Dynamic Layouts - Properties, Functions and references

What are functions?

Certain properties of elements within the document can be defined as a function or formula. This function can refer to other elements properties and variable values.

To turn a static frame property into a calculated value based on a function, you simply click the function button next to the property input field in the interface.

Case Sensitivity

Important to know, functions, tags and references are not Case Sensitive.

E.g. The variable with name "AddWidth" can be used in a formula as "addwidth".

E.g. The PageWidth can be used in a calculation as "pageWidth"

A function field will appear below the property input field. The property input field is now no longer editable because the value is calculated based on the function defined in the function input field.

If a function is not valid and cannot be calculated properly, the last calculated value is kept.

Errors

When a function does not work out, it will turn red, and you'll get a notification.

What is supported within a function?

Arithmic operators

+	adding
-	substracting
*	multiplying
/	deviding
()	parentheses

Parentheses will influence the order of calculation.

Referencing

In the functions, you can use absolute numbers, or you can reference other elements.

E.g. Start my frame 10mm left of the left side of the page / output

E.g. Position the top right of my logo 200px from the top/left corner of my banner

If the output then resized, the relative position of the element will move with the resize.

Functions can reference properties of frames, the page and also reference variable values. The way to do this is:

For frames:
By typing the frame tag followed by a dot and the name of the property you want to reference. If frame tag contains a space or special character, the frame tag can still be used in the function but must be put between brackets. For example: [My frame tag]

Page:
By typing “Page” followed by a dot, and the name of the property you want to reference.
Paragraph within a text frame:
A text paragraph can be tagged, and can also be referenced in a Dynamic Layout function. This is possible by first typing the name (tag) of the frame, followed by a dot, followed by the name of the paragraph (tag)

Variable:
By typing the name of the variable, nothing more.

Properties (to reference of)

These properties can be used from the page, frame, inline frame or tagged paragraph which is referenced by the tag of the frame.

X	The X position of the referenced rotated frame (note reference point) (or 0 for page)
Y	The Y position of the referenced rotated frame (note reference point) (or 0 for page)
Top	The Y value of the top of the referenced rotated frame (or 0 for page)
Bottom	The Y value of the bottom of the referenced rotated frame or page height
Left	The X value of the left of the referenced rotated frame (or 0 for page)
Right	The X value of the right of the referenced rotated frame or page width
CenterY	The Y value of the center of the referenced rotated frame or page
CenterX	The X value of the center of the referenced rotated frame or page
Width	The width of the referenced frame or page (note value is scaled)
NonScaledWidth	The non scaled width of the referenced frame
Height	The height of the referenced frame or page (note value is scaled)
NonScaledHeight	The non scaled height of the referenced frame
Rotation	Rotation of the frame (note doesn't exist on inline frames)
ScaleX	X Scale of the frame
ScaleY	Y Scale of the frame

Examples

page.width
frametag.height
frametag.paragraphtag.centerX

Self

When using a formula in the location of a frame, you can use the tag of the frame, but you can also use "self".

E.g. self.height refers to the own height of the frame.

Below an example to align the frame to the bottom, by using a rather complex formula combined with a reference point at the top.

You can set the Y position, to the page height (would be bottom) minus the own (self) height.

Variables

It is possible to use variables in the calculation, but only variables of type number or coordinate. For now, only the value of the variable can be referenced. No other meta information.

"variable.value" or "variable" will both resolve to the actual value of the variable.

In case a variable has the same name as a frame tag, this property being used will indicate if the user intends to use the variable value or the frame property. (there is no "value" property on frames and no width, height, etc on a variable)

If page.property is used in a calculated value, it will always refer to the page in the document, never to a frame with tag "page".

Functions within the calculation

Following additional functions are available for application in the calculations

MinMax(min, max, input)

Clamps a given value between a minimum and maximum value.

E.g. MinMax(300,700, addwidth)

When the width of the add is lower than 300, the function will return 300.
If the width is above 700, the function will return 700.
If the addwidth is somewhere between, it will return the actual value (e.g. 450)

ClampMin(min, input)

If the input value is less than the minimum, return the minimum value otherwise return the input value

ClampMax(max, input)

If the input value is greater than the maximum, return the maximum value otherwise return the input value

Use of units within a function

Units (millimeters, inches, points, pixels) can be used within a function.

If no unit are specified the Dynamic layout engine will assume the value is in points. Multiple units can be used within a single function.

E.g.:

frameA.width=50mm+10in+5pt