GioApplicationadd_main_option_entries

Adds main option entries to be handled by application.

This function is comparable to g_option_context_add_main_entries().

After the commandline arguments are parsed, the GApplication::handle-local-options signal will be emitted. At this point, the application can inspect the values pointed to by arg_data in the given GOptionEntrys.

Unlike GOptionContext, GApplication supports giving a NULL arg_data for a non-callback GOptionEntry. This results in the argument in question being packed into a GVariantDict which is also passed to GApplication::handle-local-options, where it can be inspected and modified. If G_APPLICATION_HANDLES_COMMAND_LINE is set, then the resulting dictionary is sent to the primary instance, where g_application_command_line_get_options_dict() will return it. As it has been passed outside the process at this point, the types of all values in the options dict must be checked before being used. This “packing” is done according to the type of the argument — booleans for normal flags, strings for strings, bytestrings for filenames, etc. The packing only occurs if the flag is given (ie: we do not pack a “false” GVariant in the case that a flag is missing).

In general, it is recommended that all commandline arguments are parsed locally. The options dictionary should then be used to transmit the result of the parsing to the primary instance, where g_variant_dict_lookup() can be used. For local options, it is possible to either use arg_data in the usual way, or to consult (and potentially remove) the option from the options dictionary.

This function is new in GLib 2.40. Before then, the only real choice was to send all of the commandline arguments (options and all) to the primary instance for handling. GApplication ignored them completely on the local side. Calling this function “opts in” to the new behaviour, and in particular, means that unrecognized options will be treated as errors. Unrecognized options have never been ignored when G_APPLICATION_HANDLES_COMMAND_LINE is unset.

If GApplication::handle-local-options needs to see the list of filenames, then the use of G_OPTION_REMAINING is recommended. If arg_data is NULL then G_OPTION_REMAINING can be used as a key into the options dictionary. If you do use G_OPTION_REMAINING then you need to handle these arguments for yourself because once they are consumed, they will no longer be visible to the default handling (which treats them as filenames to be opened).

It is important to use the proper GVariant format when retrieving the options with g_variant_dict_lookup(): - for G_OPTION_ARG_NONE, use b - for G_OPTION_ARG_STRING, use &s - for G_OPTION_ARG_INT, use i - for G_OPTION_ARG_INT64, use x - for G_OPTION_ARG_DOUBLE, use d - for G_OPTION_ARG_FILENAME, use ^&ay - for G_OPTION_ARG_STRING_ARRAY, use ^a&s - for G_OPTION_ARG_FILENAME_ARRAY, use ^a&ay.

Available since: 2.40