cugl::WidgetValue Class Reference

#include <CUWidgetValue.h>

Public Member Functions
	WidgetValue ()
	~WidgetValue ()
bool	init (const std::shared_ptr< JsonValue > &json)
const std::shared_ptr< JsonValue >	getJson () const
std::vector< std::string >	getVariables () const
std::shared_ptr< JsonValue >	substitute (const std::shared_ptr< JsonValue > &values) const
bool	isValid () const

Static Public Member Functions
static std::shared_ptr< WidgetValue >	alloc (std::shared_ptr< JsonValue > json)

Protected Attributes
std::shared_ptr< JsonValue >	_json

Detailed Description

This class represents an externally defined widget in JSON form.

A widget is a JSON with substitution semantics. That is, it has variables that refer to nodes in the JSON tree, and allows these nodes to be replaced with other JSON trees. The purpose of this is to manage heavily nested JSON structures, such as those specifying Figma scene graphs.

More specifically, a widget value is a JSON object with two keys: "variables" and "contents". The former is JSON object with (string) keys mapping to paths in "contents". For example:

{
    "variables" : {
        "first" :  ["outer", "inner", "one"],
        "second" : ["outer" , "middle"]
    },
        "contents : {
            "outer" : {
                "inner" : {
                    "one" : 1,
                    "two" : 2,
            },
            "middle": 3
        }
    }
}

A call to substitute on the JSON { "first": 4} will return the JSON object

{
    "inner" : {
        "outer" : {
            "one" : 4,
            "two" : 2,
        },
        "middle": 3
    }
}

The substitution semantics is rather simple. That means it is undefined if any of the variables are prefixes of one another. The method isValid is used to check for valid widgets.

Constructor & Destructor Documentation

WidgetValue()

cugl::WidgetValue::WidgetValue ( )

inline

Creates a null WidgetValue.

NEVER USE A CONSTRUCTOR WITH NEW. If you want to allocate an object on the heap, use one of the static constructors instead.

~WidgetValue()

cugl::WidgetValue::~WidgetValue ( )

inline

Deletes this WidgetValue and all of its resources.

If no other references own the descendants of this node, they will all be recursively deleted as well.

Member Function Documentation

alloc()

static std::shared_ptr< WidgetValue > cugl::WidgetValue::alloc ( std::shared_ptr< JsonValue >  json )

inlinestatic

Returns a newly allocated WidgetValue to wrap the given JsonValue.

Parameters

json	The JSON definition of this widget.

Returns

a newly allocated WidgetValue wrapping the provided JsonValue.

getJson()

const std::shared_ptr< JsonValue > cugl::WidgetValue::getJson ( ) const

inline

Returns the JsonValue representation of this widget.

Returns

a shared pointer to the JsonValue representation of this widget.

getVariables()

std::vector< std::string > cugl::WidgetValue::getVariables

(

)

const

Returns the list of variables in this widget.

The variables are JSON locations in the tree that can be substituted with new JSON values. Variables names are used in conjuction with substitute to produce a new JSON value

Returns

the list of variables in this widget.

init()

bool cugl::WidgetValue::init ( const std::shared_ptr< JsonValue > &  json )

inline

Initializes a new WidgetValue to wrap the give JsonValue.

This initializer simply wraps the provided JSON

Parameters

json	A shared pointer to JsonValue that defines this widget.

Returns

true if the JsonValue is not a nullptr, false otherwise.

isValid()

bool cugl::WidgetValue::isValid

(

)

const

Returns true if this widget value is valid.

A valid widget value is a JSON in the correct format, and which does not have any variables that are prefixes of another.

Returns

true if this widget value is valid.

substitute()

std::shared_ptr< JsonValue > cugl::WidgetValue::substitute

(

const std::shared_ptr< JsonValue > &

values

)

const

Returns the JSON value resulting from substituting the specified values.

The values should be a JSON object whose entries are collection are some subset of getVariables. For each entry, this function will find the internal node for that variable, and replace the subtree with the value for that variable.

This function creates a new JsonValue, and does not modify the widget. Therefore, the widget can be safely reused for other substitutions.

Parameters

values

The variable substitutions

Returns

the JSON value resulting from substituting the specified values.

Member Data Documentation

_json

std::shared_ptr<JsonValue> cugl::WidgetValue::_json

protected

The JSON entry representing this widget

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The documentation for this class was generated from the following file:

• /Users/wmwhite/Developer/CUGL/include/cugl/core/assets/CUWidgetValue.h