path: root/modules/plugin-python/e-plugin-python.c

/*
 * e-plugin-python.c
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

/* Include <Python.h> first to avoid:
 * warning: "_POSIX_C_SOURCE" redefined */
#include <Python.h>

#include "e-plugin-python.h"

#include <sys/types.h>
#include <string.h>

struct _EPluginPythonPrivate {
    PyObject *pModule;
    PyObject *pClass;
    PyObject *pFunc;
    PyObject *pDict;
    GHashTable *methods;
};

static gpointer parent_class;
static GType plugin_python_type;

static gchar *
get_xml_prop (xmlNodePtr node,
              const gchar *id)
{
    xmlChar *prop;
    gchar *out = NULL;

    prop = xmlGetProp (node, (xmlChar *) id);

    if (prop != NULL) {
        out = g_strdup ((gchar *) prop);
        xmlFree (prop);
    }

    return out;
}

static void
plugin_python_finalize (GObject *object)
{
    EPluginPython *plugin_python;

    plugin_python = E_PLUGIN_PYTHON (object);

    g_free (plugin_python->location);
    g_free (plugin_python->module_name);
    g_free (plugin_python->pClass);

    g_hash_table_destroy (plugin_python->priv->methods);

    /* Chain up to parent's finalize() method. */
    G_OBJECT_CLASS (parent_class)->finalize (object);
}

static gint
plugin_python_construct (EPlugin *plugin,
                         xmlNodePtr root)
{
    EPluginPython *plugin_python;

    /* Chain up to parent's construct() method. */
    if (E_PLUGIN_CLASS (parent_class)->construct (plugin, root) == -1)
        return -1;

    plugin_python = E_PLUGIN_PYTHON (plugin);
    plugin_python->location = get_xml_prop (root, "location");
    plugin_python->module_name = get_xml_prop (root, "module_name");
    plugin_python->pClass = get_xml_prop (root, "pClass");

    return (plugin_python->location != NULL) ? 0 : -1;
}

static gpointer
plugin_python_invoke (EPlugin *plugin,
                      const gchar *name,
                      gpointer data)
{
    EPluginPython *plugin_python;
    EPluginPythonPrivate *priv;
    PyObject *pModuleName, *pFunc;
    PyObject *pValue = NULL;

    plugin_python = E_PLUGIN_PYTHON (plugin);
    priv = plugin_python->priv;

    /* We need to do this every time since we may be called
     * from any thread for some uses. */
    Py_Initialize ();

    if (priv->pModule == NULL) {
        gchar *string;

        pModuleName = PyString_FromString (plugin_python->module_name);

        string = g_strdup_printf (
            "import sys; "
            "sys.path.insert(0, '%s')",
            plugin_python->location);
        PyRun_SimpleString (string);
        g_free (string);

        priv->pModule = PyImport_Import (pModuleName);

        Py_DECREF (pModuleName);

        if (priv->pModule == NULL) {
            PyErr_Print ();
            g_warning (
                "Can't load python module '%s'",
                plugin_python->location);
            return NULL;
        }

        priv->pDict = PyModule_GetDict (priv->pModule);

        if (plugin_python->pClass != NULL) {
            priv->pClass = PyDict_GetItemString (
                priv->pDict, plugin_python->pClass);
        }
    }

    if (priv->pClass) {

        if (PyCallable_Check (priv->pClass)) {
            PyObject *pInstance;

            pInstance = PyObject_CallObject (priv->pClass, NULL);
            pValue = PyObject_CallMethod (pInstance, (gchar *) name, NULL);
        }

    } else {

        pFunc = PyDict_GetItemString (priv->pDict, name);

        if (pFunc && PyCallable_Check (pFunc))
            pValue = PyObject_CallObject (pFunc, NULL);
        else
            PyErr_Print ();
    }

    if (pValue) {
        Py_DECREF (pValue);
        /* Fixme */
        return NULL;
    } else
        return NULL;
}

static void
plugin_python_class_init (EPluginPythonClass *class)
{
    GObjectClass *object_class;
    EPluginClass *plugin_class;

    parent_class = g_type_class_peek_parent (class);
    g_type_class_add_private (class, sizeof (EPluginPythonPrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->finalize = plugin_python_finalize;

    plugin_class = E_PLUGIN_CLASS (class);
    plugin_class->construct = plugin_python_construct;
    plugin_class->invoke = plugin_python_invoke;
    plugin_class->type = "python";
}

static void
plugin_python_init (EPluginPython *plugin_python)
{
    GHashTable *methods;

    methods = g_hash_table_new_full (
        g_str_hash, g_str_equal,
        (GDestroyNotify) g_free,
        (GDestroyNotify) NULL);

    plugin_python->priv = G_TYPE_INSTANCE_GET_PRIVATE (
        plugin_python, E_TYPE_PLUGIN_PYTHON, EPluginPythonPrivate);
    plugin_python->priv->methods = methods;
}

GType
e_plugin_python_get_type (void)
{
    return plugin_python_type;
}

void
e_plugin_python_register_type (GTypeModule *type_module)
{
    static const GTypeInfo type_info = {
        sizeof (EPluginPythonClass),
        (GBaseInitFunc) NULL,
        (GBaseFinalizeFunc) NULL,
        (GClassInitFunc) plugin_python_class_init,
        (GClassFinalizeFunc) NULL,
        NULL,  /* class_data */
        sizeof (EPluginPython),
        0,     /* n_preallocs */
        (GInstanceInitFunc) plugin_python_init,
        NULL   /* value_table */
    };

    plugin_python_type = g_type_module_register_type (
        type_module, E_TYPE_PLUGIN,
        "EPluginPython", &type_info, 0);

    /* TODO Does this mean I can cache the instance of pyobjects? */
    Py_Initialize ();
}