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Searching Indexing Service With ASP
Indexing Service makes it very straightforward to create search solutions that would cost many thousands of dollars to implement using alternative technologies.
This article describes what is required to use Indexing Service from within ASP. It assumes you have access to a web server running Internet Information Services in a Microsoft Windows environment.
Creating a search form
The first thing to do is to create a page containing a form in which the user can enter their search word or phrase. You can of course have a combined search form page and search results page, but I prefer to keep them separate. An example search form is shown below. This code should be saved as SearchForm.asp:
As you can see from this HTML, it is a simple form that will post a single text field called query to the page called SearchResults.asp.
Creating a search results page
The following code can be used for a basic search results page. It should be saved as SearchResults.asp.
The first part of the search results page initialises variables and constants:
The search string was posted from the SearchForm.asp search form page, and the word or phrase to be searched for are extracted from the query item in the Request.Form collection.
The SEARCH_CATALOG constant is also defined. This name will vary so you will have to change it. If your site is hosted with a hosting company then they will usually set up a catalog on the Indexing Service for you, then let you know the name of your search catalog. If you are using your own web server, then you should be able to determine the catalog name from the Indexing Service Management Console. Describing how to set up and use Indexing Service catalogs is beyond the scope of this article.
The next part of the search results page initialises the Indexing Service Query COM component which enables the search to be performed:
Further details of the Query objects methods and properties are to be found in the IIS 4.0 online documentation. The properties of the object set in the sample code above are as follows:
Finally, an ADO RecordSet is created from the records found for this search. The neat thing about Indexing Service is that the returned RecordSet of search results can be used in an almost identical fashion to RecordSets returned from databases. A list of results is, therefore, displayed simply by looping through this RecordSet and displaying fields from the RecordSet:
This code loops through the records corresponding to the matching documents found and displays some of the properties of each document. This is where the columns property of the Indexing Service Query are used: these specify the column names that are returned for each record. In the sample code above, FileName refers to the records name on disk.
doctitle corresponds to the documents title (i.e. <title> tag if the document is HTML). Size is the size in bytes of the file on disk. Create is the date and time the document was created, whereas Write is the date and time the document was modified. Finally, Characterization is a summary of the document. The summary corresponds to the Description meta tag in HTML files, so it is worthwhile putting this tag into documents. If the Description tag isnt present, Indexing Service will display the first one or two sentences from the document.
Unfortunately the FileName property only contains the file's name in lower case. This can lead to problems if you are building a cross-platform search solution with operating systems that use case sensitive filenames (e.g. Unix and Linux).
Finally at the bottom of the page the objects are released:
An example screenshot of the search results page is below as described above, the page displays the FileName, doctitle, Size, Create and Characterization for each matching document:
As you can see the page is fairly basic, so a few cosmetic improvements would be required if the page was to be used on a production website. Further suggestions for improving the display of search results are in the article "More about Searching Indexing Service With ASP".