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Add Autocomplete to Your Application

how-to

March 16, 2025

+ 12

Use autocomplete to add suggestions for a user’s Search query as they type in your application.

After you create and configure a Search index that supports autocomplete, configure your application to return results from the Search Service.

Prerequisites

You’ve deployed the Search Service on a node in your database.
You have a bucket with scopes and collections in your database.
Your user account has the Search Admin role for the bucket where you want to create the index.
You’ve created a compatible Search index. For more information, see Configure an Autocomplete Search Index.

Procedure

To add autocomplete with the Serach Service to your application:

To test that your Search index was configured correctly, do one of the following:
1. Run a Search query from the REST API with 2-8 characters in the query property.
2. Run a Search query from the Web Console with 2-8 characters in the Search field.
For example, with the travel-sample bucket, you could enter the strings Be, Bea, Beau, and Beauf to find a document with the text Beaufort Hotel.

Configure your application to return results from the Search Service.

The following examples simulate a user typing an input string and return search results for each partial string:

C#
Go
Java
JavaScript
Python

csharp
ViewCopy
using Couchbase;
using Couchbase.Search.Queries.Simple;

await using var cluster = await Cluster.ConnectAsync(new ClusterOptions
{
    ConnectionString = "CB_HOSTNAME",
    UserName = "CB_USERNAME",
    Password = "CB_PASSWORD",
    Buckets = new List<string>{"travel-sample"}
}.ApplyProfile("wan-development"));

var searchString = "Beaufort Hotel";
for (var i = 2; i <= 8; i++)
{
    var lettersEntered = searchString.Substring(0, i);
    Console.WriteLine($"Input <{lettersEntered}>, len: {lettersEntered.Length}");
    await FtsMatchPrefix(lettersEntered);
}

async Task FtsMatchPrefix(string letters)
{
    try
    {
        var results = await cluster.SearchQueryAsync("e-ngram-2-8",
            new QueryStringQuery(letters),
            options =>
            {
                options.Limit(8);
                options.Fields("name");
            });
        results.Hits.ToList().ForEach(row => { Console.WriteLine($"{row.Id}, {row.Fields}"); });
        Console.WriteLine(results);
    }
    catch (Exception e)
    {
        Console.WriteLine(e);
    }
}

go
ViewCopy
package main

import (
    "os"
    "fmt"
    "math"
    "log"
    "github.com/couchbase/gocb/v2"
    "github.com/couchbase/gocb/v2/search"
)

func main() {
    cluster, err := gocb.Connect(
	os.Getenv("CB_HOSTNAME"),                    
	gocb.ClusterOptions{
        Authenticator: gocb.PasswordAuthenticator{
            Username: os.Getenv("CB_USERNAME"),      
            Password: os.Getenv("CB_PASSWORD"),      
        },
    })
    if err != nil {
        log.Fatal(err)
    }

    iterStr := "Beaufort Hotel"
    maxsz := int(math.Min(float64(len(iterStr)), float64(8)))
    for i := 2;  i <= maxsz; i++ {
        testStr := iterStr[0:i]
	fmt.Printf("Input <%s>, len: %d\n", testStr, len(testStr));
	results, err := cluster.SearchQuery(
	    "e-ngram-2-8",
	    search.NewQueryStringQuery(testStr), 
	    &gocb.SearchOptions { Fields: []string{"name"}, Limit: 8, },
	)
	if err != nil {
	    log.Fatal(err)
	}

	for results.Next() {
	    row := results.Row()
	    docID := row.ID
	    var fields interface {}
	    err := row.Fields( & fields)
	    if err != nil {
		panic(err)
	    }
	    fmt.Printf("Document ID: %s, fields: %v\n", docID, fields)
	}

	err = results.Err()
	if err != nil {
	    log.Fatal(err)
	}
    }
}

java
ViewCopy
import com.couchbase.client.java.Cluster;
import com.couchbase.client.java.json.JsonObject;
import com.couchbase.client.java.search.SearchOptions;
import com.couchbase.client.java.search.SearchQuery;
import com.couchbase.client.java.search.result.SearchResult;
import com.couchbase.client.java.search.result.SearchRow;

public class MockTypeAheadEnGram {
  static String connstrn = System.getenv("CB_HOSTNAME"); 
  static String username = System.getenv("CB_USERNAME"); 
  static String password = System.getenv("CB_PASSWORD"); 
  
  public static void main(String... args) {
    Cluster cluster = Cluster.connect(connstrn, username, password);
    
    String iterStr = "Beaufort Hotel";
    for (int i=2; i<=Math.min(8, iterStr.length());i++) {
    	String testStr = iterStr.substring(0, i);
    	System.out.println("Input <" + testStr + ">, len: " + testStr.length());
    
    	SearchQuery query = SearchQuery.queryString(testStr);
    	SearchOptions options = SearchOptions.searchOptions().limit(8).skip(0).explain(false).fields("name");
    	SearchResult result = cluster.searchQuery("e-ngram-2-8" , query, options);
    	for (SearchRow row : result.rows()) {
    		System.out.println(row.id() + "," + row.fieldsAs(JsonObject.class) );
    	}
    }
  }
}

javascript
ViewCopy
const couchbase = require('couchbase')

const main = async () => {
  const hostname = process.env.CB_HOSTNAME
  const username = process.env.CB_USERNAME
  const password = process.env.CB_PASSWORD
  const bucketName = 'travel-sample'

  const cluster = await couchbase.connect(hostname, {username: username, password: password })

  const ftsMatchPrefix = async (term) => {
    try {
      const result =  await cluster.searchQuery(
        "e-ngram-2-8",
        couchbase.SearchQuery.queryString(term), { limit: 8, fields: ["name"] }
      )
      result.rows.forEach((row) => { console.log(row.id,row.fields)})
    } catch (error) {
      console.error(error)
    }
  }

  const inputStr = "Beaufort Hotel"
  for (let i = 2; i <= 8; i++) {
    var testStr = inputStr.substring(0, i);
    console.log("Input <" + testStr + ">, len: " + testStr.length)
    const res = await ftsMatchPrefix(testStr)
  }
}

main()

python
ViewCopy
from couchbase.cluster import Cluster, ClusterOptions
from couchbase.auth import PasswordAuthenticator
from couchbase.exceptions import CouchbaseException
import couchbase.search as search
import os

username = os.getenv("CB_USERNAME", default=None)
password = os.getenv("CB_PASSWORD", default=None)
hostname = os.getenv("CB_HOSTNAME", default=None)

cluster = Cluster.connect(
    "couchbase://" + hostname,
    ClusterOptions(PasswordAuthenticator(username,password)))

try:
    inputStr = "Beaufort Hotel"
    for i in range(2, min(8,len(inputStr))):
        testStr = inputStr[0:i]
        print("Input <" + testStr + ">, len: " + str(len(testStr)));

        result = cluster.search_query(
            "e-ngram-2-8", 
            search.QueryStringQuery(testStr),
            search.SearchOptions(limit=8, fields=["name"]))

        for row in result.rows():
            print(row.id,row.fields)

except CouchbaseException as ex:
    import traceback
    traceback.print_exc()

Next Steps

After you add autocomplete to your application, to improve your search results, you can:

Customize your Search index with the Web Console.
Change the JSON payload for your Search index.