JavaScript.html

<script>

//loaded from server on page load
var data = {
  'randomizer_choices':{},
  'names_corpora':{}
};


//event handlers
function onload(e) {
  setButtonsDisabled(true);
  displayWarning('Please wait - loading data');
  google.script.run.withSuccessHandler(onloadSuccess).withFailureHandler(onloadFailure).getData();
}

function handleClick(endpoint) {
  clearWarning();
  displayHeader(endpoint);
  displayOutput('Generating...');
  handleRandomize(endpoint).then(onRandomizeSuccess, onRandomizeFailure);
}

function refresh(e) {
  google.script.run.showSidebar();
}

function onloadSuccess(result) {
  setButtonsDisabled(false);
  clearWarning();
  displayOutput('');
  data = result;
}

function onloadFailure(error) {
  displayWarning('Failed to load data - please try again');
  displayOutput('');
}

function handleRandomize(endpoint) {
  return new Promise((resolve, reject) => {
    try {
      data['user_vars'] = {}; //reset user-defined variables
      var input = data['randomizer_choices'][endpoint][0]; //each endpoint is an array of length one
      if (input.toString().trim().length == 0) throw ('Endpoint "' + endpoint + '" is empty');
      var output = randomize(input);
      resolve(output);
    } catch(e) {
      reject(e);
    }
  });
}

function onRandomizeSuccess(output) {
  displayOutput(output);
}

function onRandomizeFailure(error) {
  displayWarning('ERROR: ' + error);
  displayOutput('');
}

function randomize(input) {
  //search for curly-bracketed syntax, strip brackets and parse inner text
  var output = input.replace(/{([^{]+)}/g, function(match, p1, offset, string) {
    try {
      return parse(p1);
    } catch (e) {
      displayWarning('ERROR: ' + e);
      return match;
    }
  });
  //repeat until no change
  if (input == output) {
    return output;
  } else {
    return randomize(output);
  }
}

function parse(input) {
  /*
  determine format of input (outer brackets have been stripped)
    {key}
    {[list|of|some options]}
    {#0-100}
    {@varname:key}
    {@varname:[list|of|some options]}
    {@varname:#0-100}
    {@varname}
  */
  var match;
  
  //match @varname:statement
  match = input.match(/^@(\w+):(\w+)$/);
  if (match) {
    var varname = match[1];
    var value = parse(match[2]);
    data['user_vars'][varname] = value;
    return value;
  }
  
  //match @varname
  match = input.match(/^@(\w+)$/);
  if (match) {
    var varname = match[1];
    if (data['user_vars'].hasOwnProperty(varname)) {
      return data['user_vars'][varname];
    } else {
      throw ('the variable "@' + varname + '" is undefined');
    }
  }
  
  //match [list|of|some options]
  match = input.match(/^\[([\W\w]+)]$/);
  if (match) {
    var choices = match[1].split('|');
    return choices[Math.floor(Math.random() * choices.length)];
  }
  
  //match #0-100
  match = input.match(/^#(\d+)-(\d+)$/);
  if (match) {
    var min = parseInt(match[1]);
    var max = parseInt(match[2]);
    return (Math.floor(Math.random() * (max - min + 1) ) + min).toString(); //result is inclusive
  }
  
  //match label
  match = input.match(/^(\w+)$/);
  if (match) {
    var key = match[1];
    if (data['randomizer_choices'].hasOwnProperty(key)) {
      //get random choice
      var choices = data['randomizer_choices'][key];
      if (choices.length == 0) throw ('the label "' + key + '" does not define any options');
      return choices[Math.floor(Math.random() * choices.length)];
    } else if (data['names_corpora'].hasOwnProperty(key)) {
      //generate name
      var corpus = data['names_corpora'][key];
      var name;
      do {
        name = generateName(corpus);
      } while(!name.match(/[aeiouy]+/)); //ensure name contains at least one vowel
      name = capitalize(name);
      return name;
    } else {
      throw ('the label "' + key + '" is undefined');
    }
  }
  
  //no match
  throw ('invalid syntax: "' + input + '"');
}

function generateName(corpus) {
  //choose random starting characters
  var name = corpus['<s>'][Math.floor(Math.random() * corpus['<s>'].length)];
  var keyLength = name.length;
  //choose next character at random until sentinel symbol encountered
  while (true) {
    var nextKey = name.substring(name.length - keyLength);
    var next = corpus[nextKey][Math.floor(Math.random() * corpus[nextKey].length)];
    if (next != '</s>') name += next;
    else break;
  }
  return name;
}

function capitalize(str) {
  return str.replace(/(\w)([\w]*)/g, function(match, p1, p2, offset, string) {
    return p1.toUpperCase() + p2;
  });
}

function displayHeader(header) {
  document.getElementById('header').innerHTML = header;
}

function displayOutput(output) {
  document.getElementById('output').innerHTML = output;
}

function displayWarning(msg) {
  if (!document.getElementById('warning').innerHTML.includes(msg)) {
    document.getElementById('warning').innerHTML += msg + "\n";
  }
}

function clearWarning() {
  document.getElementById('warning').innerHTML = '';
}

function setButtonsDisabled(bool) {
  var buttons = document.getElementsByClassName('endpoint');
  for (var i = 0; i < buttons.length; i++) {
    buttons[i].disabled = bool;
  }
}
</script>