Highlight Index Search Results

Configure a Map index for highlighting:

In order to search and get fragments with highlighted terms,
the index-field on which you search must be configured with:

• Store the index-field in the index

• Configure the index-field for Full-Text search

• Store the index-field term vector with position and offsets

// Define a Map index:
// ===================
class Employees_ByNotes extends AbstractJavaScriptIndexCreationTask {
    constructor () {
        super();

        this.map("employees", employee => {
            return {
                EmployeeNotes: employee.Notes[0]
            };
        });

        // Configure index-field 'EmployeeNotes' for highlighting:
        // =======================================================
        this.store("EmployeeNotes", "Yes");
        this.index("EmployeeNotes", "Search");
        this.termVector("EmployeeNotes", "WithPositionsAndOffsets");
    }
}

Query the index with search:

// Define a param that will get the highlighted text fragments
let managerHighlights;

const employeesResults = await session
     // Query the map index
    .query({ indexName: "Employees/ByNotes" })
     // Search for documents containing the term 'manager'
    .search("EmployeeNotes", "manager")
     // Request to highlight the searched term by calling 'highlight'
    .highlight({
        fieldName: "EmployeeNotes",
        fragmentLength: 35,
        fragmentCount: 2
    }, x => { managerHighlights = x; })
    .all();

from index "Employees/ByNotes"
where search(EmployeeNotes, "manager")
include highlight(EmployeeNotes, 35, 2)

Query the index with whereEquals:

// Define a param that will get the highlighted text fragments
let managerHighlights;

const employeesResults = await session
    // Query the map index
    .query({ indexName: "Employees/ByNotes" })
    // Search for documents containing the term 'manager'
    .whereEquals("EmployeeNotes", "manager")
    // Request to highlight the searched term by calling 'highlight'
    .highlight({
        fieldName: "EmployeeNotes",
        fragmentLength: 35,
        fragmentCount: 2
    }, x => { managerHighlights = x; })
    .all();

from index "Employees/ByNotes"
where EmployeeNotes == "manager"
include highlight(EmployeeNotes, 35, 2)

Process results:

// 'employeesResults' contains all Employee DOCUMENTS that contain the term 'manager'.
// 'managerHighlights' contains the text FRAGMENTS that highlight the 'manager' term.

let fragmentsHtml = "<ul>";

employeesResults.forEach((employee) => {
    // Call 'getFragments' to get all fragments for the specified employee id
    let fragments = managerHighlights.getFragments(employee.id);
    
    fragments.forEach((fragment) => {
        fragmentsHtml += `<li>Doc: ${employee.id}</li>`
        fragmentsHtml += `<li>Fragment: ${fragment}</li>`;
        fragmentsHtml += `<li></li>`;
    });
});

fragmentsHtml += "</ul>";

// The resulting fragmentsHtml:
// ============================

// <ul>
//   <li>Doc: employees/2-A</li>
//   <li>Fragment:  to sales <b style="background:yellow">manager</b> in January</li>
//   <li></li>
//   <li>Doc: employees/5-A</li>
//   <li>Fragment:  to sales <b style="background:yellow">manager</b> in March</li>
//   <li></li>
// </ul>

Configure a Map-Reduce index for highlighting:

In order to search and get fragments with highlighted terms in a Map-Reduce index:

• The index-field on which you search must be configured with:

  • Store the index-field in the index

  • Configure the index-field for Full-Text search

  • Store the index-field term vector with position and offsets

• The index-field by which you group-by must be stored in the index.

// Define a Map-Reduce index:
// ==========================
class ContactDetailsPerCountry extends AbstractJavaScriptIndexCreationTask {
    constructor () {
        super();

        // The 'map' function defines what will be indexed from each document in the collection
        this.map("companies", company => {
            return {
                Country: company.Address.Country,
                ContactDetails: company.Contact.Name + " " + company.Contact.Title
            };
        });

        // The 'reduce' function specifies how data is grouped and aggregated
        this.reduce(results => results.groupBy(x => x.Country).aggregate(g => {
            return {
                // Set 'Country' as the group-by key
                // 'ContactDetails' will be grouped per 'Country'
                Country: g.key,

                // Specify the aggregation
                // here we use 'join' as the aggregation function
                ContactDetails: g.values.map(x => x.ContactDetails).join(' ')
            }
        }));

        // Configure index-field 'Country' for highlighting:
        // =================================================
        this.store("Country", "Yes");

        // Configure index-field 'ContactDetails' for highlighting:
        // =======================================================
        this.store("ContactDetails", "Yes");
        this.index("ContactDetails", "Search");
        this.termVector("ContactDetails", "WithPositionsAndOffsets");
    }
}

Query the index:

// Define the key by which the resulting fragments are grouped:
// ============================================================
const options = {
    // Set 'groupKey' to be the index's group-by key
    // The resulting fragments will be grouped per 'Country'
    groupKey: "Country"
};

let agentHighlights;

// Query the map-reduce index:
// ===========================
const detailsPerCountry  = await session
    .query({ indexName: "ContactDetailsPerCountry" })
     // Search for results containing the term 'agent'
    .search("ContactDetails", "agent")
     // Request to highlight the searched term by calling 'highlight'
     // Pass the defined 'options'
    .highlight({
        fieldName: "ContactDetails",
        fragmentLength: 35,
        fragmentCount: 2,
        ...options
    }, x => { agentHighlights = x; })
    .all();

from index "ContactDetailsPerCountry"
where search(ContactDetails, "agent")
include highlight(ContactDetails, 35, 2, $p0)
{"p0":{"groupKey":"Country"}}

Process results:

// 'detailsPerCountry' contains the contacts details grouped per country.
// 'agentHighlights' contains the text FRAGMENTS that highlight the 'agent' term.

let fragmentsHtml = "<ul>";

employeesResults.forEach((item) => {
    // Call 'getFragments' to get all fragments for the specified country key
    let fragments = agentHighlights.getFragments(item.Country);
    
    fragments.forEach((fragment) => {
        fragmentsHtml += `<li>Doc: ${item.Country}</li>`
        fragmentsHtml += `<li>Fragment: ${fragment}</li>`;
        fragmentsHtml += `<li></li>`;
    });
});

fragmentsHtml += "</ul>";

// The resulting fragmentsHtml:
// ============================

// <ul>
//   <li>Country: UK</li>
//   <li>Fragment: Devon Sales <b style="background:yellow">Agent</b> Helen Bennett</li>
//   <li></li>
//   <li>Country: France</li>
//   <li>Fragment: Sales <b style="background:yellow">Agent</b> Carine Schmit</li>
//   <li></li>
//   <li>Country: France</li>
//   <li>Fragment: Saveley Sales <b style="background:yellow">Agent</b> Paul Henriot</li>
//   <li></li>
//   <li>Country: Argentina</li>
//   <li>Fragment: Simpson Sales <b style="background:yellow">Agent</b> Yvonne Moncad</li>
//   <li></li>
//   <li>Country: Argentina</li>
//   <li>Fragment: Moncada Sales <b style="background:yellow">Agent</b> Sergio</li>
//   <li></li>
//   <li>Country: Brazil</li>
//   <li>Fragment: Sales <b style="background:yellow">Agent</b> Anabela</li>
//   <li></li>
//   <li>Country: Belgium</li>
//   <li>Fragment: Dewey Sales <b style="background:yellow">Agent</b> Pascale</li>
//   <li></li>
// </ul>