/* json-generator.c - JSON streams generator
*
* This file is part of JSON-GLib
* Copyright (C) 2007 OpenedHand Ltd.
*
* This library 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) any later version.
*
* This library 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.
*
* Author:
* Emmanuele Bassi <ebassi@openedhand.com>
*/
/**
* SECTION:json-generator
* @short_description: Generates JSON data streams
*
* #JsonGenerator provides an object for generating a JSON data stream and
* put it into a buffer or a file.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdlib.h>
#include <string.h>
#include "json-marshal.h"
#include "json-generator.h"
#define JSON_GENERATOR_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), JSON_TYPE_GENERATOR, JsonGeneratorPrivate))
struct _JsonGeneratorPrivate
{
JsonNode *root;
guint indent;
gunichar indent_char;
guint pretty : 1;
};
enum
{
PROP_0,
PROP_PRETTY,
PROP_INDENT,
PROP_ROOT,
PROP_INDENT_CHAR
};
static gchar *dump_value (JsonGenerator *generator,
gint level,
const gchar *name,
JsonNode *node);
static gchar *dump_array (JsonGenerator *generator,
gint level,
const gchar *name,
JsonArray *array,
gsize *length);
static gchar *dump_object (JsonGenerator *generator,
gint level,
const gchar *name,
JsonObject *object,
gsize *length);
G_DEFINE_TYPE (JsonGenerator, json_generator, G_TYPE_OBJECT);
static void
json_generator_finalize (GObject *gobject)
{
JsonGeneratorPrivate *priv = JSON_GENERATOR_GET_PRIVATE (gobject);
if (priv->root)
json_node_free (priv->root);
G_OBJECT_CLASS (json_generator_parent_class)->finalize (gobject);
}
static void
json_generator_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
JsonGeneratorPrivate *priv = JSON_GENERATOR_GET_PRIVATE (gobject);
switch (prop_id)
{
case PROP_PRETTY:
priv->pretty = g_value_get_boolean (value);
break;
case PROP_INDENT:
priv->indent = g_value_get_uint (value);
break;
case PROP_INDENT_CHAR:
priv->indent_char = g_value_get_uint (value);
break;
case PROP_ROOT:
json_generator_set_root (JSON_GENERATOR (gobject),
g_value_get_boxed (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
json_generator_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
JsonGeneratorPrivate *priv = JSON_GENERATOR_GET_PRIVATE (gobject);
switch (prop_id)
{
case PROP_PRETTY:
g_value_set_boolean (value, priv->pretty);
break;
case PROP_INDENT:
g_value_set_uint (value, priv->indent);
break;
case PROP_INDENT_CHAR:
g_value_set_uint (value, priv->indent_char);
break;
case PROP_ROOT:
g_value_set_boxed (value, priv->root);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
json_generator_class_init (JsonGeneratorClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
g_type_class_add_private (klass, sizeof (JsonGeneratorPrivate));
gobject_class->set_property = json_generator_set_property;
gobject_class->get_property = json_generator_get_property;
gobject_class->finalize = json_generator_finalize;
/**
* JsonGenerator:pretty:
*
* Whether the output should be "pretty-printed", with indentation and
* newlines. The indentation level can be controlled by using the
* JsonGenerator:indent property
*/
g_object_class_install_property (gobject_class,
PROP_PRETTY,
g_param_spec_boolean ("pretty",
"Pretty",
"Pretty-print the output",
FALSE,
G_PARAM_READWRITE));
/**
* JsonGenerator:indent:
*
* Number of spaces to be used to indent when pretty printing.
*/
g_object_class_install_property (gobject_class,
PROP_INDENT,
g_param_spec_uint ("indent",
"Indent",
"Number of indentation spaces",
0, G_MAXUINT,
2,
G_PARAM_READWRITE));
/**
* JsonGenerator:root:
*
* The root #JsonNode to be used when constructing a JSON data
* stream.
*
* Since: 0.4
*/
g_object_class_install_property (gobject_class,
PROP_ROOT,
g_param_spec_boxed ("root",
"Root",
"Root of the JSON data tree",
JSON_TYPE_NODE,
G_PARAM_READWRITE));
/**
* JsonGenerator:indent-char:
*
* The character that should be used when indenting in pretty print.
*
* Since: 0.6
*/
g_object_class_install_property (gobject_class,
PROP_INDENT_CHAR,
g_param_spec_unichar ("indent-char",
"Indent Char",
"Character that should be used when indenting",
' ',
G_PARAM_READWRITE));
}
static void
json_generator_init (JsonGenerator *generator)
{
JsonGeneratorPrivate *priv;
generator->priv = priv = JSON_GENERATOR_GET_PRIVATE (generator);
priv->pretty = FALSE;
priv->indent = 2;
priv->indent_char = ' ';
}
static gchar *
dump_value (JsonGenerator *generator,
gint level,
const gchar *name,
JsonNode *node)
{
JsonGeneratorPrivate *priv = generator->priv;
gboolean pretty = priv->pretty;
guint indent = priv->indent;
GValue value = { 0, };
GString *buffer;
buffer = g_string_new ("");
if (pretty)
{
guint i;
for (i = 0; i < (level * indent); i++)
g_string_append_c (buffer, priv->indent_char);
}
if (name && name[0] != '\0')
g_string_append_printf (buffer, "\"%s\" : ", name);
json_node_get_value (node, &value);
switch (G_VALUE_TYPE (&value))
{
case G_TYPE_INT:
g_string_append_printf (buffer, "%d", g_value_get_int (&value));
break;
case G_TYPE_STRING:
{
gchar *tmp;
gchar *exceptions = g_malloc (128);
gint chr, i;
/* non-ascii characters can't be escaped, otherwise utf-8
* chars will break */
for (i = 0, chr = 0x7f; chr <= 0xff; chr++, i++)
exceptions[i] = chr;
tmp = g_strescape (g_value_get_string (&value), exceptions);
g_free (exceptions);
g_string_append_printf (buffer, "\"%s\"", tmp);
g_free (tmp);
}
break;
case G_TYPE_DOUBLE:
g_string_append_printf (buffer, "%f", g_value_get_double (&value));
break;
case G_TYPE_BOOLEAN:
g_string_append_printf (buffer, "%s",
g_value_get_boolean (&value) ? "true" : "false");
break;
default:
break;
}
g_value_unset (&value);
return g_string_free (buffer, FALSE);
}
static gchar *
dump_array (JsonGenerator *generator,
gint level,
const gchar *name,
JsonArray *array,
gsize *length)
{
JsonGeneratorPrivate *priv = generator->priv;
guint array_len = json_array_get_length (array);
guint i;
GString *buffer;
gboolean pretty = priv->pretty;
guint indent = priv->indent;
buffer = g_string_new ("");
if (pretty)
{
for (i = 0; i < (level * indent); i++)
g_string_append_c (buffer, priv->indent_char);
}
if (name && name[0] != '\0')
g_string_append_printf (buffer, "\"%s\" : ", name);
g_string_append_c (buffer, '[');
if (pretty)
g_string_append_c (buffer, '\n');
else
g_string_append_c (buffer, ' ');
for (i = 0; i < array_len; i++)
{
JsonNode *cur = json_array_get_element (array, i);
guint sub_level = level + 1;
guint j;
gchar *value;
switch (JSON_NODE_TYPE (cur))
{
case JSON_NODE_NULL:
if (pretty)
{
for (j = 0; j < (sub_level * indent); j++)
g_string_append_c (buffer, priv->indent_char);
}
g_string_append (buffer, "null");
break;
case JSON_NODE_VALUE:
value = dump_value (generator, sub_level, NULL, cur);
g_string_append (buffer, value);
g_free (value);
break;
case JSON_NODE_ARRAY:
value = dump_array (generator, sub_level, NULL, json_node_get_array (cur), NULL);
g_string_append (buffer, value);
g_free (value);
break;
case JSON_NODE_OBJECT:
value = dump_object (generator, sub_level, NULL, json_node_get_object (cur), NULL);
g_string_append (buffer, value);
g_free (value);
break;
}
if ((i + 1) != array_len)
g_string_append_c (buffer, ',');
if (pretty)
g_string_append_c (buffer, '\n');
else
g_string_append_c (buffer, ' ');
}
if (pretty)
{
for (i = 0; i < (level * indent); i++)
g_string_append_c (buffer, priv->indent_char);
}
g_string_append_c (buffer, ']');
if (length)
*length = buffer->len;
return g_string_free (buffer, FALSE);
}
static gchar *
dump_object (JsonGenerator *generator,
gint level,
const gchar *name,
JsonObject *object,
gsize *length)
{
JsonGeneratorPrivate *priv = generator->priv;
GList *members, *l;
GString *buffer;
gboolean pretty = priv->pretty;
guint indent = priv->indent;
guint i;
buffer = g_string_new ("");
if (pretty)
{
for (i = 0; i < (level * indent); i++)
g_string_append_c (buffer, priv->indent_char);
}
if (name && name[0] != '\0')
g_string_append_printf (buffer, "\"%s\" : ", name);
g_string_append_c (buffer, '{');
if (pretty)
g_string_append_c (buffer, '\n');
else
g_string_append_c (buffer, ' ');
members = json_object_get_members (object);
for (l = members; l != NULL; l = l->next)
{
const gchar *member_name = l->data;
JsonNode *cur = json_object_get_member (object, member_name);
guint sub_level = level + 1;
guint j;
gchar *value;
switch (JSON_NODE_TYPE (cur))
{
case JSON_NODE_NULL:
if (pretty)
{
for (j = 0; j < (sub_level * indent); j++)
g_string_append_c (buffer, priv->indent_char);
}
g_string_append_printf (buffer, "\"%s\" : null", member_name);
break;
case JSON_NODE_VALUE:
value = dump_value (generator, sub_level, member_name, cur);
g_string_append (buffer, value);
g_free (value);
break;
case JSON_NODE_ARRAY:
value = dump_array (generator, sub_level, member_name,
json_node_get_array (cur), NULL);
g_string_append (buffer, value);
g_free (value);
break;
case JSON_NODE_OBJECT:
value = dump_object (generator, sub_level, member_name,
json_node_get_object (cur), NULL);
g_string_append (buffer, value);
g_free (value);
break;
}
if (l->next != NULL)
g_string_append_c (buffer, ',');
if (pretty)
g_string_append_c (buffer, '\n');
else
g_string_append_c (buffer, ' ');
}
g_list_free (members);
if (pretty)
{
for (i = 0; i < (level * indent); i++)
g_string_append_c (buffer, priv->indent_char);
}
g_string_append_c (buffer, '}');
if (length)
*length = buffer->len;
return g_string_free (buffer, FALSE);
}
/**
* json_generator_new:
*
* Creates a new #JsonGenerator. You can use this object to generate a
* JSON data stream starting from a data object model composed by
* #JsonNode<!-- -->s.
*
* Return value: the newly created #JsonGenerator instance
*/
JsonGenerator *
json_generator_new (void)
{
return g_object_new (JSON_TYPE_GENERATOR, NULL);
}
/**
* json_generator_to_data:
* @generator: a #JsonGenerator
* @length: return location for the length of the returned buffer, or %NULL
*
* Generates a JSON data stream from @generator and returns it as a
* buffer.
*
* Return value: a newly allocated buffer holding a JSON data stream. Use
* g_free() to free the allocated resources.
*/
gchar *
json_generator_to_data (JsonGenerator *generator,
gsize *length)
{
JsonNode *root;
gchar *retval = NULL;
g_return_val_if_fail (JSON_IS_GENERATOR (generator), NULL);
root = generator->priv->root;
if (!root)
{
if (length)
*length = 0;
return NULL;
}
switch (JSON_NODE_TYPE (root))
{
case JSON_NODE_ARRAY:
retval = dump_array (generator, 0, NULL, json_node_get_array (root), length);
break;
case JSON_NODE_OBJECT:
retval = dump_object (generator, 0, NULL, json_node_get_object (root), length);
break;
case JSON_NODE_NULL:
retval = g_strdup ("null");
if (length)
*length = 4;
break;
case JSON_NODE_VALUE:
retval = NULL;
break;
}
return retval;
}
/**
* json_generator_to_file:
* @generator: a #JsonGenerator
* @filename: path to the target file
* @error: return location for a #GError, or %NULL
*
*
) is private.
