Augment search results with highlighted excerpts.
Adding relevant excerpts with highlighted search terms to your search results display makes it much easier for end users to scan the page and assess which hits look promising, dramatically improving their search experience.
Adaptations to indexer.pl
uses information generated at index time. To save resources, highlighting is disabled by default and must be turned on for individual fields.
c
{
String *field_str = Str_newf("content");
FullTextType *type = FullTextType_new((Analyzer*)analyzer);
FullTextType_Set_Highlightable(type, true);
Schema_Spec_Field(schema, field_str, (FieldType*)type);
DECREF(type);
DECREF(field_str);
}
perl
my $highlightable = Lucy::Plan::FullTextType->new(
analyzer => $easyanalyzer,
highlightable => 1,
);
$schema->spec_field( name => 'content', type => $highlightable );
Adaptations to search.cgi
To add highlighting and excerpting to the search.cgi sample app, create a
$highlighter
object outside the hits iterating loop...
c
String *content_str = Str_newf("content");
Highlighter *highlighter
= Highlighter_new((Searcher*)searcher, (Obj*)query,
content_str, 200);
perl
my $highlighter = Lucy::Highlight::Highlighter->new(
searcher => $searcher,
query => $q,
field => 'content'
);
... then modify the loop and the per-hit display to generate and include the excerpt.
``` c String *title_str = Str_newf("title"); String *url_str = Str_newf("url"); HitDoc *hit; i = 1;
// Loop over search results.
while (NULL != (hit = Hits_Next(hits))) {
String *title = (String*)HitDoc_Extract(hit, title_str);
char *title_c = Str_To_Utf8(title);
String *url = (String*)HitDoc_Extract(hit, url_str);
char *url_c = Str_To_Utf8(url);
String *excerpt = Highlighter_Create_Excerpt(highlighter, hit);
char *excerpt_c = Str_To_Utf8(excerpt);
printf("Result %d: %s (%s)\n%s\n\n", i, title_c, url_c, excerpt_c);
free(excerpt_c);
free(url_c);
free(title_c);
DECREF(excerpt);
DECREF(url);
DECREF(title);
DECREF(hit);
i++;
}
DECREF(url_str);
DECREF(title_str);
DECREF(hits);
DECREF(query_str);
DECREF(highlighter);
DECREF(content_str);
DECREF(searcher);
DECREF(folder);
```
``` perl
Create result list.
my $report = ''; while ( my $hit = $hits->next ) { my $score = sprintf( "%0.3f", $hit->get_score ); my $excerpt = $highlighter->create_excerpt($hit); $report .= qq|
$hit->{title}
$score
$excerpt
$hit->{url}
Next chapter: Query objects
Our next tutorial chapter, , illustrates how to build an "advanced search" interface using objects instead of query strings.