1. A method for generating a web application, comprising: selecting, by a computer processor, a webpage in the web application; implementing, by the computer processor, a custom user interface (UI) action on the webpage, wherein implementing the custom UI action on the webpage comprises: creating, by an automated tool, a hidden component on the webpage; associating the custom UI action with the hidden component; receiving, by the automated tool, input specifying at least one input for the hidden component based on the custom UI action; receiving, by the automated tool, input specifying at least one output target for the hidden component based on the custom UI action; and automatically configuring the hidden component to be executable on a client device to publish lifecycle events for consumption by at least one target on the client device, the lifecycle events indicating occurrences, on the client device, of particular stages of a lifecycle of the custom UI action on the client device; associating the hidden component with a custom UI action trigger event, the custom UI action trigger event being a type of event other than a lifecycle event; and deploying, by the automated tool, the web application, after implementing the custom UI action on the webpage, by automatically creating a file that includes the webpage, the hidden component, and the custom UI action, for execution on the client device.