Get items based on Metadata using Sitecore AdvancedDatabaseCrawler Lucene index

This is the 3rd and last in the series on using the open source AdvancedDatabaseCrawler Lucene index. From Sitecore 6.5, Sitecore is deprecating the old Lucene index. This means that we have to redo our index work. Fortunately, Alex Shyba has created an open source module that makes indexing and retrieving easy.

This is article 3 of 3 articles:

Part 1 – Configuring the index: Using the Sitecore open source AdvancedDatabaseCrawler Lucene indexer
Part 2 – Simple search: Get latest news using Sitecore AdvancedDatabaseCrawler Lucene index
Part 3 – Multivalue search: Get items based on Metadata using Sitecore AdvancedDatabaseCrawler Lucene index

If you have not read the first article, you should read it, as it explains how to compile the module and how to set up an index that indexes your WEB database.

This is the second-most common Lucene index task: How to get a list of items scattered all over your website based on GUID values in a multilist field. For example, if you use metadata to tag pages, and you need to show a list of all pages with a certain set of metadata.

Here is my scenario: I have a list of metadata categories:

Metadata Categories

These metadata are applied to my pages through the Categories field multiselect box:

Metadata applied to a page

Any page can have 0-n categories. Now I would like to get all pages that have both “Childrens Books” and “Classical Literature” metdata.

My index is already set up so it indexes every field in my solution (read about the configuration of the index here), so I only have to set up a search. And thanks to Alex Shybas AdvancedDatabaseCrawler, this is easy:

using System;
using System.Collections.Generic;
using System.Linq;
using Sitecore.Data.Items;
using Sitecore.SharedSource.Searcher;
using Sitecore.SharedSource.Searcher.Parameters;

namespace PT.Prototype.Search
{
  public partial class _default : System.Web.UI.Page
  {
    protected void Page_Load(object sender, EventArgs e)
    {
      DataBind();
    }

    public IEnumerable<Item> GetClassicalChildrensBooks()
    {
      // The Refinements are a list of field/value searches that must be performed.
      // My list is simple, as I search in the field "categories" for the GUID of
      // "Childrens Books" and "Classical Literature"
      List<MultiFieldSearchParam.Refinement> refinements = new List<MultiFieldSearchParam.Refinement>();
      refinements.Add(new MultiFieldSearchParam.Refinement("categories", "{4481D164-CF7C-421B-BC98-6189AB754C65}"));
      refinements.Add(new MultiFieldSearchParam.Refinement("categories", "{C813518E-6880-4FBE-A10F-7F8CE51AA52D}"));

      MultiFieldSearchParam searchParam = new MultiFieldSearchParam();

      // The name of the database to search in
      searchParam.Database = "web";
      // The language to return
      searchParam.Language = "en";
      // The AND/OR/NOT condition between fields
      searchParam.InnerCondition = Sitecore.Search.QueryOccurance.Must;
      // The fields to search in
      searchParam.Refinements = refinements;

      // Run the Query on the index called "web"
      QueryRunner runner = new QueryRunner("web");
      IEnumerable<SkinnyItem> items = runner.GetItems(searchParam);

      // Return the items found
      return items.Select(item => Sitecore.Context.Database.GetItem(item.ItemID));
    }
  }
}

All I need to do now is to create an asp:Repeater and databind it to the function:

<%@ Register TagPrefix="sc" Namespace="Sitecore.Web.UI.WebControls" Assembly="Sitecore.Kernel" %>

<asp:Repeater ID="repClassicalChildrensBooks" DataSource="<%# GetClassicalChildrensBooks() %>" runat="server">
  <HeaderTemplate>
    <ul>
  </HeaderTemplate>
  <FooterTemplate>
    </ul>
  </FooterTemplate>
  <ItemTemplate>
    <li>
      <a href="<%# Sitecore.Links.LinkManager.GetItemUrl(Container.DataItem as Sitecore.Data.Items.Item) %>">
        <sc:FieldRenderer ID="FieldRenderer2" FieldName="Title" runat="server" Item="<%# Container.DataItem as Sitecore.Data.Items.Item %>" />
      </a>
    </li>
  </ItemTemplate>
</asp:Repeater>

If I modify the searchParam.InnerCondition to Sitecore.Search.QueryOccurance.Should, I get an “OR” clause, returning all items with that is tagged with either “Childrens Books” or “Classical Literature” (or both).
If modified to Sitecore.Search.QueryOccurance.MustNot I get a “NOT” clause, returning any item not tagged with the 2 categories.

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