Empty Arrays

Thiago Macieira thiago at kde.org
Sun Jan 28 16:41:30 PST 2007

Kevin Krammer wrote:
>Today I found a problem when retrieving a zero length string array.
>The dbus_message_iter_recurse() call does not indicate whether the entry
>iterator points to a valid position and I haven't found a function which
>would tell me (might have missed it though).
>Right now I recurse and then detect that dbus_message_iter_get_arg_type
> is 0, i.e. directly checking this literal. In case this is the way to
> do this, is there a an official define/typedef to check against?

That is the correct way to detect it.

the dbus_message_iter_has_next function is broken: it tells you if there's 
at least 2 items in the array, so it can't be used as loop conditionals.

Generally, you can loop like this:

  dbus_message_iter_recurse(&array_it, &element_it);
  while (dbus_message_iter_get_arg_type(&element_It) == DBUS_TYPE_INVALID)
    /* do something with element_it */

This should work for 0-, 1- and many-sized arrays.

  Thiago Macieira  -  thiago (AT) macieira.info - thiago (AT) kde.org
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