To use connect(), you need to define a special function called mapStateToProps that tells how to transform the current Redux store state into the props you want to pass to a presentational component you are wrapping.

why JSX?

can you have more than one root dom nodes?

How do you render an element into the dom?

Are React elements mutable?

There are two ways of defining a component: as a function and as a ...

What is the advantage of a class component over a functional component?

How do you add local state to a class?

why are lifecycle hooks important?

Does redux work only with react?

Core concepts: actions reducers

what's an action for redux?

What's the purpose of a reducer?

what are the 2 params passed to a reducer?

what are the advantages of a single store?

How is Redux different from Flux?

advantage of immutability in Redux?

Redux architecture revolves around a strict unidirectional data flow.

Data lifecycle: 1. You call store.dispatch(action) 2. Redux store calls the reducer function 3. combine output of multiple reducer into on single state tree 4. Redux store returns the complete state tree (returned by the root reducer)

Ex with a combineReducers() function todos(state = [], action) { // Somehow calculate it... return nextState } ​ function visibleTodoFilter(state = 'SHOW_ALL', action) { // Somehow calculate it... return nextState } ​ let todoApp = combineReducers({ todos, visibleTodoFilter })

React bindings for Redux embrace the idea of separating presentational and container components.

Container Components: How things work (data fetching, state updates) Dispatch Redux actions Are usually generated by React Redux

Presentational Components How things look (markup, styles) Invoke callbacks from props to change data Are written by hand

You could write a container component by hand, but we suggest instead generating container components with the React Redux library's connect() function, which provides many useful optimizations to prevent unnecessary re-renders.

In addition to reading the state, container components can dispatch actions. In a similar fashion, you can define a function called mapDispatchToProps() that receives the dispatch() method and returns callback props that you want to inject into the presentational component.

Connecting react and redux: import { connect } from 'react-redux' ​ const VisibleTodoList = connect( mapStateToProps, mapDispatchToProps )(TodoList) ​ export default VisibleTodoList

Redux component <Provider> : is used to magically make the store available to all container components in the application without passing it explicitly. You only need to use it once when you render the root component:

How do you use <provider> ?

In the early days of jazz, it was ensemble music: everybody playing all together. Nobody really stood out.

When I listen to most forms of music, in their most raw and pure, it all has a punk edge to me, like Lead Belly, Jimmie Rodgers, Otis Redding or Nirvana.

There is nothing more boring for an intelligent woman than to spend endless amounts of time with small children.

I'm very conscious of other people's opinions and of people not liking me.

I had no need to apologize that the look-wider, search-more affirmative action that Princeton and Yale practiced had opened doors for me. That was its purpose: to create the conditions whereby students from disadvantaged backgrounds could be brought to the starting line of a race many were unaware was even being run.

I come from a middle class family, and my parents weren't too supportive of my career choices.

The most interesting thing about a postage stamp is the persistence with which it sticks to its job.

When I first started in the industry back home in Australia at 18, there was a lot of push and shove as to how I should dress, if I was allowed to cut my hair short, if I had too many tattoos. If I didn't get a campaign, or if I didn't get a role, they would always come back to, 'Well, she dresses like a boy.'

I didn't realize it. It looks like my career happened overnight, but it didn't. I was basically living on my own from when I was 17 on.

My real fear with fighting is just not letting it go out there and hang out. I don't fear other guys. I'm just scared I'm not going to go out there and give everything I have. Like I'm only going to give a fraction of the things we trained and worked on.

I travel so much that when I'm not traveling, I'm just kind of curled up in a ball here, not wanting to leave or see anyone.

People think of the greatest home run hitters of all time and think of Babe Ruth; they don't think about that Warren Spahn hit more than anybody.

We don't know what may yet happen to us, what military and political defeats we may yet have to face.

When you owe money to people, you're always going to owe money to people, so you should take care of it as soon as possible. It doesn't go away just because you ignore it.

I don't know if we ever fully get over the pain of watching a child trying to find their way through a world that too often doesn't understand.

Try praising your wife, even if it does frighten her at first.

If we cant begin to agree on fundamentals such as the elimination of the most abusive forms of child labor then we really are not ready to march forward into the future.

Envy...since it’s lodgement is in the heart, not the brain, no degree of intellect supplies a guarantee against it.

The day you stop learning and creating must be the most boring day.

Texas' and America's farmers are suffering. As the Member of Congress representing the 10th Congressional District of Texas, I have traveled throughout our area and have seen first-hand how the drought has affected our agricultural communities.

There is no sadder sight than a young pessimist, except an old optimist.