List_Data.js

// Internet Explorer still does not support Array.prototype.includes()
// Polyfill these methods to support IE
// See: https://stackoverflow.com/questions/31221341/ie-does-not-support-includes-method
//
// Polyfill Array.prototype.includes() method
if (!Array.prototype.includes) {
  Object.defineProperty(Array.prototype, "includes", {
    enumerable: false,
    value: function(obj) {
        var newArr = this.filter(function(el) {
          return el == obj;
        });
        return newArr.length > 0;
    }
  });
}


/**
 * Populates an HTML list with ArcGIS Online items from a group matching type, tag, and tagKeyword parameters.
 see https://developers.arcgis.com/rest/users-groups-and-items/search-reference.htm for more information on search queries.
 * @param  {ID} string          The element ID of the list to append data links into
 * @param  {group} string       ArcGIS Online group ID to search for items
 * @param  {type} string        Item type to return. Pass null to not used. Complete list of item types here: https://developers.arcgis.com/rest/users-groups-and-items/items-and-item-types.htm
 * @param  {tag} string         Item tag to filter results. Pass null if not used.
 * @param  {typeKeywords} string Type Keywords to further filter query. Pass null if not used. See URL for item types above for type keywords.
 * @param  {trim_title} boolean If true, removes the following prefix argument from start of item title, Defaults to False.
 * @param  {prefix} string      The prefix to remove from the start of the item title; defaults to MaineDMR.
 * @param  {link_to} string     What the link will direct to for feature services - MaineDMR Open Data page, Item page, or direct CSV or shapefile (only use with table types). Options are 'item_page', 'open_data', or 'direct' - only use direct with type = feature service. If directing to the Open Data page, the item must have only one layer and the layer name must be identical to the item name. Web Applications and Dashboards will link directly
 to the application.
 * @param  {count} int          The maximum number of items to return; defaults to 200.
 * @param  {use_snippet} boolean If true, the item snippet is appended after the hyperlink. Defaults to true.  
 */
function ListData(ID, group, type, tag, typeKeywords, trim_title, prefix, link_to, count, use_snippet) {
  $(document).ready(function() {
    // And now the query
    var query = 'https://www.arcgis.com/sharing/rest/search?q=group:' + group;
    // Add type
    if (type != null) {
      query += '+type:' + type;
    }
    // Add tags
    if (tag != null) {
      query += '+tags:' + tag;
    }
    // Add typeKeywords
    if (typeKeywords != null) {
      query += '+typekeywords:' + typeKeywords;
    }
    // Add end to query
    query += '&num=' + count + '&sortField=title&f=pjson';
    // List Element ID                                                             
    var $ListData = $('#' + ID);
    $('#' + ID).html('');
    $.getJSON(query, function(data) {
      $.each(data.results, function(key, val) {
        // This will create a list of hyperlinks, with the snippet describing the item afterward
        // Any value available in the query JSON can be appended
        // Title for item
        if (trim_title == true) {
          // Trim prefix from title, along with any leading whitespace or hyphens
            /**
        * Remove chars from beginning of string.
        * https://gist.github.com/jonlabelle/5375315
        */
        function ltrim(str, chars) {
          chars = chars || WHITE_SPACES;

          var start = 0,
              len = str.length,
              charLen = chars.length,
              found = true,
              i, c;

          while (found && start < len) {
              found = false;
              i = -1;
              c = str.charAt(start);

              while (++i < charLen) {
                  if (c === chars[i]) {
                      found = true;
                      start++;
                      break;
                  }
              }
          }
          return (start >= len) ? '' : str.substr(start, len);
        }
          var title = ltrim(val.title.replace(prefix, '').trim(), "-").trim();
        }
        else {
          var title = val.title;
        }
        // Snippet
        if (val.snippet == null) {var snippet = ''}
        else {var snippet = ' - ' + val.snippet}
        if (use_snippet == false) {var snippet = ''}
        // Build list with links
      var url;
      var link_str;
      // Function to return link string to feature service
      function GetURL(link_to, item_url, id, layer_id, title, snippet) {
        if (link_to == 'open_data') {
            url = 'https://dmr-maine.opendata.arcgis.com/datasets/' + id + '_' + layer_id;
            link_str = '<li><a data-name="' + title + '" href="' + url + '">' + title + '</a>' + snippet + '</li>';
          }
          else if (link_to == 'item_page') {
            url = val.url;
            link_str = '<li><a data-name="' + title + '" href="' + item_url + '">' + title + '</a>' + snippet + '</li>';
          }
          else if (link_to == 'direct') {
            if (val.typeKeywords.includes("Table")) {
              url = 'https://opendata.arcgis.com/datasets/' + id + '_' + layer_id + '.csv';
              link_str = '<li><a data-name="' + title + '" href="' + url + '"">' + title + '</a>' + snippet + '</li>';
            }
            else {
              url = 'https://opendata.arcgis.com/datasets/' + id + '_' + layer_id + '.zip';
              link_str = '<li><a data-name="' + title + '" href="' + url + '"">' + title + '</a>' + snippet + '</li>';
            }          
          }
          return link_str
      };
      // Function to build links for multilayer feature services
      function MultiLayer(item_url, item_id) {
        var query = item_url + '?f=pjson';
        $.getJSON(query, function(data) {
            $.each(data.layers, function(key, val) {
              if (trim_title == true) {
                var title = ltrim(val.name.replace(prefix, '').trim(), "-").trim();
              }
              else {
                var title = val.name;
              }
              link_str = GetURL(link_to, item_url, id = item_id, layer_id = val.id, title, snippet);
              $ListData.append(link_str);
            });
          });
      };
      // If type is feature service, get layer ID from URL
      if (val.type == 'Feature Service') {
        // If feature service has multiple layers
        if (val.typeKeywords.includes("Multilayer")) {
          MultiLayer(val.url, val.id);
          return true;
        }
        var url_split = val.url.split('/');
        var layer_id = url_split[url_split.length - 1];
        if (layer_id == 'FeatureServer' || layer_id == 'MapServer') {
          layer_id = 0;
        };
      }
      // For non-feature service items, link directly to item
      if (val.type != 'Feature Service') {
        // Dashboards get different link
        if (val.type == 'Dashboard') {
          url = 'https://maine.maps.arcgis.com/apps/opsdashboard/index.html#/' + val.id;
          link_str = '<li><a data-name="' + title + '" href="' + url +  '">' + title + '</a>' + snippet + '</li>';
        }
        else {
          url = val.url;
          link_str = '<li><a data-name="' + title + '" href="' + val.url + '">' + title + '</a>' + snippet + '</li>';
        }
      }
        else { // Feature service single layer, pass to GetURL
          link_str = GetURL(link_to, item_url = val.url, id = val.id, layer_id, title, snippet);
        }
        // Append to list
        $ListData.append(link_str);
      })
    });
  });
};