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Functions

Functions are like ready-made tools that perform specific tasks. They take in data as input, process it, and return a result.

Here are a few examples of what functions can do:

  • Count the number of characters in a text.
  • Search for a specific word in a text.
  • Determine the smallest number between two numbers.

Functions in ProtoPie have a specific structure:

  • function(argument: TYPE) → result: TYPE
  • function(argument1: TYPE, argument2: TYPE) → result: TYPE
  • function(argument1: TYPE, argument2: TYPE, argument3: TYPE) → result: TYPE

Functions usually take in one or multiple arguments (data) as input—the values a function uses to perform a task. Arguments, as well as the result, are values that are always of a specific type. A type could be a text, number, or color.

There are various categories to choose from:

Text

  • concat(source1: TEXT, source2: TEXT)TEXT

    Combine two separate texts into one.

    • Example:concat("hello", "world")"helloworld"
  • indexOf(source: TEXT, searchValue: TEXT)NUMBER

    Find the starting position of a keyword in a text. If the keyword isn't present in the text, the returned value is -1.

    • Example:indexOf("hello world", "world")6
    • Example:indexOf("hello world", "hello")0
    • Example:indexOf("hello world", "goodbye")-1
    • Use indexOf for use cases like email validation. See use case example.
  • length(source: TEXT)NUMBER

    Count the number of characters in a text.

    • Example:length("hello")5
    • Example:length("helloworld")10
    • Example:length("hello world")11
    • Use length for use cases like password validation. See use case example.
  • lowerCase(source: TEXT)TEXT

    Convert any text from uppercase to lowercase

    • Example:lowerCase("Hello")"hello"
  • upperCase(source: TEXT)TEXT

    Convert any text from lowercase to UPPERCASE.

    • Example:upperCase("Hello")"HELLO"
  • left(source: TEXT, count: NUMBER)TEXT

    Extract a part of a text from the left side based on a specific number of characters.

    • Example:left("hello", 3)"hel"
  • lpad(source: TEXT, length: NUMBER, pad: TEXT)TEXT

    Left-pad a text with another text, to a specific length.

    • Example:lpad("5", 2, "0")"05"
    • Example:lpad("5", 4, "0")"0005"
  • rpad(source: TEXT, length: NUMBER, pad: TEXT)TEXT

    Right-pad a text with another text, to a specific length.

    • Example:rpad("5", 2, "1")"51"
    • Example:rpad("5", 6, "1")"511111"
  • repeat(source: TEXT, count: NUMBER)TEXT

    Repeat a text a specific number of times.

    • Example:repeat("hello", 2)"hellohello"
    • Example:repeat("hello", 3)"hellohellohello"
  • replace(source: TEXT, from: TEXT, to: TEXT)TEXT

    Replace a part of a text with another text.

    • Example:replace("helloworld", "world", "protopie")"helloprotopie"
    • Example:replace("goodbye, John", "goodbye", "thank you")"thank you, John"
  • trim(source: TEXT)TEXT

    Remove whitespaces on both sides of a text.

    • Example:trim(" helloworld ")"helloworld"
    • Example:trim(" helloworld ")"helloworld"
  • ltrim(source: TEXT)TEXT

    Remove whitespace from the left side of a text.

    • Example:ltrim(" helloworld ")"helloworld "
  • rtrim(source: TEXT)TEXT

    Remove whitespace from the right side of a text.

    • Example:rtrim(" helloworld ")" helloworld"
  • regexextract(source: TEXT, regular expression: TEXT)TEXT

    Extracts the first substrings of a text that match the provided regular expression.

    • Example:regexextract("Google Doc 101", "[0-9]+")"101"
    • Example:regexextract("The price today is $826.25", "[0-9]*\.[0-9]+[0-9]+")"826.25"
  • regexreplace(source: TEXT, regular expression: TEXT, replacement: TEXT)TEXT

    Replaces part of a text string with a different text string using regular expressions.

    • Example:regexreplace("Google Doc 101", "[0-9]+", "777")"Google Doc 777"
    • Example:regexreplace("The price today is $826.25", "[0-9]*\.[0-9]+[0-9]+", "315.75")"The price is $315.75"
  • parseJson(source: TEXT, key: TEXT)TEXT

    Parses a valid JSON string and returns the corresponding value.

    • Example:parseJson("{\"name\":\"John\", \"age\":30, \"car\":null}", "age")"30"
    • Example:parseJson("{\"name\":\"John\", \"age\":30, \"car\":null}", "name")"John"

      • For example, let's consider parseJson(var, "key"). Here, var is the text variable that stores the JSON string, and "key" is the key to parse. The latter supports nested key calling and simple references to array-like objects via the . (dot) notation.

      The parseJson function greatly simplifies working with complex data structures in ProtoPie. Additionally, since most API responses are in JSON format, being able to use parseJson within Pies makes working with APIs much more straightforward.

      You can use the parseJson function to:

    • send JSON string to pies via Bridge apps in ProtoPie Connect (e.g., message: “AutomobileSignal”, value: “json string”).
    • store a value inside a Pie variable via the Receive trigger.
    • use the data values inside the JSON string.

      • To learn more, take a look at this Pie example.

Math

  • pow(source: NUMBER, exponent: NUMBER)NUMBER

    Calculate the result of the first number raised to the power of the second number.

    • Example:pow(2, 3)8
  • sqrt(source: NUMBER)NUMBER

    Calculate the square root of a number. This doesn't work for negative numbers.

    • Example:sqrt(9)3
    • Example:sqrt(2)1.41
  • min(source1: NUMBER, source2: NUMBER)NUMBER

    Extract the smallest of two numbers.

    • Example:min(0, 1)0
  • max(source1: NUMBER, source2: NUMBER)NUMBER

    Extract the largest of two numbers.

    • Example:max(0, 1)1
  • abs(value: NUMBER)NUMBER

    Return the absolute value of a number. In practice, this comes down to removing the negative sign in front of a number.

    • Example:abs(-1)1
    • Example:abs(5 - 25)20
  • sign(value: NUMBER)NUMBER

    Check if a number is positive or negative. Return 1 if a number is positive. Return -1 if a number is negative. Return 0 if a number is 0.

    • Example:sign(5)1
    • Example:sign(-10)-1
    • Example:sign(0)0
  • round(source: NUMBER)NUMBER

    Return the rounded value of a number.

    • Example:round(3.49)3
    • Example:round(1.5)2
    • Example:round(6.79)7
  • floor(source: NUMBER)NUMBER

    Return the nearest whole number down.

    • Example:floor(1.5)1
    • Example:floor(2.99)2
  • ceil(source: NUMBER)NUMBER

    Return the nearest whole number up.

    • Example:ceil(1.5)2
    • Example:ceil(4.3)5
  • random()NUMBER

    a random decimal number between 0 and 1

    • Example:random()a random decimal number between 0 and 1
  • random(min: NUMBER, max: NUMBER)NUMBER

    Return a decimal number randomly between two given numbers.

    • Example:random(1, 5)a random decimal number between 1 and 5
  • randomInt(min: NUMBER, max: NUMBER)NUMBER

    Return a whole number randomly between two given numbers.

    • Example:randomInt(1, 5)a random whole number between 1 and 5
  • radians(degrees: NUMBER)NUMBER

    Convert degrees to radians.

    • Example:radians(180)3.14 = π
    • Example:radians(90)1.57 = π / 2
  • degrees(radians: NUMBER)NUMBER

    Convert radians to degrees.

    • Example:degrees($pi)180
    • Example:degrees($pi / 2)90
  • sin(radian: NUMBER)NUMBER

    Calculate the sine of a number in radians.

    • Example:sin($pi / 2)1
    • Example:sin($pi / 6)0.5
  • cos(radian: NUMBER)NUMBER

    Calculate the cosine of a number in radians.

    • Example:cos(0)1
    • Example:cos($pi / 2)0
  • tan(radian: NUMBER)NUMBER

    Calculate the tangent of a number in radians.

    • Example:tan($pi / 4)1
    • Example:tan(0)0
  • asin(x: NUMBER)NUMBER

    Calculate the arcsine (in radians) of x.

    • Example:asin(1)1.57 = π / 2
    • Example:asin(0.5)0.52 = π / 6
  • acos(x: NUMBER)NUMBER

    Calculate the arccosine (in radians) of x.

    • Example:acos(1)0
    • Example:acos(0)1.57 = π / 2
  • atan(x: NUMBER)NUMBER

    Calculate the arctangent (in radians) of x.

    • Example:atan(1)0.79 = π / 4
    • Example:atan(0)0
  • atan2(x: NUMBER, y: NUMBER)NUMBER

    Calculate the arctangent (in radians) of x and y, also known as the angle in the Euclidean plane.

    • Example:atan2(1, 0)1.57 = π / 2
    • Example:atan2(1, 1)0.79 = π / 4

Color

  • color(red: NUMBER, green: NUMBER, blue: NUMBER)COLOR

    Return a color value (hex color code) based on an RGB value.

    • Example:color(255, 255, 255)#FFFFFF
    • Example:color(255, 102, 97)#FF6661
  • red(source: COLOR)NUMBER

    Return the red RGB parameter of a hex color code.

    • Example:red(#FF0000)255
    • Example:red(#008000)0
    • Example:red(#0000FF)0
  • green(source: COLOR)NUMBER

    Return the green RGB parameter of a hex color code.

    • Example:green(#FF0000)0
    • Example:green(#008000)128
    • Example:green(#0000FF)0
  • blue(source: COLOR)NUMBER

    Return the blue RGB parameter of a hex color code.

    • Example:blue(#FF0000)0
    • Example:blue(#008000)0
    • Example:blue(#0000FF)255

Type Conversion

  • number(source: TEXT)NUMBER

    Convert a text to a number. This doesn't work if the text cannot be converted to a number.

    • Example:number("1234")1234
    • Example:number("94.27")94.27
  • text(source: NUMBER)TEXT

    Convert a number to a text.

    • Example:text(1234)"1234"
    • Example:text(94.27)"94.27"
    • Example:text(1 + 3)"4"
  • format(source: NUMBER, format: TEXT)TEXT

    Convert a number to a text with a certain format. # is a placeholder for whole numbers whereas 0 represents the fractional part.

    • Example:format(1234.567, "#")"1235"
    • Example:format(1234.567, "#,###")"1,235"
    • Example:format(1234.567, "#.###,00")"1.234,57"
    • Example:format(1234.567, "#,##.00")"12,34.57"
    • Example:format(1234.567, "#,###.00")"1,234,57"
  • color(source: TEXT)COLOR

    Convert a text to a color value (hex color code). This doesn't work if the text doesn't have a hex color code structure.

    • Example:color("#FFFFFF")#FFFFFF

Layers

  • layer(source: TEXT)LAYER

    Refer to a layer.

    • Use this as part of a formula or a different function.
  • layer(source: TEXT).propertyTEXT or NUMBER

    Refer to a layer's property. Learn more about layer properties.

    • Example:layer("Rectangle 1").xx-coordinate of the layer called Rectangle 1
    • Example:layer("Oval 1").opacityOpacity of the layer called Oval 1
    • Example:layer("Input 1").textText in the input layer called Input 1
  • parent(layerName: LAYER)LAYER

    Refer to the parent layer, e.g., a container or component.

    • Use this as part of a formula or a different function.
  • parent(layerName: LAYER).propertyTEXT or NUMBER

    Refer to the parent layer's property. Learn more about layer properties.

    • Example:parent(`Rectangle 1`).xx-coordinate of Rectangle 1 its parent layer
    • Example:parent(`Oval 1`).opacityOpacity of Oval 1 its parent layer
  • initial(layerName: LAYER, layerProperty: TEXT)TEXT or NUMBER

    Return the initial value (before any interactions) of a specific layer property. Learn more about layer properties.

    • Example:initial(`Rectangle 1`, "x")Initial x-coordinate of Rectangle 1
    • Example:initial(`Oval 1`, "opacity")Initial opacity of Oval 1
    • Example:initial(`Input 1`, "text")Initial text in Input 1

Relative Coordinates

  • toLayerX(containerName: LAYER, x: NUMBER, y: NUMBER)NUMBER

    Convert a x coordinate relative to the screen into the corresponding x coordinate relative to a container or component. The coordinates of layers inside a container or component are by default relative to the container or component they are in.

    • For example, if you want to get the x coordinate relative to a container `Container 1` based on the position (100, 200) relative to the screen, use the following function:
    • toLayerX(`Container 1`, 100, 200)returns the x coordinate relative to `Container 1` based on the x coordinate `100` relative to the screen.
  • toLayerY(containerName: LAYER, x: NUMBER, y: NUMBER)NUMBER

    Convert a y coordinate relative to the screen into the corresponding y coordinate relative to a container or component. The coordinates of layers inside a container or component are by default relative to the container or component they are in.

    • For example, if you want to get the y coordinate relative to a container `Container 1` based on the position (100, 200) relative to the screen, use the following function:
    • toLayerY(`Container 1`, 100, 200)returns the y coordinate relative to `Container 1` based on the y coordinate `200` relative to the screen.
  • toScreenX(containerName: LAYER, x: NUMBER, y: NUMBER)NUMBER

    Convert a x coordinate relative to a container or component into the corresponding x coordinate relative to the screen. The coordinates of layers inside a container or component are by default relative to the container or component they are in.

    • For example, if you want to get the x coordinate relative to the screen based on the position (10, 20) relative to a container `Container 1` , use the following function:
    • toScreenX(`Container 1`, 10, 20)returns the x coordinate relative to the screen based on the x coordinate `10` relative to `Container 1`.
  • toScreenY(containerName: LAYER, x: NUMBER, y: NUMBER)NUMBER

    Convert a y coordinate relative to a container or component into the corresponding y coordinate relative to the screen. The coordinates of layers inside a container or component are by default relative to the container or component they are in.

    • For example, if you want to get the y coordinate relative to the screen based on the position (10, 20) relative to a container `Container 1`, use the following function:
    • toScreenY(`Container 1`, 10, 20)returns the y coordinate relative to the screen based on the y coordinate `20` relative to `Container 1`.

Looking to learn more about using functions in ProtoPie? Join ProtoPie’s Masterclass for detailed examples and guidance on how to use some of the functions listed in this documentation.

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