Meta collections

Introduction

A meta collection is a collection that allows users to search over one or more existing collections at the same time. For example, if you had two web collections, one for the external internet site and a second for the internal intranet, you could create a meta collection comprising the two collections to allow internal users to search both sites.

Meta collections operate in a similar manner to standard collections, except that they are not updated: the individual collections must be updated instead.

Creation

Creating a meta-collection foolws the normal collection creation process, however after creation the components (or sub-collections) of the meta collection must be configured via the "Edit Meta Components" screen shown under the "Administer" tab on the home page.

Note that if any of the selected base collections have early binding document level security, the following option must be added to the collection.cfg file for meta collection to maintain security processing for those component collections:

security.earlybinding.user-to-key-mapper=Meta

Displaying results in a meta collection

If your meta-collection comprises a number of different collection types, for example a web plus a database collection, then the search results will be a heterogeneous mix of records. The meta-collection's search templates should use an <#if /> FreeMarker clause to identify the child collection and format the record appropriately.

For example, if you had a database collection called library you could format results differently with the following:

<#if r.collection == "library">
  <a href="${r.cacheUrl}">${r.title}</a>
  <b>Library Record</b> - ${r.date?date?string.short}
  <#if r.metaData["y"]?exists>
    <span class="summary_label">ISBN:</span><${r.metaData["y"]}<br />
  </#if>
</#if>
<#if r.collection != "library">
  <a href="${r.cacheUrl}">${r.title}</a>
  <b>Other Record</b> - ${r.date?date?string.short}
  <#if r.metaData["a"]?exists>
    <span class="summary_label">Author:</span><${r.metaData["a"]}<br />
  </#if>
</#if>

Note that r.cacheUrl is used for the links to the library records as they are the rows extracted from the database (as XML files).

You might also use a hook script to transform the results so that results from a specific sub-collection are processed in a particular way.