# How to

> You can find instructions and guides related to various functionalities in app projects in this section.

You can find instructions and guides related to various functionalities in app projects in this section.

* [Set an external context using query parameters](https://docs.uipath.com/studio-web/automation-cloud/latest/user-guide/setting-an-external-context-using-query-parameters "You can set an external context to your app. This is especially helpful when starting the app from within a robotic process automation (RPA) process, or if you want your app to have a particular behavior only in a certain context. You can set the external context in two ways: when debugging your app or after publishing your app.")
* [Use arrays to populate Dropdown, Multiselect dropdown, and Radio Button controls](https://docs.uipath.com/studio-web/automation-cloud/latest/user-guide/use-arrays-to-populate-dropdown-controls)
* [Use tabular controls with Data Service entities in app projects](https://docs.uipath.com/studio-web/automation-cloud/latest/user-guide/using-tabular-controls-with-data-service-entities-in-app-projects "You can query or edit Data Service entities in tabular controls, such as the Custom List, Dropdown, Edit Grid, Multiselect Dropdown, and Table controls. Use the Data source property of the respective tabular control to create a workflow and bind it to your entity. Then, use events to define automations to perform other operations on your entity.")