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274 changes: 235 additions & 39 deletions docs/documentation/stories/universal-rendering.md
Original file line number Diff line number Diff line change
@@ -1,23 +1,32 @@
# Universal bundles
# Angular Universal Integration

Angular CLI supports generation of a Universal build for your application. This is a CommonJS-formatted bundle which can be `require()`'d into a Node application (for example, an Express server) and used with `@angular/platform-server`'s APIs to prerender your application.
The Angular CLI supports generation of a Universal build for your application. This is a CommonJS-formatted bundle which can be `require()`'d into a Node application (for example, an Express server) and used with `@angular/platform-server`'s APIs to prerender your application.

This story will show you how to set up Universal bundling for an existing `@angular/cli` project in 4 steps.
---

## Step 0: Install `@angular/platform-server`
## Example CLI Integration:

[Angular Universal-Starter](https://github.com/angular/universal-starter/tree/master/cli) - Clone the universal-starter, and check out the `/cli` folder for a working example.

---

# Integrating Angular Universal into existing CLI Applications

This story will show you how to set up Universal bundling for an existing `@angular/cli` project in 5 steps.

---

## Install Dependencies

Install `@angular/platform-server` into your project. Make sure you use the same version as the other `@angular` packages in your project.

> You'll also need @nguniversal/module-map-ngfactory-loader, as it's used to handle lazy-loading in the context of a server-render. (by loading the chunks right away)

```bash
$ npm install --save-dev @angular/platform-server
```
or
```bash
$ yarn add @angular/platform-server --dev
$ npm install --save @angular/platform-server @nguniversal/module-map-ngfactory-loader
```


## Step 1: Prepare your app for Universal rendering
## Step 1: Prepare your App for Universal rendering

The first thing you need to do is make your `AppModule` compatible with Universal by addding `.withServerTransition()` and an application ID to your `BrowserModule` import:

Expand Down Expand Up @@ -46,7 +55,7 @@ This example places it alongside `app.module.ts` in a file named `app.server.mod

### src/app/app.server.module.ts:

```javascript
```typescript
import {NgModule} from '@angular/core';
import {ServerModule} from '@angular/platform-server';

Expand All @@ -67,14 +76,15 @@ import {AppComponent} from './app.component';
export class AppServerModule {}
```

## Step 2: Create a server main file and tsconfig to build it
---
## Step 2: Create a server "main" file and tsconfig to build it

Create a main file for your Universal bundle. This file only needs to export your `AppServerModule`. It can go in `src`. This example calls this file `main.server.ts`:

### src/main.server.ts:

```javascript
export {AppServerModule} from './app/app.server.module';
```typescript
export { AppServerModule } from './app/app.server.module';
```

Copy `tsconfig.app.json` to `tsconfig.server.json` and change it to build with a `"module"` target of `"commonjs"`.
Expand Down Expand Up @@ -105,6 +115,7 @@ Add a section for `"angularCompilerOptions"` and set `"entryModule"` to your `Ap
}
```

---
## Step 3: Create a new project in `.angular-cli.json`

In `.angular-cli.json` there is an array under the key `"apps"`. Copy the configuration for your client application there, and paste it as a new entry in the array, with an additional key `"platform"` set to `"server"`.
Expand All @@ -118,16 +129,17 @@ Then, remove the `"polyfills"` key - those aren't needed on the server, and adju
...
"apps": [
{
// Keep your original application config intact here.
// It will be app 0.
// Keep your original application config intact here, this is app 0
// -EXCEPT- for outDir, udpate it to dist/browser
"outDir": "dist/browser" // <-- update this
},
{
// This is your server app. It is app 1.
"platform": "server",
"root": "src",
// Build to dist-server instead of dist. This prevents
// Build to dist/server instead of dist. This prevents
// client and server builds from overwriting each other.
"outDir": "dist-server",
"outDir": "dist/server",
"assets": [
"assets",
"favicon.ico"
Expand Down Expand Up @@ -163,41 +175,225 @@ Then, remove the `"polyfills"` key - those aren't needed on the server, and adju
With these steps complete, you should be able to build a server bundle for your application, using the `--app` flag to tell the CLI to build the server bundle, referencing its index of `1` in the `"apps"` array in `.angular-cli.json`:

```bash
# This builds the client application in dist/
# This builds the client application in dist/browser/
$ ng build --prod
...
# This builds the server bundle in dist-server/
$ ng build --prod --app 1
# This builds the server bundle in dist/server/
$ ng build --prod --app 1 --output

# outputs:
Date: 2017-07-24T22:42:09.739Z
Hash: 9cac7d8e9434007fd8da
Time: 4933ms
chunk {0} main.988d7a161bd984b7eb54.bundle.js (main) 9.49 kB [entry] [rendered]
chunk {1} styles.d41d8cd98f00b204e980.bundle.css (styles) 0 bytes [entry] [rendered]
```

## Testing the bundle
---

With this bundle built, you can use `renderModuleFactory` from `@angular/platform-server` to test it out.

```javascript
// Load zone.js for the server.
require('zone.js/dist/zone-node');
## Step 4: Setting up an Express Server to run our Universal bundles

Now that we have everything set up to -make- the bundles, how we get everything running?

PlatformServer offers a method called `renderModuleFactory()` that we can use to pass in our AoT'd AppServerModule, to serialize our application, and then we'll be returning that result to the Browser.

```typescript
app.engine('html', (_, options, callback) => {
renderModuleFactory(AppServerModuleNgFactory, {
// Our index.html
document: template,
url: options.req.url,
// DI so that we can get lazy-loading to work differently (since we need it to just instantly render it)
extraProviders: [
provideModuleMap(LAZY_MODULE_MAP)
]
}).then(html => {
callback(null, html);
});
});
```

You could do this, if you want complete flexibility, or use an express-engine with a few other built in features from [`@nguniversal/express-engine`](https://github.com/angular/universal/tree/master/modules/express-engine) found here.

```typescript
// It's used as easily as
import { ngExpressEngine } from '@nguniversal/express-engine';

app.engine('html', ngExpressEngine({
bootstrap: AppServerModuleNgFactory,
providers: [
provideModuleMap(LAZY_MODULE_MAP)
]
}));
```

Below we can see a TypeScript implementation of a -very- simple Express server to fire everything up.

> Note: This is a very bare bones Express application, and is just for demonstrations sake. In a real production environment, you'd want to make sure you have other authentication and security things setup here as well. This is just meant just to show the specific things needed that are relevant to Universal itself. The rest is up to you!

At the ROOT level of your project (where package.json / etc are), created a file named: **`server.ts`**

### ./server.ts (root project level)

```typescript
// These are important and needed before anything else
import 'zone.js/dist/zone-node';
import 'reflect-metadata';

import { renderModuleFactory } from '@angular/platform-server';
import { enableProdMode } from '@angular/core';

import * as express from 'express';
import { join } from 'path';
import { readFileSync } from 'fs';

// Faster server renders w/ Prod mode (dev mode never needed)
enableProdMode();

// Express server
const app = express();

const PORT = process.env.PORT || 4000;
const DIST_FOLDER = join(process.cwd(), 'dist');

// Our index.html we'll use as our template
const template = readFileSync(join(DIST_FOLDER, 'browser', 'index.html')).toString();

// * NOTE :: leave this as require() since this file is built Dynamically from webpack
const { AppServerModuleNgFactory, LAZY_MODULE_MAP } = require('./dist/server/main.bundle');

const { provideModuleMap } = require('@nguniversal/module-map-ngfactory-loader');

app.engine('html', (_, options, callback) => {
renderModuleFactory(AppServerModuleNgFactory, {
// Our index.html
document: template,
url: options.req.url,
// DI so that we can get lazy-loading to work differently (since we need it to just instantly render it)
extraProviders: [
provideModuleMap(LAZY_MODULE_MAP)
]
}).then(html => {
callback(null, html);
});
});

// Import renderModuleFactory from @angular/platform-server.
var renderModuleFactory = require('@angular/platform-server').renderModuleFactory;
app.set('view engine', 'html');
app.set('views', join(DIST_FOLDER, 'browser'));

// Import the AOT compiled factory for your AppServerModule.
// This import will change with the hash of your built server bundle.
var AppServerModuleNgFactory = require('./dist-server/main.988d7a161bd984b7eb54.bundle').AppServerModuleNgFactory;
// Server static files from /browser
app.get('*.*', express.static(join(DIST_FOLDER, 'browser')));

// Load the index.html file.
var index = require('fs').readFileSync('./src/index.html', 'utf8');
// All regular routes use the Universal engine
app.get('*', (req, res) => {
res.render(join(DIST_FOLDER, 'browser', 'index.html'), { req });
});

// Render to HTML and log it to the console.
renderModuleFactory(AppServerModuleNgFactory, {document: index, url: '/'}).then(html => console.log(html));
// Start up the Node server
app.listen(PORT, () => {
console.log(`Node server listening on http://localhost:${PORT}`);
});
```

## Caveats
## Step 5: Setup a webpack config to handle this Node server.ts file and serve your application!

Now that we have our Node Express server setup, we need to pack it and serve it!

Create a file named `webpack.server.config.js` at the ROOT of your application.

> This file basically takes that server.ts file, and takes it and compiles it and every dependency it has into `dist/server.js`.

### ./webpack.server.config.js (root project level)

```typescript
const path = require('path');
const webpack = require('webpack');

module.exports = {
entry: { server: './server.ts' },
resolve: { extensions: ['.ts', '.js'] },
target: 'node',
// this makes sure we include node_modules and other 3rd party libraries
externals: [/(node_modules|main\..*\.js)/],
output: {
path: path.join(__dirname, 'dist'),
filename: '[name].js'
},
module: {
rules: [
{ test: /\.ts$/, loader: 'ts-loader' }
]
},
plugins: [
// Temporary Fix for issue: https://github.com/angular/angular/issues/11580
// for "WARNING Critical dependency: the request of a dependency is an expression"
new webpack.ContextReplacementPlugin(
/(.+)?angular(\\|\/)core(.+)?/,
path.join(__dirname, 'src'), // location of your src
{} // a map of your routes
),
new webpack.ContextReplacementPlugin(
/(.+)?express(\\|\/)(.+)?/,
path.join(__dirname, 'src'),
)
]
}
```

**Almost there!**

Now let's see what our resulting structure should look like, if we open up our `/dist/` folder we should see:

```
/dist/
/browser/
/server/
```

To fire up the application, in your terminal enter

```bash
node dist/server.js
```

:sparkles:

Now lets create a few handy scripts to help us do all of this in the future.

```json
"scripts": {

// These will be your common scripts
"build:dynamic": "npm run build:client-and-server-bundles && npm run webpack:server",
"serve:dynamic": "node dist/server.js",

// Helpers for the above scripts
"build:client-and-server-bundles": "ng build --prod && ng build --prod --app 1 --output-hashing=false",
"webpack:server": "webpack --config webpack.server.config.js --progress --colors"
}
```

In the future when you want to see a Production build of your app with Universal (locally), you can simply run:

```bash
npm run build:dynamic && npm run serve:dynamic
```

Enjoy!

Once again to see a working version of everything, check out the [universal-starter](https://github.com/angular/universal-starter/tree/master/cli).

---

# Gotchas & Caveats

[Full list of important Gotchas available here](https://github.com/angular/universal#universal-gotchas)

Brief summary of a few important gotchas:

* Lazy loading is not yet supported, but coming very soon. Currently lazy loaded routes aren't available for prerendering, and you will get a `System is not defined` error.
* The bundle produced has a hash in the filename from webpack. When deploying this to a production server, you will need to ensure the correct bundle is required, either by renaming the file or passing the bundle name as an argument to your server.
- Http calls will be executed **twice**
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I don't think this is the place to mention all of Universal Gotchas. We should just mention any Universal CLI gotchas if any,

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Fixed! 👍

- Once on the server, and again on the client
- window/document/location/localStorage/etc **do not exist on the server**
- Avoid or limit setTimeout/setInterval use
- Never manipulate the DOM directly (it doesn't exist on the server)