Generating Results Summaries

Enabling Search and Indexing for Guestbooks

Step 5 of 6

The Search application and the Asset Publisher application must display results retrieved from the search engine. Control the summarized content by implementing a ModelSummaryContributor.

A summary is a condensed, text-based version of the entity’s document that can be displayed generically. You create it by combining key parts of the entity’s data so users can browse through search resmlts to find the entity they want.

Create a GuestbookModelSummaryContributor:

@Component(
        immediate = true,
        property = "indexer.class.name=com.liferay.docs.guestbook.model.Guestbook",
        service = ModelSummaryContributor.class
)
public class GuestbookModelSummaryContributor
    implements ModelSummaryContributor {

    @Override
    public Summary getSummary(
        Document document, Locale locale, String snippet) {

        Summary summary = createSummary(document);

        summary.setMaxContentLength(200);

        return summary;
    }

    private Summary createSummary(Document document) {
        String prefix = Field.SNIPPET + StringPool.UNDERLINE;

        String title = document.get(prefix + Field.TITLE, Field.TITLE);

        return new Summary(title, StringPool.BLANK);
    }

}

First override getSummary and set the maximum summary length on the summary returned. The value 200 is a Liferay standard. Control the summary creation in a utility method called createSummary. Create a prefix variable using two constants, Field.SNIPPET and Stringpool.UNDERLINE. The snippet_title field is returned from the document.get call, and added to the summary. Using the snippet field provides two benefits:

1. Snippet text can be highlighted so matching keywords are emphasized.

2. Snippet text can be shortened automatically by the Search application so a sensible portion of the field’s text is displayed in the search results.

Guestbook titles are likely short, so only the highlighting behavior is useful for the title field of Guestbooks. For longer fields (like some content fields), the clipping behavior is more useful. Additional highlighting behavior can be configured via the index.search.highlight.* properties in portal.properties.

Create summaries by combining key parts of the entity’s data so users can browse through search results to find the entity they want.

Once all the search and indexing logic is in place, update the service layer so add, update, and delete service calls trigger the new logic.