[budget] Add 'notes' functionality to engine

Add ability to save notes on each budget value (account/period).

libgnucash/engine/gnc-budget.c

@@ -589,6 +589,60 @@ gnc_budget_get_account_period_value(const GncBudget *budget,
 }
 
 
+void
+gnc_budget_set_account_period_note(GncBudget *budget, const Account *account,
+                                    guint period_num, const gchar *note)
+{
+    gchar path_part_one [GUID_ENCODING_LENGTH + 1];
+    gchar path_part_two [GNC_BUDGET_MAX_NUM_PERIODS_DIGITS];
+
+    /* Watch out for an off-by-one error here:
+     * period_num starts from 0 while num_periods starts from 1 */
+    if (period_num >= GET_PRIVATE(budget)->num_periods)
+    {
+        PWARN("Period %i does not exist", period_num);
+        return;
+    }
+
+    g_return_if_fail (budget != NULL);
+    g_return_if_fail (account != NULL);
+
+    make_period_path (account, period_num, path_part_one, path_part_two);
+
+    gnc_budget_begin_edit(budget);
+    if (note == NULL)
+        qof_instance_set_kvp (QOF_INSTANCE (budget), NULL, 3, GNC_BUDGET_NOTES_PATH, path_part_one, path_part_two);
+    else
+    {
+        GValue v = G_VALUE_INIT;
+        g_value_init (&v, G_TYPE_STRING);
+        g_value_set_string (&v, note);
+
+        qof_instance_set_kvp (QOF_INSTANCE (budget), &v, 3, GNC_BUDGET_NOTES_PATH, path_part_one, path_part_two);
+    }
+    qof_instance_set_dirty(&budget->inst);
+    gnc_budget_commit_edit(budget);
+
+    qof_event_gen( &budget->inst, QOF_EVENT_MODIFY, NULL);
+
+}
+
+const gchar *
+gnc_budget_get_account_period_note(const GncBudget *budget,
+                                   const Account *account, guint period_num)
+{
+    gchar path_part_one [GUID_ENCODING_LENGTH + 1];
+    gchar path_part_two [GNC_BUDGET_MAX_NUM_PERIODS_DIGITS];
+    GValue v = G_VALUE_INIT;
+
+    g_return_val_if_fail(GNC_IS_BUDGET(budget), NULL);
+    g_return_val_if_fail(account, NULL);
+
+    make_period_path (account, period_num, path_part_one, path_part_two);
+    qof_instance_get_kvp (QOF_INSTANCE (budget), &v, 3, GNC_BUDGET_NOTES_PATH, path_part_one, path_part_two);
+    return (G_VALUE_HOLDS_STRING(&v)) ? g_value_get_string(&v) : NULL;
+}
+
 time64
 gnc_budget_get_period_start_date(const GncBudget *budget, guint period_num)
 {

libgnucash/engine/gnc-budget.h

@@ -90,6 +90,8 @@ GType gnc_budget_get_type(void);
 
 #define GNC_BUDGET_MAX_NUM_PERIODS_DIGITS 3 // max num periods == 999
 
+#define GNC_BUDGET_NOTES_PATH "notes"
+
 gboolean gnc_budget_register(void);
 
 /**
@@ -150,6 +152,11 @@ gnc_numeric gnc_budget_get_account_period_value(
 gnc_numeric gnc_budget_get_account_period_actual_value(
     const GncBudget *budget, Account *account, guint period_num);
 
+void gnc_budget_set_account_period_note(GncBudget *budget,
+    const Account *account, guint period_num, const gchar *note);
+const gchar *gnc_budget_get_account_period_note(const GncBudget *budget,
+    const Account *account, guint period_num);
+
 /* Returns some budget in the book, or NULL. */
 GncBudget* gnc_budget_get_default(QofBook *book);