qudt.js

"use strict";


var _alphabetSearch;


function showErr(err) {
   let spinner = document.getElementById("spinner");
   spinner.style.display = "none";
   console.log(err);
   alert(err.message);
}


function setMessage(message) {
   const spinner = document.getElementById("spinner");
   const messageDiv = document.getElementById("message");
   if (!message) {
      spinner.style.display = "none";
      messageDiv.style.display = "none";
   } else {
      spinner.style.display = "block";
      messageDiv.style.display = "block";
      messageDiv.innerHTML = message;
   }
}


function bin(data) {
   var letter;
   var bins = {};

   for (var i = 0, ien = data.length; i < ien; i++) {
      const link = data[i];
      const text = link.match(/<a[^>]*>([^<]+)<\/a>/)[1];
      letter = text.charAt(0).toUpperCase();
      
      if (bins[letter]) {
         bins[letter]++;
      }
      else {
         bins[letter] = 1;
      }
   }

   return bins;
}


function parseUnitOwlText(owlText) {
   setMessage("Parsing data...");
   const units = [];
   let unit = {
      Unit: "",
      Label: "",
      UCUM: "",
      Description: "",
      UnitType: ""
   };
   const allLines = owlText.split(/\r\n|\n/);
   allLines.forEach((line) => {
      if (line.substring(0, 5) === "unit:") {
         const id = line.substring(5);
         const href = '"https://qudt.org/vocab/unit/' + id + '.html"';
         const a = '<a href=' + href + '>' + id + '</a>';
         unit = {
            Unit: a,
            Label: "",
            UCUM: "",
            Description: "",
            UnitType: "",
            LabelLang: ""
         };
         units.push(unit);
      } else if (line.substring(0, 36) === "  qudt:hasQuantityKind quantitykind:") {
         const unitType = line.substring(36, line.length - 2);
         if (!unit.UnitType) {
            unit.UnitType = unitType;
         }
         else {
            unit.UnitType += ", " + unitType;
         }
      } else if (line.substring(0, 27) === "  qudt:plainTextDescription" && !unit.Description) {
         unit.Description = line.substring(29, line.length - 3);
      } else if (line.substring(0, 15) === "  qudt:ucumCode" && !unit.UCUM) {
         let ucum = line.substring(17);
         ucum = ucum.substring(0, ucum.indexOf('"'));
         unit.UCUM = ucum;
      } else if (line.substring(0, 12) === "  rdfs:label") {
         // Prefer the en-us version of the label
         let label = line.substring(14);
         const at = label.indexOf('"@')
         // The language is the part between the @ symbol and the semi-colon
         const lang = label.substring(at + 2, label.length - 1).trim();
         label = label.substring(0, at);
         if (!unit.Label || lang === "en-us") {
            unit.Label = label;
            unit.LabelLang = lang;
         }
         else if (lang === "en" && unit.LabelLang !== "en-us") {
            unit.Label = label;
            unit.LabelLang = lang;
         }
      }
   });
   return units;
}


function renderTable(units) {
   setMessage("Rendering table...");
   const table = document.getElementById("unitTable");
   table.style.display = "block";
   var dataTable = $("#unitTable").DataTable({
      data: units,
      columns: [{
         data: "Unit"
      },
      {
         data: "Label"
      },
      {
         data: "UCUM"
      },
      {
         data: "Description"
      },
      {
         data: "UnitType"
      }
      ],
      order: [
         [0, "asc"]
      ],
      paging: false
   });

   // Initialize filter by letter
   var alphabet = $('<div class="alphabet"/>').append('Filter: ');
   var columnData = dataTable.column(0).data();
   var bins = bin(columnData);

   $('<span class="clear active"/>')
      .data('letter', '')
      .data('match-count', columnData.length)
      .html('All')
      .appendTo(alphabet);

   for (var i = 0; i < 26; i++) {
      var letter = String.fromCharCode(65 + i);

      $('<span/>')
         .data('letter', letter)
         .data('match-count', bins[letter] || 0)
         .addClass(!bins[letter] ? 'empty' : '')
         .html(letter)
         .appendTo(alphabet);
   }

   alphabet.insertBefore(dataTable.table().container());

   alphabet.on('click', 'span', function () {
      alphabet.find('.active').removeClass('active');
      $(this).addClass('active');

      _alphabetSearch = $(this).data('letter');
      dataTable.draw();
   });

   var info = $('<div class="alphabetInfo"></div>')
      .appendTo(alphabet);

   alphabet
      .on('mouseenter', 'span', function () {
         info
            .css({
               opacity: 1,
               left: $(this).position().left,
               width: $(this).width()
            })
            .html($(this).data('match-count'))
      })
      .on('mouseleave', 'span', function () {
         info.css('opacity', 0);
      });

   setMessage("");
}


function fetchUnits(qudtUnitListUri) {
   setMessage("Fetching data...");
   fetch(qudtUnitListUri)
      .then((response) => response.text())
      .then((owlText) => parseUnitOwlText(owlText))
      .then((units) => renderTable(units))
      .catch((err) => showErr(err));
}


$.fn.dataTable.ext.search.push(function (settings, searchData) {
   if (!_alphabetSearch) { // No search term - all results shown
      return true;
   }

   if (searchData[0].charAt(0) === _alphabetSearch) {
      return true;
   }

   return false;
});


window.onload = function () {
   const qudtUnitListUri = "https://qudt.org/vocab/unit/";  // not CORS friendly
   fetchUnits(qudtUnitListUri);
};