Concepts

Jinaga is a state-management framework for building web and mobile applications. When building an application with Jinaga, you perform three basic operations:

• Storing information
• Writing specifications
• Projecting results

You store information whenever the user performs an action. This saves the data in local storage, sends it to the server, and updates the user interface.

await j.fact(new Post(
  new Date(),
  site
));

You write a specification to describe the shape of the information you want to retrieve. A specification function matches a template, and applies conditions.

const postsInSite = model.given(Site).match((site, facts) =>
  facts.ofType(Post)
    .join(post => post.site, site)
    .select(post => ({
      hash: j.hash(post),
      titles: facts.ofType(PostTitle)
        .join(title => title.post, post)
        .select(title => title.value)
    }))
);

You retrieve information any time you need the application to answer a question. It could be a query that you run just when you need the data.

const posts = await j.query(postsInSite, site);

Or it could be watching to for changes so that you can update the UI.

const { loading, data, error } = useSpecification(j, postsInSite, site);