//+-------------------------------------------------------------------------
//
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.
//
// Copyright (c) 1998-1999 Microsoft Corporation. All Rights Reserved.
//
// Sample Name: HtmlProp - Sample Filter Implementation
//
//--------------------------------------------------------------------------
Description
===========
The HtmlProp sample is an example IFilter implementation that specializes
the Indexing Service (IS) HTML filter to extract value-type properties.
It converts HTML meta properties to data types other than strings as
specified by a configuration file.
Path
====
Source: mssdk\samples\winbase\indexing\HtmlProp\
User's Guide
============
* To build the sample
1. Set the Lib environment variable to "D:\mssdk\Lib;%Lib%" and the
Include environment variable to "D:\mssdk\Include;%Include%",
where D: is the drive on which you installed the Platform SDK.
2. Correctly set the CPU environment variable to, for example, "i386".
3. Open a command window and change the directory to the source path
of the sample.
4. Build the filter DLL by entering, at the command-line prompt, "nmake".
* To register the sample
1. Copy the filter DLL file HtmlProp.dll to your %windir%\System32
directory.
2. Self-register the filter by entering, at the command-line prompt,
"regsvr32.exe %windir%\System32\HtmlProp.dll".
3. Enable automatic registration of the filter by adding it, after
the entry for nlhtml.dll, to the value MULTI_SZ DLLsToRegister in
the registry under the following key.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ContentIndex
* To filter files using the sample
1. Update htmlprop.ini to specify data types for the HTML meta
properties you have defined in your HTML files. Update your HTML
files to contain properties that match the definitions. For examples,
refer to the sample files htmlprop.ini, dog1.htm, dog2.htm, and
dog3.htm.
2. Copy the file htmlprop.ini to your %windir%\System32 directory.
3. Copy the properties you defined in htmlprop.ini to your .IDQ file
and/or update your .ASP script to define these properties.
4. Restart the CISVC service. If the files don't need to be filtered,
touch files containing all of the meta properties added in the file
htmlprop.ini and wait for them to be filtered.
5. Using the Indexing Service MMC snap-in, update the property cache
to contain the properties you have defined. Be sure to choose the
equivalent data type for each property or queries won't work.
For example, DBTYPE_I4 is the same as VT_I4.
6. Force a full re-scan of all files and wait for the index to be updated.
Note: Don't commit properties when scans are in progress. Wait for
scans to complete. Index Server 2.0 has a bug that will cause your index
to become corrupt. The bug is fixed in Indexing Service 3.0, in non-U.S.
Index Server 2.0 versions, and in Windows NT<4E> 4.0 Service Pack 4.
You need to repeat steps 5 and 6 when your index is corrupt. Index Server
2.0 doesn't retain the list of properties in the property cache when your
index becomes corrupt. Indexing Service 3.0, non-U.S. releases of Index
Server 2.0, and Windows NT 4.0 Service Pack 4 actually remember the
properties.
* To query using the sample
Issue queries using the properties and/or retrieve the values in their
native types. The following are some sample queries using the sample
files.
@breedWeight > 10
@breedOrigin = Australia
@breedFirstBred = 1840
Programming Notes
=================
The HTMLProp filter loads the default HTML filter (nlhtml.dll) and passes
most of the processing to that filter. If the htmlprop.ini configuration
file specifies that certain HTML meta properties should be converted into
non-string data types, HTMLProp takes the string value from the HTML filter
and coerces it into the desired type.
This is useful because if htmlprop.dll is installed and properly configured,
the following actions are possible.
* You can query HTML meta property values using data types other than
strings.
* You can sort meta properties using native data types, rather than just
strings.
* You can retieve properties in .HTX/.ASP scripts in their native types,
rather than as strings.
HTMLProp supports the following data types.
DBTYPE_UI1, DBTYPE_I2, DBTYPE_UI2, DBTYPE_I4, DBTYPE_UI4,
DBTYPE_I8, DBTYPE_UI8, DBTYPE_R4, DBTYPE_R8, and VT_FILETIME
By modifying htmlprop.cxx, additional data types can be supported, and
additional date formats can be added. Currently, only the Indexing Service
syntax is supported for date specifications.
VT_FILETIME values can be in any time zone you like, but the .HTX file parser
in Indexing Service assume all times are Coordinated Universal Time (UTC) and
will be displayed as such.
