crossdocument

Crossdocument, or cross-document, is a general term used to describe methods and patterns for interaction, communication, or linkage across separate documents. In computing and information systems, the concept often centers on enabling a process in one document to convey data or requests to another document, potentially in a different environment or origin.

In web development, cross-document messaging is the most common concrete instantiation. This technique uses interfaces such as window.postMessage to send messages between a window or iframe and its parent or another window. A sender transmits a structured data payload to a target window, while the receiver listens for message events and validates information such as the event.origin and the source of the message before acting. This approach facilitates scenarios like embedded widgets, cross-origin collaboration, or dynamic content updates across documents. Security is a central concern, and proper implementation relies on strict origin checks, careful data validation, and minimal privileges to reduce the risk of cross-site scripting or data leakage.

Beyond web messaging, cross-document concepts appear in document management and authoring environments. Cross-document linking or referencing enables items in one document to refer to content in another, supporting reuse, navigation, and consistent updates across a collection of documents. In information retrieval and indexing, cross-document analysis aggregates and compares content across multiple documents to extract relationships or synthesize knowledge.

Overall, crossdocument encompasses techniques and practices that connect, coordinate, or relate separate documents, balancing interoperability with appropriate security and governance considerations. See also: same-origin policy, postMessage, cross-origin communication, and cross-document referencing.