Conventions

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This section details the conventions upon which the typed client is built.

Structure

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The Typed client lives in the typedapi package within the go-elasticsearch repository.

The entire client is summed in an index at the root of the package for convenient access after instantiation.

Each endpoint resides in its own package within typedapi and contains the client for this endpoint, and the Request struct if applicable.

The requests are based on a collection of structures generated from the elasticsearch-specification repository and gathered in a types package within typedapi.

Naming

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Whenever appropriate, names may be suffixed with an underscore:

  • To avoid collision with protected keywords (range, if, type, and so on).
  • To reflect the presence of a leading underscore in the API like \_index vs Index_ or \_source vs Source_.

Endpoints

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All the available endpoints are generated in separate packages and assembled in the client. The core namespace is duplicated at the root of the client for convenient access.

Each endpoint follows a factory pattern which returns a pointer to a new instance each time.

res, err := es.Search().Index("index_name").AllowPartialSearchResults(true).Do(context.Background())

If parameters are needed for the specific endpoint you are using, those will be present as arguments in the same order as the API:

es.Create("index_name", "doc_id").Do(context.Background())

Otherwise, you can find them within the builder:

es.Search().Index("index_name").Do(context.Background())

Alternatively each endpoint can be instantiated directly from its package:

transport, err := elastictransport.New(elastictransport.Config{})
res, err = search.New(transport).Do(context.Background())

The Do method takes an optional context, runs the request through the transport and returns the results as well as an error.

For body-empty endpoints such as core.Exists, an additional method IsSuccess is available. As the Do method, it takes an optional context, drains and closes the body if needed, and returns a boolean alongside an error

if exists, err := es.Core.Exists("index_name", "doc_id").IsSuccess(context.Background()); exists {
    // The document exists!
} else if err != nil {
    // An error occurred.
}

Requests

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Requests are modeled around structures that follows as closely as possible the Elasticsearch API and uses the standard json/encoding for serialization. Corresponding request can be found withing the same package as its endpoint and comes with a Builder that allows you to deep dive into the API by following the types.

types.Query{
    Term: map[string]types.TermQuery{
        "name": {Value: "Foo"},
    },
}

Responses

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While not part of the initial release responses will be added at a later date.

Types

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Requests and responses are relying on a collection of structures generated from the elasticsearch-specification in the types package. Each type comes with json tags.

Enums

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The Elasticsearch API has several instances of enumerations, each has a package within types/enums. An enum is declared as a type and each member of the enum is an exported variable with its value. The enum types serializes to the relevant API value, for example the refresh options which can be found in the Search API:

refresh.True => "true"
refresh.False => "false"
refresh.Waitfor => "wait_for"

Unions

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To capture the expressiveness of the API union fields are represented by a type alias to an interface.