feat: add options DisallowNotExistedVar

context.go

@@ -71,6 +71,8 @@ type ExecutionContext struct {
 	Public     Context
 	Private    Context
 	Shared     Context
+
+	DisallowNotExistedVar bool
 }
 
 var pongo2MetaContext = Context{

options.go

@@ -8,6 +8,9 @@ type Options struct {
 
 	// If this is set to true leading spaces and tabs are stripped from the start of a line to a block. Defaults to false
 	LStripBlocks bool
+
+	// If this is set to true, the Execute() would returns error when var not exists
+	DisallowNotExistedVar bool
 }
 
 func newOptions() *Options {

template.go

@@ -159,6 +159,7 @@ func (tpl *Template) newContextForExecution(context Context) (*Template, *Execut
 
 	// Create operational context
 	ctx := newExecutionContext(parent, newContext)
+	ctx.DisallowNotExistedVar = tpl.Options.DisallowNotExistedVar
 
 	return parent, ctx, nil
 }

variable.go

@@ -379,6 +379,9 @@ func (vr *variableResolver) resolve(ctx *ExecutionContext) (*Value, error) {
 
 		if !current.IsValid() {
 			// Value is not valid (anymore)
+			if ctx.DisallowNotExistedVar {
+				return nil, fmt.Errorf("invalid identifier %s", vr.String())
+			}
 			return AsValue(nil), nil
 		}