Project status -------------- [](https://www.npmjs.com/package/couchdb-web-node-plugin) [](https://www.npmjs.com/package/couchdb-web-node-plugin) [](https://github.com/thaibault/couchdb-web-node-plugin/actions/workflows/build.yaml) [](https://github.com/thaibault/couchdb-web-node-plugin/actions/workflows/build-package-and-push.yaml) [](https://github.com/thaibault/couchdb-web-node-plugin/actions/workflows/check-types.yaml) [](https://github.com/thaibault/couchdb-web-node-plugin/actions/workflows/lint.yaml) [](https://github.com/thaibault/couchdb-web-node-plugin/actions/workflows/test-coverage-report.yaml) [](https://coveralls.io/github/thaibault/couchdb-web-node-plugin) [](https://github.com/thaibault/couchdb-web-node-plugin/actions/workflows/deploy-web-documentation.yaml) [](https://torben.website/couchdb-web-node-plugin) Use case -------- PouchDB with model specification/checking, user authentication and right management as web-node plugin. Foreign Key management ---------------------- The plugin provides a foreign key management for PouchDB. It allows to define foreign keys in the model specification and automatically checks the existence of the referenced documents when creating or updating documents. It also provides a way to automatically delete or update the referenced documents when the referencing document is deleted or updated. ### Mechanism #### Initialization During application start the plugin analyzes the model specification and creates a map of model types to properties that are defined as foreign keys and which model type they reference. It than goes through all documents having referencing properties and checks if the referenced documents exist. If not, it deletes the reference and if yes, it stores the reference in an internal map of referenced documents to referencing documents. #### Document creation and update When creating or updating a document, the plugin checks if the document has referencing properties. If yes, it checks if the referenced documents exist. If not, it deletes the reference and if yes, it stores the reference in the internal map of referenced documents to referencing documents. It also removes references from the internal map if they are no longer present.