Module elastic::types::document
[−]
[src]
Base requirements for indexable document mappings.
Structures that can be indexed in Elasticsearch should implement DocumentType
.
The DocumentType
is composed of typical mapping metadata, as well as the mapping
for each of its properties.
Documents can be mapped as indexable types, or as an object field on another type.
Examples
Define your Elasticsearch types using Plain Old Rust Structures.
Derive Mapping
Mapping can be generated by deriving ElasticType
on a struct:
#[derive(Serialize, ElasticType)] pub struct MyType { pub my_date: Date<DefaultDateFormat>, pub my_string: String, pub my_num: i32 }
This will produce the following field mapping:
{ "type": "nested", "properties": { "my_date": { "type": "date", "format": "basic_date_time" }, "my_string": { "type": "text", "fields": { "keyword":{ "type":"keyword", "ignore_above":256 } } }, "my_num": { "type": "integer" } } }
It's also possible to adjust the mapping using the #[elastic]
attribute.
Override Default Mapping Properties
You can override the mapping meta properties for an object by providing your own mapping type with #[elastic(mapping="{TypeName}")]
:
#[derive(Serialize, ElasticType)] #[elastic(mapping="MyTypeMapping")] pub struct MyType { pub my_date: Date<DefaultDateFormat>, pub my_string: String, pub my_num: i32 } #[derive(Default)] pub struct MyTypeMapping; impl DocumentMapping for MyTypeMapping { //Give your own name to a type fn name() -> &'static str { "my_type" } fn data_type() -> &'static str { OBJECT_DATATYPE } }
This will produce the following field mapping:
{ "type": "object", "properties": { "my_date": { "type": "date", "format": "basic_date_time" }, "my_string": { "type": "text", "fields": { "keyword":{ "type":"keyword", "ignore_above":256 } } }, "my_num": { "type": "integer" } } }
Ignore or Rename Fields
You can then serialise type mappings with #[serde]
attributes:
#[derive(ElasticType, Serialize)] pub struct MyType { #[serde(rename="my_renamed_date")] pub my_date: Date<DefaultDateFormat>, #[serde(skip_serializing)] pub ignored: String, pub my_num: i32 }
NOTE: Fields with a
#[serde(skip_deserializing)]
attribute will still be mapped, because they can still be indexed in Elasticsearch.
Limitations
Automatically deriving mapping has the following limitations:
- Generics aren't supported by auto deriving.
So you can't
#[derive(ElasticType)]
onMyType<T>
. - Mapping types can't be shared. This is because they need to map the type fields, so are specific to that type.
So you can't share
MyTypeMapping
betweenMyType
andMyOtherType
.
All of the above limitations can be worked around by implementing the mapping manually.
Remember that Elasticsearch will automatically update mappings based on the objects it sees though, so if your 'un-mapped' field is serialised, then an inferred mapping will be added for it.
Manually Implement Mapping
You can build object mappings by manually implementing the DocumentMapping
and PropertiesMapping
traits:
#[derive(Serialize)] pub struct MyType { pub my_date: Date<DefaultDateFormat>, pub my_string: String, pub my_num: i32 } //Implement DocumentType for your type. This binds it to the mapping impl DocumentType for MyType { type Mapping = MyTypeMapping; } //Define the type mapping for our type #[derive(Default)] pub struct MyTypeMapping; impl DocumentMapping for MyTypeMapping { fn name() -> &'static str { "my_type" } } impl PropertiesMapping for MyTypeMapping { fn props_len() -> usize { 3 } fn serialize_props<S>(state: &mut S) -> Result<(), S::Error> where S: serde::ser::SerializeStruct { try!(field_ser(state, "my_date", Date::<DefaultDateFormat>::mapping())); try!(field_ser(state, "my_string", String::mapping())); try!(field_ser(state, "my_num", i32::mapping())); Ok(()) } }
Links
Modules
mapping |
Mapping for Elasticsearch document types. |
prelude |
Includes all types for document types. |
Structs
IndexDocumentMapping |
A wrapper type for serialising user types. |
ValueDocumentMapping |
Mapping for an anonymous json object. |
Traits
DocumentType |
The additional fields available to an indexable Elasticsearch type. |
FieldType |
The base representation of an Elasticsearch data type. |
Functions
doc_ser |
Serialise a document mapping as a field using the given serialiser. |
field_ser |
Serialise a field mapping as a field using the given serialiser. |