AuthGoogle Dart Reference Documentation
CkAuthGoogle
Current Version: 11.6.1
Chilkat.AuthGoogle
Authenticate server-to-server using a Google service account rather than
an interactive browser-based user consent flow.
Load service account credentials from modern JSON private keys or from
legacy P12 private key files.
Specify the OAuth scopes required by the target Google API and add custom
JWT claims when needed.
Use domain-wide delegation by setting a subject email when the service
account is authorized to act on behalf of a Google Workspace user.
Inspect the generated access token, expiration time, remaining lifetime,
and validity state before using or refreshing credentials.
Pass the resulting bearer token to Chilkat HTTP, REST, storage, mail, or
other Google API request workflows.
For an extended overview, see
AuthGoogle Class Overview.
Obtain Google OAuth 2.0 access tokens using a service account.
Chilkat.AuthGoogle obtains OAuth 2.0 access tokens for Google
Cloud Platform APIs and Google Apps APIs using a Google service account. It
supports JSON private keys and P12 private keys, OAuth scopes, optional
delegated user access, custom JWT claims, access-token validity tracking,
token lifetime settings, and integration with Chilkat request classes that
need a Google bearer token.
Service account auth
JSON or P12 keys
Scopes and claims
Delegated user access
Access-token tracking
Chilkat API integration
Scope, optional delegated SubEmailAddress,
and token lifetime, then call ObtainAccessToken. Use
AuthGoogle for service-account OAuth flows; use
Chilkat.OAuth2 when the application needs an interactive
three-legged OAuth flow involving a user's browser consent.
Object Creation
// pubspec.yaml:
// dependencies:
// chilkat: ^11.6.1
import 'package:chilkat/chilkat.dart';
// Once per process, before any other Chilkat call:
Chilkat.unlockBundle('Anything for 30-day trial'); // shorthand for CkGlobal().unlockBundle(..)
final authGoogle = CkAuthGoogle();
// ... the native object is released when `authGoogle` is garbage collected, or now with authGoogle.dispose().Creates the underlying native Chilkat object. Use a CkAuthGoogle only from the isolate that created it: Chilkat objects cannot be sent between isolates. Every call is synchronous; in a Flutter app, run long operations (network, large files) inside Isolate.run, creating the Chilkat objects inside the isolate.
Releases the native object immediately instead of waiting for garbage collection (useful for a large CkBinData or an open socket). Calling it more than once is harmless; any other use of the object afterwards throws a StateError. isDisposed tells whether it has been called.
Errors
A method that can fail throws a ChilkatException: a method whose only outcome is success or failure returns void and throws on failure; a method producing a String or an object returns it and throws where Chilkat would have returned null. The exception carries the object's LastErrorText at the time of the failure (lastErrorText), the class and method names (className, methodName) and a one-line message. Properties never throw, and methods that answer a question (has..., is..., ...) return a plain bool.
try {
authGoogle.someMethod(...);
} on ChilkatException catch (e) {
print(e); // CkAuthGoogle.someMethod failed: <reason>
print(e.lastErrorText); // the full Chilkat log of the failed call
}Properties
AccessToken
String get accessToken
set accessToken(String value)
The access token to be used in Google API requests. This property is set on a successful call to ObtainAccessToken.
Important: This class is used for authenticating calls to the Google Cloud Platform API and Google Apps API using a service account.. For 3-legged OAuth2, where a browser must be used to interactively get permission from the Google account owner, use the Chilkat OAuth2 class/object.
topDebugLogFilePath
String get debugLogFilePath
set debugLogFilePath(String value)
If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.
Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.
Possible causes of hangs include:
- A timeout property set to 0, indicating an infinite timeout.
- A hang occurring within an event callback in the application code.
- An internal bug in the Chilkat code causing the hang.
EmailAddress
String get emailAddress
set emailAddress(String value)
The client email address of the service account. If a JSON key is used, then the client_email should already be specified within the JSON key, and this property is unused. This property must be set if using a P12 key.
ExpireNumSeconds
int get expireNumSeconds
set expireNumSeconds(int value)
The expiration time, in seconds, of the access token to be requested. The maximum value is 1 hour (3600 seconds). The default value is 3600.
topIat
int get iat
set iat(int value)
This property can be set to override the default current date/time value for the iat claim of the JWT. It can be set to a value indicating the number of seconds from 1970-01-01T00:00:00Z UTC.
The default value is 0, which indicates to use the iat value for the current system date/time. Unless explicitly needed, always leave this property at the default value.
topJsonKey
String get jsonKey
set jsonKey(String value)
The JSON key for obtaining an access token. An application must set either the P12 or JSON private key, but not both.
LastErrorHtml
String get lastErrorHtml
Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastErrorText
String get lastErrorText
Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
LastErrorXml
String get lastErrorXml
Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastMethodSuccess
bool get lastMethodSuccess
set lastMethodSuccess(bool value)
Indicates the success or failure of the most recent method call: true means success, false means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.
NumSecondsRemaining
int get numSecondsRemaining
If the access token is valid, contains the number of seconds remaining until it expires. A value of 0 indicates an invalid or expired access token.
topScope
String get scope
set scope(String value)
A space-delimited list of the permissions that the application requests.
topSubEmailAddress
String get subEmailAddress
set subEmailAddress(String value)
The email address of the user for which the application is requesting delegated access.
topValid
bool get valid
true if the AccessToken property contains a valid non-expired access token obtained via the call to ObtainAccessToken.
VerboseLogging
bool get verboseLogging
set verboseLogging(bool value)
If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.
Version
String get version
Methods
AddClaims
Adds additional custom claims to the JWT claims set.
Returns normally on success; throws a ChilkatException on failure.
GetP12
Returns the private key in a PFX (P12) object. This is only possible if the private key was previously set by calling SetP12.
Throws a ChilkatException on failure (where the description says null is returned, the Dart method throws instead).
ObtainAccessToken
Sends the HTTP request to fetch the access token. When this method completes successfully, the access token is available in the AccessToken property. The connection is an existing connection to www.googleapis.com.
Important: Make sure your computer's date/time is accurately set to the current date/time, otherwise you'll get a 400 response status code with this error: Invalid JWT: Token must be a short-lived token (60 minutes) and in a reasonable timeframe. Check your iat and exp values and use a clock with skew to account for clock differences between systems..
Returns normally on success; throws a ChilkatException on failure.
SetP12
Sets the P12 private key to be used for obtaining an access token. An application must set either the P12 or JSON private key, but not both.
Returns normally on success; throws a ChilkatException on failure.
Events
All Chilkat methods are synchronous: the call returns when the work is done. During a call, CkAuthGoogle raises three events so your application can show progress and offer a way out. Each event is a nullable callback property on the object; assign a function to receive it, or null to stop receiving it:
final authGoogle = CkAuthGoogle();
authGoogle.onPercentDone = (pct) {
print('$pct%');
return false; // return true to abort the method in progress
};
authGoogle.onProgressInfo = (name, value) => print('$name: $value');
authGoogle.heartbeatMs = 250; // raise onAbortCheck 4 times per second during Chilkat calls
authGoogle.onAbortCheck = () => _userPressedCancel;AbortCheck fires at regular intervals controlled by the HeartbeatMs property (0, the default, disables it); PercentDone fires when an operation's completion percentage is known; ProgressInfo delivers named progress values. Returning true from onAbortCheck or onPercentDone aborts the running method, which then throws a ChilkatException.
Events fire on the thread that called the method, before that method returns. An exception thrown inside a callback aborts the running method and is rethrown from it once the native library has returned. In a Flutter app the callbacks run inside the worker isolate that owns the object; forward progress to the UI through a SendPort, and let onAbortCheck read a flag the UI sets the same way.
AbortCheck
bool Function()? onAbortCheck
Enables a method call to be aborted by triggering the AbortCheck event at intervals defined by the HeartbeatMs property. If HeartbeatMs is set to its default value of 0, no events will occur. For instance, set HeartbeatMs to 200 to trigger 5 AbortCheck events per second.
Example:
authGoogle.heartbeatMs = 250; // call onAbortCheck 4 times per second
var cancelRequested = false;
authGoogle.onAbortCheck = () => cancelRequested;
// ... set cancelRequested = true (e.g. from a message received on a ReceivePort) to abort the method in progressPercentDone
bool Function(int pctDone)? onPercentDone
This provides the percentage completion for any method involving network communications or time-consuming processing, assuming the progress can be measured as a percentage. This event is triggered only when it's possible and logical to express the operation's progress as a percentage. The pctDone argument will range from 1 to 100. For methods that finish quickly, the number of PercentDone callbacks may vary, but the final callback will have pctDone equal to 100. For longer operations, callbacks will not exceed one per percentage point (e.g., 1, 2, 3, ..., 98, 99, 100).
The PercentDone callback also acts as an AbortCheck event. For fast methods where PercentDone fires, an AbortCheck event may not trigger since the PercentDone callback already provides an opportunity to abort. For longer operations, where time between PercentDone callbacks is extended, AbortCheck callbacks enable more responsive operation termination.
To abort the operation, set the abort output argument to true. This will cause the method to terminate and return a failure status or corresponding failure value.
Example:
authGoogle.onPercentDone = (pct) {
// pct ranges from 1 to 100.
print('Percent done: $pct');
return false; // return true to abort the method in progress
};ProgressInfo
void Function(String name, String value)? onProgressInfo
This event callback provides tag name/value pairs that detail what occurs during a method call. To discover existing tag names, create code to handle the event, emit the pairs, and review them. Most tag names are self-explanatory.
Note: Some Chilkat methods don't fire any ProgressInfo events.
Example:
authGoogle.onProgressInfo = (name, value) => print('$name: $value');