[Technology] "Error: Unsupported type void, deriving from fundamental void"

I have an issue trying to use GHashTable as a property in an introspected GObject from Javascript (using gjs).  I was trying to create a test case, but I encountered this when trying to construct my object from gjs:

"Error: Unsupported type void, deriving from fundamental void"

The object was dead-simple, and derived from GObject, so I wasn't sure what the problem was.  Ultimately, it turned out that that was gjs's way of telling me it didn't have a definition for my constructor.  Yikes.  Ultimately, I had to specify a 'shared-library' attribute for the 'namespace' element in the .gir and .typelib files that gjs was using for introspection.  I wasted a couple hours trying to figure that out.  Whee.

For now, I filed a bug, 706906, requesting a useful error message when definitions aren't found, rather than ambiguously complaining about void types.

Writing the Object and test file

First I created a quick object using Vala for my test case.

namespace Foo {
public class Bar : GLib.Object {
public GLib.HashTable hashtable { get; set; }
public Bar () {
this.hashtable = new GLib.HashTable (GLib.str_hash, GLib.str_equal);

Well, that was quick.  Next I wrote a small .js file

const Foo = imports.gi.Foo;
var bar = new Foo.Bar ();

Compiling the Vala object and introspection files

Of ourse, first you'll need to compile your shared library, Foo.

valac --library=foo --gir=Foo-0.1.gir --vapi foo.vapi -H foo.h -g Foo.vala -X -fPIC -X -shared -o libfoo.so

If you try to run test.js now, it won't find the library and will report the error:

"Requiring Foo, version none: Typelib file for namespace 'Foo' (any version) not found"

To access Foo via introspection, we'll of course need to compile the .typelib too!

g-ir-compiler --shared-library=libfoo.so Foo-0.1.gir --output Foo-0.1.typelib

If you don't specify the name of the shared-library, that's when you'll see the earlier error, "Error: Unsupported type void, deriving from fundamental void" when trying to actually use the objects from gjs, as they're defined, they're only declared through their typelib

If you still see the Typelib file not found, it might not be in your GI_TYPELIB_PATH, so you might want to set that.  Lots of typelibs get installed to /usr/lib64/girepository-1.0/.  For my test case, I set GI_TYPELIB_PATH=. since my typelib is in the current directory.

GHashTable properties: the original problem

Now all I need to do is find a solution to my original problem, "Error: Unable to introspect element-type of container in GValue", where I can't access a GHashTable as a property. :\  (Now bug 706907)

Keine Kommentare:

Kommentar veröffentlichen

Dieses Blog durchsuchen


#Technology #GNOME gnome gxml fedora bugs linux vala google #General firefox security gsoc GUADEC android bug xml fedora 18 javascript libxml2 programming web blogger encryption fedora 17 gdom git libgdata memory mozilla open source serialisation upgrade web development API Spain design emacs evolution fedora 16 fedora 20 fedora 22 fedup file systems friends future glib gnome shell internet luks music performance phone photos preupgrade tablet testing yum #Microblog Network Manager adb art automation bash brno catastrophe containers css data loss deja-dup disaster emusic errors ext4 facebook fedora 19 gee gir gitlab gitorious gmail gobject google talk google+ html libxml mail microsoft mtp namespaces nautilus php picasaweb podman ptp resizing rpm school selinux sms speech dispatcher systemd technology texting time management typescript uoguelph usability video web design youtube #Tech Air Canada C Empathy Europe GError GNOME 3 GNOME Files Go Google Play Music Grimes IRC Mac OS X Mario Kart Memento Nintendo Nintendo Switch PEAP Selenium Splatoon UI VPN Xiki accessibility advertising ai albums anaconda anonymity apache apple ask asus eee top automake autonomous automobiles b43 backup battery berlin bit rot broadcom browsers browsing canada canadian english cars chrome clarity comments communication compiler complaints computer computers configuration console constructive criticism cron customisation dataloss dconf debian debug symbols debugging design patterns desktop summit development discoverability distribution diy dnf docker documentation drm duplicity e-mail efficiency email english environment estate experimenting ext3 fedora 11 festival file formats firejail flac forgottotagit freedom friendship fuse galaxy nexus galton gay rights gdb german germany gimp gio gjs gnome software gnome-control-center google assistant google calendar google chrome google hangouts google reader gqe graphviz growth gtest gtg gtk gvfs gvfs metadata hard drive hard drives hardware help hp humour identity instagram installation instant messaging integration intel interactivity introspection jabber java java 13 jobs kernel keyboard language languages law learning lenovo letsencrypt libreoffice librpm life livecd liveusb login macbook maintainership mario memory leaks messaging mounting mouse mysql netflix new zealand node nodelist numix obama oci ogg oggenc oh the humanity open open standards openoffice optimisation org-mode organisation package management packagekit paint shedding parallelism pdo perl pipelight pitivi privacy productivity progress progressive web apps pumpkin pwa python quality recursion redhat refactoring repairs report rhythmbox sandboxes scheduling screenshots self-navigating car shell signal sleep smartphones software software engineering speed sql ssd synergy tabs test tests themes thesis tracker travel triumf turtles tv tweak twist typing university update usb user experience valadoc volunteering vpnc waf warm wayland weather web apps website wifi wiki wireless wishes work xinput xmpp xorg xpath
Powered by Blogger.