SessionTokenHandler class

This class is used for Google Places API (New) Autocomplete / Details requests

Session tokens are user-generated strings (or objects) that track Autocomplete (New) calls as sessions. Autocomplete (New) uses session tokens to group the query and selection phases of a user autocomplete search into a discrete session for billing purposes.

Users are responsible for creating session tokens for each session. Session tokens must be URL- and filename-safe base64 strings. Users can generate session tokens in any manner, although Google recommends using version 4 universally unique identifiers (UUIDs) for session tokens.

The session begins with a call to Autocomplete (New), and concludes with a call to Place Details (New) or Address Validation. Each session can have multiple Autocomplete (New) queries, followed by one request to Place Details (New) or Address Validation. The API key(s) used for each request within a session must belong to the same Google Cloud Console project.

⭐️ Note: Session tokens cannot be exchanged between Places API endpoints and Places API (New) or Address Validation endpoints. For example, Place Autocomplete request can be followed by a Place Details request in the same session, but it cannot be followed by a Place Details (New) request or an Address Validation request in the same session.

⭐️ Note: You can optionally omit the Autocomplete (New) session token from a request. If the session token is omitted, each request is billed separately and charges the Autocomplete – Per Request SKU.

Once a session has concluded, the token is no longer valid; your app must generate a fresh token for each new session. If the sessionToken parameter is omitted, or if you reuse a session token, the new session is charged as if no session token was provided (each request is billed separately).

Documentation: https://developers.google.com/maps/documentation/places/web-service/place-session-tokens

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Using this class, you can create a session token for Google Places API (New) and use it for each Autocomplete request and Place Details request.

How to use:

Initialize: final sessionToken = SessionTokenHandler();
Use sessionToken.token on each Autocomplete session request: final responseAutocomplete = await placesAPI.searchAutocomplete( filter: AutocompleteSearchFilter( input: input, sessionToken: sessionToken.token, ), );
Use sessionToken.token on final Place Details request: final response = await placesAPI.getDetails( id: placeId ?? '', instanceFields: Place( id: '', displayName: LocalizedText(), ), filter: PlaceDetailsFilter( sessionToken: token, ), );
That's all.

Usage Notes:

sessionToken.token has a TTL (Time To Live) of 2 minutes.
Every time you call sessionToken.token, it will increase the used count (only for logging purposes) and will also generate a new token if TTL expired.
sessionToken.refresh() can be called to force a new token generation.
sessionToken.cacheSuggestions(text: text, data: data) can be called to cache the PlacesSuggestions data for a given text.
sessionToken.suggestionsFromCache(text) can be called to get any PlacesSuggestions already in cache for a given text.
sessionToken.cachePlaceDetails(id: placeId, data: data) can be called to cache the Place data for a given placeId, this function will also refresh the token as it assumes this Place is the result of a call to Place Details after several calls to Autocomplete Search which means the session has already concluded.
sessionToken.placeFromCache(placeId) can be called to get any Place already in cache for a given placeId.

Constructors

Properties

Methods

Operators

places_new library