initial custom action library, "hello, world" quality

installer/adblockplusie.wxs

 <?xml version="1.0" encoding="UTF-8"?>
 <!--
   Compilation Note:
   You may see linking errors that look like these:
     <quote>LGHT0217 : Error executing ICE action 'ICExx' [...] The error code is 2738.</quote>
   The documentation for this error code talks about custom actions,
     even though the CustomAction keyword does not appear in this source.
   Certain WiX elements are implemented by MSI custom actions,
     which means this source implicitly declares some insofar as the Windows Installer sees it.
   These errors are benign and can be avoided by some fiddling with the registry on the development machine.
@@ skipping 71 matching lines @@
     <MediaTemplate EmbedCab="yes"/>
 
     <!--
       User interface
     -->
     <UIRef Id="custom_WixUI_InstallDir"/>
     <UIRef Id="WixUI_ErrorProgressText"/>
     <Property Id="WIXUI_INSTALLDIR" Value="INSTALLFOLDER"/>
 
     <!--
+      Define and schedule a "Custom Action Type 1" to ensure that IE is closed before installation.

[Felix Dahlke, 2013/09/06 16:59:03]

This paragraph describes something that's pretty apparent in the WiX docs, and
it's rather obvious when reading the source IMO. The next paragraph makes sense,
"check" is non-obvious.

+      Because WiX is closely tied to the MSI database format, there are multiple tags required to do this.
+      The "CustomAction" tag defines the tag itself, but doesn't sequence it;
+        it defines an entry in the "CustomAction" table.
+      The "Binary" tag describe an asset that's incorporated into the MSI but that is not an installed component.
+      The "Custom" tag defines the sequencing of an action;
+        it defines an entry in one of the sequence tables (there are six).
+      
+      Attribute "Return" sets the "Custom Action Return Processing Options" to zero,
+        which indicates to block the installer until the action completes
+        and to treat a non-zero return value from the action as an error.
+    -->
+    <CustomAction
+        Id="Close_IE"
+        BinaryKey="installer_ca"
+        DllEntry="abp_close_applications"
+        Return="check"
+    />
+    <Binary Id="installer_ca" SourceFile="..\build\ia32\$(var.Configuration)\installer-ca.dll"/>    
+    <InstallUISequence>
+      <!--
+        The LaunchConditions action occurs near the beginning, before any of the expensive operations.
+      -->
+      <Custom
+        Action="Close_IE"
+        After="LaunchConditions"
+      />
+    </InstallUISequence>
+
+    <!--
       We have only a single feature, since there aren't any optional parts.
       The display is hidden for the same reason; there's nothing to choose from.
     -->
     <Feature Id="ProductFeature"
       Title="!(loc.Title)" Description="!(loc.UI_Description)"
       Display="hidden">
       <ComponentGroupRef Id="Installation_Folders"/>
       <ComponentGroupRef Id="Binaries"/>
       <ComponentGroupRef Id="HTML_Tree"/>
       <ComponentGroupRef Id="Locale_Files"/>
@@ skipping 634 matching lines @@
     </ComponentGroup>
     <DirectoryRef Id="ABP_APPDATA_FOLDER">
       <Directory Id="ini" FileSource="..\files">
         <Component Id="ini_settings.ini" Guid="dc30c3b0-d713-11e2-8b8b-0800200c9a66">
           <File Name="settings.ini"/>
         </Component>
       </Directory>
     </DirectoryRef>
   </Product>
 </Wix>