Learn Apollo, React-router and Svelte

JavaScript community has been shaken recently by a release of Svelte 3 and for a good reason - it's a completely different approach than React or Vue. To quote the docs:

"[Svelte](https://svelte.dev/) is a radical new approach to building user interfaces. Whereas traditional frameworks like React and Vue do the bulk of their work in the browser, Svelte shifts that work into a compile step that happens when you build your app."

**The best part?** If you have 26 spare minutes you can learn the basics of Svelte 3 and start building your own apps with it!

Enjoy!



The magical disappearing UI framework

 - The web's JavaScript bloat crisis, solved. Svelte turns your templates into tiny, framework-less vanilla JavaScript.
 - Simple and familiar. Build apps out of composable, easy-to-write blocks using languages you already know.
 - Super fast, rock solid. Compile-time static analysis ensures the browser does no more work than it needs to.

svelte

Up and running with Svelte 3

GraphQL is a fan favorite for good reason. It lets a client make specific, complex, and/or aggregate queries for data, and it’s user-friendly to boot.

If you’ve been meaning to learn GraphQL and start harnessing its powers, this is a great place to start.

This course is for GraphQL newbies with a basic understanding of React. It focuses on the client-side implementation of GraphQL usage using the Apollo client.

We’ll start with a guide on how to add the Apollo client to an existing project, then move on using the Query and Mutation components to fetch and manipulate data using a GraphQL API.

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

GraphQL Data in React with Apollo Client

Most developers would raise an eyebrow if they saw database queries being done in a for-loop, but GraphQL provides just enough abstraction that it isn't always intuitive exactly how many times each resolver fires at scale, nor is it obvious how to batch operations efficiently and still return the correct results to the correct consumer.

You'll learn how to use the GraphQL Data Loader pattern to improve the performance of your application, and solve scaling issues before they become a problem.

To do this, we'll first implement our own naive version of the pattern to understand why the API is shaped how it is. Then we will switch over to the official DataLoader package and explore the benefits further.

## Skills you'll Gain

- Implement a cache layer to optimize your requests
- Batch requests so your Database isn't overloaded
- Build a performant GraphQL API

Apollo provides a universal GraphQL API on top of your existing services, so you can build new application features fast without waiting on backend changes.

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Use GraphQL Data Loaders to Prevent Scaling Issues by Batching & Caching Database Requests

At the core of a good client-side GraphQL library is a cache. The cache is very important for improving the efficiency of your data retrieval and providing your users with a clean user experience.

In this course, we're going to see how Apollo's powerful cache helps easily solve complex UI problems, such as pagination, handling loading and error states, optimistic updates, and minimizing network requests.

We'll start from the basics, and look at how to make queries and mutations, but then we'll look at how the cache is behind most of Apollo's immediate benefits. We'll explore in-depth how it works, how it stores data, and how we can manually modify it manually for advanced scenarios.

Even if your backend doesn't fully support GraphQL yet, we'll look at how to write GraphQL queries in your components that retrieve local client state under the hood - or that can even make REST API calls.

Manage State in React Apps with Apollo Client and GraphQL

**Get started building dynamic apps with GraphQL and Vue3.**

As your app scales, so does the complexity of managing your routes and API endpoints. 

It gets tiresome. 

But this aspect of web development can be streamlined considerably! 

GraphQL is a powerful tool for querying and mutating your data. In this course, we are going to create a Vue3 app that leverages GraphQL to create a dynamic front end.

But what does GraphQL *do*? 

Its power comes from giving you a *single* endpoint that you make all your queries to. Instead of making a request to a specific endpoint and getting a fixed response, you can write flexible queries to a single endpoint.

![REST vs GraphQL diagram](https://res.cloudinary.com/dg3gyk0gu/image/upload/v1638989029/course-resources/create-a-graphql-powered-vue-3-application/rest_vs_graphql.png)

Vue3 has some great new features that we will be exploring, such as the setup script syntax. But you won't just be exploring Vue3's new features, we will be building a dynamic front end with an index, view pages generated from data, and forms.

To make our frontend dynamic, we will be powering it with GraphQL. We start with the basics by creating queries but we move on to more advanced topics such as query params, mutations, and pagination.

To actually use GraphQL in our Vue app we will be using the Vue Apollo Client. Which gives us convenient methods for making queries, getting the data back into the client, and handling errors.

## Gain These Skills

- Add GraphQL to a Vue 3 project
- Query and mutate data with GraphQL in Vue 3
- Create data-driven views with Apollo client
- Handle routing within a Vue 3 project
- Implement optimistic updates and infinite scroll

## Prerequisites

Some entry-level knowledge on Vue and GraphQL is recommended, but this course is beginner-friendly enough to where it isn't a strict requirement.

If you want to build a deeper foundation for both Vue and GraphQL we have a couple of awesome courses that you can hack through. 

For Vue, check out **[The Beginner's Guide to Vue 3](https://egghead.io/courses/the-beginner-s-guide-to-vue-3-1c46da8b),** which is also by Kevin. It's great for both newcomers to web dev and veterans alike. 

And for GraphQL, work through **[GraphQL Query Language](https://egghead.io/courses/graphql-query-language)** from Eve Porcello. Eve literally wrote the book on learning GraphQL and her course is similarly top quality. 

## What's Next?

Progressive Web Apps are a more advanced topic, and converting an existing Single Page **Vue** App into one makes for an excellent follow-up project. **->** [Offline-First Progressive Web Apps (PWA) in Vue.js](https://egghead.io/courses/offline-first-progressive-web-apps-pwa-in-vue-js)

If you want to take your **GraphQL** game to the next level, then becoming an expert in designing GraphQL schemas is the way to go. **->** [Designing GraphQL Schemas](https://egghead.io/courses/designing-graphql-schemas-99db)

And I know the following recommendation is a React course but *it really is that good*. You will learn some **advanced** techniques that will be applicable to Vue or any other Apollo compatible framework that you work with. **->** [Manage State in React Apps with Apollo Client and GraphQL](https://egghead.io/courses/manage-state-in-react-apps-with-apollo-client-and-graphql-a45b3b89)

Vue (pronounced /vjuː/, like view) is a progressive framework for building user interfaces. Unlike other monolithic frameworks, Vue is designed from the ground up to be incrementally adoptable. The core library is focused on the view layer only, and is very easy to pick up and integrate with other libraries or existing projects. On the other hand, Vue is also perfectly capable of powering sophisticated Single-Page Applications when used in combination with modern tooling and supporting libraries.

Create a GraphQL Powered Vue 3 Application

React-router is the community favourite routing solution - it can handle all of your complex routing needs and in this lesson we’ll cover what’s needed to enable it’s use within Preact. https://github.com/ReactTraining/react-router

Integrate react-router with Preact

React Router is a complete routing library for React.

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In this lesson, we’ll install React Router as a project dependency and add links that will update the url via pushState to avoid reloading our page on changes.

Add React Router to a Redux Application

In this lesson, we’ll wire up React Router to pass a url based filter parameter into our component and create a selector function to filter our state data between the store and our components by hooking into the `ownProps` parameter of `mapStateToProps`.

Filter State Data in Redux with a Selector Function and React Router

In this lesson I refactor a simple application built with Apollo, GraphQL, and React to utilize Apollo Boost. Apollo Boost combines many of the Apollo libraries we had to import and configure separately into one awesome API. 

Resources:

[What's in Apollo Boost](https://github.com/apollographql/apollo-client/tree/master/packages/apollo-boost#whats-in-apollo-boost)

[Zero config GraphQL State Management](https://dev-blog.apollodata.com/zero-config-graphql-state-management-27b1f1b3c2c3)


Zero-config Apollo + GraphQL with Apollo Boost

In this lesson we look at how the Apollo @client directive can be used to fetch client-side state along with server data with one query. I also show how to update the client-side state using a mutation connected to a button.

Additional Resources [Apollo Client 2.0](https://dev-blog.apollodata.com/apollo-client-2-0-beyond-graphql-apis-888807b53afe)


Fetch Server Data and Client-side State in One Query using React Apollo + GraphQL

In this lesson we'll use the `match.path` value passed in by React Router to setup dynamic routes for Tabs. This will allow us to setup dynamic tabs which can be navigated to based upon the URL. With this pattern we can change the base path and our tab routes will automatically match and render correctly.

Create Nested Tab Routes with Dynamic Paths with React-Router

In this lesson we'll show how to setup the Prompt component from React Router. We'll prompt with a static message, as well as a dynamic method with the message as a function. Finally we'll show that you can return `true` from the message as a function to dynamically allow navigation.

Prevent Navigation with the React Router Prompt Component

In this lesson we'll show how the Link component `to` prop can receive an object. This allows  us to pass `state` to the route. With the nav state we destructure off of location we can determine if a user wants to open a modal or on a cold visit show an image embedded in the page.

Create a Modal Route with Link and Nav State in React Router

In this lesson we'll create a protected route just for logged in users. We'll combine a Route with a render prop and use a loggedIn prop to determine if the route should be allowed to be accessed. Finally we'll use nav state to preserve the location the user visited and redirect them back to the protected route once they login.

Create a ProtectedRoute Component in React Router

In this lesson we'll use the `matchPath` function exported by react-router to find active nested routes inside of a parent component. This technique can be used for comparing routes outside of a React component, or even inside of life cycle methods to do data loading.

Use matchPath to Match Nested Route Paths in Parent Routes with React-Router

In this lesson I refactor a React component that utilizes a higher-order component for mutations to the new Mutation render prop component baked into react-apollo 2.1.

Additional Resources:
https://dev-blog.apollodata.com/introducing-react-apollo-2-1-c837cc23d926

Update Application State with React Apollo Mutation Component

In this lesson I refactor some code that utilizes the Mutation component to update client-side cache to use the new ApolloConsumer component baked into react-apollo 2.1.

Additional Resources: 
https://dev-blog.apollodata.com/introducing-react-apollo-2-1-c837cc23d926

Update Application State with React Apollo ApolloConsumer Component

In this lesson we’ll execute GraphQL queries using our AWS AppSync API and show how to display the returned data inside of our React application using the AWS AppSync GraphQL client.

We'll create a query string using `gql` (`graphql-tag`) and pass that query into a `graphql` Higher-order component where we will pass the resulting data in our exisiting app.


Execute Queries to an AWS AppSync GraphQL API from a React Application

In this lesson, we’ll execute GraphQL mutations using our AWS AppSync API and show how to add data to the database from a React web application using the AWS AppSync GraphQL client.

We'll create a `mutation` query string that will call `createTodo` that is defined in our WAS AppSync GraphQL client. This query will be passed in as props from a Higher-order component and we'll wire up input in React to feed values into this query.

Execute Mutations to an AWS AppSync GraphQL API from a React Application

In this lesson, we’ll show how you can have your mutations work when the user is offline. We’ll handle the offline mutation with an optimistic response, then when the user comes back online the data will be sent to the dashboard for a seamless user experience.



Implement an Optimistic Response to a React UI & Showcasing Offline Functionality

In this lesson we’ll show how to use GraphQL subscriptions coming from our AWS AppSync API to listen to real time data changes in a React application and render the new data as it comes in.