Learn Redux-observable, Sequelize and Tmux

Handling async actions that affect your application’s state sounds like a tall order, but Redux makes it possible — and a win-win for you and your app’s users.

In this course, we will begin with nothing more than an empty directory and a text editor. Through small, focused lessons, we’ll learn how to set up a React project that uses Redux for state management and redux-observable for asynchronous actions. We’ll see how ‘epics’ are registered and how they each receive a ‘stream’ of actions from the store.

With an understanding of how things work, we’ll move onto solving common problems like: 
- Ajax cancellation
- creating sequences of async actions
- enabling code reuse through higher-order Observables 
- and much more.

RxJS 5-based middleware for Redux. Compose and cancel async actions to create side effects and more.

redux-observable

Asynchronous State Management with redux-observable v1

***Note: RxJS imports have changed since the publication of this course. Operators now must be passed into `.pipe` to be applied to an observable.***

In this course we will begin with nothing more than an empty directory & a text editor. Through small, focussed lessons we’ll learn how to setup a React project that uses Redux for state management and redux-observable for asynchronous actions. We’ll see how ‘epics’ are registered and how they each receive a ‘stream’ of actions from the store. 

With an understanding of how things work, we’ll move onto solving common problems such as Ajax cancellation, creating sequences of async actions, enabling code reuse through higher-order Observables and much more. 

## **UPDATE:** 
This course is outdated, view updated material here: [Asynchronous State Management with redux-observable v1](https://egghead.io/courses/asynchronous-state-management-with-redux-observable-v1)

React is one of the web’s most popular frameworks for building JavaScript applications. 

If you know what you’re doing, React can drastically simplify how you build, use, and maintain code.

Whether you’re a React newbie or you’re ready for advanced techniques, you can level-up with egghead. Explore our in-depth courses, lessons, and community resources to build more powerful applications and crack open your career.

react

Up and Running with redux-observable

Learn to manage your terminal sessions and work more effectively from the command line using tmux. If you use the command line at all, tmux can make your life easier.

tmux bills itself as a terminal multiplexer. It allows you to wrangle multiple terminal sessions from one window. Instead of keeping track of many terminal windows yourself, you can use tmux to create, organize, and navigate between them. Even more importantly, tmux lets you detach from and re-attach sessions, so that you can leave your terminal sessions running in the background and resume them later. This is especially useful if you're working on a remote server: you can set up a persistent session that will continue running when you close your laptop. You can even share a tmux session to facilitate pair programming.

It lets you switch easily between several programs in one terminal, detach them (they keep running in the background) and reattach them to a different terminal.

tmux

Wrangle your terminal with tmux

Redux is a predictable state container for JavaScript apps.
It helps you write applications that behave consistently, run in different environments (client, server, and native), and are easy to test.

redux

In this lesson we’ll learn exactly what’s needed to incorporate redux-observable into an existing React/Redux application. We’ll learn what ‘Epics’ are, and how they receive a stream of actions and return a stream of actions. In-between is where we get to apply side-effects, call out to external services etc etc. In this lesson we’ll demonstrate the ‘async’ nature of epics by responding to an action with another, delay action.

Add redux-observable to an existing Redux project

In this lesson we’ll learn how to perform an Ajax request to an external API in response to an action in the redux store. We’ll see how, within the epic, we get access to actions after any reducers have been executed and how we can convert that incoming action into a resulting one that will save the data received into the redux store.

Use redux-observable for simple Ajax requests

With redux-observable, we have the power of RxJS at our disposal - this means tasks that would otherwise be complicated and imperative, become simple and declarative. In this lesson we’ll respond to an action by queuing up 2 separate Ajax requests that will execute sequentially. Then we’ll group the results from both into an array and produce a single action from our epic that will save the data into the redux store

Create a queue of Ajax requests with redux-observable and group the results.

When accepting user input and converting it into a request that talks to the outside world, we can often end up in a situation where responses are no longer relevant. This is a common case in type-ahead style input fields - we would only want to call an external search API after the user has stopped typing for a short amount of time. In this lesson we’ll see how we can begin to combine RxJS operators to solve such problems. 

Debounce user input to avoid repeated Ajax requests

Any application that uses external services such as APIs should be able to handle errors gracefully. Often this requires no more that displaying a message to the user and ensuring the application continues to function. In this lesson we’ll look at how we can convert an error from the network into an action that is dispatched into the Redux store, allowing us to show an error message to the user and prevent the application from crashing.

Handle network errors gracefully

Although ‘epics’ in RxJS are often described as ‘actions in, actions out’, there may be times when you need to ‘bail out’ of an action, or to just ignore the current one given some condition. By learning about RxJS’s `filter` Operator, we’ll see how easy it is to do ‘nothing’ when you need to. We’ll also see how the composition techniques available in RXJS allow us to control the UI in a declarative manner.

Filter a stream to exclude empty values

In certain situations, you care more about the final state of the redux store than you do about the particular stream of events coming out of an epic. In this lesson we explore a technique for dispatching actions direction into the store, having the epic execute as they would normally in production, and then assert on the updated store’s state.

Use tests to verify updates to the Redux store

In this lesson, we'll learn how to detach from a running tmux session and leave it running in the background. Then, we can re-attach to it later.

We'll cover:
- How to exit a session by killing all active panes
- Detaching explicitly with C-b d
- Detaching a specific session with C-b D
- Viewing all running tmux sessions using tmux ls
- Reattaching with tmux attach -t

Reuse terminal workspaces using tmux sessions

In tmux, a window is a collection of panes. Creating multiple windows is a great way to organize your workspace. In this lesson, we'll cover:

- How to create a new window within a tmux session, using `C-b c`
- Navigating between windows with `C-b n` and `C-b p`

Create collections of panes using tmux windows

In this lesson, we'll look at how to manage your history between tmux sessions, and ensure that your setup preserves your bash history between multiple windows. By adding a special PROMPT_COMMAND to your .bashrc, you can update and reload your history after every command, regardless of if you're in a different session, window, or tab.


Handle history in tmux sessions

Sometimes you'll want to zoom in on a specific pane within a tmux window. We'll learn to use C-b z to temporarily zoom in on one pane, as well as how to resize your panes with C-b -L, -R, -U, and -D.


Zoom and resize to view a particular pane within tmux

Sequelize is a promise-based ORM for Node.js and io.js. It supports the dialects PostgreSQL, MySQL, MariaDB, SQLite and MSSQL and features solid transaction support, relations, read replication and more.

sequelize

Sequelize attribute getters and setters are a convenient way to encapsulate extra logic for model properties. In this video, we'll cover adding getters and setters to enhance and even virtualize a column.

Sequelize: Getters, Setters and Virtual Columns

Learn to organize your workspace using tmux. We'll create a new tmux session and learn how to create and navigate panes within a tmux window.

We'll cover:

- How to create new panes via vertical splits with C-b %
- How to create new panes via horizontal splits with C-b "
- Navigating between panes with C-b and arrow keys
- Closing panes with exit or Ctrl-d
- Viewing available commands with C-b ?

Organize your terminal using tmux panes

It's a lot easier to manage your tmux session when they have sensible names. We'll cover:

- How to create a new, named tmux session with tmux new -s
- Rename an existing tmux session using tmux rename-session -t
- Renaming sessions with C-b $
- Listing sessions with C-b s

Manage terminal workspaces using session naming

One non-obvious, but extremely useful, feature in tmux is copy-pasting text between panes. This also allows you to scroll back in a tmux sessoin. We'll cover how to use copy and paste in tmux using C-b [ and C-b ], for both emacs- and vim-style keybindings.

Copy and paste text from a tmux session

You can modify tmux's behavior with your tmux configuration file, .tmux.conf. You can use your tmux config to change color schemes, set custom keybindings, set defaults, modify the status bar, and more. In this lesson, we'll change some of the default color options as well as modify the prefix key.


Customize tmux with tmux.conf

By using ssh, you can share a tmux session, making pair programming much easier. We'll learn how to share a tmux session with another user. 


Share a tmux session for pair programming with ssh

We'll learn how to use mouse mode in tmux, including enable mouse control for resizing, scrolling and selecting panes. We'll also set keybindings in our tmux configuration to control mouse mode. 