Formula Revit

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aliases:

• Revit Formulas
• Revit Element Filters tags:
• documentation
• formulas
• revit lang: en

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Language: English · Русский

Properties and methods

property(name) reads a public property of the current object. In takeDocument, the current object is Autodesk.Revit.DB.Document; in check, it is the Autodesk.Revit.DB.Element being checked, of its actual type.

!property('IsFamilyDocument')
property('Name') == 'Wall 01'
property('Width') > 0

method(name) calls a public parameterless method. The method must return a value and must not be generic.

!isnull(method('GetWarnings'))
!isnull(method('GetTypeId'))

If no matching property or method is found, null is returned. The name is case-sensitive. The name can be computed by another formula: property(if(true, 'Name', 'Id')).

Element parameters

parameter(elementDefiner, identifier) is only available in element formulas. The first argument selects the parameter source: me means the current element, type its type, host its host, and so on. If the definer returns multiple elements, the first one is used. The identifier is resolved in the following order:

1. a BuiltInParameter enum name;
2. a shared parameter GUID;
3. the parameter's display name (LookupParameter).

parameter(me, 'ALL_MODEL_INSTANCE_COMMENTS') == 'checked'
parameter(type, 'ALL_MODEL_TYPE_COMMENTS') == 'checked'
!isnullorempty(parameter(me, 'Марка'))
isnull(parameter(me, 'Missing parameter'))

You can check whether a parameter exists or has a value set using these functions:

hasparameter('Марка', me)
hasparametervalue('Марка', me)

Revit StorageType	Formula value
String	string
Integer	double
Double	double, converted from internal units to project units
ElementId	ElementId

A missing parameter returns null. Currently, Double values are converted using the document's length unit settings, so formulas for other physical quantities should be verified separately.

Element filters

Expression	What it matches
instance	Instances, but not types
type	Element types
room	Rooms
all	All elements
empty	No elements

Function	Purpose	Example
builtincategory(name)	Filter by BuiltInCategory	builtincategory('OST_Walls')
class(name)	Filter by Revit API class name	class('Wall')

Filters are combined with the words and and or; and has higher precedence. Parentheses are supported.

Leaf filters are negated with a ! prefix, using the inverted native overloads: !type, !instance, !all, !empty, !builtincategory(name) and !class(name). Compound negation such as !(A and B) is not supported — rewrite it through De Morgan (!A or !B).

instance and builtincategory('OST_Walls')
builtincategory('OST_Walls') or builtincategory('OST_Levels')
instance and (class('Wall') or class('Floor'))
instance and !builtincategory('OST_CurtainWallMullions')

Warning

Filtering formulas use the words and and or. Logical formulas in takeDocument and check use the symbols & and |.

Formula usage: user diagnostics, collision diagnostics, project parameter diagnostics. See also: Syntax, Functions.