IMPORTANT: AMP by Example has been merged into amp.dev. All new issues and pull requests should be created here.

AMP by Example

Installation

Fork the repository.
Install NodeJS. You will need version 4.0.0 or above.
Install Gulp via npm. You may need to use sudo depending on your Node installation.

$ npm install -g gulp

Set up the repository:

$ git clone https://github.com/YOUR_GITHUB_NAME/amp-by-example.git
$ cd amp-by-example
$ npm install

Build and run the site:

$ gulp

If everything went well, gulp should now be running the site on http://localhost:8000/

Creating a new sample

Create a new example with gulp create. Set the title via --name or -n and add it to an existing section using --dest or -d:

$ gulp create --name amp-img --dest src/20_Components
$ vim src/20_Components/amp-img.html

For more descriptive example names including whitespaces use quotes:

$ gulp create --name 'Hello World' --dest src/10_Introduction
$ vim src/10_Introduction/Hello_World.html

If you want to create a new sample category, use --category or -c. Prefix the name with two digits followed by a space to define the sort order:

$ gulp create --name amp-awesome --category "50 More Awesomeness"
$ vim src/50_More_Awesomeness/amp-awesome.html

Run validate to validate all examples against AMP spec:

$ gulp validate

Run build to generate all examples:

$ gulp build

While working on an example you can start a local webserver with auto-reload on http://localhost:8000/ by running gulp:

$ gulp

Some components, like amp-live-list require an additional server endpoint.

Writing the sample

Use HTML comments () to document your sample code:

<!-- Look! Images in AMP. -->
<amp-img src="img/image1.jpg" width="200" height="100" layout="responsive"></amp-img>

This works for elements in the header as well:

<head>
  <!-- Import the amp-youtube component -->
  <script async custom-element="amp-youtube" src="https://cdn.ampproject.org/v0/amp-youtube-0.1.js"></script>
  ...
</head>

Every HTML comment creates a separate example section spanning the following HTML element.

<!-- This comment spans the whole following section including the two images -->
<section>
  <amp-img src="img/image1.jpg" width="200" height="100" layout="responsive"></amp-img>
  <amp-img src="img/image2.jpg" width="200" height="100" layout="responsive"></amp-img>
</section>

Nesting comments are not supported:

<!-- A comment -->
<div>
  <!-- This does not work because the parent div has already a comment -->
  <amp-img src="img/image1.jpg" width="200" height="100" layout="responsive"></amp-img>
</div>
<div>
  <!-- Commenting inside nested tags works though -->
  <amp-img src="img/image1.jpg" width="200" height="100" layout="responsive"></amp-img>
</div>

If your comment spans multiple elements, wrap these in an single div without any attributes. The enclosing div tag will be hidden in source code listings:

<!-- The enclosing `div` will be hidden in source code listings. -->
<div>
  <button on="tap:my-lightbox" role="button" tabindex="0">Open lightbox</button>
  <amp-lightbox id="my-lightbox" layout="nodisplay">
    <h1>Hello World!</h1>
  </amp-lightbox>
</div>

Sample Styling

Sometimes it's good to add a little bit more styling to a sample (e.g. to separate a button from an input field). To make sure that all samples have a consistent styling, please use the following CSS variables to style specific elements in your sample:

:root {
  --color-primary: #005AF0;
  --color-secondary: #00DCC0;
  --color-text-light: #fff;
  --color-text-dark: #000;
  --color-error: #B00020;
  --color-bg-light: #FAFAFC;

  --space-1: .5rem;  /* 8px */
  --space-2: 1rem;   /* 16px */
  --space-3: 1.5rem; /* 24px */
  --space-4: 2rem;   /* 32px */

  --box-shadow-1: 0 1px 1px 0 rgba(0,0,0,.14), 0 1px 1px -1px rgba(0,0,0,.14), 0 1px 5px 0 rgba(0,0,0,.12);
}

You can use them to style your samples like this:

.button {
  margin: var(--space-2);
  padding: var(--space-1);
  background-color: var(--color-primary);
  color: var(--color-text-light);
}

Only add the ones that you need to the sample. These CSS variable declarations will be added automatically to your sample, if you use gulp create ... to create the sample.

Colors

Spaces

Formatting

You can use markdown to format your documentation:

<!--
  A simple [responsive](https://www.ampproject.org/docs/guides/responsive/control_layout.html)
  image - *width* and *height* are used to determine the aspect ratio.
-->
<amp-img src="img/image1.jpg" width="200" height="100" layout="responsive"></amp-img>

Notes, Warnings & Tips

There's a special markup available for callouts:

[tip type="default|important|note|read-on"]
Tip!
[/tip]

For example:

[tip type="important"]
Warning! This might go wrong.
[/tip]

Hints

If you'd like to add additional information about a single element inside a section, use the :

<!-- A comment about the form. -->
<form method="post"
  action-xhr="https://example.com/subscribe"
  target="_top">
  <fieldset>
    <input type="text" name="username">

    <!--~ Addition explanation about the hidden field. ~-->
    <input type="hidden" name="id" value="abc">
  </fieldset>
</form>

This will make the <input> element clickable, with the additional explanation appearing on click.

Drafts

You can mark samples as drafts if they are still work-in-progress. This means the samples won't show up in the start page.

<!---
draft: true
--->

Experimental Features

If your sample is using one or more experimental features, you can add a metadata section () with the variable experiments to specify which experiments to enable. This will skip its validation and add an experimental note with instructions to your sample:

<!---
experiments:
  - amp-experiment-name
  - amp-another-experiment
--->

Preview Mode

Visually rich examples can provide a preview mode like this. Enable via metadata in the sample:

<!---
preview: default
--->

There is a special preview mode for AMP Ad samples:

<!---
preview: a4a
--->

Single Column Layout

If your sample looks better with a single column layout, you can disable the code and preview columns adding the following flags to your sample file:

<!---
hideCode: true
hidePreview: true
--->

Disabling the Playground

If it doesn't make sense for your sample to provide a playground link, you can disable it:

<!---
disablePlayground: true
--->

Running the backend server

If you need to run or write a sample that depends on the backend server, you can run a local version.

Install the Google App Engine SDK for Go.

Run the backend server in watch mode so it will recompile on change.

$ gulp backend:watch

If you get an error message can't find import: "golang.org/x/net/context", you have to manually install and configure the GO appengine environment:

# install the google.goland.org/appengine package
$ go get google.golang.org/appengine
# explicitly set the GOROOT and APPENGINE_DEV_APPSERVER env vars
$ export GOROOT=$HOME/local/google-cloud-sdk/platform/google_appengine/goroot
$ export APPENGINE_DEV_APPSERVER=$(which dev_appserver.py)

If everything went well, the full site should now be running on http://localhost:8080/

Adding backend functionality

Sample specific backend endpoints should be defined in their own file, e.g. for a sample amp-my-component.html the backend should be backends/amp-my-component.go.

How to style examples

You can’t reference external stylesheets when creating samples. AMP by Example provides a default styling for common elements (p, h1, h2, h3, a, ...) which you should use. Sample specific styles must live in the head of the document using the tag <style amp-custom>. Try to keep the additional CSS for samples to a minimum and use the default styles as often as possible. If you compile a sample via Gulp and run it, the default styling will be applied.

Please note: if you copy code from a sample's code section, you will not get the style that you can see in the preview section.

Contributing

Please see the CONTRIBUTING file for information on contributing to amp-by-example.

License

AMP by Example is made by the AMP Project, and is licensed under the Apache License, Version 2.0.