gnc-bill-term-xml-v2.c

/********************************************************************\
 * gnc-bill-term-xml-v2.c -- billing term xml i/o implementation    *
 *                                                                  *
 * Copyright (C) 2002 Derek Atkins <[email protected]>                *
 *                                                                  *
 * This program is free software; you can redistribute it and/or    *
 * modify it under the terms of the GNU General Public License as   *
 * published by the Free Software Foundation; either version 2 of   *
 * the License, or (at your option) any later version.              *
 *                                                                  *
 * This program is distributed in the hope that it will be useful,  *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of   *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    *
 * GNU General Public License for more details.                     *
 *                                                                  *
 * You should have received a copy of the GNU General Public License*
 * along with this program; if not, contact:                        *
 *                                                                  *
 * Free Software Foundation           Voice:  +1-617-542-5942       *
 * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652       *
 * Boston, MA  02110-1301,  USA       [email protected]                   *
 *                                                                  *
\********************************************************************/

#include "config.h"

#include <glib.h>
#include <stdlib.h>
#include <string.h>

#include "gnc-xml-helper.h"

#include "sixtp.h"
#include "sixtp-utils.h"
#include "sixtp-parsers.h"
#include "sixtp-utils.h"
#include "sixtp-dom-parsers.h"
#include "sixtp-dom-generators.h"

#include "gnc-xml.h"
#include "io-gncxml-gen.h"
#include "io-gncxml-v2.h"

#include "gncBillTermP.h"
#include "gncInvoice.h"
#include "gnc-bill-term-xml-v2.h"
#include "qof.h"

#include "xml-helpers.h"

#define _GNC_MOD_NAME   GNC_ID_BILLTERM

static QofLogModule log_module = GNC_MOD_IO;

const gchar *billterm_version_string = "2.0.0";

/* ids */
#define gnc_billterm_string "gnc:GncBillTerm"
#define billterm_guid_string "billterm:guid"
#define billterm_name_string "billterm:name"
#define billterm_desc_string "billterm:desc"
#define billterm_refcount_string "billterm:refcount"
#define billterm_invisible_string "billterm:invisible"
#define billterm_parent_string "billterm:parent"
#define billterm_child_string "billterm:child"
#define billterm_slots_string "billterm:slots"

#define gnc_daystype_string "billterm:days"
#define days_duedays_string "bt-days:due-days"
#define days_discdays_string "bt-days:disc-days"
#define days_discount_string "bt-days:discount"

#define gnc_proximotype_string "billterm:proximo"
#define prox_dueday_string "bt-prox:due-day"
#define prox_discday_string "bt-prox:disc-day"
#define prox_discount_string "bt-prox:discount"
#define prox_cutoff_string "bt-prox:cutoff-day"

static xmlNodePtr
billterm_dom_tree_create (GncBillTerm *term)
{
    xmlNodePtr ret, data, kvpnode;

    ret = xmlNewNode(NULL, BAD_CAST gnc_billterm_string);
    xmlSetProp(ret, BAD_CAST "version", BAD_CAST billterm_version_string);

    maybe_add_guid(ret, billterm_guid_string, QOF_INSTANCE(term));
    xmlAddChild(ret, text_to_dom_tree (billterm_name_string,
                                       gncBillTermGetName (term)));
    xmlAddChild(ret, text_to_dom_tree (billterm_desc_string,
                                       gncBillTermGetDescription (term)));

    xmlAddChild(ret, int_to_dom_tree (billterm_refcount_string,
                                      gncBillTermGetRefcount (term)));
    xmlAddChild(ret, int_to_dom_tree (billterm_invisible_string,
                                      gncBillTermGetInvisible (term)));

    kvpnode = kvp_frame_to_dom_tree (billterm_slots_string,
                                     qof_instance_get_slots (QOF_INSTANCE(term)));
    if (kvpnode) xmlAddChild (ret, kvpnode);


    /* We should not be our own child */
    if (gncBillTermGetChild(term) != term)
        maybe_add_guid(ret, billterm_child_string,
                       QOF_INSTANCE(gncBillTermGetChild (term)));

    maybe_add_guid(ret, billterm_parent_string,
                   QOF_INSTANCE(gncBillTermGetParent (term)));

    switch (gncBillTermGetType (term))
    {
    case GNC_TERM_TYPE_DAYS:
        data = xmlNewChild (ret, NULL, BAD_CAST gnc_daystype_string, NULL);
        maybe_add_int (data, days_duedays_string, gncBillTermGetDueDays (term));
        maybe_add_int (data, days_discdays_string,
                       gncBillTermGetDiscountDays (term));
        maybe_add_numeric (data, days_discount_string,
                           gncBillTermGetDiscount (term));
        break;

    case GNC_TERM_TYPE_PROXIMO:
        data = xmlNewChild (ret, NULL, BAD_CAST gnc_proximotype_string, NULL);
        maybe_add_int (data, prox_dueday_string, gncBillTermGetDueDays (term));
        maybe_add_int (data, prox_discday_string,
                       gncBillTermGetDiscountDays (term));
        maybe_add_numeric (data, prox_discount_string,
                           gncBillTermGetDiscount (term));
        maybe_add_int (data, prox_cutoff_string, gncBillTermGetCutoff (term));
        break;
    }

    return ret;
}

/***********************************************************************/

struct billterm_pdata
{
    GncBillTerm *term;
    QofBook *book;
};

static gboolean
set_int (xmlNodePtr node, GncBillTerm *term,
         void (*func)(GncBillTerm *, gint))
{
    gint64 val;
    dom_tree_to_integer (node, &val);
    func (term, val);
    return TRUE;
}

static gboolean
set_numeric (xmlNodePtr node, GncBillTerm *term,
             void (*func)(GncBillTerm *, gnc_numeric))
{
    gnc_numeric* num = dom_tree_to_gnc_numeric (node);
    g_return_val_if_fail (num, FALSE);

    func (term, *num);
    g_free (num);
    return TRUE;
}

/***********************************************************************/

static gboolean
days_duedays_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    return set_int (node, pdata->term, gncBillTermSetDueDays);
}

static gboolean
days_discdays_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    return set_int (node, pdata->term, gncBillTermSetDiscountDays);
}

static gboolean
days_discount_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    return set_numeric (node, pdata->term, gncBillTermSetDiscount);
}

static struct dom_tree_handler days_data_handlers_v2[] =
{
    { days_duedays_string, days_duedays_handler, 0, 0 },
    { days_discdays_string, days_discdays_handler, 0, 0 },
    { days_discount_string, days_discount_handler, 0, 0 },
    { NULL, 0, 0, 0 }
};

static gboolean
dom_tree_to_days_data (xmlNodePtr node, struct billterm_pdata *pdata)
{
    gboolean successful;

    successful = dom_tree_generic_parse (node, days_data_handlers_v2, pdata);

    if (!successful)
        PERR ("failed to parse billing term days data");

    return successful;
}

/***********************************************************************/

static gboolean
prox_dueday_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    return set_int (node, pdata->term, gncBillTermSetDueDays);
}

static gboolean
prox_discday_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    return set_int (node, pdata->term, gncBillTermSetDiscountDays);
}

static gboolean
prox_discount_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    return set_numeric (node, pdata->term, gncBillTermSetDiscount);
}

static gboolean
prox_cutoff_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    return set_int (node, pdata->term, gncBillTermSetCutoff);
}

static struct dom_tree_handler prox_data_handlers_v2[] =
{
    { prox_dueday_string, prox_dueday_handler, 0, 0 },
    { prox_discday_string, prox_discday_handler, 0, 0 },
    { prox_discount_string, prox_discount_handler, 0, 0 },
    { prox_cutoff_string, prox_cutoff_handler, 0, 0 },
    { NULL, 0, 0, 0 }
};

static gboolean
dom_tree_to_prox_data (xmlNodePtr node, struct billterm_pdata *pdata)
{
    gboolean successful;

    successful = dom_tree_generic_parse (node, prox_data_handlers_v2, pdata);

    if (!successful)
        PERR ("failed to parse billing term prox data");

    return successful;
}

/***********************************************************************/

static gboolean
set_parent_child (xmlNodePtr node, struct billterm_pdata *pdata,
                  void (*func)(GncBillTerm *, GncBillTerm *))
{
    GncGUID *guid;
    GncBillTerm *term;

    guid = dom_tree_to_guid(node);
    g_return_val_if_fail (guid, FALSE);
    term = gncBillTermLookup (pdata->book, guid);
    if (!term)
    {
        term = gncBillTermCreate (pdata->book);
        gncBillTermBeginEdit (term);
        gncBillTermSetGUID (term, guid);
        gncBillTermCommitEdit (term);
    }
    g_free (guid);
    g_return_val_if_fail (term, FALSE);
    func (pdata->term, term);

    return TRUE;
}

static gboolean
set_string (xmlNodePtr node, GncBillTerm *term,
            void (*func)(GncBillTerm *, const char *))
{
    char* txt = dom_tree_to_text(node);
    g_return_val_if_fail(txt, FALSE);
    func (term, txt);
    g_free(txt);
    return TRUE;
}

static gboolean
billterm_guid_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    GncGUID *guid;
    GncBillTerm *term;

    guid = dom_tree_to_guid(node);
    g_return_val_if_fail (guid, FALSE);
    term = gncBillTermLookup (pdata->book, guid);
    if (term)
    {
        gncBillTermDestroy (pdata->term);
        pdata->term = term;
        gncBillTermBeginEdit (term);
    }
    else
    {
        gncBillTermSetGUID(pdata->term, guid);
    }

    g_free(guid);

    return TRUE;
}

static gboolean
billterm_name_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    return set_string (node, pdata->term, gncBillTermSetName);
}

static gboolean
billterm_desc_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    return set_string (node, pdata->term, gncBillTermSetDescription);
}

static gboolean
billterm_refcount_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    gint64 val;

    dom_tree_to_integer(node, &val);
    gncBillTermSetRefcount (pdata->term, val);
    return TRUE;
}

static gboolean
billterm_invisible_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    gint64 val;

    dom_tree_to_integer(node, &val);
    if (val)
        gncBillTermMakeInvisible (pdata->term);
    return TRUE;
}

static gboolean
billterm_parent_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    return set_parent_child (node, pdata, gncBillTermSetParent);
}

static gboolean
billterm_child_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    return set_parent_child (node, pdata, gncBillTermSetChild);
}

static gboolean
billterm_days_data_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;

    g_return_val_if_fail (node, FALSE);
    g_return_val_if_fail (gncBillTermGetType (pdata->term) == 0, FALSE);

    gncBillTermSetType (pdata->term, GNC_TERM_TYPE_DAYS);
    return dom_tree_to_days_data (node, pdata);
}

static gboolean
billterm_prox_data_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;

    g_return_val_if_fail (node, FALSE);
    g_return_val_if_fail (gncBillTermGetType (pdata->term) == 0, FALSE);

    gncBillTermSetType (pdata->term, GNC_TERM_TYPE_PROXIMO);
    return dom_tree_to_prox_data (node, pdata);
}

static gboolean
billterm_slots_handler (xmlNodePtr node, gpointer billterm_pdata)
{
    struct billterm_pdata *pdata = billterm_pdata;
    return dom_tree_to_kvp_frame_given (node,
                                        qof_instance_get_slots (QOF_INSTANCE(pdata->term)));
}

static struct dom_tree_handler billterm_handlers_v2[] =
{
    { billterm_guid_string, billterm_guid_handler, 1, 0 },
    { billterm_name_string, billterm_name_handler, 1, 0 },
    { billterm_desc_string, billterm_desc_handler, 1, 0 },
    { billterm_refcount_string, billterm_refcount_handler, 1, 0 },
    { billterm_invisible_string, billterm_invisible_handler, 1, 0 },
    { billterm_parent_string, billterm_parent_handler, 0, 0 },
    { billterm_child_string, billterm_child_handler, 0, 0 },
    { billterm_slots_string, billterm_slots_handler, 0, 0 },
    { gnc_daystype_string, billterm_days_data_handler, 0, 0 },
    { gnc_proximotype_string, billterm_prox_data_handler, 0, 0 },
    { NULL, 0, 0, 0 }
};

static GncBillTerm*
dom_tree_to_billterm (xmlNodePtr node, QofBook *book)
{
    struct billterm_pdata billterm_pdata;
    gboolean successful;

    billterm_pdata.term = gncBillTermCreate (book);
    billterm_pdata.book = book;
    gncBillTermBeginEdit (billterm_pdata.term);

    successful = dom_tree_generic_parse (node, billterm_handlers_v2,
                                         &billterm_pdata);

    if (successful)
    {
        gncBillTermCommitEdit (billterm_pdata.term);
    }
    else
    {
        PERR ("failed to parse billing term tree");
        gncBillTermDestroy (billterm_pdata.term);
        billterm_pdata.term = NULL;
    }

    return billterm_pdata.term;
}

static gboolean
gnc_billterm_end_handler(gpointer data_for_children,
                         GSList* data_from_children, GSList* sibling_data,
                         gpointer parent_data, gpointer global_data,
                         gpointer *result, const gchar *tag)
{
    GncBillTerm *term;
    xmlNodePtr tree = (xmlNodePtr)data_for_children;
    gxpf_data *gdata = (gxpf_data*)global_data;
    QofBook *book = gdata->bookdata;


    if (parent_data)
    {
        return TRUE;
    }

    /* OK.  For some messed up reason this is getting called again with a
       NULL tag.  So we ignore those cases */
    if (!tag)
    {
        return TRUE;
    }

    g_return_val_if_fail(tree, FALSE);

    term = dom_tree_to_billterm (tree, book);
    if (term != NULL)
    {
        gdata->cb(tag, gdata->parsedata, term);
    }

    xmlFreeNode(tree);

    return term != NULL;
}

static sixtp *
billterm_sixtp_parser_create(void)
{
    return sixtp_dom_parser_new(gnc_billterm_end_handler, NULL, NULL);
}

static void
do_count (QofInstance *term_p, gpointer count_p)
{
    int *count = count_p;
    (*count)++;
}

static int
billterm_get_count (QofBook *book)
{
    int count = 0;
    qof_object_foreach (_GNC_MOD_NAME, book, do_count, (gpointer) &count);
    return count;
}

static void
xml_add_billterm (QofInstance *term_p, gpointer out_p)
{
    xmlNodePtr node;
    GncBillTerm *term = (GncBillTerm *) term_p;
    FILE *out = out_p;

    if (ferror(out))
        return;

    node = billterm_dom_tree_create (term);
    xmlElemDump(out, NULL, node);
    xmlFreeNode (node);
    if (ferror(out) || fprintf(out, "\n") < 0)
        return;
}

static gboolean
billterm_write (FILE *out, QofBook *book)
{
    qof_object_foreach_sorted (_GNC_MOD_NAME, book, xml_add_billterm, (gpointer) out);
    return ferror(out) == 0;
}

static gboolean
billterm_is_grandchild (GncBillTerm *term)
{
    return (gncBillTermGetParent(gncBillTermGetParent(term)) != NULL);
}

static GncBillTerm *
billterm_find_senior (GncBillTerm *term)
{
    GncBillTerm *temp, *parent, *gp = NULL;

    temp = term;
    do
    {
        /* See if "temp" is a grandchild */
        parent = gncBillTermGetParent(temp);
        if (!parent)
            break;
        gp = gncBillTermGetParent(parent);
        if (!gp)
            break;

        /* Yep, this is a grandchild.  Move up one generation and try again */
        temp = parent;
    }
    while (TRUE);

    /* Ok, at this point temp points to the most senior child and parent
     * should point to the top billterm (and gp should be NULL).  If
     * parent is NULL then we are the most senior child (and have no
     * children), so do nothing.  If temp == term then there is no
     * grandparent, so do nothing.
     *
     * Do something if parent != NULL && temp != term
     */
    g_assert (gp == NULL);

    /* return the most senior term */
    return temp;
}

/* build a list of bill terms that are grandchildren or bogus (empty entry list). */
static void
billterm_scrub_cb (QofInstance *term_p, gpointer list_p)
{
    GncBillTerm *term = GNC_BILLTERM(term_p);
    GList **list = list_p;

    if (billterm_is_grandchild(term))
    {
        *list = g_list_prepend(*list, term);

    }
    else if (!gncBillTermGetType(term))
    {
        GncBillTerm *t = gncBillTermGetParent(term);
        if (t)
        {
            /* Fix up the broken "copy" function */
            gchar guidstr[GUID_ENCODING_LENGTH+1];
            guid_to_string_buff(qof_instance_get_guid(QOF_INSTANCE(term)),guidstr);
            PWARN("Fixing broken child billterm: %s", guidstr);

            gncBillTermBeginEdit(term);
            gncBillTermSetType(term, gncBillTermGetType(t));
            gncBillTermSetDueDays (term, gncBillTermGetDueDays(t));
            gncBillTermSetDiscountDays (term, gncBillTermGetDiscountDays(t));
            gncBillTermSetDiscount (term, gncBillTermGetDiscount(t));
            gncBillTermSetCutoff (term, gncBillTermGetCutoff(t));
            gncBillTermCommitEdit(term);

        }
        else
        {
            /* No parent?  Must be a standalone */
            *list = g_list_prepend(*list, term);
        }
    }
}

/* for each invoice, check the bill terms.  If the bill terms are
 * grandchildren, then fix them to point to the most senior child
 */
static void
billterm_scrub_invoices (QofInstance * invoice_p, gpointer ht_p)
{
    GHashTable *ht = ht_p;
    GncInvoice *invoice = GNC_INVOICE(invoice_p);
    GncBillTerm *term, *new_bt;
    gint32 count;

    term = gncInvoiceGetTerms(invoice);
    if (term)
    {
        if (billterm_is_grandchild(term))
        {
            gchar guidstr[GUID_ENCODING_LENGTH+1];
            guid_to_string_buff(qof_instance_get_guid(QOF_INSTANCE(invoice)),guidstr);
            PWARN("Fixing i-billterm on invoice %s\n", guidstr);
            new_bt = billterm_find_senior(term);
            gncInvoiceBeginEdit(invoice);
            gncInvoiceSetTerms(invoice, new_bt);
            gncInvoiceCommitEdit(invoice);
            term = new_bt;
        }
        if (term)
        {
            count = GPOINTER_TO_INT(g_hash_table_lookup(ht, term));
            count++;
            g_hash_table_insert(ht, term, GINT_TO_POINTER(count));
        }
    }
}

static void
billterm_scrub_cust (QofInstance * cust_p, gpointer ht_p)
{
    GHashTable *ht = ht_p;
    GncCustomer *cust = GNC_CUSTOMER(cust_p);
    GncBillTerm *term;
    gint32 count;

    term = gncCustomerGetTerms(cust);
    if (term)
    {
        count = GPOINTER_TO_INT(g_hash_table_lookup(ht, term));
        count++;
        g_hash_table_insert(ht, term, GINT_TO_POINTER(count));
        if (billterm_is_grandchild(term))
        {
            gchar custstr[GUID_ENCODING_LENGTH+1];
            gchar termstr[GUID_ENCODING_LENGTH+1];
            guid_to_string_buff(qof_instance_get_guid(QOF_INSTANCE(cust)),custstr);
            guid_to_string_buff(qof_instance_get_guid(QOF_INSTANCE(term)),termstr);
            PWARN("customer %s has grandchild billterm %s\n", custstr,termstr);
        }
    }
}

static void
billterm_scrub_vendor (QofInstance * vendor_p, gpointer ht_p)
{
    GHashTable *ht = ht_p;
    GncVendor *vendor = GNC_VENDOR(vendor_p);
    GncBillTerm *term;
    gint32 count;

    term = gncVendorGetTerms(vendor);
    if (term)
    {
        count = GPOINTER_TO_INT(g_hash_table_lookup(ht, term));
        count++;
        g_hash_table_insert(ht, term, GINT_TO_POINTER(count));
        if (billterm_is_grandchild(term))
        {
            gchar vendstr[GUID_ENCODING_LENGTH+1];
            gchar termstr[GUID_ENCODING_LENGTH+1];
            guid_to_string_buff(qof_instance_get_guid(QOF_INSTANCE(vendor)),vendstr);
            guid_to_string_buff(qof_instance_get_guid(QOF_INSTANCE(term)),termstr);
            PWARN("vendor %s has grandchild billterm %s\n", vendstr, termstr);
        }
    }
}

static void
billterm_reset_refcount (gpointer key, gpointer value, gpointer notused)
{
    GncBillTerm *term = key;
    gint32 count = GPOINTER_TO_INT(value);

    if (count != gncBillTermGetRefcount(term) && !gncBillTermGetInvisible(term))
    {
        gchar termstr[GUID_ENCODING_LENGTH+1];
        guid_to_string_buff(qof_instance_get_guid(QOF_INSTANCE(term)),termstr);
        PWARN("Fixing refcount on billterm %s (%" G_GINT64_FORMAT " -> %d)\n",
                termstr, gncBillTermGetRefcount(term), count);
        gncBillTermSetRefcount(term, count);
    }
}

static void
billterm_scrub (QofBook *book)
{
    GList *list = NULL;
    GList *node;
    GncBillTerm *parent, *term;
    GHashTable *ht = g_hash_table_new(g_direct_hash, g_direct_equal);

    DEBUG("scrubbing billterms...");
    qof_object_foreach (GNC_ID_INVOICE,  book, billterm_scrub_invoices, ht);
    qof_object_foreach (GNC_ID_CUSTOMER, book, billterm_scrub_cust, ht);
    qof_object_foreach (GNC_ID_VENDOR,   book, billterm_scrub_vendor, ht);
    qof_object_foreach (GNC_ID_BILLTERM, book, billterm_scrub_cb, &list);

    /* destroy the list of "grandchildren" bill terms */
    for (node = list; node; node = node->next)
    {
        gchar termstr[GUID_ENCODING_LENGTH+1];
        term = node->data;

        guid_to_string_buff(qof_instance_get_guid(QOF_INSTANCE(term)), termstr);
        PWARN ("deleting grandchild billterm: %s\n", termstr);

        /* Make sure the parent has no children */
        parent = gncBillTermGetParent(term);
        gncBillTermSetChild(parent, NULL);

        /* Destroy this bill term */
        gncBillTermBeginEdit(term);
        gncBillTermDestroy(term);
    }

    /* reset the refcounts as necessary */
    g_hash_table_foreach(ht, billterm_reset_refcount, NULL);

    g_list_free(list);
    g_hash_table_destroy(ht);
}

static gboolean
billterm_ns(FILE *out)
{
    g_return_val_if_fail(out, FALSE);
    return
        gnc_xml2_write_namespace_decl(out, "billterm")
        && gnc_xml2_write_namespace_decl(out, "bt-days")
        && gnc_xml2_write_namespace_decl(out, "bt-prox");
}

void
gnc_billterm_xml_initialize (void)
{
    static GncXmlDataType_t be_data =
    {
        GNC_FILE_BACKEND_VERS,
        gnc_billterm_string,
        billterm_sixtp_parser_create,
        NULL,                   /* add_item */
        billterm_get_count,
        billterm_write,
        billterm_scrub,
        billterm_ns,
    };

    qof_object_register_backend (_GNC_MOD_NAME,
                                 GNC_FILE_BACKEND,
                                 &be_data);
}

GncBillTerm *
gnc_billterm_xml_find_or_create(QofBook *book, GncGUID *guid)
{
    GncBillTerm *term;
    gchar guidstr[GUID_ENCODING_LENGTH+1];

    guid_to_string_buff(guid, guidstr);
    g_return_val_if_fail(book, NULL);
    g_return_val_if_fail(guid, NULL);
    term = gncBillTermLookup(book, guid);
    DEBUG("looking for billterm %s, found %p", guidstr, term);
    if (!term)
    {
        term = gncBillTermCreate(book);
        gncBillTermBeginEdit(term);
        gncBillTermSetGUID(term, guid);
        gncBillTermCommitEdit(term);
        DEBUG("Created term: %p", term);
    }
    else
        gncBillTermDecRef(term);

    return term;
}