Method ExecuteWriter

view/jet.go:337–414

ExecuteWriter should execute a template by its filename with an optional layout and bindingData.

(w io.Writer, filename string, layout string, bindingData interface{})

// ExecuteWriter should execute a template by its filename with an optional layout and bindingData.
func (s *JetEngine) ExecuteWriter(w io.Writer, filename string, layout string, bindingData interface{}) error {
	tmpl, err := s.Set.GetTemplate(filename)
	if err != nil {
		return err
	}

	var vars JetRuntimeVars

	if ctx, ok := w.(*context.Context); ok {
		runtimeVars := ctx.Values().Get(JetRuntimeVarsContextKey)
		if runtimeVars != nil {
			if jetVars, ok := runtimeVars.(JetRuntimeVars); ok {
				vars = jetVars
			}
		}

		if viewContextData := ctx.GetViewData(); len(viewContextData) > 0 { // fix #1876
			if vars == nil {
				vars = make(JetRuntimeVars)
			}

			for k, v := range viewContextData {
				val, ok := v.(reflect.Value)
				if !ok {
					val = reflect.ValueOf(v)
				}
				vars[k] = val
			}
		}

		if v := ctx.Values().Get(s.jetDataContextKey); v != nil {
			if bindingData == nil {
				// if bindingData is nil, try to fill them by context key (a middleware can set data).
				bindingData = v
			} else if m, ok := bindingData.(context.Map); ok {
				// else if bindingData are passed to App/Context.View
				// and it's map try to fill with the new values passed from a middleware.
				if mv, ok := v.(context.Map); ok {
					for key, value := range mv {
						m[key] = value
					}
				}
			}
		}

	}

	if bindingData == nil {
		return tmpl.Execute(w, vars, nil)
	}

	if vars == nil {
		vars = make(JetRuntimeVars)
	}

	/* fixed on jet v4.0.0, so no need of this:
	if m, ok := bindingData.(context.Map); ok {
		var jetData interface{}