Variant support in chakracore-delphi

The new experimental/variants branch of chakracore-delphi introduces some experimental support for Variants. It's now possible to write code similar to the following:

	// Calling javascript methods on variants creates temporary variant arrays for passing parameters.
	// To avoid access violations after freeing the runtime, make sure all your code using Variants gets out of scope first.
	procedure Test(Context: TChakraCoreContext);
	var
	Global, Json, MyObj: Variant;
	begin
	// assign javascript Global to a Variant
	Global := JsValueToVariant(Context.Global);
	// read its (JSON) property and assign it to another Variant
	Json := Global.JSON;
	// call its method, assign result to another Variant
	MyObj := Json.parse('{ "name": "world" }');
	// access property
	Writeln(Format('Hello, %s!', [MyObj.name]));
	// call another method
	Writeln(Json.stringify(MyObj));
	end;
	procedure Main;
	var
	Runtime: TChakraCoreRuntime;
	Context: TChakraCoreContext;
	begin
	Runtime := nil;
	Context := nil;
	try
	Runtime := TChakraCoreRuntime.Create;
	Context := TChakraCoreContext.Create(Runtime);
	Context.Activate;
	Test(Context);
	finally
	Context.Free;
	Runtime.Free;
	end;
	end;

view raw test.dpr hosted with ❤ by GitHub

The example above is using Javascript built-in JSON object and its methods: parse and stringify. On Windows, it's possible to expose an Automation object to your script, using late (IDispatch) binding. An example of this is shown in the new WmiSample demo:

	// ask host to create an Automation object instance
	let locator = createOleObject('WbemScripting.SWbemLocator');
	const computerName = '.';
	const namespace = '';
	const userName = '';
	const password = '';
	// use it (access its properties and methods) from Javascript
	let service = locator.ConnectServer(computerName, namespace, userName, password);
	const className = 'Win32_OperatingSystem';
	console.log(`***** InstancesOf('${className}') *****`);
	let items = service.InstancesOf(className);
	items.forEach((item, i) => {
	if (i > 0) {
	console.log('');
	}
	item.Properties_.forEach((p) => {
	console.log(`${p.Name}: ${item[p.Name]}`);
	});
	});

view raw wmi-example.js hosted with ❤ by GitHub

and its output:

	***** InstancesOf('Win32_OperatingSystem') *****
	BootDevice: \Device\HarddiskVolume1
	BuildNumber: 19041
	BuildType: Multiprocessor Free
	Caption: Microsoft Windows 10 Pro
	CodeSet: 1252
	CountryCode: 1
	CreationClassName: Win32_OperatingSystem
	CSCreationClassName: Win32_ComputerSystem
	CSDVersion: null
	CSName: TLEILAX
	CurrentTimeZone: 60
	DataExecutionPrevention_32BitApplications: true
	DataExecutionPrevention_Available: true
	DataExecutionPrevention_Drivers: true
	DataExecutionPrevention_SupportPolicy: 2
	Debug: false
	Description:
	Distributed: false
	EncryptionLevel: 256
	ForegroundApplicationBoost: 2
	FreePhysicalMemory: 11170572
	FreeSpaceInPagingFiles: 2451164
	FreeVirtualMemory: 13871392
	InstallDate: 20200610091003.000000+060
	LargeSystemCache: null
	LastBootUpTime: 20201030112159.586692+060
	LocalDateTime: 20201030143957.032000+060
	Locale: 0409
	Manufacturer: Microsoft Corporation
	MaxNumberOfProcesses: -1
	MaxProcessMemorySize: 137438953344
	MUILanguages: en-US,de-DE,en-GB
	Name: Microsoft Windows 10 Pro|C:\WINDOWS|\Device\Harddisk0\Partition2
	NumberOfLicensedUsers: null
	NumberOfProcesses: 171
	NumberOfUsers: 2
	OperatingSystemSKU: 48
	Organization:
	OSArchitecture: 64-bit
	OSLanguage: 1033
	OSProductSuite: 256
	OSType: 18
	OtherTypeDescription: null
	PAEEnabled: null
	PlusProductID: null
	PlusVersionNumber: null
	PortableOperatingSystem: false
	Primary: true
	ProductType: 1
	RegisteredUser: ???????
	SerialNumber: ?????-?????-?????-?????
	ServicePackMajorVersion: 0
	ServicePackMinorVersion: 0
	SizeStoredInPagingFiles: 2490368
	Status: OK
	SuiteMask: 272
	SystemDevice: \Device\HarddiskVolume2
	SystemDirectory: C:\WINDOWS\system32
	SystemDrive: C:
	TotalSwapSpaceSize: null
	TotalVirtualMemorySize: 19267124
	TotalVisibleMemorySize: 16776756
	Version: 10.0.19041
	WindowsDirectory: C:\WINDOWS

view raw wmi-example.txt hosted with ❤ by GitHub

For more example code, you can also check out the associated tests.

FastMM5 released

Check it out:

First non-beta release of FastMM version 5 (a complete rewrite) has just been made public on GitHub.

Lazarus 2.0.8 released

Lazarus 2.0.8 has been announced today.

Also see:

Release notes
Fixes

Happy coding :-)