JSON-AM-Data-Format

JSON AM Data Format

JSON AM descriptor

A descriptor in JSON AM Data Format is represented as a JSON object { } (not to be confused with the Photoshop API Object type, whose tag is "<object>" as described below), where each item in the descriptor is expressed as a unique key unified ID string associated with a “typed value”:

Typed Value	Parameters	ActionDescriptor Methods
{ "<boolean>": Boolean } or [ "<boolean>", Boolean ]	Boolean : true or false	desc.getBoolean desc.putBoolean
{ "<class>": Class } or [ "<class>", Class ]	Class : class unified ID string	desc.getClass desc.putClass
{ "<data>": Data } or [ "<data>", Data ]	Data : raw byte data string	desc.getData desc.putData (only from CS2)
{ "<double>": Double } or [ "<double>", Double ]	Double : number	desc.getDouble desc.putDouble
{ "<enumerated>": { EnumType: EnumValue } } or [ "<enumerated>", [ EnumType, EnumValue ] ]	EnumType : enumType unified ID string EnumValue : enumValue unified ID string	desc.getEnumerationType desc.getEnumerationValue desc.putEnumerated
{ "<integer>": Integer } or [ "<integer>", Integer ]	Integer : number (signed integer)	desc.getInteger desc.putInteger
{ "<largeInteger>": LargeInteger } or [ "<largeInteger>", LargeInteger ]	LargeInteger : number (signed integer)	desc.getLargeInteger desc.putLargeInteger (only from CS6)
{ "<list>": List } or [ "<list>", List ]	List : JSON AM list array	desc.getList desc.putList
{ "<object>": { Class: Descriptor } } or [ "<object>", [ Class, Descriptor ] ]	Class : class unified ID string Descriptor : JSON AM descriptor object	desc.getObjectType desc.getObjectValue desc.putObject
{ "<path>": Path } or [ "<path>", Path ]	Path : file system path string	desc.getPath desc.putPath
{ "<reference>": Reference } or [ "<reference>", Reference ]	Reference : JSON AM reference array	desc.getReference desc.putReference
{ "<string>": String } or [ "<string>", String ]	String : string	desc.getString desc.putString
{ "<unitDouble>": { Unit: Double } } or [ "<unitDouble>", [ Unit, Double ] ]	Unit : unit unified ID string Double : number	desc.getUnitDoubleType desc.getUnitDoubleValue desc.putUnitDouble

Example

{
    "mode": { "<class>": "RGBColorMode" },
    "width": { "<unitDouble>": { "distanceUnit": 512 } },
    "height": { "<unitDouble>": { "distanceUnit": 512 } },
    "resolution": { "<unitDouble>": { "densityUnit": 72 } },
    "pixelScaleFactor": { "<double>": 1 },
    "fill": { "<enumerated>": { "fill": "white" } },
    "depth": { "<integer>": 8 },
    "profile": { "<string>": "sRGB IEC61966-2.1" }
}

or

{
    "mode": [ "<class>", "RGBColorMode" ],
    "width": [ "<unitDouble>", [ "distanceUnit", 512 ] ],
    "height": [ "<unitDouble>", [ "distanceUnit", 512 ] ],
    "resolution": [ "<unitDouble>", [ "densityUnit", 72 ] ],
    "pixelScaleFactor": [ "<double>", 1 ],
    "fill": [ "<enumerated>", [ "fill", "white" ] ],
    "depth": [ "<integer>", 8 ],
    "profile": [ "<string>", "sRGB IEC61966-2.1" ]
}

JSON AM list

A list in JSON AM Data Format is represented as a JSON array [ ], where each element of the array is a “typed value”:

Typed Value	Parameters	ActionList Methods
{ "<boolean>": Boolean } or [ "<boolean>", Boolean ]	Boolean : true or false	list.getBoolean list.putBoolean
{ "<class>": Class } or [ "<class>", Class ]	Class : class unified ID string	list.getClass list.putClass
{ "<data>": Data } or [ "<data>", Data ]	Data : raw byte data string	list.getData list.putData (only from CS2)
{ "<double>": Double } or [ "<double>", Double ]	Double : number	list.getDouble list.putDouble
{ "<enumerated>": { EnumType: EnumValue } } or [ "<enumerated>", [ EnumType, EnumValue ] ]	EnumType : enumType unified ID string EnumValue : enumValue unified ID string	list.getEnumerationType list.getEnumerationValue list.putEnumerated
{ "<integer>": Integer } or [ "<integer>", Integer ]	Integer : number (signed integer)	list.getInteger list.putInteger
{ "<largeInteger>": LargeInteger } or [ "<largeInteger>", LargeInteger ]	LargeInteger : number (signed integer)	list.getLargeInteger list.putLargeInteger (only from CS6)
{ "<list>": List } or [ "<list>", List ]	List : JSON AM list array	list.getList list.putList
{ "<object>": { Class: Descriptor } } or [ "<object>", [ Class, Descriptor ] ]	Class : class unified ID string Descriptor : JSON AM descriptor object	list.getObjectType list.getObjectValue list.putObject
{ "<path>": Path } or [ "<path>", Path ]	Path : file system path string	list.getPath list.putPath
{ "<reference>": Reference } or [ "<reference>", Reference ]	Reference : JSON AM reference array	list.getReference list.putReference
{ "<string>": String } or [ "<string>", String ]	String : string	list.getString list.putString
{ "<unitDouble>": { Unit: Double } } or [ "<unitDouble>", [ Unit, Double ] ]	Unit : unit unified ID string Double : number	list.getUnitDoubleType list.getUnitDoubleValue list.putUnitDouble

Example

[
    { "<string>": "Times" },
    { "<string>": "Helvetica" },
    { "<string>": "Monaco" }
]

or

[
    [ "<string>", "Times" ],
    [ "<string>", "Helvetica" ],
    [ "<string>", "Monaco" ]
]

JSON AM reference

A reference in JSON AM Data Format is represented as a JSON array [ ], where each element of the array is either:
{ DesiredClass: TypedValue }
or
[ DesiredClass, TypedValue ]

DesiredClass is a class unified ID string, and TypedValue is a “typed value”:

Typed Value	Parameters	ActionReference Methods
{ "<class>": null } or [ "<class>", null ]	(none)	(none) ref.putClass
{ "<enumerated>": { EnumType: EnumValue } } or [ "<enumerated>", [ EnumType, EnumValue ] ]	EnumType : enumType unified ID string EnumValue : enumValue unified ID string	ref.getEnumeratedType ref.getEnumeratedValue ref.putEnumerated
{ "<identifier>": Identifier } or [ "<identifier>", Identifier ]	Identifier : number (unsigned integer)	ref.getIdentifier ref.putIdentifier
{ "<index>": Index } or [ "<index>", Index ]	Index : number (unsigned integer)	ref.getIndex ref.putIndex
{ "<name>": Name } or [ "<name>", Name ]	Name : string	ref.getName ref.putName
{ "<offset>": Offset } or [ "<offset>", Offset ]	Offset : number (signed integer)	ref.getOffset ref.putOffset
{ "<property>": Property } or [ "<property>", Property ]	Property : property (key) unified ID string	ref.getProperty ref.putProperty

Example

[
    { "property": { "<property>": "histogram" } },
    { "channel": { "<enumerated>": { "channel": "green" } } },
    { "layer": { "<name>": "Hulk" } },
    { "document": { "<index>": 1 } }
]

or

[
    [ "property", [ "<property>", "histogram" ] ],
    [ "channel", [ "<enumerated>", [ "channel", "green" ] ] ],
    [ "layer", [ "<name>", "Hulk" ] ],
    [ "document", [ "<index>", 1 ] ]
]

Unified ID string

ID String	Unified Syntax	Examples	Application Methods
CharID	Four-letter “mnemonic” string surrounded by single quotation marks: "'xxxx'"	"'Rd  '" "'Grn '" "'Bl  '" "'H   '" "'Axis'" "'#Pxl'"	app.charIDToTypeID app.typeIDToCharID
StringID	Plain “human-readable” text string: "xxxxxxxx"	"red" "green" "blue" "hue" "axis" "pixelsUnit"	app.stringIDToTypeID app.typeIDToStringID

Note: In Photoshop, all internal IDs are strictly positive integers; they are normally represented by more “readable” strings known as CharIDs and StringIDs, converted to numerical IDs by app.charIDToTypeID and app.stringIDToTypeID respectively. Any CharID or StringID can actually be used as long as they are equivalent, i.e., they get converted to the same numerical ID.

Notes

• A JSON object is an unordered collection of name/value pairs. It begins with { (left brace) and ends with } (right brace). Each name is a string followed by : (colon) and the name/value pairs are separated by , (comma).

• A JSON array is an ordered sequence of values. It begins with [ (left bracket) and ends with ] (right bracket). Values are separated by , (comma).

• A value can only be: a string, a number, an object, an array, or true, false and null.

• All strings must be enclosed in double quotes.

• As an extra reminder, it should be noted that the following JavaScript statements:

var myObject = { };
var myArray = [ ];

are strictly equivalent to:

var myObject = new Object ();
var myArray = new Array ();