Function DeclareContextProto

cel/options.go:828–853

DeclareContextProto returns an option to extend CEL environment with declarations from the given context proto. Each field of the proto defines a variable of the same name in the environment. https://github.com/google/cel-spec/blob/master/doc/langdef.md#evaluation-environment If using JSONFieldName

(descriptor protoreflect.MessageDescriptor)

//
// If using JSONFieldNames(), ensure that the option is set before DeclareContextProto is provided.
func DeclareContextProto(descriptor protoreflect.MessageDescriptor) EnvOption {
	return func(e *Env) (*Env, error) {
		if e.contextProto != nil {
			return nil, fmt.Errorf("context proto already declared as %q, got %q",
				e.contextProto.FullName(), descriptor.FullName())
		}
		e.contextProto = descriptor
		fields := descriptor.Fields()
		vars := make([]*decls.VariableDecl, 0, fields.Len())
		jsonFieldNames := e.HasFeature(featureJSONFieldNames)
		for i := 0; i < fields.Len(); i++ {
			field := fields.Get(i)
			variable, err := fieldToVariable(field, jsonFieldNames)
			if err != nil {
				return nil, err
			}
			vars = append(vars, variable)
		}
		var err error
		e, err = VariableDecls(vars...)(e)
		if err != nil {
			return nil, err
		}
		return Types(dynamicpb.NewMessage(descriptor))(e)
	}
}

// ContextProtoVars uses the fields of the input proto.Messages as top-level variables within an Activation.
//