Expr class

Represents a textual expression in the Common Expression Language (CEL) syntax.

CEL is a C-like expression language. The syntax and semantics of CEL are documented at https://github.com/google/cel-spec.

Example (Comparison):

title: "Summary size limit"
description: "Determines if a summary is less than 100 chars"
expression: "document.summary.size() \< 100"

Example (Equality):

title: "Requestor is owner"
description: "Determines if requestor is the document owner"
expression: "document.owner == request.auth.claims.email"

Example (Logic):

title: "Public documents"

description: "Determine whether the document should be publicly visible" expression: "document.type != 'private' && document.type != 'internal'"

Example (Data Manipulation):

title: "Notification string"
description: "Create a notification string with a timestamp."
expression: "'New message received at ' + string(document.create_time)"

The exact variables and functions that may be referenced within an expression are determined by the service that evaluates it. See the service documentation for additional information.

Constructors

Expr({String? description, String? expression, String? location, String? title})

Expr.fromJson(Map json_)

Properties

description ↔ String?

Description of the expression.

getter/setter pair

expression ↔ String?

Textual representation of an expression in Common Expression Language syntax.

getter/setter pair

hashCode → int

The hash code for this object.

no setter, inherited

location ↔ String?

String indicating the location of the expression for error reporting, e.g. a file name and a position in the file.

getter/setter pair

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

title ↔ String?

Title for the expression, i.e. a short string describing its purpose.

getter/setter pair

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toJson() → Map<String, dynamic>

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited