QScriptEngine¶

Inheritance diagram of QScriptEngine

Synopsis¶

Functions¶

def abortEvaluation ([result=QScriptValue()])
def agent ()
def availableExtensions ()
def canEvaluate (program)
def clearExceptions ()
def collectGarbage ()
def convert (value, type, ptr)
def create (type, ptr)
def currentContext ()
def defaultPrototype (metaTypeId)
def evaluate (program)
def evaluate (program[, fileName=”“[, lineNumber=1]])
def globalObject ()
def hasUncaughtException ()
def importExtension (extension)
def importedExtensions ()
def installTranslatorFunctions ([object=QScriptValue()])
def isEvaluating ()
def newActivationObject ()
def newArray ([length=0])
def newDate (value)
def newDate (value)
def newObject ()
def newObject (scriptClass[, data=QScriptValue()])
def newQMetaObject (metaObject[, ctor=QScriptValue()])
def newQObject (object[, ownership=QtOwnership[, options=0]])
def newQObject (scriptObject, qtObject[, ownership=QtOwnership[, options=0]])
def newRegExp (pattern, flags)
def newRegExp (regexp)
def newVariant (object, value)
def newVariant (value)
def nullValue ()
def objectById (id)
def popContext ()
def processEventsInterval ()
def pushContext ()
def reportAdditionalMemoryCost (size)
def setAgent (agent)
def setDefaultPrototype (metaTypeId, prototype)
def setGlobalObject (object)
def setProcessEventsInterval (interval)
def toObject (value)
def toStringHandle (str)
def uncaughtException ()
def uncaughtExceptionBacktrace ()
def uncaughtExceptionLineNumber ()
def undefinedValue ()

Signals¶

def signalHandlerException (exception)

Static functions¶

def convertV2 (value, type, ptr)

Detailed Description¶

The PySide.QtScript.QScriptEngine class provides an environment for evaluating Qt Script code.

See the QtScript documentation for information about the Qt Script language, and how to get started with scripting your C++ application.

Evaluating Scripts¶

Use PySide.QtScript.QScriptEngine.evaluate() to evaluate script code; this is the C++ equivalent of the built-in script function eval() .
myEngine = QScriptEngine()
three = myEngine.evaluate("1 + 2")
PySide.QtScript.QScriptEngine.evaluate() returns a PySide.QtScript.QScriptValue that holds the result of the evaluation. The PySide.QtScript.QScriptValue class provides functions for converting the result to various C++ types (e.g. QScriptValue.toString() and QScriptValue.toNumber() ).

The following code snippet shows how a script function can be defined and then invoked from C++ using QScriptValue.call() :
fun = myEngine.evaluate("function(a, b) { return a + b }");
args = QScriptValueList()
args << 1 << 2
threeAgain = fun.call(QScriptValue(), args)
As can be seen from the above snippets, a script is provided to the engine in the form of a string. One common way of loading scripts is by reading the contents of a file and passing it to PySide.QtScript.QScriptEngine.evaluate() :
fileName = "helloworld.qs"
scriptFile = QFile(fileName)
if !scriptFile.open(QIODevice.ReadOnly):
    # handle error
stream = QTextStream(scriptFile)
contents = stream.readAll()
scriptFile.close()
myEngine.evaluate(contents, fileName)
Here we pass the name of the file as the second argument to PySide.QtScript.QScriptEngine.evaluate() . This does not affect evaluation in any way; the second argument is a general-purpose string that is used to identify the script for debugging purposes (for example, our filename will now show up in any PySide.QtScript.QScriptEngine.uncaughtExceptionBacktrace() involving the script).

Engine Configuration¶

The PySide.QtScript.QScriptEngine.globalObject() function returns the Global Object associated with the script engine. Properties of the Global Object are accessible from any script code (i.e. they are global variables). Typically, before evaluating “user” scripts, you will want to configure a script engine by adding one or more properties to the Global Object:
myEngine.globalObject().setProperty("myNumber", 123)
...
myNumberPlusOne = myEngine.evaluate("myNumber + 1")
Adding custom properties to the scripting environment is one of the standard means of providing a scripting API that is specific to your application. Usually these custom properties are objects created by the PySide.QtScript.QScriptEngine.newQObject() or PySide.QtScript.QScriptEngine.newObject() functions, or constructor functions created by newFunction() .

Script Exceptions¶

PySide.QtScript.QScriptEngine.evaluate() can throw a script exception (e.g. due to a syntax error); in that case, the return value is the value that was thrown (typically an Error object). You can check whether the evaluation caused an exception by calling PySide.QtScript.QScriptEngine.hasUncaughtException() . In that case, you can call toString() on the error object to obtain an error message. The current uncaught exception is also available through PySide.QtScript.QScriptEngine.uncaughtException() . Calling PySide.QtScript.QScriptEngine.clearExceptions() will cause any uncaught exceptions to be cleared.
result = myEngine.evaluate(...)
if myEngine.hasUncaughtException():
    line = myEngine.uncaughtExceptionLineNumber()
    print "uncaught exception at line", line, ":", result.toString()
The checkSyntax() function can be used to determine whether code can be usefully passed to PySide.QtScript.QScriptEngine.evaluate() .

Script Object Creation¶

Use PySide.QtScript.QScriptEngine.newObject() to create a standard Qt Script object; this is the C++ equivalent of the script statement new Object() . You can use the object-specific functionality in PySide.QtScript.QScriptValue to manipulate the script object (e.g. QScriptValue.setProperty() ). Similarly, use PySide.QtScript.QScriptEngine.newArray() to create a Qt Script array object. Use PySide.QtScript.QScriptEngine.newDate() to create a Date object, and PySide.QtScript.QScriptEngine.newRegExp() to create a RegExp object.

QObject Integration¶

Use PySide.QtScript.QScriptEngine.newQObject() to wrap a PySide.QtCore.QObject (or subclass) pointer. PySide.QtScript.QScriptEngine.newQObject() returns a proxy script object; properties, children, and signals and slots of the PySide.QtCore.QObject are available as properties of the proxy object. No binding code is needed because it is done dynamically using the Qt meta object system.
button = QPushButton()
QScriptValue scriptButton = myEngine.QObject(button)
myEngine.globalObject().setProperty("button", scriptButton)

myEngine.evaluate("button.checkable = True")

print scriptButton.property("checkable").toBoolean()
scriptButton.property("show").call() # call the show() slot
Use qScriptConnect() to connect a C++ signal to a script function; this is the Qt Script equivalent of QObject.connect() . When a script function is invoked in response to a C++ signal, it can cause a script exception; you can connect to the PySide.QtScript.QScriptEngine.signalHandlerException() signal to catch such an exception.

Use PySide.QtScript.QScriptEngine.newQMetaObject() to wrap a PySide.QtCore.QMetaObject ; this gives you a “script representation” of a PySide.QtCore.QObject -based class. PySide.QtScript.QScriptEngine.newQMetaObject() returns a proxy script object; enum values of the class are available as properties of the proxy object. You can also specify a function that will be used to construct objects of the class (e.g. when the constructor is invoked from a script). For classes that have a “standard” Qt constructor, Qt Script can provide a default script constructor for you; see scriptValueFromQMetaObject() .

See the QtScript documentation for more information on the PySide.QtCore.QObject integration.

Support for Custom C++ Types¶

Use PySide.QtScript.QScriptEngine.newVariant() to wrap a PySide.QtCore.QVariant . This can be used to store values of custom (non- PySide.QtCore.QObject ) C++ types that have been registered with the Qt meta-type system. To make such types scriptable, you typically associate a prototype (delegate) object with the C++ type by calling PySide.QtScript.QScriptEngine.setDefaultPrototype() ; the prototype object defines the scripting API for the C++ type. Unlike the PySide.QtCore.QObject integration, there is no automatic binding possible here; i.e. you have to create the scripting API yourself, for example by using the PySide.QtScript.QScriptable class.

Use fromScriptValue() to cast from a PySide.QtScript.QScriptValue to another type, and toScriptValue() to create a PySide.QtScript.QScriptValue from another value. You can specify how the conversion of C++ types is to be performed with qScriptRegisterMetaType() and qScriptRegisterSequenceMetaType() . By default, Qt Script will use PySide.QtCore.QVariant to store values of custom types.

Importing Extensions¶

Use PySide.QtScript.QScriptEngine.importExtension() to import plugin-based extensions into the engine. Call PySide.QtScript.QScriptEngine.availableExtensions() to obtain a list naming all the available extensions, and PySide.QtScript.QScriptEngine.importedExtensions() to obtain a list naming only those extensions that have been imported.

Call PySide.QtScript.QScriptEngine.pushContext() to open up a new variable scope, and PySide.QtScript.QScriptEngine.popContext() to close the current scope. This is useful if you are implementing an extension that evaluates script code containing temporary variable definitions (e.g. var foo = 123; ) that are safe to discard when evaluation has completed.

Native Functions¶

Use newFunction() to wrap native (C++) functions, including constructors for your own custom types, so that these can be invoked from script code. Such functions must have the signature QScriptEngine.FunctionSignature . You may then pass the function as argument to newFunction() . Here is an example of a function that returns the sum of its first two arguments:
def myAdd(context, engine):
   a = context.argument(0)
   b = context.argument(1)
   return a.toNumber() + b.toNumber()
To expose this function to script code, you can set it as a property of the Global Object:
fun = myEngine.Function(myAdd)
myEngine.globalObject().setProperty("myAdd", fun)
Once this is done, script code can call your function in the exact same manner as a “normal” script function:
result = myEngine.evaluate("myAdd(myNumber, 1)")

Long-running Scripts¶

If you need to evaluate possibly long-running scripts from the main (GUI) thread, you should first call PySide.QtScript.QScriptEngine.setProcessEventsInterval() to make sure that the GUI stays responsive. You can abort a currently running script by calling PySide.QtScript.QScriptEngine.abortEvaluation() . You can determine whether an engine is currently running a script by calling PySide.QtScript.QScriptEngine.isEvaluating() .

Garbage Collection¶

Qt Script objects may be garbage collected when they are no longer referenced. There is no guarantee as to when automatic garbage collection will take place.

The PySide.QtScript.QScriptEngine.collectGarbage() function can be called to explicitly request garbage collection.

The PySide.QtScript.QScriptEngine.reportAdditionalMemoryCost() function can be called to indicate that a Qt Script object occupies memory that isn’t managed by the scripting environment. Reporting the additional cost makes it more likely that the garbage collector will be triggered. This can be useful, for example, when many custom, native Qt Script objects are allocated.

Core Debugging/Tracing Facilities¶

Since Qt 4.4, you can be notified of events pertaining to script execution (e.g. script function calls and statement execution) through the PySide.QtScript.QScriptEngineAgent interface; see the PySide.QtScript.QScriptEngine.setAgent() function. This can be used to implement debugging and profiling of a PySide.QtScript.QScriptEngine .

See also

PySide.QtScript.QScriptValue PySide.QtScript.QScriptContext PySide.QtScript.QScriptEngineAgent

class PySide.QtScript.QScriptEngine¶

class PySide.QtScript.QScriptEngine(parent)

Parameters:	parent – `PySide.QtCore.QObject`

Constructs a PySide.QtScript.QScriptEngine object.

The PySide.QtScript.QScriptEngine.globalObject() is initialized to have properties as described in ECMA-262 , Section 15.1.

Constructs a PySide.QtScript.QScriptEngine object with the given parent .

The PySide.QtScript.QScriptEngine.globalObject() is initialized to have properties as described in ECMA-262 , Section 15.1.

PySide.QtScript.QScriptEngine.ValueOwnership¶

This enum specifies the ownership when wrapping a C++ value, e.g. by using PySide.QtScript.QScriptEngine.newQObject() .

Constant	Description
QScriptEngine.QtOwnership	The standard Qt ownership rules apply, i.e. the associated object will never be explicitly deleted by the script engine. This is the default. ( `PySide.QtCore.QObject` ownership is explained in Object Trees & Ownership .)
QScriptEngine.ScriptOwnership	The value is owned by the script environment. The associated data will be deleted when appropriate (i.e. after the garbage collector has discovered that there are no more live references to the value).
QScriptEngine.AutoOwnership	If the associated object has a parent, the Qt ownership rules apply ( `QtOwnership` ); otherwise, the object is owned by the script environment ( `ScriptOwnership` ).

PySide.QtScript.QScriptEngine.QObjectWrapOption¶

These flags specify options when wrapping a PySide.QtCore.QObject pointer with PySide.QtScript.QScriptEngine.newQObject() .

Constant	Description
QScriptEngine.ExcludeChildObjects	The script object will not expose child objects as properties.
QScriptEngine.ExcludeSuperClassMethods	The script object will not expose signals and slots inherited from the superclass.
QScriptEngine.ExcludeSuperClassProperties	The script object will not expose properties inherited from the superclass.
QScriptEngine.ExcludeSuperClassContents	Shorthand form for `ExcludeSuperClassMethods` \| `ExcludeSuperClassProperties`
QScriptEngine.ExcludeDeleteLater	The script object will not expose the `QObject.deleteLater()` slot.
QScriptEngine.ExcludeSlots	The script object will not expose the `PySide.QtCore.QObject` ‘s slots.
QScriptEngine.AutoCreateDynamicProperties	Properties that don’t already exist in the `PySide.QtCore.QObject` will be created as dynamic properties of that object, rather than as properties of the script object.
QScriptEngine.PreferExistingWrapperObject	If a wrapper object with the requested configuration already exists, return that object.
QScriptEngine.SkipMethodsInEnumeration	Don’t include methods (signals and slots) when enumerating the object’s properties.

PySide.QtScript.QScriptEngine.abortEvaluation([result=QScriptValue()])¶

Parameters:	result – `PySide.QtScript.QScriptValue`

Aborts any script evaluation currently taking place in this engine. The given result is passed back as the result of the evaluation (i.e. it is returned from the call to PySide.QtScript.QScriptEngine.evaluate() being aborted).

If the engine isn’t evaluating a script (i.e. PySide.QtScript.QScriptEngine.isEvaluating() returns false), this function does nothing.

Call this function if you need to abort a running script for some reason, e.g. when you have detected that the script has been running for several seconds without completing.

PySide.QtScript.QScriptEngine.agent()¶

Return type:	`PySide.QtScript.QScriptEngineAgent`

Returns the agent currently installed on this engine, or 0 if no agent is installed.

PySide.QtScript.QScriptEngine.availableExtensions()¶

Return type:	list of strings

Returns a list naming the available extensions that can be imported using the PySide.QtScript.QScriptEngine.importExtension() function. This list includes extensions that have been imported.

PySide.QtScript.QScriptEngine.canEvaluate(program)¶

Parameters:	program – unicode
Return type:	`PySide.QtCore.bool`

Returns true if program can be evaluated; i.e. the code is sufficient to determine whether it appears to be a syntactically correct program, or contains a syntax error.

This function returns false if program is incomplete; i.e. the input is syntactically correct up to the point where the input is terminated.

Note that this function only does a static check of program ; e.g. it does not check whether references to variables are valid, and so on.

A typical usage of PySide.QtScript.QScriptEngine.canEvaluate() is to implement an interactive interpreter for QtScript . The user is repeatedly queried for individual lines of code; the lines are concatened internally, and only when PySide.QtScript.QScriptEngine.canEvaluate() returns true for the resulting program is it passed to PySide.QtScript.QScriptEngine.evaluate() .

The following are some examples to illustrate the behavior of PySide.QtScript.QScriptEngine.canEvaluate() . (Note that all example inputs are assumed to have an explicit newline as their last character, since otherwise the QtScript parser would automatically insert a semi-colon character at the end of the input, and this could cause PySide.QtScript.QScriptEngine.canEvaluate() to produce different results.)

Given the input

if hello && world:
    print("hello world")

PySide.QtScript.QScriptEngine.canEvaluate() will return true, since the program appears to be complete.

Given the input

if hello &&

PySide.QtScript.QScriptEngine.canEvaluate() will return false, since the if-statement is not complete, but is syntactically correct so far.

Given the input

0 = 0

PySide.QtScript.QScriptEngine.canEvaluate() will return true, but PySide.QtScript.QScriptEngine.evaluate() will throw a SyntaxError given the same input.

Given the input

./test.js

PySide.QtScript.QScriptEngine.canEvaluate() will return true, even though the code is clearly not syntactically valid QtScript code. PySide.QtScript.QScriptEngine.evaluate() will throw a SyntaxError when this code is evaluated.

Given the input

foo["bar"]

PySide.QtScript.QScriptEngine.canEvaluate() will return true, but PySide.QtScript.QScriptEngine.evaluate() will throw a ReferenceError if foo is not defined in the script environment.

PySide.QtScript.QScriptEngine.clearExceptions()¶: Clears any uncaught exceptions in this engine.

See also

PySide.QtScript.QScriptEngine.hasUncaughtException()

PySide.QtScript.QScriptEngine.collectGarbage()¶

Runs the garbage collector.

The garbage collector will attempt to reclaim memory by locating and disposing of objects that are no longer reachable in the script environment.

Normally you don’t need to call this function; the garbage collector will automatically be invoked when the PySide.QtScript.QScriptEngine decides that it’s wise to do so (i.e. when a certain number of new objects have been created). However, you can call this function to explicitly request that garbage collection should be performed as soon as possible.

PySide.QtScript.QScriptEngine.convert(value, type, ptr)¶

Parameters:	value – `PySide.QtScript.QScriptValue` type – `PySide.QtCore.int` ptr – `void`
Return type:	`PySide.QtCore.bool`

static PySide.QtScript.QScriptEngine.convertV2(value, type, ptr)¶

Parameters:	value – `PySide.QtScript.QScriptValue` type – `PySide.QtCore.int` ptr – `void`
Return type:	`PySide.QtCore.bool`

PySide.QtScript.QScriptEngine.create(type, ptr)¶

Parameters:	type – `PySide.QtCore.int` ptr – `void`
Return type:	`PySide.QtScript.QScriptValue`

PySide.QtScript.QScriptEngine.currentContext()¶

Return type:	`PySide.QtScript.QScriptContext`

Returns the current context.

The current context is typically accessed to retrieve the arguments and this’ object in native functions; for convenience, it is available as the first argument in :class:`QScriptEngine.FunctionSignature<~PySide.QtScript.QScriptEngine.FunctionSignature> .

PySide.QtScript.QScriptEngine.defaultPrototype(metaTypeId)¶

Parameters:	metaTypeId – `PySide.QtCore.int`
Return type:	`PySide.QtScript.QScriptValue`

Returns the default prototype associated with the given metaTypeId , or an invalid PySide.QtScript.QScriptValue if no default prototype has been set.

PySide.QtScript.QScriptEngine.evaluate(program[, fileName=""[, lineNumber=1]])¶

Parameters:	program – unicode fileName – unicode lineNumber – `PySide.QtCore.int`
Return type:	`PySide.QtScript.QScriptValue`

Evaluates program , using lineNumber as the base line number, and returns the result of the evaluation.

The script code will be evaluated in the current context.

The evaluation of program can cause an exception in the engine; in this case the return value will be the exception that was thrown (typically an Error object). You can call PySide.QtScript.QScriptEngine.hasUncaughtException() to determine if an exception occurred in the last call to PySide.QtScript.QScriptEngine.evaluate() .

lineNumber is used to specify a starting line number for program ; line number information reported by the engine that pertain to this evaluation (e.g. PySide.QtScript.QScriptEngine.uncaughtExceptionLineNumber() ) will be based on this argument. For example, if program consists of two lines of code, and the statement on the second line causes a script exception, PySide.QtScript.QScriptEngine.uncaughtExceptionLineNumber() would return the given lineNumber plus one. When no starting line number is specified, line numbers will be 1-based.

fileName is used for error reporting. For example in error objects the file name is accessible through the “fileName” property if it’s provided with this function.

PySide.QtScript.QScriptEngine.evaluate(program)

Parameters:	program – `PySide.QtScript.QScriptProgram`
Return type:	`PySide.QtScript.QScriptValue`

Evaluates the given program and returns the result of the evaluation.

PySide.QtScript.QScriptEngine.globalObject()¶

Return type:	`PySide.QtScript.QScriptValue`

Returns this engine’s Global Object.

By default, the Global Object contains the built-in objects that are part of ECMA-262 , such as Math, Date and String. Additionally, you can set properties of the Global Object to make your own extensions available to all script code. Non-local variables in script code will be created as properties of the Global Object, as well as local variables in global code.

PySide.QtScript.QScriptEngine.hasUncaughtException()¶

Return type:	`PySide.QtCore.bool`

Returns true if the last script evaluation resulted in an uncaught exception; otherwise returns false.

The exception state is cleared when PySide.QtScript.QScriptEngine.evaluate() is called.

PySide.QtScript.QScriptEngine.importExtension(extension)¶

Parameters:	extension – unicode
Return type:	`PySide.QtScript.QScriptValue`

Imports the given extension into this PySide.QtScript.QScriptEngine . Returns PySide.QtScript.QScriptEngine.undefinedValue() if the extension was successfully imported. You can call PySide.QtScript.QScriptEngine.hasUncaughtException() to check if an error occurred; in that case, the return value is the value that was thrown by the exception (usually an Error object).

PySide.QtScript.QScriptEngine ensures that a particular extension is only imported once; subsequent calls to PySide.QtScript.QScriptEngine.importExtension() with the same extension name will do nothing and return PySide.QtScript.QScriptEngine.undefinedValue() .

PySide.QtScript.QScriptEngine.importedExtensions()¶

Return type:	list of strings

Returns a list naming the extensions that have been imported using the PySide.QtScript.QScriptEngine.importExtension() function.

PySide.QtScript.QScriptEngine.installTranslatorFunctions([object=QScriptValue()])¶

Parameters:	object – `PySide.QtScript.QScriptValue`

Installs translator functions on the given object , or on the Global Object if no object is specified.

The relation between Qt Script translator functions and C++ translator functions is described in the following table:

Script Function	Corresponding C++ Function
qsTr()	`QObject.tr()`
`QT_TR_NOOP()`	`QT_TR_NOOP()`
qsTranslate()	`QCoreApplication.translate()`
`QT_TRANSLATE_NOOP()`	`QT_TRANSLATE_NOOP()`
qsTrId() (since 4.7)	`qtTrId()`
`QT_TRID_NOOP()` (since 4.7)	`QT_TRID_NOOP()`

See also

Internationalization with Qt

PySide.QtScript.QScriptEngine.isEvaluating()¶

Return type:	`PySide.QtCore.bool`

Returns true if this engine is currently evaluating a script, otherwise returns false.

PySide.QtScript.QScriptEngine.newActivationObject()¶

Return type:	`PySide.QtScript.QScriptValue`

PySide.QtScript.QScriptEngine.newArray([length=0])¶

Parameters:	length – `PySide.QtCore.uint`
Return type:	`PySide.QtScript.QScriptValue`

Creates a QtScript object of class Array with the given length .

PySide.QtScript.QScriptEngine.newDate(value)¶

Parameters:	value – `PySide.QtCore.double`
Return type:	`PySide.QtScript.QScriptValue`

PySide.QtScript.QScriptEngine.newDate(value)

Parameters:	value – `PySide.QtCore.QDateTime`
Return type:	`PySide.QtScript.QScriptValue`

Creates a QtScript object of class Date from the given value .

See also

QScriptValue.toDateTime()

PySide.QtScript.QScriptEngine.newObject()¶

Return type:	`PySide.QtScript.QScriptValue`

Creates a QtScript object of class Object.

The prototype of the created object will be the Object prototype object.

PySide.QtScript.QScriptEngine.newObject(scriptClass[, data=QScriptValue()])

Parameters:	scriptClass – `PySide.QtScript.QScriptClass` data – `PySide.QtScript.QScriptValue`
Return type:	`PySide.QtScript.QScriptValue`

This is an overloaded function.

Creates a QtScript Object of the given class, scriptClass .

The prototype of the created object will be the Object prototype object.

data , if specified, is set as the internal data of the new object (using QScriptValue.setData() ).

PySide.QtScript.QScriptEngine.newQMetaObject(metaObject[, ctor=QScriptValue()])¶

Parameters:	metaObject – `PySide.QtCore.QMetaObject` ctor – `PySide.QtScript.QScriptValue`
Return type:	`PySide.QtScript.QScriptValue`

Creates a QtScript object that represents a PySide.QtCore.QObject class, using the the given metaObject and constructor ctor .

Enums of metaObject (declared with Q_ENUMS) are available as properties of the created PySide.QtScript.QScriptValue . When the class is called as a function, ctor will be called to create a new instance of the class.

Example:

def mySpecialQObjectConstructor(context, engine):
    parent = context.argument(0).toQObject()
    object =  QObject(parent)
    return engine.QObject(object, QScriptEngine.ScriptOwnership)

...

ctor = engine.Function(mySpecialQObjectConstructor)
metaObject = engine.QMetaObject(QObject.staticMetaObject, ctor)
engine.globalObject().setProperty("QObject", metaObject)

result = engine.evaluate(" QObject()")

See also

PySide.QtScript.QScriptEngine.newQObject() scriptValueFromQMetaObject()

PySide.QtScript.QScriptEngine.newQObject(object[, ownership=QtOwnership[, options=0]])¶

Parameters:	object – `PySide.QtCore.QObject` ownership – `PySide.QtScript.QScriptEngine.ValueOwnership` options – `PySide.QtScript.QScriptEngine.QObjectWrapOptions`
Return type:	`PySide.QtScript.QScriptValue`

Creates a QtScript object that wraps the given PySide.QtCore.QObject object , using the given ownership . The given options control various aspects of the interaction with the resulting script object.

Signals and slots, properties and children of object are available as properties of the created PySide.QtScript.QScriptValue . For more information, see the QtScript documentation.

If object is a null pointer, this function returns PySide.QtScript.QScriptEngine.nullValue() .

If a default prototype has been registered for the object ‘s class (or its superclass, recursively), the prototype of the new script object will be set to be that default prototype.

If the given object is deleted outside of QtScript ‘s control, any attempt to access the deleted PySide.QtCore.QObject ‘s members through the QtScript wrapper object (either by script code or C++) will result in a script exception.

PySide.QtScript.QScriptEngine.newQObject(scriptObject, qtObject[, ownership=QtOwnership[, options=0]])

Parameters:	scriptObject – `PySide.QtScript.QScriptValue` qtObject – `PySide.QtCore.QObject` ownership – `PySide.QtScript.QScriptEngine.ValueOwnership` options – `PySide.QtScript.QScriptEngine.QObjectWrapOptions`
Return type:	`PySide.QtScript.QScriptValue`

This is an overloaded function.

Initializes the given scriptObject to hold the given qtObject , and returns the scriptObject .

This function enables you to “promote” a plain Qt Script object (created by the PySide.QtScript.QScriptEngine.newObject() function) to a PySide.QtCore.QObject proxy, or to replace the PySide.QtCore.QObject contained inside an object previously created by the PySide.QtScript.QScriptEngine.newQObject() function.

The prototype() of the scriptObject will remain unchanged.

If scriptObject is not an object, this function behaves like the normal PySide.QtScript.QScriptEngine.newQObject() , i.e. it creates a new script object and returns it.

This function is useful when you want to provide a script constructor for a PySide.QtCore.QObject -based class. If your constructor is invoked in a new expression ( QScriptContext.isCalledAsConstructor() returns true), you can pass QScriptContext.thisObject() (the default constructed script object) to this function to initialize the new object.

PySide.QtScript.QScriptEngine.newRegExp(pattern, flags)¶

Parameters:	pattern – unicode flags – unicode
Return type:	`PySide.QtScript.QScriptValue`

Creates a QtScript object of class RegExp with the given pattern and flags .

The legal flags are ‘g’ (global), ‘i’ (ignore case), and ‘m’ (multiline).

PySide.QtScript.QScriptEngine.newRegExp(regexp)

Parameters:	regexp – `PySide.QtCore.QRegExp`
Return type:	`PySide.QtScript.QScriptValue`

Creates a QtScript object of class RegExp with the given regexp .

See also

QScriptValue.toRegExp()

PySide.QtScript.QScriptEngine.newVariant(value)¶

Parameters:	value – object
Return type:	`PySide.QtScript.QScriptValue`

Creates a QtScript object holding the given variant value .

If a default prototype has been registered with the meta type id of value , then the prototype of the created object will be that prototype; otherwise, the prototype will be the Object prototype object.

PySide.QtScript.QScriptEngine.newVariant(object, value)

Parameters:	object – `PySide.QtScript.QScriptValue` value – object
Return type:	`PySide.QtScript.QScriptValue`

This is an overloaded function.

Initializes the given Qt Script object to hold the given variant value , and returns the object .

This function enables you to “promote” a plain Qt Script object (created by the PySide.QtScript.QScriptEngine.newObject() function) to a variant, or to replace the variant contained inside an object previously created by the PySide.QtScript.QScriptEngine.newVariant() function.

The prototype() of the object will remain unchanged.

If object is not an object, this function behaves like the normal PySide.QtScript.QScriptEngine.newVariant() , i.e. it creates a new script object and returns it.

This function is useful when you want to provide a script constructor for a C++ type. If your constructor is invoked in a new expression ( QScriptContext.isCalledAsConstructor() returns true), you can pass QScriptContext.thisObject() (the default constructed script object) to this function to initialize the new object.

PySide.QtScript.QScriptEngine.nullValue()¶

Return type:	`PySide.QtScript.QScriptValue`

Returns a PySide.QtScript.QScriptValue of the primitive type Null.

PySide.QtScript.QScriptEngine.objectById(id)¶

Parameters:	id – `PySide.QtCore.qint64`
Return type:	`PySide.QtScript.QScriptValue`

Returns the object with the given id , or an invalid PySide.QtScript.QScriptValue if there is no object with that id.

See also

QScriptValue.objectId()

PySide.QtScript.QScriptEngine.popContext()¶: Pops the current execution context and restores the previous one. This function must be used in conjunction with PySide.QtScript.QScriptEngine.pushContext() .

See also

PySide.QtScript.QScriptEngine.pushContext()

PySide.QtScript.QScriptEngine.processEventsInterval()¶

Return type:	`PySide.QtCore.int`

Returns the interval in milliseconds between calls to QCoreApplication.processEvents() while the interpreter is running.

PySide.QtScript.QScriptEngine.pushContext()¶

Return type:	`PySide.QtScript.QScriptContext`

Enters a new execution context and returns the associated PySide.QtScript.QScriptContext object.

Once you are done with the context, you should call PySide.QtScript.QScriptEngine.popContext() to restore the old context.

By default, the this’ object of the new context is the Global Object. The context’s :meth:`PySide.QtScript.QScriptContext.callee () will be invalid.

This function is useful when you want to evaluate script code as if it were the body of a function. You can use the context’s PySide.QtScript.QScriptContext.activationObject() () to initialize local variables that will be available to scripts. Example:

engine = QScriptEngine()
context = engine.pushContext()
context.activationObject().setProperty("myArg", 123)
engine.evaluate("var tmp = myArg + 42")
...
engine.popContext()

In the above example, the new variable “tmp” defined in the script will be local to the context; in other words, the script doesn’t have any effect on the global environment.

Returns 0 in case of stack overflow

PySide.QtScript.QScriptEngine.reportAdditionalMemoryCost(size)¶

Parameters:	size – `PySide.QtCore.int`

Reports an additional memory cost of the given size , measured in bytes, to the garbage collector.

This function can be called to indicate that a Qt Script object has memory associated with it that isn’t managed by Qt Script itself. Reporting the additional cost makes it more likely that the garbage collector will be triggered.

Note that if the additional memory is shared with objects outside the scripting environment, the cost should not be reported, since collecting the Qt Script object would not cause the memory to be freed anyway.

Negative size values are ignored, i.e. this function can’t be used to report that the additional memory has been deallocated.

PySide.QtScript.QScriptEngine.setAgent(agent)¶

Parameters:	agent – `PySide.QtScript.QScriptEngineAgent`

Installs the given agent on this engine. The agent will be notified of various events pertaining to script execution. This is useful when you want to find out exactly what the engine is doing, e.g. when PySide.QtScript.QScriptEngine.evaluate() is called. The agent interface is the basis of tools like debuggers and profilers.

The engine maintains ownership of the agent .

Calling this function will replace the existing agent, if any.

See also

PySide.QtScript.QScriptEngine.agent()

PySide.QtScript.QScriptEngine.setDefaultPrototype(metaTypeId, prototype)¶

Parameters:	metaTypeId – `PySide.QtCore.int` prototype – `PySide.QtScript.QScriptValue`

Sets the default prototype of the C++ type identified by the given metaTypeId to prototype .

The default prototype provides a script interface for values of type metaTypeId when a value of that type is accessed from script code. Whenever the script engine (implicitly or explicitly) creates a PySide.QtScript.QScriptValue from a value of type metaTypeId , the default prototype will be set as the PySide.QtScript.QScriptValue ‘s prototype.

The prototype object itself may be constructed using one of two principal techniques; the simplest is to subclass PySide.QtScript.QScriptable , which enables you to define the scripting API of the type through PySide.QtCore.QObject properties and slots. Another possibility is to create a script object by calling PySide.QtScript.QScriptEngine.newObject() , and populate the object with the desired properties (e.g. native functions wrapped with newFunction() ).

See also

PySide.QtScript.QScriptEngine.defaultPrototype() qScriptRegisterMetaType() PySide.QtScript.QScriptable Default Prototypes Example

PySide.QtScript.QScriptEngine.setGlobalObject(object)¶

Parameters:	object – `PySide.QtScript.QScriptValue`

Sets this engine’s Global Object to be the given object . If object is not a valid script object, this function does nothing.

When setting a custom global object, you may want to use PySide.QtScript.QScriptValueIterator to copy the properties of the standard Global Object; alternatively, you can set the internal prototype of your custom object to be the original Global Object.

PySide.QtScript.QScriptEngine.setProcessEventsInterval(interval)¶

Parameters:	interval – `PySide.QtCore.int`

Sets the interval between calls to QCoreApplication::processEvents to interval milliseconds.

While the interpreter is running, all event processing is by default blocked. This means for instance that the gui will not be updated and timers will not be fired. To allow event processing during interpreter execution one can specify the processing interval to be a positive value, indicating the number of milliseconds between each time QCoreApplication.processEvents() is called.

The default value is -1, which disables event processing during interpreter execution.

You can use QCoreApplication.postEvent() to post an event that performs custom processing at the next interval. For example, you could keep track of the total running time of the script and call PySide.QtScript.QScriptEngine.abortEvaluation() when you detect that the script has been running for a long time without completing.

PySide.QtScript.QScriptEngine.signalHandlerException(exception)¶

Parameters:	exception – `PySide.QtScript.QScriptValue`

PySide.QtScript.QScriptEngine.toObject(value)¶

Parameters:	value – `PySide.QtScript.QScriptValue`
Return type:	`PySide.QtScript.QScriptValue`

Converts the given value to an object, if such a conversion is possible; otherwise returns an invalid PySide.QtScript.QScriptValue . The conversion is performed according to the following table:

Input Type	Result
Undefined	An invalid `PySide.QtScript.QScriptValue` .
Null	An invalid `PySide.QtScript.QScriptValue` .
Boolean	A new Boolean object whose internal value is set to the value of the boolean.
Number	A new Number object whose internal value is set to the value of the number.
String	A new String object whose internal value is set to the value of the string.
Object	The result is the object itself (no conversion).

PySide.QtScript.QScriptEngine.toStringHandle(str)¶

Parameters:	str – unicode
Return type:	`PySide.QtScript.QScriptString`

Returns a handle that represents the given string, str .

PySide.QtScript.QScriptString can be used to quickly look up properties, and compare property names, of script objects.

See also

QScriptValue.property()

PySide.QtScript.QScriptEngine.uncaughtException()¶

Return type:	`PySide.QtScript.QScriptValue`

Returns the current uncaught exception, or an invalid PySide.QtScript.QScriptValue if there is no uncaught exception.

The exception value is typically an Error object; in that case, you can call toString() on the return value to obtain an error message.

PySide.QtScript.QScriptEngine.uncaughtExceptionBacktrace()¶

Return type:	list of strings

Returns a human-readable backtrace of the last uncaught exception.

It is in the form <function-name>()@<file-name>:<line-number> .

PySide.QtScript.QScriptEngine.uncaughtExceptionLineNumber()¶

Return type:	`PySide.QtCore.int`

Returns the line number where the last uncaught exception occurred.

Line numbers are 1-based, unless a different base was specified as the second argument to PySide.QtScript.QScriptEngine.evaluate() .

PySide.QtScript.QScriptEngine.undefinedValue()¶

Return type:	`PySide.QtScript.QScriptValue`

Returns a PySide.QtScript.QScriptValue of the primitive type Undefined.

Table Of Contents

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QScriptEngine¶

Synopsis¶

Functions¶

Signals¶

Static functions¶

Detailed Description¶

Evaluating Scripts¶

Engine Configuration¶

Script Exceptions¶

Script Object Creation¶

QObject Integration¶

Support for Custom C++ Types¶

Importing Extensions¶

Native Functions¶

Long-running Scripts¶

Garbage Collection¶

Core Debugging/Tracing Facilities¶

Table Of Contents

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QScriptEngine¶

Synopsis¶

Functions¶

Signals¶

Static functions¶

Detailed Description¶

Evaluating Scripts¶

Engine Configuration¶

Script Exceptions¶

Script Object Creation¶

QObject Integration¶

Support for Custom C++ Types¶

Importing Extensions¶

Native Functions¶

Long-running Scripts¶

Garbage Collection¶

Core Debugging/Tracing Facilities¶