Render local rows in a Viewer
Deprecated (5.x only)
This page applies to the 5.x line only (npm 5.1.x, branch 5.x). @ahoo-wang/fetcher-viewer is deprecated on npm (every version) and frozen there: existing functionality is maintained, with no new features. It is replaced by @ahoo-wang/wow-view-engine in the Wow repository (typescript/, wow.ahoo.me), on npm from Wow 9.2.0 (9.2.1 or later accepts fetcher 6). The two use different models and APIs, so migration requires adaptation.
Prerequisites
Use the complete local Viewer example, which includes the consumer installation, entry file, and maintained LocalViewer.tsx. It runs in React with Viewer peers and does not need a Wow server. Leave the bell-shaped data monitor disabled: that separate feature needs a real count endpoint.
Mount the maintained implementation
Follow the example's Run in your application steps and mount <LocalViewer />. For repository verification, select Docs → Local Viewer → Local Data in Storybook. The play function performs interactions automatically; reload the story or use the consumer app to inspect an untouched initial state.
The source has three inputs with different responsibilities:
| Input | Role in the example |
|---|---|
ViewDefinition | Names ID, Name and Active fields and the available Active filter |
ViewState | Chooses visible columns, initial condition, sorting, page size and view identity |
PagedList<User> | Supplies the currently calculated rows and total to dataSource |
The field marked primaryKey supplies stable row identity. Keep definitionId aligned between the initial view and definition. dataUrl and countUrl are required metadata; local data loading and count callbacks calculate in memory and do not fetch them.
Verify displayed rows
At the initial state, page 1 contains Ada and Lin, while total is four and page size is two. Page 2 contains Grace and Zoe. The source's queryUsers filters the full dataset, sorts it, then slices it; Viewer does not automatically transform rows passed to dataSource.
For a single view without a saved-view collection, choose View. Choose Viewer here because subsequent tasks include switching and saving views. Neither component creates a remote data source merely because the definition has URLs.
Failures and cleanup
The example catches unsupported local filter/sort inputs, displays an alert, and clears rows. It intentionally implements only the displayed controls; do not treat it as a general Wow query evaluator. The local rows and saved views live in component memory and disappear on unmount. No data-request controller is needed for synchronous local calculations; remote adapters need their own cancellation.
Continue with pagination and sorting, models and state, and View/Viewer ownership.