Sample code for rooftop geocoding

class PostcoderRooftop{
  
  constructor(config) {
    this.config = config
    this.init()
  }

  init = () => {

    this.endpointGB = 'https://ws.postcoder.com/pcw/' + this.config.apikey + '/pafaddressbase/'
    this.endpointIE = 'https://ws.postcoder.com/pcw/' + this.config.apikey + '/address/ie/'
    this.addresses = {}

    this.addresslines = 4

    this.searchbutton = document.querySelector(this.config.searchbutton)
    this.searchterminput = document.querySelector(this.config.searchterm)
    this.addressselectioncontainer = document.querySelector(this.config.addressselectioncontainer)


    //hide the no result message
    this.noresultmessage = document.querySelector(this.config.noresultmessage)
    this.noresultmessage.style.display = 'none'

    // add an empty container to show the selected address
    this.addresscontainer = document.createElement('div')
    this.addresscontainer.classList.add('address')
    this.addressselectioncontainer.parentNode.insertBefore(this.addresscontainer, this.addressselectioncontainer.nextSibling)

    // create an empty select and place it hidden in the page
    this.select = document.createElement('select')
    this.select.style.display = 'none'
    this.addressselectioncontainer.appendChild(this.select)

    // create and append the top 'select an address' option.
    let option = document.createElement('option')
    option.text = 'Select an address'
    this.select.appendChild(option)

    // add select change event listener to the dropdown
    this.select.addEventListener('change', this.handleSelectChange )

    // add click event listener to the search button, to call the search function
    this.searchbutton.addEventListener('click', this.search)

    // add 'enter' event listener to the search input, to call the search function
    this.searchterminput.addEventListener('keyup', event =>{
      if (event.keyCode === 13) {
        event.preventDefault()
        this.search()
      }
    })

    // initalise an OpenLayers map and marker, on London
    window.onload = (event) => {
  		
    	const london = ol.proj.fromLonLat([-0.12755, 51.507222])

    	this.view = new ol.View({
  			center: london,
  			zoom: 9,
		  })

    	this.map = new ol.Map({
    		target: this.config.mapcontainer,
    		controls: ol.control.defaults({ attribution: false }),
    		layers: [
	      		new ol.layer.Tile({
    	    		source: new ol.source.OSM()
      			})
    		],
    		view: this.view,
  		})

      this.markerlayer = new ol.layer.Vector({
  			source: new ol.source.Vector(),
  				style: new ol.style.Style({
    				image: new ol.style.Icon({
      				anchor: [0.5, 1],
      				src: 'https://postcoder.com/images/svg/map-pin.svg'
    			})
  			})
		  })

		  this.map.addLayer(this.markerlayer)

		  this.marker = new ol.Feature(new ol.geom.Point(london))
		  this.markerlayer.getSource().addFeature(this.marker)

    }
  
  }

  handleSelectChange = event => {

      // check to see if this selection was to load the next page of results
      if( this.select.value.charAt(0) === 'p'){
      
        // search the next page of results
        let page = this.select.value.substring(1)
        this.search(event, page)

      }else{   

        this.selectAddress( this.select.value )

      }     
  }

  search = (event, page = 0) => {

    let searchterm = encodeURIComponent(this.searchterminput.value)

    //hide the no result message
    this.noresultmessage.style.display = 'none'

    // hide the select
    this.select.style.display = 'none'

    //determine the country
    if(typeof this.config.countrycode !== 'undefined' && this.config.countrycode !== ''){
      // defined in config
      var country = this.config.countrycode
    }else{
      // get from dropdown
      var country = document.querySelector(this.config.country).value
    }

    // if page 0, remove any previous options
    if(page === 0){
      while (this.select.options.length > 1) {                
        this.select.remove(1)
      }
    }else{
      // remove the bottom 'next page' option
      this.select.remove(this.select.options.length - 1)
    }

    // different endpoint for GB and IE
    if( country == 'IE'){
    	var url = this.endpointIE + searchterm + '?lines='+this.addresslines + '&addtags=latitude,longitude&exclude=organisation,country&page=' + page
    }else{
    	var url = this.endpointGB + searchterm + '?lines='+this.addresslines + '&exclude=organisation,country&page=' + page
    }
   	

    // fetch the json formatted result from Postcoder and pass it to processResult
    fetch(url)
      .then( response => {
        if (!response.ok) { 
          throw response 
        }
        return response.json()
      })
      .then( json => {
        this.processResult(json)
      })
      .catch( err => {

        if(typeof err.text === 'function'){
          err.text().then( errorMessage => {
            console.log('Postcoder request error ' + err.status + ' : ' + errorMessage)
          })
        }else{
          console.log(err)
        }
    })
    
  }

  processResult = addresses =>{

    this.addresses = addresses

    //if zero results, ask for manual address entry
    if( addresses.length === 0 ){
      
      //show the no result message
      this.noresultmessage.style.display = 'block'

    }
    // if one result, populate the form
    else if(addresses.length === 1){

      this.selectAddress(0)

    }
    // multiple addresses, show drop down to select from
    else{

      // create and append the address options, using the summaryline of the returned addresses
      for (let i = 0; i < addresses.length; i++) {
        let option = document.createElement('option')
        option.value = i
        option.text = addresses[i].summaryline
        this.select.appendChild(option)
      }

      // if there are morevalues, add paging
      if(this.addresses[this.addresses.length - 1]['morevalues'] === 'true'){

        // add a 'load next page' option
        let option = document.createElement('option')
        option.value = 'p' + this.addresses[this.addresses.length - 1]['nextpage']

        // last address contains total number of results, show the user how many are remaining
        let remainingresults = this.addresses[this.addresses.length - 1]['totalresults'] - this.select.options.length + 1

        option.text = 'Load more results, ' + remainingresults + ' of ' + this.addresses[this.addresses.length - 1]['totalresults'] + ' remaining'
        this.select.appendChild(option)

      }
      
      // ensure the select is visible
      this.select.style.display = 'block'

    }

  }

  selectAddress = i =>{

    // get the selected address
    let address = this.addresses[i]

    let fields = ['organisation','addressline1','addressline2','addressline3','addressline4','posttown','county','postcode']

    let displayaddress = ''

    // display the selected adress in the address container
    for (let i = 0; i < fields.length; i++) {
      if(typeof address[fields[i]] !== 'undefined'){
     	
      	displayaddress += address[fields[i]] + '<br>'

      }
     
    }

    this.addresscontainer.innerHTML = displayaddress

    this.showMap( i )

  }


  showMap = i =>{

    // get the selected address
    let address = this.addresses[i]

    if(address.latitude && address.longitude){

    	let position = ol.proj.fromLonLat([address.longitude, address.latitude])

    	this.view.animate({
    		center: position,
    		zoom: 18,
    		duration: 2000,
  		})

    	this.marker.getGeometry().setCoordinates(position)

    }

  }

}

<!doctype html>
<html lang="en">
  <head>
      <link rel="stylesheet" href="postcoder.css" >   
      <script src="postcoder_rooftop.js"></script>
      <!-- using OpenLayers map -->
      <script src="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v6.9.0/build/ol.js"></script>
  </head>
  <body>

    <form>
            
      <label for="txt_country">Country</label>
      <select id="txt_country">
        <option value="IE">Ireland</option>
        <option value="GB" selected>Great Britian</option>
      </select>


      <label for="txt_search">Search for an address or postcode</label>
      <button type="button" id="btn_search">
          Search
      </button>
      <div class="search_wrap">
          <input id="txt_search" type="search" autocomplete="off" autocapitalize="off" >
      </div>

      <div id="address_selection_container"></div>

      <div id="no_result_message">
          Address not found, please enter manually.
      </div>
      
      <div id="map" class="map"></div>

    </form>


    <script>
        
        new PostcoderRooftop({
            apikey: 'PCW45-12345-12345-1234X', 
            searchterm: '#txt_search', // query selector of the searchterm input field
            addressselectioncontainer: '#address_selection_container', // container for the address selection drop down
            noresultmessage: '#no_result_message',
            country: '#txt_country',  // Country select list; leave blank if not using a country select list 
            countrycode: '', // Hard code if not using a country select list; leave blank otherwise 
            searchbutton: '#btn_search', 
            mapcontainer: 'map' // id for the map container 
        })

    </script>


  </body>
</html>

input,
select {
	display: block;
	box-sizing: border-box;
	width: 100%;
	padding: 10px;
	height: 40px;
	margin-bottom: 0.5em;
	border-width: 1px;
	border-style: solid;
	border-color: lightgray;
}

.search_wrap {
	overflow: hidden;
}

.search_wrap div {
	font-size: 0.75em;
}

button {
	padding: 8px;
	margin-left: 0.5em;
	float: right;
	font-family: sans-serif;
}

label {
	display: block;
	margin-top: 1.25em;
	margin-bottom: 0.25em;
}
select {
	position: relative;
	z-index: 1;
	padding-right: 40px;
}

.isvalid:after {
	content: "\2713";
	color: green;
}

.notvalid:after {
	content: "\2717";
	color: red;
}

#successindicator {
	float: right;
	margin-left: 0.5em;
	display: flex;
	justify-content: center;
	align-content: center;
	flex-direction: column;
	height: 40px;
}

#json_result_container {
	margin: 5em 0 0;
	background-color: #eee;
	color: #333;
	/* border: solid lightgrey 1px; */
	padding: 1em;
	overflow: auto;
}

#autocomplete_wrap {
	position: relative;
}

#suggestion_list {
	position: absolute;
	background-color: #fff;
	outline: -webkit-focus-ring-color auto 1px;
	list-style-type: none;
	margin: 0;
	padding: 0;
	max-height: 400px;
	overflow-y: auto;
}

#suggestion_list li {
	cursor: pointer;
	padding: 10px 5px;
}

#suggestion_list li.header {
	border-bottom: 2px solid #ddd;
}

#suggestion_list li:hover,
#suggestion_list li.selected {
	background-color: #ddd;
}

#suggestion_list li span.extra-info {
	font-size: 0.75em;
	color: #666;
}

.arrow {
	border: solid black;
	border-width: 0 3px 3px 0;
	display: inline-block;
	padding: 3px;
}

.left {
	margin-left: 3px;
	transform: rotate(135deg);
	-webkit-transform: rotate(135deg);
}

.address {
	height: 140px;
	margin: 8px;
}

.map {
	height: 300px;
	width: 100%;
}

body {
	font-family: sans-serif;
	padding: 0;
	margin: 0;
}

from urllib.parse import quote
import requests
import json

# Request parameters
api_key = "PCW45-12345-12345-1234X"
search_term = "NR1 4DH"

# Prepare request and encode user-entered parameters with %xx encoding
request_url = f"https://ws.postcoder.com/pcw/{api_key}/pafaddressbase/{quote(search_term, safe='')}"

# Send request
response = requests.get(request_url)

# Process response
if response.status_code == 200:
    json = response.json()
    if len(json) > 0:
        for address in json:
            print(address["summaryline"], address["latitude"], address["longitude"])
    else:
        print("No results")
else:
    print(f"Request error: {response.content.decode()}")

// Request parameters
$api_key = "PCW45-12345-12345-1234X";
$search_term = "NR1 4DH";

// Prepare request and encode user-entered parameters with %xx encoding
$request_url = "https://ws.postcoder.com/pcw/$api_key/pafaddressbase/" . urlencode($search_term);

// Send request
$result = file_get_contents($request_url, false, stream_context_create(["http" => ["ignore_errors" => true]]));

// Process response
$status_line = $http_response_header[0];
preg_match("{HTTP\/\S*\s(\d{3})}", $status_line, $match);
$status_code = $match[1];

if ($status_code == 200) {
    $json = json_decode($result);
    if (count($json) > 0) {
      foreach ($json as $address) {
        echo("$address->summaryline $address->latitude $address->longitude <br>");
      }
    } else {
      echo("No results");
    }
} else {
    echo("Request error");
}

using System;
using System.Threading.Tasks;
using System.Web;
using System.Net.Http;
using Newtonsoft.Json.Linq;
					
public class Program
{
	public static async Task Main()
	{
		// Request parameters
		string apiKey = "PCW45-12345-12345-1234X";
		string searchTerm = "NR1 4DH";

		// Prepare request and encode user-entered parameters with %xx encoding
		string requestUrl = $"https://ws.postcoder.com/pcw/{apiKey}/pafaddressbase/{HttpUtility.UrlEncode(searchTerm)}";

		using (HttpClient client = new HttpClient())
		{
			// Send request
			var response = await client.GetAsync(requestUrl);
			var responseContent = await response.Content.ReadAsStringAsync();

			// Process response
			if (response.IsSuccessStatusCode)
			{
				JArray responseJson = JArray.Parse(responseContent);
				
				if (responseJson.Count > 0)
				{
					foreach (JObject address in responseJson)
					{
						Console.WriteLine($"{address["summaryline"]}, {address["latitude"]}, {address["longitude"]}");	
					}
				}
				else
				{
					Console.WriteLine("No results");
				}
			}
			else
			{
				Console.WriteLine($"Request error: {responseContent}");
			}
		}
	}
}