Js Unicode C Reference Documentation
Js
Current Version: 11.6.0
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.
Create/Dispose
HCkJsW instance = CkJsW_Create();
// ...
CkJsW_Dispose(instance);Creates an instance of the HCkJsW 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 CkJsW_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 CkJsW_Dispose.
Callback Functions
void CkJsW_setAbortCheck(HCkHttp cHandle, BOOL (*fnAbortCheck)(void));
Gives your application a chance to cancel a method call while it is running. Return TRUEFALSE
This callback fires periodically, at the interval set by the HeartbeatMs property. For example, set HeartbeatMs to 200 to receive five AbortCheck callbacks per second. If HeartbeatMs is 0, no callbacks are made and the operation cannot be aborted.
void CkJsW_setPercentDone(HCkHttp cHandle, BOOL (*fnPercentDone)(int pctDone));
Reports how far along a method call is, as a percentage. It applies to methods that involve network communication or time-consuming processing, and fires only when a percentage completed can actually be measured and it makes sense to express progress that way.
The pctDone argument is a value from 1 to 100. Methods that finish very quickly may produce only a few callbacks, but the final callback always reports 100. Long-running operations produce at most one callback per percentage point (for example: 1, 2, 3, … 98, 99, 100).
This callback also counts as an AbortCheck callback. When PercentDone fires, it replaces the AbortCheck callback that would otherwise have occurred at that moment.
The return value controls whether the method call continues. Return TRUEFALSE
void CkJsW_setProgressInfo(HCkHttp cHandle, void (*fnProgressInfo)(const wchar_t *name, const wchar_t *value));
A general-purpose callback that reports name/value pairs describing what is happening at various points during a method call. The information provided varies by method, and some methods provide none at all. To see what a particular method reports, write a handler that logs each name/value pair. Most are self-explanatory.
void CkJsW_setTaskCompleted(HCkHttp cHandle, void (*fnTaskCompleted)(HCkTask hTask));
Called when an asynchronous task finishes. This callback runs in the background thread rather than the thread that started the task. (While an async method is running, all callbacks occur in the background thread.)
Properties
DebugLogFilePath
void CkJsW_putDebugLogFilePath(HCkJsW cHandle, const wchar_t *newVal);
const wchar_t *CkJsW_debugLogFilePath(HCkJsW 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 wchar_t *CkJsW_lastErrorHtml(HCkJsW 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 wchar_t *CkJsW_lastErrorText(HCkJsW 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 wchar_t *CkJsW_lastErrorXml(HCkJsW 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 CkJsW_putLastMethodSuccess(HCkJsW 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 CkJsW_putTimeoutSeconds(HCkJsW 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.
VerboseLogging
void CkJsW_putVerboseLogging(HCkJsW 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
const wchar_t *CkJsW_version(HCkJsW cHandle);
Methods
CallFunction
Calls a JavaScript function. The function name and arguments are passed in funcJson. The result is returned in resultJson.
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 resultJson.
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.