Js C Reference Documentation
Js
Current Version: 11.4.0
Chilkat.Js is a small, embeddable JavaScript engine. It executes JavaScript code inside an application without requiring a browser or large runtime like Node.js. The Chilkat Js engine began as QuickJS, but after extensive redesign, refactoring, and hardening, it has evolved into a separate JavaScript engine maintained as part of the Chilkat platform.
See About the Chilkat.Js JavaScript Engine for more information.
This software includes portions of the QuickJS JavaScript engine Copyright (c) 2017-2024 Fabrice Bellard Licensed under the MIT License. The Chilkat Js engine was originally derived from QuickJS but has been extensively modified
Create/Dispose
HCkJs instance = CkJs_Create(); // ... CkJs_Dispose(instance);
Creates an instance of the HCkJs object and returns a handle ("void *" pointer). The handle is passed in the 1st argument for the functions listed on this page.
Objects created by calling CkJs_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function. Also, any handle returned by a Chilkat "C" function must also be freed by the application by calling the appropriate Dispose method, such as CkJs_Dispose.
Callback Functions
Provides the opportunity for a method call to be aborted. If TRUE is returned, the operation in progress is aborted.
Return FALSE to allow the current method call to continue.
This callback function is called periodically based on the value of the HeartbeatMs property.
(If HeartbeatMs is 0, then no callbacks are made.) As an example, to make 5 AbortCheck callbacks per second, set the HeartbeatMs property equal to 200.
See Also:C Example using Callback Functions
Provides the percentage completed for any method that involves network communications or time-consuming processing (assuming it is a method where a percentage completion can be measured). This callback is only called when it is possible to know a percentage completion, and when it makes sense to express the operation as a percentage completed. The pctDone argument will have a value from 1 to 100. For methods that complete very quickly, the number of PercentDone callbacks will vary, but the final callback should have a value of 100. For long running operations, no more than one callback per percentage point will occur (for example: 1, 2, 3, ... 98, 99, 100).
This callback counts as an AbortCheck callback, and takes the place of the AbortCheck event when it fires.
The return value indicates whether the method call should be aborted, or whether it should proceed. Return TRUE to abort, and FALSE to proceed.
This is a general callback that provides name/value information about what is happening at certain points during a method call. To see the information provided in ProgressInfo callbacks, if any, write code to handle this event and log the name/value pairs. Most are self-explanatory.
Called in the background thread when an asynchronous task completes. (Note: When an async method is running, all callbacks are in the background thread.)
Properties
DebugLogFilePath
void CkJs_putDebugLogFilePath(HCkJs cHandle, const char *newVal);
const char *CkJs_debugLogFilePath(HCkJs cHandle);
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
const char *CkJs_lastErrorHtml(HCkJs cHandle);
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
const char *CkJs_lastErrorText(HCkJs cHandle);
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
const char *CkJs_lastErrorXml(HCkJs cHandle);
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
void CkJs_putLastMethodSuccess(HCkJs cHandle, BOOL newVal);
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
void CkJs_putTimeoutSeconds(HCkJs cHandle, int newVal);
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.
Utf8
void CkJs_putUtf8(HCkJs cHandle, BOOL newVal);
When set to TRUE, all const char * arguments and return values are interpreted as UTF-8 strings. When set to FALSE, they are interpreted as ANSI strings.
In Chilkat v11.0.0 and later, the default value is TRUE. Before v11.0.0, it was FALSE.
VerboseLogging
void CkJs_putVerboseLogging(HCkJs cHandle, BOOL newVal);
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
Methods
CallFunction
Calls a JavaScript function. The function name and arguments are passed in func. The result is returned in result.
Returns TRUE for success, FALSE for failure.
CallFunctionAsync (1)
Creates an asynchronous task to call the CallFunction method with the arguments provided.
Returns NULL on failure
ConsoleOutputSb
Eval
Run jscript as a script. Return output and errors in result.
Returns TRUE for success, FALSE for failure.
EvalAsync (1)
Creates an asynchronous task to call the Eval method with the arguments provided.
Returns NULL 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 TRUE for success, FALSE for failure.