Documentation
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Overview ¶
Package expr evaluates the expressions and {{ }} templates of a workflow.
Index ¶
- func Refs(v any, name string) (keys []string, dynamic bool)
- type Expr
- func (e *Expr) Eval(input string, env any) (any, error)
- func (e *Expr) EvalOrEvalTemplate(input string, env any) (string, error)
- func (e *Expr) EvalTemplate(input string, env any) (string, error)
- func (e *Expr) EvalTemplateMap(input map[string]any, env any) (map[string]any, error)
- func (e *Expr) EvalTemplateWithTypePreservation(input string, env any) (any, error)
- func (e *Expr) Options(env any) []ex.Option
- type FieldError
- type TemplateError
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Refs ¶ added in v1.18.0
Refs returns the names that the templates in v read from the object name, as name.key or name['key']. v is a string, or a map or array of them at any depth, as a value under vars is. dynamic is true when a template reads the object in a way whose key cannot be known before it runs, such as name[k] or the object as a whole, so that it may read any key. keys come in the order they are first read, a map's values in the order of its sorted keys.
An expression that does not parse reads nothing here; evaluating it reports the error.
Types ¶
type Expr ¶
type Expr struct{}
Expr evaluates expressions and templates against an environment such as a step's context.
func (*Expr) EvalOrEvalTemplate ¶
func (*Expr) EvalTemplate ¶
EvalTemplate replaces each {{ }} template in input with the value of its expression. A template that does not compile or fails to run is an error naming the template, and no string is returned: a value with the error written into it would otherwise be sent on, as a URL or a header, as if it were right.
func (*Expr) EvalTemplateMap ¶
EvalTemplateMap evaluates every template in the values of input, at any depth, keeping the type of a value that is a single template. The errors of all the values that could not be evaluated are joined, each as a *FieldError naming its value. The map is returned with them too, holding nil where a value could not be evaluated, so that a caller can still see the values that could, such as credentials to hide from the errors.
func (*Expr) EvalTemplateWithTypePreservation ¶
func (*Expr) Options ¶
Options builds the expr options used to compile every workflow expression.
Two guards that used to live here have been removed because neither did anything. ex.DisableBuiltin had no effect on all / any / one / filter / map / count: expr's parser recognises those as predicate builtins before it looks at the disabled set (parser.go, the `predicates` table), so the calls were dead and the functions have always been reachable. A per-key blocklist that filtered the environment was equally inert, because the filtered copy only ever reached the type checker while ex.Run receives the caller's env, and enforcing it would have broken the documented way of reading credentials into `vars`.
What still bounds an expression is the length check in validateExpression, the evaluation timeout in executeWithTimeout, and the argument limits on the functions registered below.
type FieldError ¶ added in v1.18.0
FieldError is an error in the value under a key of a map evaluated by EvalTemplateMap. Path names the value from the top of that map, as in headers.authorization or items[0].name.
func (*FieldError) Error ¶ added in v1.18.0
func (e *FieldError) Error() string
func (*FieldError) Unwrap ¶ added in v1.18.0
func (e *FieldError) Unwrap() error
type TemplateError ¶ added in v1.18.0
type TemplateError struct {
Template string // The template as written, braces included
Err error // Why it could not be evaluated
}
TemplateError is a {{ }} template that could not be evaluated.
func (*TemplateError) Error ¶ added in v1.18.0
func (e *TemplateError) Error() string
func (*TemplateError) Unwrap ¶ added in v1.18.0
func (e *TemplateError) Unwrap() error
Source Files