Querying

Once data are fetched by this library, they are automatically reflected onto the frontend store and available to access throughout the application.

The Querying section of the documentation outlined several ways to query store data using class-based model definitions. If developers choose to not use class-based model definitions, they can still query data, but must define their own mechanisms for filtering the data.

TIP

If you plan on doing a lot of complex querying throughout your application, it is recommended you use the class-based syntax for defining models, because it will produce a more readable and maintainable code base.

The examples below mirror some of the examples in the querying guide, but highlight how to query store data directly:

// filter
state.todos.filter(obj => obj.done)
state.todos.filter(obj => /contains text/.test(obj.text))

// has
state.todos.filter(obj => 'text' in obj)[0]

// all
state.todos

// first
state.todos[0]
state.todos.slice(0, 5)

// last
state.todos[state.todos.length - 1]
state.todos.slice(state.todos.length - 5, state.todos.length)

// random
_.sample(_.values(state.todos), 1)

// sample
_.sampleSize(_.values(state.todos), 20)

// count
state.todos.filter(obj => obj.done).length

// sum/min/max
_.sum(state.todos.filter(obj => obj.done).map(obj => obj.priority))
_.min(state.todos.filter(obj => obj.done).map(obj => obj.priority))
_.max(state.todos.filter(obj => obj.done).map(obj => obj.priority))

// limit/offset
state.todos.slice(50, 100)

// order
_.values(state.todos).sort((a, b) => b.id - a.id)[state.todos.length - 1]

// shuffle
_.sampleSize(_.values(state.todos), state.todos.length)