Struct elasticsearch_dsl::search::highlight::PlainHighlighter

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pub struct PlainHighlighter { /* private fields */ }

Expand description

The plain highlighter uses the standard Lucene highlighter. It attempts to reflect the query matching logic in terms of understanding word importance and any word positioning criteria in phrase queries.

Warning
The plain highlighter works best for highlighting simple query matches in a single field. To accurately reflect query logic, it creates a tiny in-memory index and re-runs the original query criteria through Lucene’s query execution planner to get access to low-level match information for the current document. This is repeated for every field and every document that needs to be highlighted. If you want to highlight a lot of fields in a lot of documents with complex queries, we recommend using the unified highlighter on postings or term_vector fields.

https://www.elastic.co/guide/en/elasticsearch/reference/current/highlighting.html#plain-highlighter

Implementations

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impl PlainHighlighter

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pub fn new() -> Self

Creates a new PlainHighlighter instance

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pub fn boundary_chars(self, boundary_chars: impl Into<String>) -> Self

A string that contains each boundary character. Defaults to .,!? \t\n.

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pub fn boundary_max_scan(self, boundary_max_scan: u32) -> Self

How far to scan for boundary characters. Defaults to 20.

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pub fn encoder(self, encoder: Encoder) -> Self

Indicates if the snippet should be HTML encoded.

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pub fn force_source(self, force_source: bool) -> Self

Highlight based on the source even if the field is stored separately. Defaults to false.

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pub fn fragment_size(self, fragment_size: u32) -> Self

The size of the highlighted fragment in characters. Defaults to 100.

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pub fn highlight_query(self, highlight_query: impl Into<Query>) -> Self

Highlight matches for a query other than the search query. This is especially useful if you use a rescore query because those are not taken into account by highlighting by default.

Warning
Elasticsearch does not validate that highlight_query contains the search query in any way so it is possible to define it so legitimate query results are not highlighted. Generally, you should include the search query as part of the highlight_query.

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pub fn no_match_size(self, no_match_size: u32) -> Self

The amount of text you want to return from the beginning of the field if there are no matching fragments to highlight. Defaults to 0 (nothing is returned).

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pub fn number_of_fragments(self, number_of_fragments: u32) -> Self

The maximum number of fragments to return. If the number of fragments is set to 0, no fragments are returned. Instead, the entire field contents are highlighted and returned. This can be handy when you need to highlight short texts such as a title or address, but fragmentation is not required. If number_of_fragments is 0, fragment_size is ignored. Defaults to 5.

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pub fn order(self, order: Order) -> Self

Sorts highlighted fragments by score when set to score. By default, fragments will be output in the order they appear in the field (order: none). Setting this option to score will output the most relevant fragments first. Each highlighter applies its own logic to compute relevancy scores. See the document How highlighters work internally for more details how different highlighters find the best fragments.

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pub fn require_field_match(self, require_field_match: bool) -> Self

By default, only fields that contains a query match are highlighted. Set require_field_match to false to highlight all fields. Defaults to true.

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