func_sorcery.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Fairview 5 Engineering, LLC
 *
 * George Joseph <[email protected]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Get a field from a sorcery object
 *
 * \author \verbatim George Joseph <[email protected]> \endverbatim
 *
 * \ingroup functions
 *
 */

/*** MODULEINFO
 <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/app.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/sorcery.h"

/*** DOCUMENTATION
 <function name="AST_SORCERY" language="en_US">
 <synopsis>
 Get a field from a sorcery object
 </synopsis>
 <syntax>
 <parameter name="module_name" required="true">
 <para>The name of the module owning the sorcery instance.</para>
 </parameter>
 <parameter name="object_type" required="true">
 <para>The type of object to query.</para>
 </parameter>
 <parameter name="object_id" required="true">
 <para>The id of the object to query.</para>
 </parameter>
 <parameter name="field_name" required="true">
 <para>The name of the field.</para>
 </parameter>
 <parameter name="retrieval_method" required="false">
 <para>Fields that have multiple occurrences may be retrieved in two ways.</para>
 <enumlist>
 <enum name="concat"><para>Returns all matching fields concatenated
 in a single string separated by <replaceable>separator</replaceable>
 which defaults to <literal>,</literal>.</para></enum>

 <enum name="single"><para>Returns the nth occurrence of the field
 as specified by <replaceable>occurrence_number</replaceable> which defaults to <literal>1</literal>.
 </para></enum>
 </enumlist>
 <para>The default is <literal>concat</literal> with separator <literal>,</literal>.</para>
 </parameter>
 <parameter name="retrieval_details" required="false">
 <para>Specifies either the separator for <literal>concat</literal>
 or the occurrence number for <literal>single</literal>.</para>
 </parameter>
 </syntax>
 </function>
***/

static int sorcery_function_read(struct ast_channel *chan,
 const char *cmd, char *data, struct ast_str **buf, ssize_t len)
{
 char *parsed_data = ast_strdupa(data);
 RAII_VAR(struct ast_sorcery *, sorcery, NULL, ast_sorcery_unref);
 RAII_VAR(void *, sorcery_obj, NULL, ao2_cleanup);
 struct ast_variable *change_set;
 struct ast_variable *it_change_set;
 int found, field_number = 1, ix, method;
 char *separator = ",";

 enum methods {
 CONCAT,
 SINGLE,
 };

 AST_DECLARE_APP_ARGS(args,
 AST_APP_ARG(module_name);
 AST_APP_ARG(object_type);
 AST_APP_ARG(object_id);
 AST_APP_ARG(field_name);
 AST_APP_ARG(method);
 AST_APP_ARG(method_arg);
 );

 /* Check for zero arguments */
 if (ast_strlen_zero(parsed_data)) {
 ast_log(AST_LOG_ERROR, "Cannot call %s without arguments\n", cmd);
 return -1;
 }

 AST_STANDARD_APP_ARGS(args, parsed_data);

 if (ast_strlen_zero(args.module_name)) {
 ast_log(AST_LOG_ERROR, "Cannot call %s without a module name to query\n", cmd);
 return -1;
 }

 if (ast_strlen_zero(args.object_type)) {
 ast_log(AST_LOG_ERROR, "Cannot call %s with an empty object type\n", cmd);
 return -1;
 }

 if (ast_strlen_zero(args.object_id)) {
 ast_log(AST_LOG_ERROR, "Cannot call %s with an empty object name\n", cmd);
 return -1;
 }

 if (ast_strlen_zero(args.field_name)) {
 ast_log(AST_LOG_ERROR, "Cannot call %s with an empty field name\n", cmd);
 return -1;
 }

 if (ast_strlen_zero(args.method)) {
 method = CONCAT;
 } else {
 if (strcmp(args.method, "concat") == 0) {
 method = CONCAT;
 if (ast_strlen_zero(args.method_arg)) {
 separator = ",";
 } else {
 separator = args.method_arg;
 }

 } else if (strcmp(args.method, "single") == 0) {
 method = SINGLE;
 if (!ast_strlen_zero(args.method_arg)) {
 if (sscanf(args.method_arg, "%30d", &field_number) <= 0 || field_number <= 0 ) {
 ast_log(AST_LOG_ERROR, "occurrence_number must be a positive integer\n");
 return -1;
 }
 }
 } else {
 ast_log(AST_LOG_ERROR, "Retrieval method must be 'concat' or 'single'\n");
 return -1;
 }
 }

 sorcery = ast_sorcery_retrieve_by_module_name(args.module_name);
 if (!sorcery) {
 ast_log(AST_LOG_ERROR, "Failed to retrieve sorcery instance for module %s\n", args.module_name);
 return -1;
 }

 sorcery_obj = ast_sorcery_retrieve_by_id(sorcery, args.object_type, args.object_id);
 if (!sorcery_obj) {
 return -1;
 }

 change_set = ast_sorcery_objectset_create(sorcery, sorcery_obj);
 if (!change_set) {
 return -1;
 }

 ix=1;
 found = 0;
 for (it_change_set = change_set; it_change_set; it_change_set = it_change_set->next) {

 if (method == CONCAT && strcmp(it_change_set->name, args.field_name) == 0) {
 ast_str_append(buf, 0, "%s%s", it_change_set->value, separator);
 found = 1;
 continue;
 }

 if (method == SINGLE && strcmp(it_change_set->name, args.field_name) == 0 && ix++ == field_number) {
 ast_str_set(buf, len, "%s", it_change_set->value);
 found = 1;
 break;
 }
 }

 ast_variables_destroy(change_set);

 if (!found) {
 return -1;
 }

 if (method == CONCAT) {
 ast_str_truncate(*buf, -1);
 }

 return 0;
}

static struct ast_custom_function sorcery_function = {
 .name = "AST_SORCERY",
 .read2 = sorcery_function_read,
};

static int unload_module(void)
{
 return ast_custom_function_unregister(&sorcery_function);
}

static int load_module(void)
{
 return ast_custom_function_register(&sorcery_function);
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Get a field from a sorcery object");