functions.js

//
// Initialization
//

var version = {
  major: 2,
  minor: 0,
  revision: 0,
  date: new Date('July 30, 2007'),
  extensions: {}
};

// passage storage, story history, Macros
var tale,
    state,
    macros = {};

//
// Section: General-purpose functions
//

//
// Function: $
// Returns the DOM element with the id passed.
//
// Parameters:
// id - the id to look up
//
// Returns:
// A DOM element, or null if none with the id exist.
//

function $(id){
  'use strict';
  if (typeof id === 'string') {
    return document.getElementById(id);
  } else {
    return id;
  }
}

//
// Function: clone
// Performs a shallow copy of an object.
//
// Parameters:
// original - the object to copy
//
// Returns:
// The copied object.
//

function clone(original){
  'use strict';
  var copy = {};
  for (var property in original) {
    if (original.hasOwnProperty(property)) {
      copy[property] = original[property];
    }
  }
  return copy;
}

//
// Function: insertText
// Places text in a DOM element.
//
// Parameters:
// place - the element to add text to
// text - text to insert
//
// Returns:
// The newly created DOM text node.
//

function insertText(place, text){
  'use strict';
  return place.appendChild(document.createTextNode(text));
}

//
// Function: insertElement
// A shortcut function for creating a DOM element. All parameters are
// optional.
//
// Parameters:
// place - the parent element
// type - the type of element to create -- e.g. 'div' or 'span'
// id - the id to give the element
// className - the CSS class to give the element
// text - text to place inside the element. This is *not* interpreted
//        as HTML.
//
// Returns:
// The newly created element.
//

function insertElement(place, type, id, className, text){
  'use strict';
  var el = document.createElement(type);
  if (id) {
    el.id = id;
  }
  if (className) {
    el.className = className;
  }
  if (text) {
    insertText(el, text);
  }
  if (place) {
    place.appendChild(el);
  }
  return el;
}

//
// Function: removeChildren
// Removes all child elements from a DOM element.
//
// Parameters:
// el - the element to strip
//
// Returns:
// nothing
//

function removeChildren(el){
  'use strict';
  while (el.hasChildNodes()) {
    el.removeChild(el.firstChild);
  }
}

//
// Function: addStyle
// Adds CSS styles to the document.
//
// Parameters:
// source - the CSS styles to add
//
// Returns:
// nothing
//

function addStyle(source){
  'use strict';
  var el;
  if (document.createStyleSheet) {
    document.getElementsByTagName('head')[0].insertAdjacentHTML('beforeEnd', '&nbsp;<style>' + source + '</style>');
  } else {
    el = document.createElement('style');
    el.type = 'text/css';
    el.appendChild(document.createTextNode(source));
    document.getElementsByTagName('head')[0].appendChild(el);
  }
}

//
// Function: Math.easeInOut
// Eases a decimal number from 0 to 1.
//
// Parameters:
// i - the number to ease. Must be between 0 and 1.
//
// Returns:
// The eased value.
//

Math.easeInOut = function(i){
  'use strict';
  return(1 - ((Math.cos(i * Math.PI) + 1) / 2));
};

//
// Function: String.readMacroParams
// Parses a list of macro parameters.
//
// Parameters:
// none
//
// Returns:
// An array of parameters.
//

String.prototype.readMacroParams = function(){
  'use strict';
  var regexpMacroParam = new RegExp("(?:\\s*)(?:(?:\"([^\"]*)\")|(?:'([^']*)')|(?:\\[\\[([^\\]]*)\\]\\])|([^\"'\\s]\\S*))","mg"),
      params = [],
      match;
  do {
    match = regexpMacroParam.exec(this);
    if (match) {
      if (match[1]) {
        // Double quoted
        params.push(match[1]);
      } else if (match[2]) {
        // Single quoted
        params.push(match[2]);
      } else if (match[3]) {
        // Double-square-bracket quoted
        params.push(match[3]);
      } else if (match[4]) {
        // Unquoted
        params.push(match[4]);
      }
    }
  } while(match);
  return params;
};

//
// Function: String.readBracketedList
// Parses a list of bracketed links -- e.g. *[[my link]]*.
//
// Parameters:
// none
//
// Returns:
// an array of link titles.
//

String.prototype.readBracketedList = function(){
  'use strict';
  var bracketedPattern = '\\[\\[([^\\]]+)\\]\\]',
      unbracketedPattern = '[^\\s$]+',
      pattern = '(?:' + bracketedPattern + ')|(' + unbracketedPattern + ')',
      re = new RegExp(pattern, 'mg'),
      tiddlerNames = [],
      match;
  do {
    match = re.exec(this);
    if (match) {
      if (match[1]) {
        // Bracketed
        tiddlerNames.push(match[1]);
      } else if(match[2]) {
        // Unbracketed
        tiddlerNames.push(match[2]);
      }
    }
  } while(match);
  return(tiddlerNames);
};

//
// Function: String.trim
// Removes whitespace from the beginning and end of a string.
//
// Parameters:
// none
//
// Returns:
// The trimmed string.
//

String.prototype.trim = function(){
  'use strict';
  return this.replace(/^\s\s*/, '').replace(/\s\s*$/, '');
};