How does it work?

The SearchComponent class is a search component that can be used to bind with different kinds of search UI widgets. For example:

• a category filter component,
• a search bar component,
• a price range component,
• a location filter component,
• a component to render the search results.

Constructor

The constructor of the SearchComponent class is called with the following properties:

const searchComponent = new SearchComponent(properties);

Properties

Configure appbase.io environment

index

Refers to an index of the Elasticsearch cluster.

Note: Multiple indexes can be connected to by specifying comma-separated index names.

url

URL for the Elasticsearch cluster

credentials

Basic Auth credentials if required for authentication purposes. It should be a string of the format username:password. If you are using an appbase.io cluster, you will find credentials under the Security > API credentials section of the appbase.io dashboard.

appbaseConfig

allows you to customize the analytics experience when appbase.io is used as a backend. It accepts an object which has the following properties:

• recordAnalytics Boolean allows recording search analytics (and click analytics) when set to true and appbase.io is used as a backend. Defaults to false.
• enableQueryRules Boolean If false, then appbase.io will not apply the query rules on the search requests. Defaults to true.
• enableSearchRelevancy Boolean defaults to true. It allows you to configure whether to apply the search relevancy or not.
• userId string It allows you to define the user id to be used to record the appbase.io analytics. Defaults to the client's IP address.
• useCache Boolean This property when set allows you to cache the current search query. The useCache property takes precedence irrespective of whether caching is enabled or disabled via the dashboard.
• customEvents Object It allows you to set the custom events which can be used to build your own analytics on top of appbase.io analytics. Further, these events can be used to filter the analytics stats from the appbase.io dashboard.
• enableTelemetry Boolean When set to false, disable the telemetry. Defaults to true.

To configure the ReactiveSearch API

The following properties can be used to configure the appbase.io ReactiveSearch API:

id

unique identifier of the component, can be referenced in other components' react prop.

type

This property represents the type of the query which is defaults to search, valid values are search, term, range & geo. You can read more here.

dataField

index field(s) to be connected to the component’s UI view. SearchComponent accepts an Array in addition to string, which is useful for searching across multiple fields with or without field weights.
Field weights allow weighted search for the index fields. A higher number implies a higher relevance weight for the corresponding field in the search results.
You can define the dataField property as an array of objects of the DataField type to set the field weights.
The DataField type has the following shape:

type DataField = {
    field: string;
    weight: number;
};

enablePredictiveSuggestions

Defaults to false. When set to true, it predicts the next relevant words from a field's value based on the search query typed by the user. When set to false (default), the entire field's value would be displayed. This may not be desirable for long-form fields (where average words per field value is greater than 4 and may not fit in a single line).

// pass this prop as true in searchComponent to enable predictive suggestions
enablePredictiveSuggestions: true,

value

Represents the value for a particular query type. Depending on the query type, the value format would differ. You can refer to the different value formats over here.

queryFormat

Sets the query format, can be or or and. Defaults to or.

• or returns all the results matching any of the search query text's parameters. For example, searching for "bat man" with or will return all the results matching either "bat" or "man".
• On the other hand with and, only results matching both "bat" and "man" will be returned. It returns the results matching all of the search query text's parameters.

react

react prop is useful for components whose data view should reactively update when on or more dependent components change their states, e.g. a component to display the results can depend on the search component to filter the results.

• key string one of and, or, not defines the combining clause.
  • and clause implies that the results will be filtered by matches from all of the associated component states.
  • or clause implies that the results will be filtered by matches from at least one of the associated component states.
  • not clause implies that the results will be filtered by an inverse match of the associated component states.
• value string or Array or Object
  • string is used for specifying a single component by its id.
  • Array is used for specifying multiple components by their id.
  • Object is used for nesting other key clauses.

An example of a react clause where all three clauses are used and values are Object, Array and string.

const resultComponent = new SearchComponent({
	react: {
		and: {
			or: ['CityComp', 'TopicComp'],
			not: 'BlacklistComp',
		},
	},
});

Here, we are specifying that the result component should update whenever one of the blacklist items is not present and simultaneously any one of the city or topics matches.

size

Number of suggestions and results to fetch per request.

from

To define from which page to start the results, it is important to implement pagination.

includeFields

fields to be included in search results.

excludeFields

fields to be excluded in search results.

sortBy

sort the results by either asc or desc order. The count option can also be used to filter the aggregations based on count if the query type is as term.

aggregationField

One of the most important use-cases this enables is showing DISTINCT results (useful when you are dealing with sessions, events, and logs type data). It utilizes composite aggregations which are newly introduced in ES v6 and offer vast performance benefits over a traditional terms aggregation. You can read more about it over here. You can use aggregationData using onAggregationData callback or subscriber.

const component = new SearchComponent({
    index: 'good-book-ds-latest',
    url: 'https://scalr.api.appbase.io',
    credentials: 'IPM14ICqp:8e573e86-8802-4a27-a7a1-4c7d0c62c186',
    dataField: 'original_title',
    aggregationField: 'original_title.keyword',
});
// using callback
component.onAggregationData(next, prev) {}
// using subscriber
component.subscribeToStateChanges(
    ({ changes }) => {
        console.log("Aggregations =>", changes.aggregationData.next);
    },
    'aggregationData'
);

• aggregationSize

To set the number of buckets to be returned by aggregations.

Note: This is a new feature and only available for appbase versions >= 7.41.0.

highlight

whether highlighting should be enabled in the returned results.

highlightField

when highlighting is enabled, this prop allows specifying the fields which should be returned with the matching highlights. When not specified, it defaults to applying highlights on the field(s) specified in the dataField prop.

customHighlight

It can be used to set the custom highlight settings. You can read the Elasticsearch docs for the highlight options at here.

categoryField

Data field which has the category values mapped.

categoryValue

This is the selected category value. It is used for informing the search result.

nestedField

set the nested field path that allows an array of objects to be indexed in a way that can be queried independently of each other. Applicable only when dataField's mapping is of nested type.

fuzziness

Set a maximum edit distance on the search parameters, which can be 0, 1, 2, or "AUTO". This is useful for showing the correct results for an incorrect search parameter by taking the fuzziness into account. For example, with a substitution of one character, the fox can become a box. Read more about it in the elastic search docs

enableSynonyms

This property can be used to control (enable/disable) the synonyms behavior for a particular query. Defaults to true, if set to false then fields having .synonyms suffix will not affect the query.

searchOperators

Defaults to false. If set to true, then you can use special characters in the search query to enable the advanced search.
Read more about it here.

queryString

Defaults to false. If set to true than it allows you to create a complex search that includes wildcard characters, searches across multiple fields, and more. Read more about it here.

pagination

This property allows you to implement the pagination for term type of queries. If pagination is set to true then appbase will use the composite aggregations of Elasticsearch instead of terms aggregations.

after

This property can be used to implement the pagination for aggregations. We use the composite aggregations of Elasticsearch to execute the aggregations' query, the response of composite aggregations includes a key named after_key which can be used to fetch the next set of aggregations for the same query. You can read more about the pagination for composite aggregations at here.

You need to define the after property in the next request to retrieve the next set of aggregations.

showMissing

Defaults to false. When set to true then it also retrieves the aggregations for missing fields.

missingLabel

Defaults to N/A. It allows you to specify a custom label to show when showMissing is set to true.

includeNullValues

If you have sparse data or documents or items not having the value in the specified field or mapping, then this prop enables you to show that data.

interval

To set the histogram bar interval, applicable when aggregations value is set to ["histogram"]. Defaults to Math.ceil((range.end - range.start) / 100) || 1.

aggregations

It helps you to utilize the built-in aggregations for range type of queries directly, valid values are:

• max: to retrieve the maximum value for a dataField,
• min: to retrieve the minimum value for a dataField,
• histogram: to retrieve the histogram aggregations for a particular interval

selectAllLabel

This property allows you to add a new property in the list with a particular value in such a way that when selected i.e value is similar/contains to that label(selectAllLabel) then term query will make sure that the field exists in the results.

To configure the AutoSuggestions

enablePopularSuggestions

Defaults to false. When enabled, it can be useful to curate search suggestions based on actual search queries that your users are making. Read more about it over here.

showDistinctSuggestions

Show 1 suggestion per document. If set to false multiple suggestions may show up for the same document as the searched value might appear in multiple fields of the same document, this is true only if you have configured multiple fields in dataField prop. Defaults to true.

Example if you have showDistinctSuggestions is set to false and have the following configurations

// Your document:
{
    "name": "Warn",
    "address": "Washington"
}
// SearchComponent:
dataField=['name', 'address']
// Search Query:
"wa"

Then there will be 2 suggestions from the same document as we have the search term present in both the fields specified in dataField.

Warn
Washington

To configure the query execution

headers

set custom headers to be sent with each server request as key/value pairs. For example:

const component = new SearchComponent({
	index: 'gitxplore-app',
	url: 'https://@arc-cluster-appbase-demo-6pjy6z.searchbase.io',
	credentials: 'a03a1cb71321:75b6603d-9456-4a5a-af6b-a487b309eb61',
	headers: {
		secret: 'searchbase-is-awesome',
	},
});

transformRequest

Enables transformation of network request before execution. This function will give you the request object as the param and expect an updated request in return, for execution.
For example, we will add the credentials property in the request using transformRequest.

const component = new SearchComponent({
    index: 'gitxplore-app',
    url: 'https://@arc-cluster-appbase-demo-6pjy6z.searchbase.io',
    credentials: 'a03a1cb71321:75b6603d-9456-4a5a-af6b-a487b309eb61',
    transformRequest: request =>
        Promise.resolve({
            ...request,
            credentials: include,
        }),
});

transformResponse

Enables transformation of search network response before rendering them. It is an asynchronous function which will accept an Elasticsearch response object as param and is expected to return an updated response as the return value.
For example:

const component = new SearchComponent({
	index: 'gitxplore-app',
	url: 'https://@arc-cluster-appbase-demo-6pjy6z.searchbase.io',
	credentials: 'a03a1cb71321:75b6603d-9456-4a5a-af6b-a487b309eb61',
	transformResponse: async elasticsearchResponse => {
		const ids = elasticsearchResponse.hits.hits.map(item => item._id);
		const extraInformation = await getExtraInformation(ids);
		const hits = elasticsearchResponse.hits.hits.map(item => {
			const extraInformationItem = extraInformation.find(
				otherItem => otherItem._id === item._id,
			);
			return {
				...item,
				...extraInformationItem,
			};
		});

		return {
			...elasticsearchResponse,
			hits: {
				...elasticsearchResponse.hits,
				hits,
			},
		};
	},
});

Note

transformResponse function is expected to return data in the following structure.

    {
        // Elasticsearch hits response
        hits: {
            hits: [...],
            total: 100
        },
        // Elasticsearch aggregations response
        aggregations: {

        }
        took: 1
    }

defaultQuery

is a callback function that takes the SearchComponent instance as parameter and returns the data query to be applied to the source component, as defined in Elasticsearch Query DSL, which doesn't get leaked to other components. In simple words, defaultQuery is used with data-driven components to impact their own data. It is meant to modify the default query which is used by a component to render the UI.

Some of the valid use-cases are:

• To modify the query to render the suggestions or results in search type of components.
• To modify the aggregations in term type of components.

For example, in a term type of component showing a list of cities, you may only want to render cities belonging to India.

const component = new SearchComponent({
    index: 'gitxplore-app',
    url: 'https://@arc-cluster-appbase-demo-6pjy6z.searchbase.io',
    credentials: 'a03a1cb71321:75b6603d-9456-4a5a-af6b-a487b309eb61',
    defaultQuery: () => ({
        query: {
            terms: {
                country: ['India'],
            },
        },
    }),
});

customQuery

takes SearchComponent instance as parameter and returns the query to be applied to the dependent components by react prop, as defined in Elasticsearch Query DSL.

For example, the following example has two components search-component(to render the suggestions) and result-component(to render the results). The result-component depends on the search-component to update the results based on the selected suggestion. The search-component has the customQuery prop defined that will not affect the query for suggestions(that is how customQuery is different from defaultQuery) but it'll affect the query for result-component because of the react dependency on search-component.

const searchBase = new SearchBase({
    index: 'gitxplore-app',
    url: 'https://@arc-cluster-appbase-demo-6pjy6z.searchbase.io',
    credentials: 'a03a1cb71321:75b6603d-9456-4a5a-af6b-a487b309eb61',
});

searchBase.register('search-component', {
    customQuery: () => ({
        timeout: '1s',
        query: {
            match_phrase_prefix: {
                fieldName: {
                    query: 'hello world',
                    max_expansions: 10,
                },
            },
        },
    }),
});

searchBase.register('result-component', {
    react: {
        and: ['search-component'],
    },
});

Miscellaneous

beforeValueChange

is a callback function which accepts the component's future value as a parameter and returns a promise. It is called every time before a component's value changes. The promise, if and when resolved, triggers the execution of the component's query and if rejected, kills the query execution. This method can act as a gatekeeper for query execution since it only executes the query after the provided promise has been resolved.
For example:

const component = new SearchComponent({
    index: 'gitxplore-app',
    url: 'https://@arc-cluster-appbase-demo-6pjy6z.searchbase.io',
    credentials: 'a03a1cb71321:75b6603d-9456-4a5a-af6b-a487b309eb61',
    beforeValueChange: value =>
        function(value) {
            // called before the value is set
            // returns a promise
            return new Promise((resolve, reject) => {
                // update state or component props
                resolve();
                // or reject()
            });
        },
});

An example with all properties

const component = new SearchComponent({
    index: 'gitxplore-app',
    url: 'https://@arc-cluster-appbase-demo-6pjy6z.searchbase.io',
    credentials: 'a03a1cb71321:75b6603d-9456-4a5a-af6b-a487b309eb61',
    appbaseConfig: {
        recordAnalytics: true,
        enableQueryRules: true,
        userId: 'jon@appbase.io',
        customEvents: {
            platform: "ios",
            device: "iphoneX"
        }
    },
    headers: {
        secret: "searchbase-is-awesome",
    },
    id: 'search-component',
    type: 'search',
    highlight: true,
    highlightFields: ["original_title", "original_title.raw"],
    value: "",
    fuzziness: "AUTO",
    searchOperators: true,
    queryFormat: "or",
    size: 10,
    from: 0,
    dataField: "original_title",
    includeFields: ["*"],
    excludeFields: [],
    sortBy: "asc",
    nestedField: "",
    transformRequest: (request) => Promise.resolve({
        ...request,
        credentials: "true"
    }),
    transformResponse: response => Promise.resolve({
        ...response,
        hits: {
            ...response.hits,
            hits: [
                {
                    _id: "promoted",
                    _source: {
                        original_title: "Harry potter and the cursed child"
                    }
                },
                ...response.hits
            ]
        }
    }),
    beforeValueChange:  value => new Promise((resolve, reject) => {
        if(/[^a-zA-Z0-9]/.test(value)) {
            resolve(value)
        } else {
            reject('Special characters not allowed.')
        }
    }),
})

Getter properties

These properties are automatically calculated or managed by the SearchBase class. The library user is not expected to modify these properties.

results

It is an object which contains the following details of results query response.

• data: Array<Object> contains the (promoted data + parsed hits)
• raw: Object Response returned by ES query in the raw form.
• numberOfResults: number Total number of results found
• time: number Total time taken by request (in ms)
• hidden: number Total number of hidden results found
• promoted: number Total number of promoted results found
• promotedData: Array<Object> An array of promoted results obtained from the applied query.
• customData: Object An object of custom data obtained from the reactivesearch-v3 API.
• rawData: Object An object of raw response as-is from elasticsearch query.

aggregationData

It is an object which contains the following details of aggregations query response.

• data: Array<Object> contains the parsed aggregations
• raw: Object Response returned by ES composite aggs query in the raw form.
• rawData: Object An object of raw response as-is from elasticsearch query.
• afterKey: Object If the number of composite buckets is too high (or unknown) to be returned in a single response use the afterKey parameter to retrieve the next results. This property will only be present for composite aggregations.

suggestions

This method can be used to get the parsed suggestions from the results. If enablePopularSuggestions property is set to true then the popular suggestions will get appended at the top with a top-level property named _popular_suggestion as true. The suggestion object will have the following shape:

{
    label: string;
    value: string;
    source: Object;
}

query

The last query that has been executed

requestPending

Useful for getting the status of the API, whether it has been executed or not

requestStatus

Represents the current state of the request, can have values as INACTIVE, PENDING or ERROR.

micStatus

Returns the current status of the mic. Can be INACTIVE, ACTIVE or DENIED

micActive

Returns true if mic is active

micInactive

Returns true if mic is inactive

micDenied

Returns true if it doesn't have access to the mic

• micInstance

Returns the current mic instance. Can be used to set mic language and other properties of mic

Setters

Note: All of the methods accept options as the second parameter which has the following shape:

{
    triggerDefaultQuery?: boolean, // defaults to `true`
    triggerCustomQuery?: boolean, // defaults to `false`
    stateChanges?: boolean // defaults to `true`
};

• triggerDefaultQuery true executes the query for a particular component
• triggerCustomQuery true executes the query for the dependent components (dependencies defined in the react property)
• stateChanges true invokes the subscribed functions to subscribeToStateChanges method, i.e trigger the re-render after making changes

The following methods of SearchComponent class can be used to set or update the search properties:

setHeaders

can be used to set the headers property

setSize

can be used to set the size property

setFrom

can be used to set the from property, which is useful while implementing pagination

setAfter

can be used to set the after property, which is useful while implementing pagination when the type of the component is term. The after key is a a property of aggregationData.

setFuzziness

can be used to set the fuzziness property

setIncludeFields

can be used to set the includeFields property

setExcludeFields

can be used to set the excludeFields property

setSortBy

can be used to set the sortBy property

setSortByField

can be used to set the sortByField property

setNestedField

can be used to set the nestedField property

setDataField

can be used to set the dataField property

setResults

can be used to set the custom results

setValue

can be used to set the value property

setCategoryValue

can be used to set the categoryValue property.

setReact

can be used to set the react property

setDefaultQuery

can be used to set the default query

setCustomQuery

can be used to set the custom query

Callback of change events

You can define the callback of the following event to listen for the search state changes. The callback function accepts the updated value as the first param and the previous value as the second param. These callback functions may be used in the following scenarios:

1. Perform side-effects e.g. make a network request,
2. Update the UI. However, it is recommended to use the subscribeToStateChanges to update the UI which uses SearchComponent properties.

onValueChange

can be used to listen for the `value` property changes. <br/>

const component = new SearchComponent({
	index: 'gitxplore-app',
	url: 'https://@arc-cluster-appbase-demo-6pjy6z.searchbase.io',
	credentials: 'a03a1cb71321:75b6603d-9456-4a5a-af6b-a487b309eb61',
});
component.onValueChange = (nextValue, prevValue) => {
	// do something with the updated or previous values
};

onResults

can be used to listen for the results property changes

onAggregationData

can be used to listen for the aggregationData property changes

const component = new SearchComponent({
    index: 'gitxplore-app',
    url: 'https://@arc-cluster-appbase-demo-6pjy6z.searchbase.io',
    credentials: 'a03a1cb71321:75b6603d-9456-4a5a-af6b-a487b309eb61',
    type: 'term',
    dataField: 'category.keyword',
});
// using callback
component.onAggregationData(next, prev) {}

onError

called when there is an error while fetching results

onRequestStatusChange

called when request status changes

onQueryChange

called when query changes

onMicStatusChange

called when mic status changes

Execute queries

The following methods can be used to trigger the queries for components.

triggerDefaultQuery

This method can be used to execute the default query for a particular component. For examples,

• to display the suggestions or results for a search type of component,
• to display the filter options(aggregations) for a term type of component

triggerCustomQuery

This method can be used to execute queries for the dependent components.

Subscribe to the properties changes

Although we have callbacks for change events that can be used to update the UI based on particular property changes, the subscribeToStateChanges method gives you more control over the UI rendering logic and is more efficient.

How does it work?

1. This method is controlled by the stateChanges property which can be defined in the setters while updating a particular property. If stateChanges is set to true, then only the subscribed functions will be called, unlike events callback which gets called every time when a property changes its value.
   So basically, subscribeToStateChanges provides more control over the event's callback in a way that you can define whether to update the UI or not while setting a particular property's value.
   
2. You can define the properties for which you want to update the UI.
3. It allows you to register multiple callback functions for search state updates.

Usage

subscribeToStateChanges(
    fn: Function,
    propertiesToSubscribe?: string | Array<string>
): void

You can use the subscribeToStateChanges method of SearchComponent class to subscribe to the state changes of the properties.
A common use-case is to subscribe to a component or DOM element to a particular property or a set of properties & update the UI according to the changes.
The callback function accepts an object in the following shape:

{
    [propertyName]: { // property name for example, `results`
        prev: any; // previous value of the property
        next: any; // next value of the property
    }
}

These are the properties that can be subscribed for the changes:

• results
• aggregationData
• requestStatus
• error
• value
• categoryValue
• query
• micStatus
• dataField
• size
• from
• fuzziness
• includeFields
• excludeFields
• sortBy
• react
• defaultQuery
• customQuery

Let's check this example to bind a React component with the results property change.

import React from 'react';

class Results extends React.Component {
    constructor(props) {
        super(props);
        this.state = {
            results: []
        }
        this.component = new SearchComponent(config);
        this.component.subscribeToStateChanges(this.stateChangeHandler, 'results');
    }
    stateChangeHandler = ({ results }) => {
        console.log('prev value', results.prev);
        console.log('next value', results.next);
        // Update the component state based on the value changes
        this.setState({
            results: results.next
        });
    }
    render() {
        return (
            <div id="results">
                {this.state.results.map(result => <Results {..results} />)}
            </div>
        )
    }
}

Unsubscribe to the properties changes

It is recommended to unsubscribe the callback functions after the component has been unmounted.

For example in React, we can use the componentWillUnmount life cycle method to unsubscribe to the changes.

componentWillUnmount() {
    this.component.unsubscribeToStateChanges(this.stateChangeHandler);
}

Record Analytics

The SearchComponent class provides the methods to record clicks and conversions for search results.

recordClick

Enables recording click analytics of a search request. Pass isSuggestionClick=true, if you want to record a suggestion click.

const component = new SearchComponent({
    index: 'good-book-ds',
    url: 'https://arc-cluster-appbase-demo-ps1pgt.component.io',
    credentials: 'a03a1cb71321:75b6603d-9456-4a5a-af6b-a487b309eb61',
    appbaseConfig: {
        recordAnalytics: true,
        enableQueryRules: true,
    },
    dataField: 'original_title',
});
// using recordClick
component.recordClick({ 'cf827a07-60a6-43ef-ab93-e1f8e1e3e1a8': 2 }, true);

Here cf827a07-60a6-43ef-ab93-e1f8e1e3e1a8 is the ES docId and 2 is the click position.

recordConversions

Enables recording a search conversion.

const component = new SearchComponent({
    index: 'good-book-ds',
    url: 'https://arc-cluster-appbase-demo-ps1pgt.searchbase.io',
    credentials: 'a03a1cb71321:75b6603d-9456-4a5a-af6b-a487b309eb61',
    appbaseConfig: {
        recordAnalytics: true,
        enableQueryRules: true,
    },
    dataField: 'original_title',
});
// using recordConversions
component.recordConversions(['cf827a07-60a6-43ef-ab93-e1f8e1e3e1a8']);

Here cf827a07-60a6-43ef-ab93-e1f8e1e3e1a8 is the ES docId.