1 <?xml version="1.0" encoding="utf-8"?>

     2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->

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     4 "Eclipse Public License v1.0" which accompanies this distribution, 

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     6 <!-- Initial Contributors:

     7     Nokia Corporation - initial contribution.

     8 Contributors: 

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    10 <!DOCTYPE task

    11   PUBLIC "-//OASIS//DTD DITA Task//EN" "task.dtd">

    12 <task id="GUID-895A685E-83E8-51A3-A823-3A0E07B1E609" xml:lang="en"><title>Exporting

    13 the Implementation Factories </title><abstract><p>An implementation collection gathers one or more interface implementations

    14 in a DLL. It provides necessary information to the plug-in framework to use

    15 them. The collection must export a single function that provides an array.

    16 This array maps the UID of each implementation it contains with a pointer

    17 to its factory instantiation function (NewL() in our example). </p></abstract><prolog><metadata><keywords/></metadata></prolog><taskbody>

    18 <steps id="GUID-B972BA4F-6146-59A7-AA8E-8ACC704F34FB">

    19 <step id="GUID-E2BCAA54-9873-5AB5-93F8-6F1CE28D184D"><cmd/>

    20 <info>Define a UID for each implementation. This UID maps to the instantiation

    21 function of the implementation. Construct an array of UID's for all the implementations

    22 in the collection. </info>

    23 <stepxmp><codeblock id="GUID-F1292D30-2559-5F6C-ACD5-CEFD60F84EA7" xml:space="preserve">// Define the interface UIDs

    24 const TImplementationProxy ImplementationTable[] = 

    25     {

    26     {{0x10009DC3}, CImplementationClassOne::NewL();},

    27     {{0x10009DC4}, CImplementationClassTwo::NewL();}

    28     };

    29     }</codeblock> </stepxmp>

    30 </step>

    31 <step id="GUID-D465B0AD-350A-597F-A0AB-D71F44F1CAEB"><cmd/>

    32 <info>The signature of this exported function must be: </info>

    33 <stepxmp><codeblock id="GUID-847AC15E-6714-5399-827C-2C04423A8CE7" xml:space="preserve">const TImplementationProxy* ImplementationGroupProxy(TInt&amp; aTableCount);</codeblock> </stepxmp>

    34 </step>

    35 <step id="GUID-43C85534-AD27-5F72-A57E-5271397C1C21"><cmd/>

    36 <info>The exported function returns a pointer to an array of <xref href="GUID-A91AD391-D638-3FD4-93E3-B77B85767CCD.dita"><apiname>TImplementationProxy</apiname></xref> objects. </info>

    37 </step>

    38 <step id="GUID-D66DC4B4-3B8A-59CF-A74E-2FE499F5CA83"><cmd/>

    39 <info>Each <codeph>TImplementationProxy</codeph> contains a UID and a function

    40 pointer. </info>

    41 <info> <codeph>aTableCount</codeph> should be set to the number of items in

    42 the array. </info>

    43 <stepxmp><codeblock id="GUID-2AAD649D-BC66-55B1-9EA1-9C30CF96BB4B" xml:space="preserve">EXPORT_C const TImplementationProxy* ImplementationGroupProxy(TInt&amp; aTableCount)

    44     {

    45     aTableCount = sizeof(ImplementationTable) / sizeof(TImplementationProxy);

    46 

    47     return ImplementationTable;

    48     }</codeblock> </stepxmp>

    49 </step>

    50 </steps>

    51 </taskbody></task>