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GNOME Data Access 3.0 manual | ![]() |
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GdaReferer; gboolean gda_referer_activate (GdaReferer *iface); void gda_referer_deactivate (GdaReferer *iface); gboolean gda_referer_is_active (GdaReferer *iface); GSList* gda_referer_get_ref_objects (GdaReferer *iface); void gda_referer_replace_refs (GdaReferer *iface, GHashTable *replacements);
GdaReferer is implemented by GdaParameter, GdaQueryFieldFunc, GdaQueryJoin, GdaQueryFieldAgg, GdaDictConstraint, GdaQueryFieldValue, GdaQueryCondition, GdaQueryFieldAll, GdaQueryTarget, GdaQuery and GdaQueryFieldField.
Some objects can be initialized in an uncomplete state. This is the case for example of a primary key database constraint, when we don't know, at creation time, which field it applies to. These objects implement this interface to at least signal when they are ready to be used.
Also some objects need to be created <b>before</b> other objects they will need to be operational even exist; they implement this interface.
This interface is particularly important for the GdaQuery and related objects: the individual components of a query are completely defined when they reference objects defined in a data dictionary (a GdaDict object). When any of the components of a query relates to an element not defined in a dictionary, the query can still be used but it's not completely defined.
gboolean gda_referer_activate (GdaReferer *iface);
Tries to activate the object, does nothing if the object is already active.
|
an object which implements the GdaReferer interface |
Returns : |
TRUE if the object is active after the call |
void gda_referer_deactivate (GdaReferer *iface);
Deactivates the object. This is the opposite to function gda_referer_activate()
.
If the object is already non active, then nothing happens.
|
an object which implements the GdaReferer interface |
gboolean gda_referer_is_active (GdaReferer *iface);
Get the status of an object
|
an object which implements the GdaReferer interface |
Returns : |
TRUE if the object is active |
GSList* gda_referer_get_ref_objects (GdaReferer *iface);
Get the list of objects which are referenced by iface
. The returned list is a
new list. If iface
is not active, then the returned list is incomplete.
|
an object which implements the GdaReferer interface |
Returns : |
a new list of referenced objects |
void gda_referer_replace_refs (GdaReferer *iface, GHashTable *replacements);
Ask iface
to replace references to objects listed as keys in the replacements
hash table
with references to objects of the corresponding value.
It's up to the caller to make sure each pair of (key, value) objects in replacements
are of the
same type, and that it makes sense to procede to the replacement.
The object implementing this interface will accept to do any work only if it is already active.
|
an object which implements the GdaReferer interface |
|
a GHashTable |
"activated"
signalvoid user_function (GdaReferer *gdareferer, gpointer user_data) : Run First
|
the object which received the signal. |
|
user data set when the signal handler was connected. |
"deactivated"
signalvoid user_function (GdaReferer *gdareferer, gpointer user_data) : Run First
|
the object which received the signal. |
|
user data set when the signal handler was connected. |