action.md

Action module

import { actions } from '@muze-labs/simplyflow/actions'

Actions are named application functions. In normal apps you configure them through app({ actions }).

app({ actions })

app({
  data: { count: 0 },

  actions: {
    increment({ amount = 1 } = {}) {
      this.data.count += amount
    }
  },

  commands: {
    addOne() {
      this.actions.increment({ amount: 1 })
    }
  }
})

Inside an action, this is the app instance.

Named parameters

SimplyFlow encourages actions that take one object argument with named values:

actions: {
  selectContact({ id, tab = 'details' }) {
    this.data.selectedContactId = id
    this.data.tab = tab
  }
}

This style works well with route action shorthand and commands.

Error handling

When the app has onError, action errors are caught and passed to it.

app({
  data: {},

  onError(error, context) {
    console.error('Action failed', error, context)
  },

  actions: {
    async save() {
      throw new Error('not saved')
    }
  }
})

context is the action function that failed.

Without onError, action errors throw normally.

Unknown actions

Reading or calling a missing action logs a warning once per missing action name.

simplyflow/action: unknown action "svae". Did you mean "save"?

If there is no close match, the warning omits the suggestion.

actions(options)

Lower-level factory.

const actionApi = actions({
  app: myApp,
  actions: {
    save() {}
  }
})

When options.app is supplied, returned action functions are bound to that app. When no app is supplied, actions(options) returns options unchanged.