<?xml version="1.0" encoding="utf-8" ?> <!DOCTYPE erlref SYSTEM "erlref.dtd"> <erlref> <header> <copyright> <year>2003</year><year>2016</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. </legalnotice> <title>megaco_transport</title> <prepared>Micael Karlberg</prepared> <responsible>Micael Karlberg</responsible> <docno></docno> <approved>Micael Karlberg</approved> <checked></checked> <date>2007-06-15</date> <rev>%VSN%</rev> <file>megaco_transport.xml</file> </header> <module>megaco_transport</module> <modulesummary>Megaco transport behaviour.</modulesummary> <description> <p>The following functions should be exported from a <c><![CDATA[megaco_transport]]></c> callback module:</p> <list type="bulleted"> <item> <p><seealso marker="#send_message">send_message/2</seealso> [<c><![CDATA[mandatory]]></c>]</p> </item> <item> <p><seealso marker="#send_message">send_message/3</seealso> [<c>optional</c>]</p> </item> <item> <p><seealso marker="#resend_message">resend_message/2</seealso> [<c><![CDATA[optional]]></c>]</p> </item> <item> </item> </list> <marker id="send_message"></marker> </description> <funcs> <func> <name>Module:send_message(Handle, Msg) -> ok | {cancel, Reason} | Error</name> <name>Module:send_message(Handle, Msg, Resend) -> ok | {cancel, Reason} | Error</name> <fsummary>Send a megaco message.</fsummary> <type> <v>Handle = term()</v> <v>Msg = binary() | iolist()</v> <v>Resend = boolean()</v> <v>Reason = term()</v> <v>Error = term()</v> </type> <desc> <p>Send a megaco message. </p> <p>If the function returns <c><![CDATA[{cancel, Reason}]]></c>, this means the transport module decided not to send the message. This is <em>not</em> an error. No error messages will be issued and no error counters incremented. What actions this will result in depends on what kind of message was sent. </p> <p>In the case of requests, megaco will cancel the message in much the same way as if <c><![CDATA[megaco:cancel]]></c> had been called (after a successfull send). The information will be propagated back to the user differently depending on how the request(s) where issued: For requests issued using <seealso marker="megaco#call">megaco:call</seealso>, the info will be delivered in the return value. For requests issued using <c><![CDATA[megaco:cast]]></c> the info will be delivered via a call to the callback function <seealso marker="megaco_user#trans_reply">handle_trans_reply</seealso>. </p> <p>In the case of reply, megaco will cancel the reply and information of this will be returned to the user via a call to the callback function <seealso marker="megaco_user#trans_ack">handle_trans_ack</seealso>. </p> <p>The function <c>send_message/3</c> will only be called if the <seealso marker="megaco#ui_resend_indication">resend_indication</seealso> config option has been set to the value <c>flag</c>. The third argument, <c>Resend</c> then indicates if the message send is a resend or not. </p> <marker id="resend_message"></marker> </desc> </func> <func> <name>Module:resend_message(Handle, Msg) -> ok | {cancel, Reason} | Error</name> <fsummary>Re-send a megaco message.</fsummary> <type> <v>Handle = term()</v> <v>Msg = binary() | iolist()</v> <v>Reason = term()</v> <v>Error = term()</v> </type> <desc> <p>Re-send a megaco message. </p> <p>Note that this function will only be called if the user has set the <seealso marker="megaco#ui_resend_indication">resend_indication</seealso> config option to <c><![CDATA[true]]></c><em>and</em> it is in fact a message resend. If not <em>both</em> of these condition's are meet, <c><![CDATA[send_message]]></c> will be called. </p> <p>If the function returns <c><![CDATA[{cancel, Reason}]]></c>, this means the transport module decided not to send the message. This is <em>not</em> an error. No error messages will be issued and no error counters incremented. What actions this will result in depends on what kind of message was sent. </p> <p>In the case of requests, megaco will cancel the message in much the same way as if <c><![CDATA[megaco:cancel]]></c> had been called (after a successfull send). The information will be propagated back to the user differently depending on how the request(s) where issued: For requests issued using <seealso marker="megaco#call">megaco:call</seealso>, the info will be delivered in the return value. For requests issued using <c><![CDATA[megaco:cast]]></c> the info will be delivered via a call to the callback function <seealso marker="megaco_user#trans_reply">handle_trans_reply</seealso>. </p> <p>In the case of reply, megaco will cancel the reply and information of this will be returned to the user via a call to the callback function <seealso marker="megaco_user#trans_ack">handle_trans_ack</seealso>. </p> </desc> </func> </funcs> </erlref>