Class DataProxy

Upon errors FALSE will be returned and error will be assigned a #GError from the #GDA_DATA_MODEL_ERROR domain.

Upon errors -1 will be returned and error will be assigned a #GError from the #GDA_DATA_MODEL_ERROR domain.

Upon errors -1 will be returned and error will be assigned a #GError from the #GDA_DATA_MODEL_ERROR domain.

Whenever the source_property is changed the target_property is updated using the same value. For instance:

  g_object_bind_property (action, "active", widget, "sensitive", 0);

Will result in the "sensitive" property of the widget #GObject instance to be updated with the same value of the "active" property of the action #GObject instance.

If flags contains %G_BINDING_BIDIRECTIONAL then the binding will be mutual: if target_property on target changes then the source_property on source will be updated as well.

The binding will automatically be removed when either the source or the target instances are finalized. To remove the binding without affecting the source and the target you can just call g_object_unref() on the returned #GBinding instance.

Removing the binding by calling g_object_unref() on it must only be done if the binding, source and target are only used from a single thread and it is clear that both source and target outlive the binding. Especially it is not safe to rely on this if the binding, source or target can be finalized from different threads. Keep another reference to the binding and use g_binding_unbind() instead to be on the safe side.

A #GObject can have multiple bindings.

This function is the language bindings friendly version of g_object_bind_property_full(), using #GClosures instead of function pointers.

Depending on the data model's implementation, a new #GdaDataModelIter object may be created, or a reference to an already existing #GdaDataModelIter may be returned. For example if model only supports being accessed using a forward moving cursor (say a the result of a SELECT executed by SQLite with a cursor access mode specified), then this method will always return the same iterator.

If a new #GdaDataModelIter is created, then the row it represents is undefined.

For models which can be accessed randomly, any row can be set using gda_data_model_iter_move_to_row(), and for models which are accessible sequentially only then use gda_data_model_iter_move_next() (and gda_data_model_iter_move_prev() if supported).

Note: for the #GdaDataProxy data model (which proxies any #GdaDataModel for modifications and has twice the number of columns of the proxied data model), this method will create an iterator in which only the columns of the proxied data model appear. If you need to have a #GdaDataModelIter in which all the proxy's columns appear, create it using:

WARNING: the returned #GdaColumn object belongs to the model model and and should not be destroyed; any modification will affect the whole data model.

The following environment variables can affect the resulting output: GDA_DATA_MODEL_DUMP_ROW_NUMBERS: if set, the first column of the output will contain row numbers GDA_DATA_MODEL_DUMP_ATTRIBUTES: if set, also dump the data model's columns' types and value's attributes GDA_DATA_MODEL_DUMP_TITLE: if set, also dump the data model's title GDA_DATA_MODEL_NULL_AS_EMPTY: if set, replace the 'NULL' string with an empty string for NULL values GDA_DATA_MODEL_DUMP_TRUNCATE: if set to a numeric value, truncates the output to the width specified by the value. If the value is -1 then the actual terminal size (if it can be determined) is used

The following environment variables can affect the resulting output: GDA_DATA_MODEL_DUMP_ROW_NUMBERS: if set, the first column of the output will contain row numbers GDA_DATA_MODEL_DUMP_TITLE: if set, also dump the data model's title GDA_DATA_MODEL_NULL_AS_EMPTY: if set, replace the 'NULL' string with an empty string for NULL values GDA_DATA_MODEL_DUMP_TRUNCATE: if set to a numeric value, truncates the output to the width specified by the value. If the value is -1 then the actual terminal size (if it can be determined) is used

Specifically, the parameters in the options list can be: "SEPARATOR": a string value of which the first character is used as a separator in case of CSV export "QUOTE": a string value of which the first character is used as a quote character in case of CSV export. The default if not specified is the double quote character "FIELD_QUOTE": a boolean value which can be set to FALSE if no quote around the individual fields is requeted, in case of CSV export "NAMES_ON_FIRST_LINE": a boolean value which, if set to %TRUE and in case of a CSV or %GDA_DATA_MODEL_IO_TEXT_TABLE export, will add a first line with the name each exported field (note that "FIELDS_NAME" is also accepted as a synonym) "NAME": a string value used to name the exported data if the export format is XML or %GDA_DATA_MODEL_IO_TEXT_TABLE "OVERWRITE": a boolean value which tells if the file must be over-written if it already exists. "NULL_AS_EMPTY": a boolean value which, if set to %TRUE and in case of a CSV or %GDA_DATA_MODEL_IO_TEXT_TABLE export, will render and NULL value as the empty string (instead of the 'NULL' string) "INVALID_AS_NULL": a boolean value which, if set to %TRUE, considers any invalid data (for example for the date related values) as NULL "COLUMN_SEPARATORS": a boolean value which, if set to %TRUE, adds a separators lines between each column, if the export format is %GDA_DATA_MODEL_IO_TEXT_TABLE "SEPARATOR_LINE": a boolean value which, if set to %TRUE, adds an horizontal line between column titles and values, if the export format is %GDA_DATA_MODEL_IO_TEXT_TABLE "ROW_NUMBERS": a boolean value which, if set to %TRUE, prepends a column with row numbers, if the export format is %GDA_DATA_MODEL_IO_TEXT_TABLE "MAX_WIDTH": an integer value which, if greater than 0, makes all the lines truncated to have at most that number of characters, if the export format is %GDA_DATA_MODEL_IO_TEXT_TABLE

Warning: this function uses a #GdaDataModelIter iterator, and if model does not offer a random access (check using gda_data_model_get_access_flags()), the iterator will be the same as normally used to access data in model previously to calling this method, and this iterator will be moved (point to another row).

Upon errors %FALSE will be returned and error will be assigned a #GError from the #GDA_DATA_MODEL_ERROR domain.

Warning: this function uses a #GdaDataModelIter iterator, and if model does not offer a random access (check using gda_data_model_get_access_flags()), the iterator will be the same as normally used to access data in model previously to calling this method, and this iterator will be moved (point to another row).

See also gda_data_model_dump_as_string();

This is necessary for accessors that modify multiple properties to prevent premature notification while the object is still being modified.

The value can be:

• an empty #GValue initialized by %G_VALUE_INIT, which will be automatically initialized with the expected type of the property (since GLib 2.60)
• a #GValue initialized with the expected type of the property
• a #GValue initialized with a type to which the expected type of the property can be transformed

In general, a copy is made of the property contents and the caller is responsible for freeing the memory by calling g_value_unset().

Note that g_object_get_property() is really intended for language bindings, g_object_get() is much more convenient for C programming.

NOTE: the cols_index array MUST contain a column index for each value in values

This method is similar to gda_data_model_get_value_at(), except that it also allows one to specify the expected #GType of the value to get: if the data model returned a #GValue of a type different than the expected one, then this method returns %NULL and an error code.

Note: the same limitations and usage instructions apply as for gda_data_model_get_value_at().

Upon errors %NULL will be returned and error will be assigned a #GError from the #GDA_DATA_MODEL_ERROR domain.

Upon errors %NULL will be returned and error will be assigned a #GError from the #GDA_DATA_MODEL_ERROR domain.

This is the main function for accessing data in a model which allows random access to its data. To access data in a data model using a cursor, use a #GdaDataModelIter object, obtained using gda_data_model_create_iter().

Note1: the returned #GValue must not be modified directly (unexpected behaviours may occur if you do so).

Note2: the returned value may become invalid as soon as any Libgda part is executed again, which means if you want to keep the value, a copy must be made, however it will remain valid as long as the only Libgda usage is calling gda_data_model_get_value_at() for different values of the same row.

If you want to modify a value stored in a #GdaDataModel, use the gda_data_model_set_value_at() or gda_data_model_set_values() methods.

Upon errors %NULL will be returned and error will be assigned a #GError from the #GDA_DATA_MODEL_ERROR domain.

Upon errors FALSE will be returned and error will be assigned a #GError from the #GDA_DATA_MODEL_ERROR domain.

The cols_trans is a hash table for which keys are to columns numbers and the values are the corresponding column numbers in the from data model. To set the values of a column in to to NULL, create an entry in the hash table with a negative value. For example:

Upon errors FALSE will be returned and error will be assigned a #GError from the #GDA_DATA_MODEL_ERROR domain.

Upon errors FALSE will be returned and error will be assigned a #GError from the #GDA_DATA_MODEL_ERROR domain.

When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.

Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.

This function omits the property name lookup, hence it is faster than g_object_notify().

One way to avoid using g_object_notify() from within the class that registered the properties, and using g_object_notify_by_pspec() instead, is to store the GParamSpec used with g_object_class_install_property() inside a static array, e.g.:

  enum
  {
    PROP_0,
    PROP_FOO,
    PROP_LAST
  };

  static GParamSpec *properties[PROP_LAST];

  static void
  my_object_class_init (MyObjectClass *klass)
  {
    properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "The foo",
                                             0, 100,
                                             50,
                                             G_PARAM_READWRITE);
    g_object_class_install_property (gobject_class,
                                     PROP_FOO,
                                     properties[PROP_FOO]);
  }

and then notify a change on the "foo" property with:

  g_object_notify_by_pspec (self, properties[PROP_FOO]);

Since GLib 2.56, if GLIB_VERSION_MAX_ALLOWED is 2.56 or greater, the type of object will be propagated to the return type (using the GCC typeof() extension), so any casting the caller needs to do on the return type must be explicit.

In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one.

Since GLib 2.56, the type of object will be propagated to the return type under the same conditions as for g_object_ref().

Upon errors FALSE will be returned and error will be assigned a #GError from the #GDA_DATA_MODEL_ERROR domain.

This method should only be used by #GdaDataModel implementations to signal that a row has been inserted.

This method should only be used by #GdaDataModel implementations to signal that a row has been removed

This method should only be used by #GdaDataModel implementations to signal that a row has been updated.

This function should only be called from object system implementations.

If the object already had an association with that name, the old association will be destroyed.

Internally, the key is converted to a #GQuark using g_quark_from_string(). This means a copy of key is kept permanently (even after object has been finalized) — so it is recommended to only use a small, bounded set of values for key in your program, to avoid the #GQuark storage growing unbounded.

Upon errors FALSE will be returned and error will be assigned a #GError from the #GDA_DATA_MODEL_ERROR domain.

If any value in values is actually %NULL, then the value in the corresponding column is left unchanged.

Upon errors FALSE will be returned and error will be assigned a #GError from the #GDA_DATA_MODEL_ERROR domain.

void
object_add_to_user_list (GObject     *object,
                         const gchar *new_string)
{
  // the quark, naming the object data
  GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
  // retrieve the old string list
  GList *list = g_object_steal_qdata (object, quark_string_list);

  // prepend new string
  list = g_list_prepend (list, g_strdup (new_string));
  // this changed 'list', so we need to set it again
  g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
}
static void
free_string_list (gpointer data)
{
  GList *node, *list = data;

  for (node = list; node; node = node->next)
    g_free (node->data);
  g_list_free (list);
}

Using g_object_get_qdata() in the above example, instead of g_object_steal_qdata() would have left the destroy function set, and thus the partial string list would have been freed upon g_object_set_qdata_full().

Duplicate notifications for each property are squashed so that at most one #GObject::notify signal is emitted for each property, in the reverse order in which they have been queued.

It is an error to call this function when the freeze count is zero.

If the pointer to the #GObject may be reused in future (for example, if it is an instance variable of another object), it is recommended to clear the pointer to %NULL rather than retain a dangling pointer to a potentially invalid #GObject instance. Use g_clear_object() for this.

When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.

Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.