Elastic issue #493

issue-493.go

// Copyright 2012-present Oliver Eilhard. All rights reserved.
// Use of this source code is governed by a MIT-license.
// See http://olivere.mit-license.org/license.txt for details.

package main

import (
	"fmt"
	"log"
	"os"

	"golang.org/x/net/context"

	elastic "gopkg.in/olivere/elastic.v5"
)

// Tweet is a structure used for serializing/deserializing data in Elasticsearch.
type Tweet struct {
	User    string                `json:"user"`
	City    string                `json:"city,omitempty"`
	Suggest *elastic.SuggestField `json:"suggest_field,omitempty"`
}

const (
	mapping = `{
	"settings":{
		"number_of_shards":1,
		"number_of_replicas":0
	},
	"mappings":{
		"_default_": {
			"_all": {
				"enabled": true
			}
		},
		"place":{
			"properties":{
				"user":{
					"type":"keyword"
				},
				"city":{
					"type":"text"
				},
				"suggest_field":{
					"type":"completion"
				}
			}
		}
	}
}`

	IndexName = "places"
	TypeName  = "place"
)

func main() {
	// Starting with elastic.v5, you must pass a context to execute each service
	ctx := context.Background()

	// Obtain a client and connect to the default Elasticsearch installation
	// on 127.0.0.1:9200. Of course you can configure your client to connect
	// to other hosts and configure it in various other ways.
	client, err := elastic.NewClient(
		elastic.SetTraceLog(log.New(os.Stdout, "", 0)),
	)
	if err != nil {
		// Handle error
		panic(err)
	}

	// Use the IndexExists service to check if a specified index exists.
	exists, err := client.IndexExists(IndexName).Do(ctx)
	if err != nil {
		// Handle error
		panic(err)
	}
	if exists {
		_, err = client.DeleteIndex(IndexName).Do(ctx)
		if err != nil {
			// Handle error
			panic(err)
		}
	}
	// Create a new index.
	createIndex, err := client.CreateIndex(IndexName).Body(mapping).Do(ctx)
	if err != nil {
		// Handle error
		panic(err)
	}
	if !createIndex.Acknowledged {
		// Not acknowledged
	}

	// Index a tweet (using JSON serialization)
	tweets := []Tweet{
		Tweet{
			User: "olivere",
			City: "Gatlinburg",
			// Suggest:  elastic.NewSuggestField("gatlinburg"),
		},
		Tweet{
			User: "olivere",
			City: "Galenberg",
			// Suggest:  elastic.NewSuggestField("galenberg"),
		},
	}
	for i, tweet := range tweets {
		_, err = client.Index().
			Index(IndexName).
			Type(TypeName).
			Id(fmt.Sprintf("%d", i)).
			BodyJson(tweet).
			Do(ctx)
		if err != nil {
			// Handle error
			panic(err)
		}
	}

	// Flush to make sure the documents got written.
	_, err = client.Flush().Index(IndexName).Do(ctx)
	if err != nil {
		panic(err)
	}

	// Suggest
	phraseSuggester := elastic.NewPhraseSuggester("place_spelling_suggestions").
		Field("city").
		Text("Gatlinberg")
	searchSource := elastic.NewSearchSource().
		Suggester(phraseSuggester).
		FetchSource(false).
		TrackScores(true).
		Timeout("100ms")
	searchResult, err := client.Search().
		Index(IndexName).
		Type(TypeName).
		SearchSource(searchSource).
		Pretty(true).
		Do(ctx)
	if err != nil {
		// Handle error
		panic(err)
	}

	// searchResult is of type SearchResult and returns hits, suggestions,
	// and all kinds of other information from Elasticsearch.
	fmt.Printf("Query took %d milliseconds\n", searchResult.TookInMillis)

	// Delete an index.
	deleteIndex, err := client.DeleteIndex(IndexName).Do(ctx)
	if err != nil {
		// Handle error
		panic(err)
	}
	if !deleteIndex.Acknowledged {
		// Not acknowledged
	}
}

Request and response:

POST /places/place/_search?pretty=true HTTP/1.1
Host: 127.0.0.1:9200
User-Agent: elastic/5.0.32 (darwin-amd64)
Transfer-Encoding: chunked
Accept: application/json
Content-Type: application/json
Accept-Encoding: gzip

90
{"_source":false,"suggest":{"place_spelling_suggestions":{"text":"Gatlinberg","phrase":{"field":"city"}}},"timeout":"100ms","track_scores":true}
0


HTTP/1.1 200 OK
Transfer-Encoding: chunked
Content-Type: application/json; charset=UTF-8

235
{
  "took" : 16,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "failed" : 0
  },
  "hits" : {
    "total" : 0,
    "max_score" : 0.0,
    "hits" : [ ]
  },
  "suggest" : {
    "place_spelling_suggestions" : [
      {
        "text" : "Gatlinberg",
        "offset" : 0,
        "length" : 10,
        "options" : [
          {
            "text" : "gatlinburg",
            "score" : 0.70695555
          },
          {
            "text" : "galenberg",
            "score" : 0.66353446
          }
        ]
      }
    ]
  }
}