Does anyone have any pointers as to how I could add a pull down menu to the main navbar, that displays the current month, and maybe the last 2 or 3 months.
And then, how can I use that click request in the Controllers actionView() as a parameter ?
You can use DropDownButton to make the "pull down menu" : http://www.yiiframework.com/doc-2.0/yii-bootstrap-buttondropdown.html
'label' => 'Months',
'dropdown' => [
'items' => [
['label' => 'March', 'url' => ['/site/view', 'month' => 'march']],
['label' => 'February', 'url' => ['/site/view', 'month' => 'february']],
['label' => 'January', 'url' => ['/site/view', 'month' => 'january']],
And in your action view :
public function actionView($month)