withPartialActionBind

withPartialActionBind is a Higher Order Component that allows you to connect a Redux action and bind some of action's arguments with incoming props or redux state.

Instalation

npm i @surglogs/with-partial-action-bind recompose

What is this library good for?

It helps you to cut the boilerplate that is often needed when dispatching a Redux action.

Todo list example

Let's say we have a list of todos stored in the redux store. User did some changes to them and we have to send the edited todos to our server. Therefore we need to get the todos from our state and dispatch updateTodos action. We can do these two things nicely at once using withPartialActionBind:

import withPartialActionBind from '@surglogs/with-partial-action-bind'

// We will not go into the details how the the todos are actually updated
// We will simply assume there is some Redux middleware for handling async workflow like redux thunk, redux saga or redux promise middleware which sends them to the server
const updateTodos = (todos) => {
  return {
    type: 'UPDATE_TODOS',
    payload: {
      todos
    }
  }
}

const SaveTodosButton = ({ updateTodos }) => <button onClick={updateTodos}>Save todos</button>

const ConnectedSaveTodosButton = withPartialActionBind({
  action: updateTodos,
  name: 'updateTodos',
  args: [state => state.todos]
})(SaveTodosButton)

export default ConnectedSaveTodosButton

That's it! In args: [state => state.todos] we binded the todos argument to be state.todos, therefore we can directly pass the binded action updateTodos to the button as an onClick handler.

Let's say now that we have multiple todo lists, therefore if we want to update todos of one todo list we also need to send the name of the todo list. The name is passed as a prop name to the ConnectedSaveTodosButton component. Our code will look like this:

const updateTodos = (todos, todoListName) => {
  return {
    type: 'UPDATE_TODOS',
    payload: {
      todos,
      todoListName
    }
  }
}

const SaveTodosButton = ({ updateTodos }) => <button onClick={updateTodos}>Save todos</button>

const ConnectedSaveTodosButton = withPartialActionBind({
  action: updateTodos,
  name: 'updateTodos',
  args: [state => state.todos, 'name']
  // args: [state => state.todos, (state, props) => props.name] // also works :)
})(SaveTodosButton)

As you can see, we changed our args to [state => state.todos, 'name']. By putting 'name' we are telling that the second argument should be an incoming prop name.

We will change our component again. Let's say for some reason we do not want to bind the todoListName argument. That is also possible:

const SaveTodosButton = ({ updateTodos }) => <button onClick={() => updateTodos('our great todoList')}>Save todos</button>

const ConnectedSaveTodosButton = withPartialActionBind({
  action: updateTodos,
  name: 'updateTodos',
  args: [state => state.todos]
})(SaveTodosButton)

If we do not bind all of the arguments in withPartialActionBind, we can just pass them when calling the action.

Finally, what if we don't want to bind the todoListName again but it is the first argument of the action? Like this:

const updateTodos = (todoListName, todos) => {
  return {
    type: 'UPDATE_TODOS',
    payload: {
      todos,
      todoListName
    }
  }
}

We can pass a special function builder, that allows us to pass the argument using custom logic:

const SaveTodosButton = ({ updateTodos }) => <button onClick={() => updateTodos('our great todoList')}>Save todos</button>

const ConnectedSaveTodosButton = withPartialActionBind({
  action: updateTodos,
  name: 'updateTodos',
  args: [state => state.todos],
  builder: ({ action, args: [todos] }) => {
    return (todoListName) => action(todoListName, todos)
  }
})(SaveTodosButton)