How to implement autosuggest using amp-list, amp-mustache, amp-form, and amp-bind?

Question

How to implement autosuggest using amp-list, amp-mustache, amp-form, and amp-bind?

would like to implement autosuggest for intra-page search

have studied this Google example

would like autosuggest to find US state capitals on a single page in this format

<div id='4'>Little Rock is ...</div>

our JSON structure looks like this

{
  "items": [{
    "query": "",
    "results": [{"Montgomery, Alabama","id='1'"},
    {"Juneau, Alaska","id='2'"},
    {"Phoenix, Arizona","id='3'"},
    {"Little Rock, Arkansas","id='4'"}]
  }]
}

have implemented an MCV (minimal, complete, verifiable) example here

how to modify the example to navigate to a specific item on a page based on the selection in results-list?

Answer 1

Here's a quick summary of what you need to do

1. Make a server endpoint that filters results. Make sure it has the appropriate CORS headers.

2. Render the autosuggest items with the ID from the JSON endpoint with a numeric ID

3. Put IDs on each of your or

tags.

#2 will look like this

{{#results}}
    <div
        class='select-option no-outline'
        role='option'
        tabindex='0'
        on='tap:autosuggest-list.hide,{{id}}.scrollTo'
        option='{{title}}'
    >{{title}}</div>
{{/results}}

Here is the specific build process (Steps A – D)

A. HTML and AMP code:

server endpoint https://example.com/state_capitals/query

amp-form

<form
  method='post'
  action-xhr='https://example.com/state_capitals'
  target='_blank'
  id='search-form'
  on='submit:autosuggest-list.hide;submit-success:results.show'
  autocomplete='off'
>

HTML input

<div class='search-container'>
<input
  id='query'
  name='query'
  type='text'
  class='search-box'
  on="input-debounced:AMP.setState({
      query: event.value,
      autosuggest: event.value
    }),
    autosuggest-list.show,
    results.hide"
  [value]="query || ''"
/>
<button class='search-submit' type='submit'>Search</button>
</div>

Above code sets Input Box

amp-list next, bind results from '/state_capitals/query' endpoint to amp-list and amp-selector components as below:

<amp-list
  class='autosuggest-box'
  layout='fixed-height'
  height='120'
  src='/state-capitals/query'
  [src]="'/state-capitals/query?q=' + (autosuggest || '')"
  id='autosuggest-list'
  hidden
>

Source of the amp-list component is from the result of /state-capitals/query in JSON format.

JSON endpoint structure

{"items":[{
    "query": "",
    "results": [
        {"title": "Little Rock, Arkansas", "id":"4"},
        {"title": "Olympia, Washington", "id":"47"},
        {"title": "Charleston, West Virginia", "id":"48"},
        {"title": "Madison, Wisconsin", "id":"49"},
        ...
]}]}

amp-template print result of JSON format using amp-mustache component.

<amp-list ...>
<template type='amp-mustache'>
{{#results}}
  <amp-selector
    keyboard-select-mode='focus'
    layout='container'
    on='select:AMP.setState({query: event.targetOption}),
    autosuggest-list.hide,{{id}}.scrollTo'
  >
    <div
      class='select-option no-outline'
      role='option'
      tabindex='0'
      on='tap:autosuggest-list.hide'
      option='{{title}}'
    >{{title}}</div>
{{/results}}
  </amp-selector>
</template>
</amp-list>

Quick note about amp-selector and on= The following code:

on='select:AMP.setState({
  query: event.targetOption}),
  autosuggest-list.hide,{{id}}.scrollTo'

will scroll to:

{{id}}.scrollTo

Where the table row id, for example, is 107

<li><a href="1">Montgomery</a></li>
<li><a href="2">Juneau</a></li>
<li><a href="3">Phoenix</a></li>
<li><a href="4">Little Rock</a></li>

B. Endpoint implementation

1. Declare JSON object data as:

Data = [
  {"title": "Little Rock, Arkansas", "id":"4"},
  ...
  {"title": "Olympia, Washington", "id":"47"},
  {"title": "Charleston, West Virginia", "id":"48"},
  {"title": "Madison, Wisconsin", "id":"49"},
];

2. implement a node.js server

app.use('/state_capitals/query', (req, res) => {
  assertCors(req, res, ['GET']);
  const MAX_RESULTS = 4;
  const query = req.query.q;

3. apply node.js script

if (!query) {
  res.json({
    items: [{
      query: "",
      results: capitals.slice(0, MAX_RESULTS)
    }]
  });
} else {
  const lowerCaseQuery = query.toLowerCase();
  const filtered = capitals.filter(function(e) {return e.title.toLowerCase().includes(lowerCaseQuery)});
    res.json({
      items: [{
          query: "",
          results: filtered.slice(0, MAX_RESULTS)
      }]
    });
  }
});

C. NGINX settings

Node.js application runs on domain:< … > and specified port.

Ask Nginx to forward all traffic of port number 80 to a specified port when user runs your website in a browser. This is accomplished using location settings in conf file as

location /state_capitals/ {
  proxy_pass http://domain:3002/;
}

D: Implementation

Here is a working version