Get a random newspaper article from the Trove API.

trove-random-article.js

$(function(){
  var trove_api_key = "Your API key"; // Add your API key
  var trove_api_url = "http://api.trove.nla.gov.au/result?zone=newspaper";
  var start_year = 1803;
  var end_year = 1954;
  var current_year = 0;
  
  function get_random_article() {
    current_year = get_random_year(); // Get a random year first to limit the query size
    var query = trove_api_url + "&q=date:[" + current_year + " TO " + current_year + "]&n=0&l-category=Article&encoding=json&key=" + trove_api_key;
    get_api_result(query, 'total');
  }
  
  function get_api_result(query, type) {
    $.ajax({
      "dataType": "jsonp",
      "url": query,
      "success": function(results) {
          process_results(results, type);
        }
    });
  }
  
  function process_results(results, type) {
    if (type == 'total') {
      var total = results.response.zone[0].records.total;
      var number = Math.floor(Math.random() * total); // Get one random result from the total set
      var query = trove_api_url + "&q=date:[" + current_year + " TO " + current_year + "]&s=" + number + "&n=1&l-category=Article&encoding=json&key=" + trove_api_key;
      get_api_result(query, 'article');
    } else if (type == 'article') {
      var article = results.response.zone[0].records.article[0];
      // Do something with the returned article
    }
  }
  
  function get_random_year() {
    var range = (end_year - start_year) + 1;
    var year = start_year + Math.floor(Math.random() * range);
    return year;
  }
  
  get_random_article();
});