path: root/lib/cosEvent/doc/src/CosEventChannelAdmin_ProxyPullSupplier.xml

<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE erlref SYSTEM "erlref.dtd">

<erlref>
  <header>
    <copyright>
      <year>1997</year>
      <year>2013</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.

  The Initial Developer of the Original Code is Ericsson AB.
    </legalnotice>

    <title>CosEventChannelAdmin_ProxyPullSupplier</title>
    <prepared></prepared>
    <responsible></responsible>
    <docno></docno>
    <approved>Lars Thors</approved>
    <checked></checked>
    <date>1997-11-13</date>
    <rev>PA1</rev>
    <file>CosEventChannelAdmin_ProxyPullSupplier.xml</file>
  </header>
  <module>CosEventChannelAdmin_ProxyPullSupplier</module>
  <modulesummary>This module implements a ProxyPullSupplier interface which acts as a middleman between pull consumer and the event channel.</modulesummary>
  <description>
    <p>The ProxyPullSupplier interface defines the second step for connecting pull consumers to the event channel. A proxy supplier is similar to a normal supplier,
      but includes an additional method for connecting a consumer to the proxy
      supplier.</p>
    <p>To get access to all definitions, e.g., exceptions,
      include necessary <c><![CDATA[hrl]]></c> files by using:<br></br><c><![CDATA[-include_lib("cosEvent/include/*.hrl").]]></c></p>
    <p>Any object that possesses an object reference that supports the ProxyPullSupplier
      interface can perform the following operations:</p>
  </description>
  <funcs>
    <func>
      <name>connect_pull_consumer(Object, PullConsumer) -> Return</name>
      <fsummary>Connect the pull consumer to the proxy pull supplier</fsummary>
      <type>
        <v>Object       = #objref</v>
        <v>PullConsumer = #objref of PullConsumer type</v>
        <v>Return = ok | {'EXCEPTION', #'CosEventChannelAdmin_AlreadyConnected'{}}</v>
      </type>
      <desc>
        <p>This operation connects PullConsumer object to the ProxyPullSupplier object.
          A nil object reference can be passed to this operation. If so a channel
          cannot invoke the disconnect_pull_consumer operation on the consumer;
          the consumer may be disconnected from the channel without being 
          informed. If the ProxyPullSupplier is already connected to a 
          PullConsumer, then the <c><![CDATA[CosEventChannelAdmin_AlreadyConnected]]></c> 
          exception is raised.</p>
      </desc>
    </func>
    <func>
      <name>disconnect_pull_supplier(Object) -> Return</name>
      <fsummary>Disconnect the ProxyPullSupplier object from the event channel.</fsummary>
      <type>
        <v>Object = #objref</v>
        <v>Return = ok</v>
      </type>
      <desc>
        <p>This operation disconnects proxy pull supplier from the event channel.
          It sends a notification about the loss of the connection to the pull consumer
          attached to it, unless nil object reference was passed at the connection
          time.</p>
      </desc>
    </func>
    <func>
      <name>pull(Object) -> Return</name>
      <fsummary>Transmit data from suppliers to consumers.</fsummary>
      <type>
        <v>Object = #objref</v>
        <v>Return = any</v>
      </type>
      <desc>
        <p>This operation blocks until the event data is available or the 
          <c><![CDATA[CosEventComm_Disconnected]]></c> exception is raised. 
          It returns the event data to the consumer.</p>
      </desc>
    </func>
    <func>
      <name>try_pull(Object) -> Return</name>
      <fsummary>Transmit data from suppliers to consumers.</fsummary>
      <type>
        <v>Object = #objref</v>
        <v>Return = {any, bool()}</v>
      </type>
      <desc>
        <p>This operation does not block: if the event data is available, it returns 
          the event data and sets the data availability flag to true; otherwise
          it returns a long with an undefined value and sets the data availability to
          false. If the event communication has already been disconnected, the 
          <c><![CDATA[CosEventComm_Disconnected]]></c> exception is raised.</p>
      </desc>
    </func>
  </funcs>
  
</erlref>