Appium UI Automation

• Appium is an open-source project and ecosystem designed for UI automation of many app platforms.
• Appium 2 aims to make platform-specific automation capabilities available under a cross-platform, standard API.
• The project wants to allow easy API access from any programming language and provide tools for community development of Appium extensions.
• Appium seeks to enable UI automation code for various platforms via a single, unified API.

Appium's Choice of API

• Appium leverages Selenium, a pioneer in UI automation for web browsers, adopting the WebDriver specification as its API.
• Selenium collaborated with browser vendors and the W3C to standardize its API into the WebDriver specification.
• Main browsers now implement automation capabilities based on the WebDriver spec.
• WebDriver spec provides automation API primitives (finding elements, interacting with elements, loading pages or screens) applicable to any platform.
• Appium supports user interaction differences between web, mobile, and TV through the WebDriver spec's built-in extensibility.
• Appium uses the standard WebDriver spec with the possibility of unsupported commands and extensions beyond WebDriver API command list.
• Using Appium means utilizing the WebDriver protocol via Appium Clients in the user's language of choice.

Platform Automation Behaviour

• Appium assigns the mapping of the WebDriver protocol to automation behavior on platforms to Appium drivers.
• Drivers are pluggable modules that enable Appium to automate a specific platform by implementing an Appium-internal interface representing the WebDriver protocol.
• Drivers utilize platform-specific automation technologies, such as the XCUITest driver for iOS app automation, which converts the WebDriver protocol to XCUITest library calls.
• Appium lets users select and use only the drivers needed for their automation tasks, managed via Appium's CLI.
• Platform drivers can be written by the Appium team or anyone else.

Universal Programming Language Access

• Appium provides automation capabilities to people by utilizing the WebDriver specification, which is an HTTP-based protocol designed to be used over a network.
• The client-server architecture allows separation of the automation implementer (server) from the automation runner (client).
• Client libraries encode HTTP requests to the server in a language-appropriate way.
• Appium is an HTTP server that must run as a process accessible on the network and using Appium for automation involves an Appium Client in the language of choice.
• The Appium server and client can run on different computers, facilitating cloud provider use.
• Appium's universal accessibility allows it to work with various test runners and frameworks.

Appium's Huge Scope

• Appium aims to automate everything under a single API via community-driven development on top of Appium as a platform.
• Anyone can create a driver as a Node.js module conforming to conventions and implementing the WebDriver protocol and drivers can be shared publicly or privately, open or closed source.
• Appium has a plugin system for building and sharing modules that change how Appium works.
• Plugins are published and consumed via a Plugin CLI and possess minimal limitations, for example, adding the ability to find and interact with screen regions based on a template image (as in the images plugin).