Js Dart Reference Documentation
CkJs
Current Version: 11.6.1
Chilkat.Js
Use
Run JavaScript code from inside the host application without launching an
external scripting process.
Start from a restricted execution environment and selectively expose only
the capabilities the script should use.
Allow scripts to use selected Chilkat classes when the host application
wants JavaScript to perform controlled Chilkat operations.
Optionally restrict filesystem access so scripts can read or write only
within approved locations.
Execute JavaScript, pass data through the host-controlled environment,
and retrieve results or diagnostics from the script run.
Use JavaScript as an embedded extension language for application-defined
workflows while keeping host resources protected.
For an extended overview, see
Js Class Overview.
Also see
About the Chilkat.Js JavaScript Engine.
Execute sandboxed JavaScript inside an application with controlled access to Chilkat features.
Chilkat.Js when an application needs to execute JavaScript
internally while retaining control over what the script is allowed to access.
By default, scripts run in a closed sandbox with the JavaScript language and
standard library available, but without filesystem, network, or Chilkat
class access unless the host application explicitly enables those
capabilities.
Embedded JavaScript engine
Sandboxed by default
Enable Chilkat classes
Filesystem restrictions
Script input and output
Controlled automation
Js object, load or provide the JavaScript code, enable
only the Chilkat classes and filesystem locations the script is permitted to
use, run the script, and inspect the result or diagnostic output. Use
Chilkat.Js when the application needs scriptability with a
security boundary controlled by the host.
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 js = CkJs();
// ... the native object is released when `js` is garbage collected, or now with js.dispose().Creates the underlying native Chilkat object. Use a CkJs 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 {
js.someMethod(...);
} on ChilkatException catch (e) {
print(e); // CkJs.someMethod failed: <reason>
print(e.lastErrorText); // the full Chilkat log of the failed call
}Properties
DebugLogFilePath
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.
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.
TimeoutSeconds
int get timeoutSeconds
set timeoutSeconds(int value)
Specify a timeout in seconds to prevent JavaScript from running indefinitely, such as in an infinite loop. By default, the value is 0, meaning no timeout is set and infinite loops will continue forever.
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
CallFunction
Calls a JavaScript function. The function name and arguments are passed in funcJson. The result is returned in resultJson.
Returns normally on success; throws a ChilkatException on failure.
ConsoleOutputSb
Eval
Run jscript as a script. Return output and errors in resultJson.
Returns normally on success; throws a ChilkatException on failure.
SetCkPermission
Sets sandbox related permissions for Chilkat objects. The chilkatClassName is the name of the Chilkat class (case-insensitive), such as Http, Rest, "MailMan", "Ftp2", "Ssh", etc. The chilkatClassName can also be set to "all" to apply the permission to all Chilkat classes.
Possible values for permission are:
disable- Your JavaScript code is not allowed to create an instance of the Chilkat class. A JavaScript exception is thrown when trying to create a Chilkat object of a class that is disabled.sandbox- Objects for the Chilkat class can be instantiated in JavaScript, but they have no read or write access to the local filesystem.readOnly- Objects for the Chilkat class can be instantiated in JavaScript and have read-only access to the local filesystem.writeOnly- Objects for the Chilkat class can be instantiated in JavaScript and have write-only access to the local filesystem.readWrite- Objects for the Chilkat class can be instantiated in JavaScript and have read/write access to the local filesystem.
By default, all Chilkat classes are disabled. Your application must enable "all" or specific Chilkat classes before calling Eval or CallFunction .
Returns normally on success; throws a ChilkatException on failure.