util.js

实现自动刷新页面 本例实现页面自动刷新的效果

/*
 * Copyright 2005 Joe Walker
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Declare an object to which we can add real functions.
 */
if (dwr == null) var dwr = {};
if (dwr.util == null) dwr.util = {};
if (DWRUtil == null) var DWRUtil = dwr.util;

/** @private The flag we use to decide if we should escape html */
dwr.util._escapeHtml = true;

/**
 * Set the global escapeHtml flag
 */
dwr.util.setEscapeHtml = function(escapeHtml) {
  dwr.util._escapeHtml = escapeHtml;
}

/** @private Work out from an options list and global settings if we should be esccaping */
dwr.util._shouldEscapeHtml = function(options) {
  if (options && options.escapeHtml != null) {
    return options.escapeHtml;
  }
  return dwr.util._escapeHtml;
}

/**
 * Return a string with &, <, >, ' and " replaced with their entities
 * @see TODO
 */
dwr.util.escapeHtml = function(original) {
  var div = document.createElement('div');
  var text = document.createTextNode(original);
  div.appendChild(text);
  return div.innerHTML;
}

/**
 * Replace common XML entities with characters (see dwr.util.escapeHtml())
 * @see TODO
 */
dwr.util.unescapeHtml = function(original) {
  var div = document.createElement('div');
  div.innerHTML = original.replace(/<\/?[^>]+>/gi, '');
  return div.childNodes[0] ? div.childNodes[0].nodeValue : '';
}

/**
 * Replace characters dangerous for XSS reasons with visually similar characters
 * @see TODO
 */
dwr.util.replaceXmlCharacters = function(original) {
  original = original.replace("&", "+");
  original = original.replace("<", "\u2039");
  original = original.replace(">", "\u203A");
  original = original.replace("\'", "\u2018");
  original = original.replace("\"", "\u201C");
  return original;
}

/**
 * Return true iff the input string contains any XSS dangerous characters
 * @see TODO
 */
dwr.util.containsXssRiskyCharacters = function(original) {
  return (original.indexOf('&') != -1
    && original.indexOf('<') != -1
    && original.indexOf('>') != -1
    && original.indexOf('\'') != -1
    && original.indexOf('\"') != -1);
}

/**
 * Enables you to react to return being pressed in an input
 * @see http://getahead.org/dwr/browser/util/selectrange
 */
dwr.util.onReturn = function(event, action) {
  if (!event) event = window.event;
  if (event && event.keyCode && event.keyCode == 13) action();
};

/**
 * Select a specific range in a text box. Useful for 'google suggest' type functions.
 * @see http://getahead.org/dwr/browser/util/selectrange
 */
dwr.util.selectRange = function(ele, start, end) {
  ele = dwr.util._getElementById(ele, "selectRange()");
  if (ele == null) return;
  if (ele.setSelectionRange) {
    ele.setSelectionRange(start, end);
  }
  else if (ele.createTextRange) {
    var range = ele.createTextRange();
    range.moveStart("character", start);
    range.moveEnd("character", end - ele.value.length);
    range.select();
  }
  ele.focus();
};

/**
 * Find the element in the current HTML document with the given id or ids
 * @see http://getahead.org/dwr/browser/util/$
 */
if (document.getElementById) {
  dwr.util.byId = function() {
    var elements = new Array();
    for (var i = 0; i < arguments.length; i++) {
      var element = arguments[i];
      if (typeof element == 'string') {
        element = document.getElementById(element);
      }
      if (arguments.length == 1) {
        return element;
      }
      elements.push(element);
    }
    return elements;
  };
}
else if (document.all) {
  dwr.util.byId = function() {
    var elements = new Array();
    for (var i = 0; i < arguments.length; i++) {
      var element = arguments[i];
      if (typeof element == 'string') {
        element = document.all[element];
      }
      if (arguments.length == 1) {
        return element;
      }
      elements.push(element);
    }
    return elements;
  };
}

/**
 * Alias $ to dwr.util.byId
 * @see http://getahead.org/dwr/browser/util/$
 */
var $;
if (!$) {
  $ = dwr.util.byId;
}

/**
 * Like toString but aimed at debugging
 * @see http://getahead.org/dwr/browser/util/todescriptivestring
 */
dwr.util.toDescriptiveString = function(data, level, depth) {
  var reply = "";
  var i = 0;
  var value;
  var obj;
  if (level == null) level = 0;
  if (depth == null) depth = 0;
  if (data == null) return "null";
  if (dwr.util._isArray(data)) {
    if (data.length == 0) reply += "[]";
    else {
      if (level != 0) reply += "[\n";
      else reply = "[";
      for (i = 0; i < data.length; i++) {
        try {
          obj = data[i];
          if (obj == null || typeof obj == "function") {
            continue;
          }
          else if (typeof obj == "object") {
            if (level > 0) value = dwr.util.toDescriptiveString(obj, level - 1, depth + 1);
            else value = dwr.util._detailedTypeOf(obj);
          }
          else {
            value = "" + obj;
            value = value.replace(/\/n/g, "\\n");
            value = value.replace(/\/t/g, "\\t");
          }
        }
        catch (ex) {
          value = "" + ex;
        }
       if (level != 0)  {
          reply += dwr.util._indent(level, depth + 2) + value + ", \n";
       }
        else {
          if (value.length > 13) value = value.substring(0, 10) + "...";
          reply += value + ", ";
          if (i > 5) {
            reply += "...";
            break;
          }
        }
      }
      if (level != 0) reply += dwr.util._indent(level, depth) + "]";
      else reply += "]";
    }
    return reply;
  }
  if (typeof data == "string" || typeof data == "number" || dwr.util._isDate(data)) {
    return data.toString();
  }
  if (typeof data == "object") {
    var typename = dwr.util._detailedTypeOf(data);
    if (typename != "Object")  reply = typename + " ";
    if (level != 0) reply += "{\n";
    else reply = "{";
    var isHtml = dwr.util._isHTMLElement(data);
    for (var prop in data) {
      if (isHtml) {
        // HTML nodes have far too much stuff. Chop out the constants
        if (prop.toUpperCase() == prop || prop == "title" ||
          prop == "lang" || prop == "dir" || prop == "className" ||
          prop == "form" || prop == "name" || prop == "prefix" ||
          prop == "namespaceURI" || prop == "nodeType" ||
          prop == "firstChild" || prop == "lastChild" ||
          prop.match(/^offset/)) {
          continue;
        }
      }
      value = "";
      try {
        obj = data[prop];
        if (obj == null || typeof obj == "function") {
          continue;
        }
        else if (typeof obj == "object") {
          if (level > 0) {
            value = "\n";
            value += dwr.util._indent(level, depth + 2);
            value = dwr.util.toDescriptiveString(obj, level - 1, depth + 1);
          }
          else {
            value = dwr.util._detailedTypeOf(obj);
          }
        }
        else {
          value = "" + obj;
          value = value.replace(/\/n/g, "\\n");
          value = value.replace(/\/t/g, "\\t");
        }
      }
      catch (ex) {
        value = "" + ex;
      }
      if (level == 0 && value.length > 13) value = value.substring(0, 10) + "...";
      var propStr = prop;
      if (propStr.length > 30) propStr = propStr.substring(0, 27) + "...";
      if (level != 0) reply += dwr.util._indent(level, depth + 1);
      reply += prop + ":" + value + ", ";
      if (level != 0) reply += "\n";
      i++;
      if (level == 0 && i > 5) {
        reply += "...";
        break;
      }
    }
    reply += dwr.util._indent(level, depth);
    reply += "}";
    return reply;
  }
  return data.toString();
};

/**
 * @private Indenting for dwr.util.toDescriptiveString
 */
dwr.util._indent = function(level, depth) {
  var reply = "";
  if (level != 0) {
    for (var j = 0; j < depth; j++) {
      reply += "\u00A0\u00A0";
    }
    reply += " ";
  }
  return reply;
};

/**
 * Setup a GMail style loading message.
 * @see http://getahead.org/dwr/browser/util/useloadingmessage
 */
dwr.util.useLoadingMessage = function(message) {
  var loadingMessage;
  if (message) loadingMessage = message;
  else loadingMessage = "Loading";
  dwr.engine.setPreHook(function() {
    var disabledZone = dwr.util.byId('disabledZone');
    if (!disabledZone) {
      disabledZone = document.createElement('div');
      disabledZone.setAttribute('id', 'disabledZone');
      disabledZone.style.position = "absolute";
      disabledZone.style.zIndex = "1000";
      disabledZone.style.left = "0px";
      disabledZone.style.top = "0px";
      disabledZone.style.width = "100%";
      disabledZone.style.height = "100%";
      document.body.appendChild(disabledZone);
      var messageZone = document.createElement('div');
      messageZone.setAttribute('id', 'messageZone');
      messageZone.style.position = "absolute";
      messageZone.style.top = "0px";
      messageZone.style.right = "0px";
      messageZone.style.background = "red";
      messageZone.style.color = "white";
      messageZone.style.fontFamily = "Arial,Helvetica,sans-serif";
      messageZone.style.padding = "4px";
      disabledZone.appendChild(messageZone);
      var text = document.createTextNode(loadingMessage);
      messageZone.appendChild(text);
      dwr.util._disabledZoneUseCount = 1;
    }
    else {
      dwr.util.byId('messageZone').innerHTML = loadingMessage;
      disabledZone.style.visibility = 'visible';
      dwr.util._disabledZoneUseCount++;
    }
  });
  dwr.engine.setPostHook(function() {
    dwr.util._disabledZoneUseCount--;
    if (dwr.util._disabledZoneUseCount == 0) {
      dwr.util.byId('disabledZone').style.visibility = 'hidden';
    }
  });
};

/**
 * Set a global highlight handler
 */
dwr.util.setHighlightHandler = function(handler) {
  dwr.util._highlightHandler = handler;
};

/**
 * An example highlight handler
 */
dwr.util.yellowFadeHighlightHandler = function(ele) {
  dwr.util._yellowFadeProcess(ele, 0);
};
dwr.util._yellowFadeSteps = [ "d0", "b0", "a0", "90", "98", "a0", "a8", "b0", "b8", "c0", "c8", "d0", "d8", "e0", "e8", "f0", "f8" ];
dwr.util._yellowFadeProcess = function(ele, colorIndex) {
  ele = dwr.util.byId(ele);
  if (colorIndex < dwr.util._yellowFadeSteps.length) {
    ele.style.backgroundColor = "#ffff" + dwr.util._yellowFadeSteps[colorIndex];
    setTimeout("dwr.util._yellowFadeProcess('" + ele.id + "'," + (colorIndex + 1) + ")", 200);
  }
  else {
    ele.style.backgroundColor = "transparent";
  }
};

/**
 * An example highlight handler
 */
dwr.util.borderFadeHighlightHandler = function(ele) {
  ele.style.borderWidth = "2px";
  ele.style.borderStyle = "solid";
  dwr.util._borderFadeProcess(ele, 0);
};
dwr.util._borderFadeSteps = [ "d0", "b0", "a0", "90", "98", "a0", "a8", "b0", "b8", "c0", "c8", "d0", "d8", "e0", "e8", "f0", "f8" ];
dwr.util._borderFadeProcess = function(ele, colorIndex) {
  ele = dwr.util.byId(ele);
  if (colorIndex < dwr.util._borderFadeSteps.length) {
    ele.style.borderColor = "#ff" + dwr.util._borderFadeSteps[colorIndex] + dwr.util._borderFadeSteps[colorIndex];
    setTimeout("dwr.util._borderFadeProcess('" + ele.id + "'," + (colorIndex + 1) + ")", 200);
  }
  else {
    ele.style.backgroundColor = "transparent";
  }
};

/**
 * A focus highlight handler
 */
dwr.util.focusHighlightHandler = function(ele) {
  try {
    ele.focus();
  }
  catch (ex) { /* ignore */ }
};

/** @private the current global highlight style */
dwr.util._highlightHandler = null;

/**
 * Highlight that an element has changed
 */
dwr.util.highlight = function(ele, options) {
  if (options && options.highlightHandler) {
    options.highlightHandler(dwr.util.byId(ele));
  }
  else if (dwr.util._highlightHandler != null) {
    dwr.util._highlightHandler(dwr.util.byId(ele));
  }
};

/**
 * Set the value an HTML element to the specified value.
 * @see http://getahead.org/dwr/browser/util/setvalue
 */
dwr.util.setValue = function(ele, val, options) {
  if (val == null) val = "";
  if (options == null) options = {};
  if (dwr.util._shouldEscapeHtml(options) && typeof(val) == "string") {
    val = dwr.util.escapeHtml(val);
  }

  var orig = ele;
  var nodes, node, i;
  ele = dwr.util.byId(ele);

  // We can work with names and need to sometimes for radio buttons
  if (ele == null) {
    nodes = document.getElementsByName(orig);
    if (nodes.length >= 1) ele = nodes.item(0);
  }

  if (ele == null) {
    dwr.util._debug("setValue() can't find an element with id/name: " + orig + ".");
    return;
  }

  // All paths now lead to some update so we highlight a change
  dwr.util.highlight(ele, options);

  if (dwr.util._isHTMLElement(ele, "select")) {
    if (ele.type == "select-multiple" && dwr.util._isArray(val)) dwr.util._selectListItems(ele, val);
    else dwr.util._selectListItem(ele, val);
    return;
  }

  if (dwr.util._isHTMLElement(ele, "input")) {
    if (ele.type == "radio") {