Help with Joomla component

Hi All, i have been working on developing a joomla component. This component gets the data from external database. using this data I have created a menu type variable in the admin section of the component. So when creating a new menu item for this component , a drop box lists all the cities from the database and here one city can be selected. This selected city is available in jinput variable and the idea is to query the database based on the selected city and get the results as json encoded. This json encoded data is consumed by the angularjs app to display on the joomla page. the issue here is that jinput variable is not available outside the joomla so the angularjs controller cannot query based on this. i modified the component model to query the database based on the jinput variable but the data is blank as the query should be set to utf8 and i could not get this working. So i need someone to help me get the data as json encoded and the angular js should be able to consume the results. I am not very good with joomla but i can understand the work involved Please let me know if this can be achieved. i can show you the work involved through webex. . Below is the screenshot attached of the working angularjs and the json encode being blank.