--- name: "JavaScript::Context" section: "3pm" platform: "linux" package: "libjavascript-perl" version: "1.16-3" release: "Debian 6.0 (Squeeze)" platforms: ["linux"] url: "https://new.carta.tech/JavaScript::Context" --- # JavaScript::Context(3pm) An object in which we can execute JavaScript ## NAME JavaScript::Context - An object in which we can execute JavaScript ## SYNOPSIS ``` use JavaScript; # Create a runtime and a context my $rt = JavaScript::Runtime->new(); my $cx = $rt->create_context(); # Add a function which we can call from JavaScript $cx->bind_function(print => sub { print @_; }); my $result = $cx->eval($source); ``` ## INTERFACE ### INSTANCE METHODS - bind\_class ( %args ) Defines a new class that can be used from JavaScript in the contet. It expects the following arguments - name The name of the class in JavaScript. ``` name => "MyPackage", ``` - constructor A reference to a subroutine that returns the Perl object that represents the JavaScript object. If omitted a default constructor will be supplied that calls the method `"new"` on the defined *package* (or *name* if no package is defined). ``` constructor => sub { MyPackage->new(@_); }, ``` - package The name of the Perl package that represents this class. It will be passed as first argument to any class methods and also used in the default constructor. ``` package => "My::Package", ``` - methods (fs) A hash reference of methods that we define for instances of the class. In JavaScript this would be `"o = new MyClass(); o.method()"`. The key is used as the name of the function and the value should be either a reference to a subroutine or the name of the Perl subroutine to call. ``` methods => { to_string => \&My::Package::to_string, random => "randomize" } ``` - static\_methods (static\_ps) Like *fs* but these are called on the class itself. In JavaScript this would be `"MyClass.method()"`. - properties (ps) A hash reference of properties that we define for instances of the class. In JavaScript this would be `"o = new MyClass(); f = o.property;"` The key is used as the name of the property and the value is used to specify what method to call as a get-operation and as a set-operation. These can either be specified using references to subroutines or name of subroutines. If the getter is undefined the property will be write-only and if the setter is undefined the property will be read-only. You can specify the getter/setter using either an array reference, `"[\&MyClass::get_property, \&MyClass::set_property]"`, a string, `"MyClass::set_property MyClass::get_property"` or a hash reference, `"{ getter ="` "MyClass::get\_property", setter =\> "MyClass::set\_property" }\>. ``` ps => { length => [qw(get_length)], parent => { getter => \&MyClass::get_parent, setter => \&MyClass::set_parent }, } ``` - static\_properties (static\_ps) Like *ps* but these are defined on the class itself. In JavaScript this would be `"f = MyClass.property"`. - flags A bitmask of attributes for the class. Valid attributes are: - JS\_CLASS\_NO\_INSTANCE Makes the class throw an exception if JavaScript tries to instansiate the class. - bind\_function ( name =\> $name, func =\> $subroutine ) - bind\_function ( $name =\> $subroutine ) Defines a Perl subroutine ($subroutine\_ref) as a native function with the given *$name*. The argument `$subroutine` can either be the name of a subroutine or a reference to one. - bind\_object ( $name =\> $object ) Binds a Perl object to the context under a given name. - bind\_value ( $name =\> $value ) Defines a value with a given name and value. Trying to redefine an already existing property throws an exception. - unbind\_value ( $name ) Removed a property from the context or a specified object. - call ( $name, @arguments ) - call ( $function, @arguments ) Calls a function with the given name *$name* or the **JavaScript::Function**-object *$function* and passes the rest of the arguments to the JavaScript function. - can ( $name ) Returns true if there is a function with a given *$name*, otherwise it returns false. - compile ( $source ) Pre-compiles the JavaScript given in *$source* and returns a `"JavaScript::Script"`-object that can be executed over and over again. If an error occures because of a compilation error it returns undef and $@ is set. - eval ( $source ) Evaluates the JavaScript code given in *$source* and returns the result from the last statement. If there is a compilation error (such as a syntax error) or an uncaught exception is thrown in JavaScript this method returns undef and $@ is set. - eval\_file ( $path ) Evaluates the JavaScript code in the file specified by *$path* and returns the result from the last statement. If there is a compilation error (such as a syntax error) or an uncaught exception is thrown in JavaScript this method returns undef and $@ is set. - find ( $native\_context ) Returns the `"JavaScript::Context"`-object associated with a given native context. - set\_pending\_exception ( $value ) Converts the *$value* to JavaScript and sets it as the pending exception for the context. - get\_version ( ) Returns the runtime version of the context as a string, for exmaple `1.7` or or `"ECMAv3"`. - set\_version ( $version ) Sets the runtime version of the context to that specified in the string *$version*. Some features such as `"let"` and `"yield"` might not be enabled by default and thus must be turned on by specifying what JS version we're using. A list of these can be found at \ but may vary depending on the version of your runtime. - get\_options ( ) Returns a list of the options currently enabled on the context. - has\_options ( OPTION, ... ) Tests if the options are eneabled on the context. - toggle\_options ( OPTION, ... ) Toggles the options on the context. ### OPTIONS A number of options can be set on contexts. The following are understood (case-insensitive): - strict Warn on dubious practice. - xml ECMAScript for XML (E4X) support: parse \