Built in elements

GSS includes several built-in features to help define styles:

• Colors
• Functions
• Variables

Colors

Graph Style Script comes with built-in colors that you can use by their name.

Example of using color names:

@NodeStyle {
  color: aquamarine
  color-hover: Darker(cyan)
}

Example of using color codes:

@NodeStyle {
  color: #7FFFD4
  color-hover: Darker(#00FFFF)
}

The color names come from a list of the X11 colors supported by popular browsers with the addition of gray/grey variants from SVG 1.0.

Functions

Graph Style Script has a large number of built-in functions:

• Color functions
• Conditional functions
• Graph functions
• Map functions
• Math functions
• Text functions
• Array functions
• Type functions
• Utility functions

With these functions, you can achieve the right style for your graph.

Color functions

Darker(color)

Returns a darker version of the given color.

Example:

• color-hover: Darker(#dd2222) will make the hover event color darker.

Inputs:

• color: Color

Outputs:

• Color

Lighter(color)

Returns a lighter version of the given color.

Example:

• color-hover: Lighter(#dd2222) sets a lighter on hover event color.

Inputs:

• color: Color

Outputs:

• Color

Mix(color1, color2)

Mixes given colors (performs linear interpolation).

Example:

• Mix(#1B5E20, orange)

Inputs:

• color1: Color
• color2: Color

Outputs:

• Color

Red(color)

Returns the red component of a given color. The value will be between 0 and 255 (both inclusive).

Examples:

• Red(mediumseagreen) will return the value 60.
• Red(#6a0dad) will return the value 106.

Inputs:

• color: Color

Outputs:

• number

Green(color)

Returns the green component of a given color. The value will be between 0 and 255 (both inclusive).

Examples:

• Green(mediumseagreen) will return the value 179.
• Green(#6a0dad) will return the value 13.

Inputs:

• color: Color

Outputs:

• number

Blue(color)

Returns the blue component of a given color. The value will be between 0 and 255 (both inclusive).

Examples:

• Blue(mediumseagreen) will return the value 113.
• Blue(#6a0dad) will return the value 173.

Inputs:

• color: Color

Outputs:

• number

RGB(red, green, blue)

Creates a new color with given components.

Example:

• RGB (128, 159, 255) will return the color that has value #809fff.

Inputs:

• red: number
• green: number
• blue: number

Outputs:

• Color

RGBA(red, green, blue, alpha)

Creates a new color with given components. Same as RGB with an additional alpha value (between 0 and 1) for transparency.

Example:

• RGBA(128, 159, 255, 0.2) will return the color that has value #809fff33.

Inputs:

• red: number
• green: number
• blue: number
• alpha: number

Outputs:

• Color

Hue(color)

Returns the hue (HSL) component of a given color. The value will be between 0 and 359 (both inclusive).

Example:

• Hue(aliceblue) will return value 208.
• Hue(#00FFFF) will return value 180.

Inputs:

• color: Color

Outputs:

• number

Saturation(color)

Returns the saturation (HSL) component of a given color. The value will be between 0 and 100 (both inclusive).

Example:

• Saturation(aliceblue) will return value 100.
• Saturation(#77a4ab) will return value 24.

Inputs:

• color: Color

Outputs:

• number

Lightness(color)

Returns the lightness (HSL) component of a given color. The value will be between 0 and 100 (both inclusive).

Example:

• Lightness(aliceblue) will return value 97.
• Lightness(#FFFF00) will return value 50.

Inputs:

• color: Color

Outputs:

• number

HSL(hue, saturation, lightness)

Creates a new color with given HSL (hue, saturation, lightness) values. Hue value must be between 0 and 359 (both inclusive), saturation and lightness values must be between 0 and 100 (both inclusive).

Example:

• HSL(282, 23, 56) will return the color that has value #9975a9.

Inputs:

• hue: number
• saturation: number
• lightness: number

Outputs:

• Color

HSLA(hue, saturation, lightness, alpha)

Creates a new color with given components. Same as HSL with an additional alpha value (between 0 and 1) for transparency.

Example:

• HSLA(282, 23, 56, 0.2) will return the color that has value #9975a933.

Inputs:

• hue: number
• saturation: number
• lightness: number
• alpha: number

Outputs:

• Color

Alpha(color)

Returns alpha (transparency) component of a given color. The value will be between 0 and 1 (both inclusive).

Examples:

• Alpha(aliceblue) will return value 1.
• Alpha(#FFFF0033) will return value 0.2.
• Alpha(RGBA(282, 23, 56, 0.8)) will return value 0.8.
• Alpha(HSLA(282, 23, 56, 0.2)) will return value 0.2.

Inputs:

• color: Color

Outputs:

• number

Conditional functions

And(value...)

Returns True if all the given values are Truthy. Returns False otherwise. Expressions after the first expression that evaluates to Falsy are not evaluated.

In GSS, there are six Falsy values: False , 0 , "" , Null , [] (empty array), and {} (empty map). Everything else is considered Truthy.

Example:

• And(HasProperty(node, "a"), HasProperty(node, "b")) will return True if node has properties a and b.

Inputs:

• value1: any
• value2: any
• valueN: any

Outputs:

• boolean

Or(value...)

Returns True if any of the given values is Truthy. Returns False otherwise. Expressions after the first expression that evaluates to Truthy are not evaluated.

In GSS, there are six Falsy values: False , 0 , "" , Null , [] (empty array), and {} (empty map). Everything else is considered Truthy.

Example:

• Or(Less(Property(node, "age"),20), Greater(Property(node, "age"),40)) returns True if the node’s age property is either less than 20 or greater than 40.

Inputs:

• value1: any
• value2: any
• valueN: any

Outputs:

• boolean

Not(value)

Returns True if the value is Falsy and returns False if the value is Truthy.

In GSS, there are six Falsy values: False , 0 , "" , Null , [] (empty array), and {} (empty map). Everything else is considered Truthy.

Example:

• @NodeStyle Not(HasProperty(node, "count")) {...} will apply the defined styles to the nodes without the count property.

Inputs:

• value: any

Outputs:

• boolean

Equals(value1, value2)

Returns True if given values are equal, False otherwise. Numbers, Strings and Booleans are compared by value, Arrays and Maps by the content, Nodes and Edges are compared by identity.

Example:

• Equals(Property(edge, "category"), "Food") checks if edge.category equals to text “Food”.
• Equals(Property(node, "name"), "Jon Snow") returns True if the condition is met.

Inputs:

• value1: any
• value2: any

Outputs:

• boolean

Greater(value1, value2)

Returns True if value1 is greater than value2, False otherwise.

Example:

• Greater(Size(Labels(node)), 0)

Inputs:

• value1: number
• value2: number

Outputs:

• boolean

Less(number1, number2)

Returns True if value1 is less than value2, False otherwise.

Example:

• Less(Property(node, "age"),40) will return True if given node.age is less than 40.

Inputs:

• value1: number
• value2: number

Outputs:

• boolean

If(condition, then, else)

If condition is Truthy returns the then value, otherwise returns the else value.

In GSS, there are six Falsy values: False , 0 , "" , Null , [] (empty array), and {} (empty map). Everything else is considered Truthy.

Example:

• label: If(HasProperty(node, "name"), Property(node, "name"), "No name") returns the property name as label if the node has one, or No name if the node doesn’t have it.

Inputs:

• condition: any
• then: any
• else: any

Outputs:

• any

Graph functions

HasLabel(node, label)

Returns True if the given graph node has a label, False otherwise.

Example:

• HasLabel(node, "Category") will return True if a node has a label with the name Category.

Inputs:

• node: Node
• label: string

Outputs:

• boolean

HasProperty(nodeOrEdge, propertyName)

Returns True if a given graph node or relationship has the property propertyName.

Example:

• HasProperty(node, "City") will return True if a node has a property with the name City.

Inputs:

• nodeOrEdge: Node | Relationship
• propertyName: string

Outputs:

• boolean

Id(nodeOrEdge)

Returns the ID of a given graph node or edge.

Example:

• label: AsText(Id(node)) sets the label to be the node ID.

Inputs:

• nodeOrEdge: Node | Relationship

Outputs:

• number

Identity(nodeOrEdge)

Returns the ID of a given graph node or edge.

Example:

• label: AsText(Identity(node)) sets the label to be the node ID.

Inputs:

• nodeOrEdge: Node | Relationship

Outputs:

• number

Labels(node)

Returns the list of labels of the given graph node.

Example:

• label: Labels(node) sets the label to be a list of all the node’s labels.

Inputs:

• node: Node

Outputs:

• List[string]

Property(nodeOrEdge, propertyName)

Returns the property with the name propertyName of given graph node or relationship.

Example:

• label: AsText(Property(node, "name")) creates a label using the node’s name property.

Inputs:

• nodeOrEdge: Node | Relationship
• propertyName: string

Outputs:

• any

Type(edge)

Returns the type of a given graph relationship.

Example:

• label: Type(edge) sets the label to the relationship type.

Inputs:

• edge: Relationship

Outputs:

• string

InEdges(node)

Returns the list of inbound edges from a given graph node.

Example:

• size: Size(InEdges(node)) sets the size to be equal to the count of inbound edges.

Inputs:

• node: Node

Outputs:

• List[Relationship]

OutEdges(node)

Returns the list of outbound edges from a given graph node.

Example:

• size: Size(OutEdges(node)) sets the size to be equal to the count of outbound edges.

Inputs:

• node: Node

Outputs:

• List[Relationship]

Edges(graphOrNode)

Returns the list of inbound and outbound edges from a given graph node. It returns all the edges in the graph if the input is a graph.

Examples:

• size: Size(Edges(graph)) sets the size to be equal to the count of all graph edges.
• size: Size(Edges(node)) sets the size to be equal to the count of inbound and outbound edges.

Inputs:

• graphOrNode: Graph | Node

Outputs:

• List[Relationship]

InNodes(node)

Returns the list of unique inbound node from a given graph node.

Example:

• size: Size(InNodes(node)) sets the size to be equal to the count of unique inbound nodes.

Inputs:

• node: Node

Outputs:

• List[Node]

OutNodes(node)

Returns the list of unique outbound nodes from a given graph node.

Example:

• size: Size(OutNodes(node)) sets the size to be equal to the count of unique outbound nodes.

Inputs:

• node: Node

Outputs:

• List[Node]

Nodes(graphOrEdge)

Returns the list of start and end nodes from a given graph edge. It returns all the nodes in the graph if the input is a graph.

Examples:

• size: Size(Nodes(graph)) sets the size to be equal to the count of all graph nodes.
• size: Size(Nodes(edge)) sets the size to be equal to the count of nodes that edge connects (usually 2).

Inputs:

• graphOrEdge: Graph | Relationship

Outputs:

• List[Node]

AdjacentNodes(node)

Returns the list of adjacent nodes for a given graph node. An adjacent node is a node connected directly with a single edge, inbound or outbound.

Example:

• size: Size(AdjacentNodes(node)) sets the size to be equal to the count of adjacent nodes.

Inputs:

• node: Node

Outputs:

• List[Node]

StartNode(edge)

Returns the start (source) node for a given graph edge.

Example:

• label: AsText(Id(StartNode(edge))) sets the label of the edge to be the start node ID.

Inputs:

• edge: Relationship

Outputs:

• Node

EndNode(edge)

Returns the end (target) node for a given graph edge.

Example:

• label: AsText(Id(EndNode(edge))) sets the label of the edge to be the end node ID.

Inputs:

• edge: Relationship

Outputs:

• Node

NodeCount(graph)

Returns the total number of nodes in the graph.

Example:

• size: NodeCount(graph) sets the size to be the total number of nodes in the graph.

Inputs:

• graph: Graph

Outputs:

• number

EdgeCount(graph)

Returns the total number of edges in the graph.

Example:

• size: EdgeCount(graph) sets the size to be the total number of edges in the graph.

Inputs:

• graph: Graph

Outputs:

• number

IsTreeStructure(graph: Graph, minDepth?: number)

Determines whether the given graph is a directed tree structure, meaning it contains no cycles and each node has at most one inbound edge. By default, the graph must have a minimum depth of 2 hops to qualify as a tree structure. You can adjust this requirement using the optional minDepth parameter.

Example:

• Apply a “tree” layout to the view if the graph is a tree structure:

@ViewStyle IsTreeStructure(graph) {
  view: "tree"
}

Inputs:

• graph: Graph
• minDepth: number?

Outputs:

• boolean

Map functions

MapKeys(map)

Returns an array of all map keys.

Example:

• MapKeys(AsMap("key1", "value1", "key2", "value2"))) will return an array ["key1", "key2"].

Inputs:

• map: Map[string, any]

Outputs:

• List[string]

MapValues(map)

Returns an array of all map values.

Example:

• MapValues(AsMap("key1", "value1", "key2", 12))) will return an array ["value1", 12].

Inputs:

• map: Map[string, any]

Outputs:

• List[any]

Check other map functions down below: AsMap, IsMap, Get, Set, Del.

Math functions

Add(value...)

Returns the sum of given values.

Example:

• Add(10, Property(node, "age")) will give node.age + 10 if age is defined (as a number).

Inputs:

• value1: number
• value2: number
• valueN: number

Outputs:

• number

Div(value1, value2)

Returns value1 divided by value2.

Example:

• Div(Property(node, "population"), 2) will divide node.population with 2 if population is defined (as a number).

Inputs:

• value1: number
• value2: number

Outputs:

• number

Exp(value)

Returns 2.71828… raised to the power value.

Example: -Exp(2) will return the number 7.38905609893

Inputs:

• value: number

Outputs:

• number

Log(value)

Returns the logarithm (to the base e) of a value.

Example:

• Log(Property(node, "sales"))

Inputs:

• value: number

Outputs:

• number

Log10(value)

Returns the logarithm (to the base 10) of a value.

Example:

• Log10(Property(node, "sales"))

Inputs:

• value: number

Outputs:

• number

Mul(value...)

Returns the product of given values.

Example:

• Mul(2,10,3) returns 60 (2103).

Inputs:

• value1: number
• value2: number
• valueN: number

Outputs:

• number

Random()

Returns a random number between 0 (inclusive) and 1 (exclusive). All the possible numbers are equally likely to be returned.

Example:

• Random()

Outputs:

• number

RandomInt(bound)

Returns a random integer between 0 (inclusive) and bound (exclusive). All the possible numbers are equally likely to be returned.

Example:

• RandomInteger(Property(node, "population")) will return an integer between 0 and node.population if population is defined (as a number).

Inputs:

• bound: number

Outputs:

• number

Sqrt(value)

Returns the square root of a value.

Example:

• Sqrt(Property(node, "surface")) will return the square root of a node.surface.

Inputs:

• value: number

Outputs:

• number

Sub(value1, value2)

Subtracts value2 from value1.

Example:

• Sub(Property(node, "age"),10) returns node.age - 10 if age is defined (as a number).

Inputs:

• value1: number
• value2: number

Outputs:

• number

Floor(value)

Returns the largest integer less than or equal to the input value.

Examples:

• Floor(2.8) will return number 2.
• Floor(2) will return number 2.

Inputs:

• value: number

Outputs:

• number

Ceil(value)

Returns the smallest integer greater than or equal to the input value.

Examples:

• Ceil(2.1) will return number 3.
• Ceil(2) will return number 2.

Inputs:

• value: number

Outputs:

• number

Round(value)

Returns the closest integer to the input value.

Examples:

• Round(2.1) will return number 2.
• Round(2.5) will return number 3.
• Round(2.8) will return number 3.

Inputs:

• value: number

Outputs:

• number

Sum(array)

Returns the sum of all numbers in the input array. For an empty array, it returns 0.

Example:

• Sum(AsArray()) will return number 0.
• Sum(AsArray(1, 2, 3, 4)) will return number 10.
• Sum(AsArray(5.0, 6.5)) will return number 11.5.

Inputs:

• array: List[number]

Outputs:

• number

Avg(array)

Returns the average of all numbers in the input array. An array should have at least one number.

Example:

• Avg(AsArray(1)) will return number 1.
• Avg(AsArray(1, 2, 3, 4, 5)) will return number 3.
• Avg(AsArray(4.8, 6.2)) will return number 5.5.

Inputs:

• array: List[number]

Outputs:

• number

Min(array)

Returns the minimum of all numbers in the input array. An array should have at least one number.

Example:

• Min(AsArray(1)) will return number 1.
• Min(AsArray(1, 2, 3, 4, 5)) will return number 1.
• Min(AsArray(4.8, 6.2)) will return number 4.8.

Inputs:

• array: List[number]

Outputs:

• number

Max(array)

Returns the maximum of all numbers in the input array. An array should have at least one number.

Example:

• Max(AsArray(1)) will return number 1.
• Max(AsArray(1, 2, 3, 4, 5)) will return number 5.
• Max(AsArray(4.8, 6.2)) will return number 6.2.

Inputs:

• array: List[number]

Outputs:

• number

Text functions

Concat(value...)

Concatenates given strings or arrays.

Example:

• Concat("City", " ", "of", " ", "London") will return City of London.
• Concat(AsArray(1, 2, 3), AsArray(4, 5)) will return [1, 2, 3, 4, 5].

Inputs:

• value1: string | List[any] - value2: string | List[any] - valueN: string | List[any]

Outputs:

• string | List[any]

Slice(value, start, end?)

Returns a string or array slice defined by the start and optional end index. Negative indexes will also work.

Examples:

• Slice("Hello", 1) will return "ello".
• Slice("Hello", -3, -1) will return "ll".
• Slice(AsArray(1, 2, 3, 4, 5), 1, 3) will return [2, 3].
• Slice(AsArray(1, 2, 3, 4, 5), -2) will return [4, 5].

Inputs:

• value: string | List[any]
• start: number
• end?: number

Outputs:

• string | List[any]

Split(text, delimiter)

Returns a string or array slice defined by the start and optional end index. Negative indexes will also work.

Examples:

• Split("Hello", "x") will return ["Hello"].
• Split("Hello", "") will return ["H", "e", "l", "l", "o"].
• Split("Hello", "lo") will return ["Hel", ""].
• Split("Hello there", " ") will return ["Hello", "there"].

Inputs:

• text: string
• delimiter: string

Outputs:

• List[string]

Format(formatString, value...)

Substitutes occurrences of curly brace pairs in formatString with textual representations of given values. The first occurrence is substituted with the first value, the second occurrence with the second value and so on.

Examples:

• Format("{}, {}!", "Hello", "World") -> "Hello, World!"

Text inside curly braces is ignored.

• Format("{name}: {age}", "Antun", 23) -> "Antun: 23"

Inputs:

• formatString: string
• value1: any
• valueN: any

Outputs:

• string

Matches(text, regex)

Returns True if text matches regex. The evaluation of the regex is done with the Javascript function RegExp.test(text).

Examples:

• Matches("Graph style script", "style") -> True
• Matches("Graph style script", "st.* script") -> True
• Matches("Graph style script", "^G") -> True
• Matches("Graph style script", "GRAPH?") -> False

Inputs:

• text: string
• regex: string

Outputs:

• boolean

Replace(text, regex, replacement)

Returns a new string where a replacement value will be used instead of the first regex match. The creation of the regex is done with the Javascript function new RegExp(text).

Examples:

• Replace("Graph style script", "xyz", "text") -> "Graph style script"
• Replace("Graph style script", "style ", "") -> "Graph script"
• Replace("Graph style script", "style.*", "rocks!") -> "Graph rocks!"
• Replace("Graph style script", "s", "S!") -> "Graph S!tyle script"

Inputs:

• text: string
• regex: string
• replacement: string

Outputs:

• string

LowerCase(text)

Returns the value of a string converted to lower case.

Example:

• AsText(LowerCase(Property(node, "name"))) will return node name in lower case.

Inputs:

• text: string

Outputs:

• string

UpperCase(text)

Returns the value of a string converted to upper case.

Example:

• AsText(UpperCase(Property(node, "name"))) will return the node name in upper case.

Inputs:

• text: string

Outputs:

• string

Trim(text)

Returns the string without starting and ending whitespaces.

Example:

• Trim(" Hello there! ") will return "Hello there!.

Inputs:

• text: string

Outputs:

• string

Array functions

Join(array, delimiter)

Returns a new string by joining array elements with the delimiter.

Example:

• label: Join(Labels(node), ", ") creates a label which is a string made out of all the labels delimited with a comma.

Inputs:

• array: List[any]
• delimiter: string

Outputs:

• string

Contains(array, value)

Returns True if the array contains the defined value, False otherwise.

Example:

• Contains(AsArray(2,7,8,9), 2) will return True.

Inputs:

• array: List[any]
• value: any

Outputs:

• boolean

RandomOf(array)

Returns a random element of the given array. All the elements are equally likely to be chosen.

Example:

• RandomOf(AsArray(1,3,5,7,11,13)) will return one of the array elements.

Inputs:

• array: List[any]

Outputs:

• any | null

Find(array, function)

Returns the first element of the given array for which the function yields Truthy value.

In GSS, there are six Falsy values: False , 0 , "" , Null , [] (empty array), and {} (empty map). Everything else is considered Truthy.

Function argument function has one input argument which is the item of the array.

Example:

• Find(AsArray(1, 2, 3, 4), Function(item, Greater(item, 2))) will return number 3.
• Find(AsArray(1, 2, 1, 1), Function(item, Greater(item, 2))) will return Null.

Inputs:

• array: List[any]
• function: Function

Outputs:

• any | null

Filter(array, function)

Returns the new array with elements of the given array for which the function yields Truthy value.

In GSS, there are six Falsy values: False , 0 , "" , Null , [] (empty array), and {} (empty map). Everything else is considered Truthy.

Function argument function has one input argument which is the item of the array.

Example:

• Filter(AsArray(1, 2, 3, 4), Function(item, Greater(item, 2))) will return array [3, 4].
• Filter(AsArray(1, 2, 1, 1), Function(item, Greater(item, 2))) will return [].

Inputs:

• array: List[any]
• function: Function

Outputs:

• List[any]

Map(array, function)

Returns the new array where each element of the given array is converted (mapped) with the defined function.

Function argument function has one input argument which is the item of the array.

Example:

• Map(AsArray(1, 2, 3, 4), Function(item, Mul(item, 2))) will return array [2, 4, 6, 8].
• Map(AdjacentNodes(node), Function(n, Property(n, "name"))) will return the list of names of adjacent nodes.

Inputs:

• array: List[any]
• function: Function

Outputs:

• List[any]

Reduce(array, function, initialValue)

The Reduce() function returns a single value generated by reducing an array of values. The function parameter has two arguments, previous reduced value and current array value. The initialValue parameter specifies the initial value used for the first reduce iteration.

Example:

• The following example does a sum of all elements in the array with the initial value of 1. Because the array is empty, the returned value is the initial one: 1.

Reduce(
  AsArray(),
  Function(prev, current, Add(prev, current)),
  1
)

• The same example as the above one, but with a defined array of three elements. The result will be number 6.

Reduce(
  AsArray(1, 2, 3),
  Function(prev, current, Add(prev, current)),
  0
)

• The following example joins all letters from an array into a single text "ABC".

Reduce(
  AsArray("A", "B", "C"),
  Function(prev, current, Format("{}{}", prev, current)),
  ""
)

Inputs:

• array: List[any]
• function: Function
• initialValue: any

Outputs:

• any

All(array, function)

Returns True if the function yields Truthy value for all elements of the given array.

In GSS, there are six Falsy values: False , 0 , "" , Null , [] (empty array), and {} (empty map). Everything else is considered Truthy.

Function argument function has one input argument which is the item of the array.

Example:

• All(AsArray(1, 2, 3, 4), Function(item, Greater(item, 2))) will return False.
• All(AsArray(1, 2, 1, 1), Function(item, Less(item, 3))) will return True.

Inputs:

• array: List[any]
• function: Function

Outputs:

• boolean

Any(array, function)

Returns True if the function yields Truthy value for any element of the given array.

In GSS, there are six Falsy values: False , 0 , "" , Null , [] (empty array), and {} (empty map). Everything else is considered Truthy.

Function argument function has one input argument which is the item of the array.

Example:

• Any(AsArray(1, 2, 3, 4), Function(item, Greater(item, 2))) will return True.
• Any(AsArray(1, 2, 1, 1), Function(item, Greater(item, 3))) will return False.

Inputs:

• array: List[any]
• function: Function

Outputs:

• boolean

Uniq(array)

Returns an array of unique elements of the given array.

Example:

• Uniq(AsArray(2,1,1,2,1,3,1)) will return [2, 1, 3].
• Uniq(AsArray("1", "1", 1, True, True, 1)) will return ["1", 1, True].

Inputs:

• array: List[any]

Outputs:

• List[any]

Reverse(array)

Returns an array with reversed elements of the given array.

Example:

• Reverse(AsArray(1, 2, 3)) will return [3, 2, 1].

Inputs:

• array: List[any]

Outputs:

• List[any]

Sort(array)

Returns an array with sorted items. The sort works only on arrays with primitive types: strings, numbers, and booleans.

Example:

• Sort(AsArray(3, 2, 1, 8, 3)) will return [1, 2, 3, 3, 8].

Inputs:

• array: List[string] | List[boolean] | List[number]

Outputs:

• List[string] | List[boolean] | List[number]

Next(iterator)

Returns the next item in the iterator. If iterator has no items, it returns Null.

Example:

• Next(AsIterator(AsArray(3, 2, 1))) will return 3.

Inputs:

• iterator: Iterator[any]

Outputs:

• any | null

Type functions

AsArray(value...)

Creates and returns an array of given values. The function can be used to convert Iterator back to the array with AsArray(AsIterator(AsArray(1, 2))).

Examples:

• AsArray("Alfa", "Bravo", "Charlie", "Delta", "Echo") -> ["Alfa", "Bravo", "Charlie", "Delta", "Echo"]
• AsArray(AsIterator(AsArray(1, 2, 3))) -> [1, 2, 3].

Inputs:

• value1: any
• value2: any
• valueN: any

Outputs:

• List[any]

AsMap(key, value, ...)

Creates and returns a map of given pairs of keys and values. There must be an even number of inputs because each key should have its own value. Keys must be type of string. Values can be any type.

Example:

• AsMap("1", 10, "2", 20) -> {"1": 10, "2": 20}

Inputs:

• key1: string
• value1: any
• keyN: string
• valueN: any

Outputs:

• Map[string, any]

AsIterator(array)

Creates and returns an iterator of given array. Iterator values can be used only once with Next function until all values have been used.

Example:

• AsIterator(AsArray(1, 2, 3)) -> (1, 2, 3)

Inputs:

• array: List[any]

Outputs:

• Iterator[any]

AsNumber(value)

Parses the given string or boolean and returns a number. The string should contain only one number in base 10 and nothing else. Boolean True returns number 1. Boolean False returns number 0.

Example:

• AsNumber("8") will return number 8.

Inputs:

• value: string | number | boolean

Outputs:

• number

AsText(value)

Returns a textual representation of a given value.

Example:

• AsText(Property(node, "age")) will return node.age as string.

Inputs:

• value: any

Outputs:

• string

TypeOf(value)

Returns the type of a given value. Type is returned as a string. Following types are used in GSS:

• "number" - represents numbers
• "boolean" - represents booleans (True and False)
• "string" - represents textual values
• "Null" - represents null value (Null)
• "Color" - represents colors
• "Node" - represents graph node
• "Edge" - represents graph relationship
• "Graph" - represents graph
• "List" - represents an array object (e.g. [1, 2, 3])
• "Iterator" - represents an iterator object (e.g. (1, 2, 3))
• "Map" - represents a map object (e.g. { "name": "GSS" })
• "Function" - represents function object

Example:

• TypeOf(Property(node, "name")) returns string.

Inputs:

• value: any

Outputs:

• string

IsArray(value)

Returns True if the input value is an array, otherwise False.

Examples:

• IsArray(10.2) returns False.
• IsArray(AsArray(1, 2, 3)) returns True.

Inputs:

• value: any

Outputs:

• boolean

IsMap(value)

Returns True if the input value is a map, otherwise False.

Examples:

• IsMap(10.2) returns False.
• IsMap(AsMap("key", "value")) returns True.

Inputs:

• value: any

Outputs:

• boolean

IsIterator(value)

Returns True if the input value is an iterator, otherwise False.

Examples:

• IsIterator(AsArray(1, 2, 3)) returns False.
• IsIterator(AsIterator(AsArray(1, 2, 3))) returns True.

Inputs:

• value: any

Outputs:

• boolean

IsNumber(value)

Returns True if the input value is a number, otherwise False.

Example:

• IsNumber(10.2) returns True.

Inputs:

• value: any

Outputs:

• boolean

IsBoolean(value)

Returns True if the input value is a boolean, otherwise False.

Example:

• IsBoolean(False) returns True.

Inputs:

• value: any

Outputs:

• boolean

IsString(value)

Returns True if the input value is a string, otherwise False.

Example:

• IsString("text") returns True.

Inputs:

• value: any

Outputs:

• boolean

IsNull(value)

Returns True if the input value is a Null, otherwise False.

Example:

• IsNull(Null) returns True.

Inputs:

• value: any

Outputs:

• boolean

Utility functions

Define(name, value)

Binds the given value to the given name. Names can be redefined.

Example:

• Define(city, "London") will set the value of the city to London.

Inputs:

• name: Variable
• value: any

Function(arg..., body)

Creates a function. body is the expression to evaluate when the function is called. All arguments except body are argument names of the function to create. When the created function is called names arg1, arg2, … are bound to function arguments and available in the body expression. This function is most useful in combination with Define.

Examples:

Define(makeGreeting, Function(firstName, Format("Hello, {}!", firstName)))
makeGreeting("World") // -> Hello, World!

Define(pow, Function(x, n, If(Equals(n, 1), x, Mul(x, pow(x, Sub(n, 1))))))
pow(2, 10) // -> 1024

Inputs:

• arg1: Variable
• argN: Variable
• body: any

Outputs:

• Function

Execute(expression...)

Executes all expressions given as arguments. The function comes in handy when there are set of commands that should be executed, e.g. setting several items on the map with Set and returning the last value.

Example:

Define(map, AsMap())
Define(mapKeys, Execute(
  Set(map, "key1", "value1"),
  Set(map, "key2", "value2"),
  MapKeys(map),
))

Variable map will be {"key1": "value1", "key2": "value2"}. Execution returns the last value of the variable mapKeys which is an array of keys: ["key1", "key2"].

Inputs:

• expression1: Expression
• expressionN: Expression

Outputs:

• any

Get(object, key, defaultValue?)

If obj is a List, returns the element with index key of list obj (indexing is zero based). If obj is a Map, returns the value for key key. If obj is a string, returns the letter with index key of string obj (indexing is zero based). If obj is a Node, returns the value for key key. If obj is a Relationship, returns the value for key key.

In case of invalid input or missing value, it returns defaultValue or Null if default value is not defined.

Examples:

• Get(AsArray(3,6,7,3), 2) returns number 7.
• Get(Property(node, "map"), "year") will get the property year` from the map of node properties.

Inputs:

• object: List | Map | string | Node | Relationship
• key: number | string
• defaultValue?: any

Outputs:

• any

Set(object, key, value)

If obj is a List, sets the value with index key (indexing is zero based). Value will be returned on successful set. If index is out of ranges of the list, nothing will be set, and Null will be returned.

If obj is a Map, sets the value for key key. Key must be a string type. Input value will be returned.

Examples:

• Define(array, AsArray(1, 2, 3)) Set(array, 1, 5) returns number 5 and array will be [1, 5, 3].
• Define(map, AsMap()) Set(map, "key", "value") returns "value" and map will be {"key": "value"}.

Inputs:

• object: List | Map
• key: number | string
• value: any

Outputs:

• any | null

Del(map, key)

Removes a value from a map under key key. Removed value will be returned. If key was missing in a map, Null will be returned.

Examples:

• Define(map, AsMap("a", 1, "b", 2)) Del(map, "a") returns 1 and map will be {"b": 2}.
• Define(map, AsMap("a", 1)) Del(map, "b") returns Null and map will be {"a": 1}.

Inputs:

• map: Map[string, any]
• key: string

Outputs:

• any | null

Size(value)

If value is of type List or Map, returns its size. If value is of type string, returns its length. If value is of type Node, returns the size of node properties. If value is of type Relationship, returns the size of relationship properties. If value is of type Graph, returns the size of the graph (nodes and relationships)

Example:

• Size(Property(node, "name")) returns the size of the node’s name property.

Inputs:

• value: List | Map | string | Node | Relationship | Graph

Outputs:

• number

Coalesce(value...)

Returns the first non-null value. In case of empty call or all values being Null, Null will be returned.

Example:

• Coalesce() returns Null
• Coalesce(Null, 1, False) returns 1

Inputs:

• value1: any
• valueN: any

Outputs:

• any | null

Variables

Graph Style Script has three built-in variables that you can use: node, edge and graph.

node

The variable node is bound to the graph node for which the style directive @NodeStyle is being evaluated. Graph node is of type Map and has all information about the node (properties, labels, id).

In the following example, you can see the usage of the variable node within the @NodeStyle directive.

@NodeStyle {
  label: Property(node, "name")
  size: Mul(Size(Edges(node)), 5)
}

If node is used outside @NodeStyle directive, a compile error will be thrown.

edge

The variable edge is bound to the graph relationship for which the style directive @EdgeStyle is being evaluated. Graph relationship is of type Map and has all information about the relationship (properties, type, start, end, id).

In the following example, you can see the usage of the variable edge within the @EdgeStyle directive.

@EdgeStyle {
  label: Format("From node {}", Property(StartNode(edge), "name"))
  size: AsNumber(Property(edge, "importance"))
}

If edge is used outside @EdgeStyle directive, a compile error will be thrown.

graph

The variable graph is bound to the overall graph that contains nodes and edges. It can be useful to get the total count of nodes and edges with the following functions: NodeCount(graph) and EdgeCount(graph).

In the following example, you can see the usage of the variable graph in the directive context (@NodeStyle, @EdgeStyle) and global context (variable EDGE_COUNT);

// Global context acts like a cache because the
// following expression will be evaluated only once
Define(EDGE_COUNT, EdgeCount(graph))

@NodeStyle {
  size: Sqrt(NodeCount(graph))
}

@EdgeStyle {
  width: If(Greater(EDGE_COUNT, 1000), 1, 2)
}

The graph variable is not bound to any of the directives (@NodeStyle, @EdgeStyle) so you can use it wherever you want in the Graph Style Script code.