[gnome-online-miners/sam/help-and-debug: 2/4] Add a helpful warning for users who start a miner from the commandline

[Sam Thursfield <sthursfield src gnome org>]

commit d7ee1e9df01700866cecd8cfe0af958265feb829
Author: Sam Thursfield <ssssam gmail com>
Date:   Sun Sep 4 01:15:35 2016 +0100

    Add a helpful warning for users who start a miner from the commandline
    
    It's not clear from any documentation how developers should test a Gnome
    Online Miner process. Starting it from the commandline just causes it to
    exit again 5 seconds later. Miners now print a message explaining the
    correct way to invoke them on stderr if they were not invoked over
    D-Bus.
    
    The message looks like this:
    
        org.gnome.OnlineMiners.Facebook: Miner process was executed but the
        RefreshDB D-Bus method was never called. You must call the
        org.gnome.OnlineMiners.Miner.RefreshDB method to cause an online miner
        to start mining.

 src/gom-application.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)
---
diff --git a/src/gom-application.c b/src/gom-application.c
index c10479a..02418ce 100644
--- a/src/gom-application.c
+++ b/src/gom-application.c
@@ -38,6 +38,7 @@ struct _GomApplication
   GQueue *queue;
   GType miner_type;
   gboolean refreshing;
+  gboolean refresh_db_called;
 };
 
 struct _GomApplicationClass
@@ -117,6 +118,8 @@ gom_application_refresh_db (GomApplication *self,
 {
   gchar **index_types;
 
+  self->refresh_db_called = TRUE;
+
   index_types = g_strdupv ((gchar **) arg_index_types);
   g_object_set_data_full (G_OBJECT (invocation), "index-types", index_types, (GDestroyNotify) g_strfreev);
   g_queue_push_tail (self->queue, g_object_ref (invocation));
@@ -196,6 +199,15 @@ gom_application_dispose (GObject *object)
 {
   GomApplication *self = GOM_APPLICATION (object);
 
+  if (! self->refresh_db_called)
+    {
+      g_printerr ("%s: Miner process was executed but the RefreshDB D-Bus "
+                  "method was never called. You must call the "
+                  "org.gnome.OnlineMiners.Miner.RefreshDB method to cause "
+                  "an online miner to start mining.\n",
+                  g_application_get_application_id (G_APPLICATION (self)));
+    }
+
   g_clear_object (&self->cancellable);
   g_clear_object (&self->miner);
   g_clear_object (&self->skeleton);