be of
the same type as the one required by param
.
param : |
a GnomeDbParameter object |
Returns : | the default value |
void gnome_db_parameter_set_default_value (GnomeDbParameter *param, const GdaValue *value);
param : |
|
value : |
void gnome_db_parameter_set_not_null (GnomeDbParameter *param, gboolean not_null);
Sets if the parameter can have a NULL value. If not_null
is TRUE, then that won't be allowed
param : |
a GnomeDbParameter object |
not_null : |
gboolean gnome_db_parameter_get_not_null (GnomeDbParameter *param);
Get wether the parameter can be NULL or not
param : |
a GnomeDbParameter object |
Returns : | TRUE if the parameter cannot be NULL |
gboolean gnome_db_parameter_set_source_field (GnomeDbParameter *param, GnomeDbField *field, GError **error);
Sets a limit on the possible values for the param
parameter: the value must be among the values of field
within
the GnomeDbEntity to which field
belongs (the GnomeDbEntity can either be a GnomeDbDataModel which already has
some data, or a GnomeDbQuery which will be converted to a GnomeDbResultset (which itself is a GnomeDbDataModel)
to have some actual data).
field
must be of the same type as the requested type for param
.
field
is not copied, just referenced.
param : |
a GnomeDbParameter object |
field : |
a GnomeDbField object or NULL |
error : |
location to store error, or NULL
|
Returns : | TRUE if no error occurred |
GnomeDbField* gnome_db_parameter_get_source_field (GnomeDbParameter *param);
param : |
|
Returns : |
void gnome_db_parameter_add_dependency (GnomeDbParameter *param, GnomeDbParameter *depend_on);
Tell param
that its value will depend on the value of depend_on
param : |
a GnomeDbParameter object |
depend_on : |
a GnomeDbParameter object |
void gnome_db_parameter_del_dependency (GnomeDbParameter *param, GnomeDbParameter *depend_on);
Remove the depend_on
dependency from param
param : |
a GnomeDbParameter object |
depend_on : |
a GnomeDbParameter object |
GSList* gnome_db_parameter_get_dependencies (GnomeDbParameter *param);
Get the list of GnomeDbParameter param
depends on
param : |
a GnomeDbParameter object |
Returns : | the list of parameters (the list should not be modified) |
void gnome_db_parameter_replace_ref (GnomeDbParameter *param, GHashTable *replacements);
Replace references to some objects by references to some other objects,
as listed in replacements
.
param : |
a GnomeDbParameter object |
replacements : |
the (objects to be replaced, replacing object) pairs |
void gnome_db_parameter_bind_to_param (GnomeDbParameter *param, GnomeDbParameter *bind_to);
Sets param
to change when bind_to
changes (and does not make bind_to
change when param
changes)
param : |
a GnomeDbParameter |
bind_to : |
a GnomeDbParameter or NULL
|
GnomeDbParameter* gnome_db_parameter_get_bind_param (GnomeDbParameter *param);
Get the parameter which makes param
change its value when the param's value is changed.
param : |
a GnomeDbParameter |
Returns : | the GnomeDbParameter or NULL
|
gboolean gnome_db_parameter_requires_user_input (GnomeDbParameter *param);
Tells if the parameter is configured in a way that even if there is a value, it requires that the user at least validates that value, or change it.
param : |
a GnomeDbParameter |
Returns : | TRUE if user input is required |
void gnome_db_parameter_set_user_input_required (GnomeDbParameter *param, gboolean input_required);
Sets if the user input is required for param
(even though it may already have
a value) and be valid.
param : |
a GnomeDbParameter |
input_required : |