util.js

ajax开发实例

/*
 * 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 (window['dojo']) dojo.provide('dwr.util');
if (typeof window['dwr'] == 'undefined') window.dwr = {};
if (typeof dwr['util'] == 'undefined') dwr.util = {};
//if (typeof window['DWRUtil'] == 'undefined') window.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) {
  return original.replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/"/g,'&quot;').replace(/'/g,'&#039;');
};

/**
 * Replace common XML entities with characters (see dwr.util.escapeHtml())
 * @see TODO
 */
dwr.util.unescapeHtml = function(original) {
  return original.replace(/&lt;/g,'<').replace(/&gt;/g,'>').replace(/&quot;/g,'"').replace(/&#039;/g,"'").replace(/&amp;/g,'&');
};

/**
 * 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/$
 */
dwr.util.byId = function() {
  var elems = [];
  for (var i = 0; i < arguments.length; i++) {
    var idOrElem = arguments[i];
    var elem;
    if (typeof idOrElem == 'string') {
      var elem = document.getElementById(idOrElem);
      // Workaround for IE and Opera that may return element based on name
      // (note use of elem.attributes.id.value due to IE bug for elem.getAttribute) 
      if (document.all && elem && elem.attributes.id.value != idOrElem) {
        elem = null;
        var maybeElems = document.all[idOrElem];
        if (maybeElems.tagName) maybeElems = [maybeElems];
        for (var j = 0; j < maybeElems.length; j++) {
          if (maybeElems[j].attributes.id.value == idOrElem) {
            elem = maybeElems[j];
            break;
          }
        }
      }
    }
    else {
      elem = idOrElem;
    }
    if (arguments.length == 1) {
      return elem;
    }
    elems.push(elem);
  }
  return elems;
}

/**
 * Alias $ to dwr.util.byId
 * @see http://getahead.org/dwr/browser/util/$
 */
if (window['$'] == null) {
  window['$'] = dwr.util.byId;
}

/**
 * This function pretty-prints simple data or whole object graphs, f ex as an aid in debugging.
 * @see http://getahead.org/dwr/browser/util/todescriptivestring
 */
dwr.util.toDescriptiveString = function(data, showLevels, options) {
  if (showLevels === undefined) showLevels = 1;
  var opt = {};
  if (dwr.util._isObject(options)) opt = options;
  var defaultoptions = {
    escapeHtml:false,
    baseIndent: "",
    childIndent: "\u00A0\u00A0",
    lineTerminator: "\n",
    oneLineMaxItems: 5,
    shortStringMaxLength: 13,
    propertyNameMaxLength: 30 
  };
  for (var p in defaultoptions) {
    if (!(p in opt)) {
      opt[p] = defaultoptions[p];
    }
  }

  var skipDomProperties = {
    document:true, ownerDocument:true,
    all:true,
    parentElement:true, parentNode:true, offsetParent:true,
    children:true, firstChild:true, lastChild:true,
    previousSibling:true, nextSibling:true,
    innerHTML:true, outerHTML:true,
    innerText:true, outerText:true, textContent:true,
    attributes:true,
    style:true, currentStyle:true, runtimeStyle:true,
    parentTextEdit:true
  };
  
  function recursive(data, showLevels, indentDepth, options) {
    var reply = "";
    try {
      // string
      if (dwr.util._isString(data)) {
        var str = data;
        if (showLevels == 0 && str.length > options.shortStringMaxLength)
          str = str.substring(0, options.shortStringMaxLength-3) + "...";
        if (options.escapeHtml) {
          // Do the escape separately for every line as escapeHtml() on some 
          // browsers (IE) will strip line breaks and we want to preserve them
          var lines = str.split("\n");
          for (var i = 0; i < lines.length; i++) lines[i] = dwr.util.escapeHtml(lines[i]);
          str = lines.join("\n");
        }
        if (showLevels == 0) { // Short format
          str = str.replace(/\n|\r|\t/g, function(ch) {
            switch (ch) {
              case "\n": return "\\n";
              case "\r": return "";
              case "\t": return "\\t";
            }
          });
        }
        else { // Long format
          str = str.replace(/\n|\r|\t/g, function(ch) {
            switch (ch) {
              case "\n": return options.lineTerminator + indent(indentDepth+1, options);
              case "\r": return "";
              case "\t": return "\\t";
            }
          });
        }
        reply = '"' + str + '"';
      }
      
      // function
      else if (dwr.util._isFunction(data)) {
        reply = "function";
      }
    
      // Array
      else if (dwr.util._isArrayLike(data)) {
        if (showLevels == 0) { // Short format (don't show items)
          if (data.length > 0)
            reply = "[...]";
          else
            reply = "[]";
        }
        else { // Long format (show items)
          var strarr = [];
          strarr.push("[");
          var count = 0;
          for (var i = 0; i < data.length; i++) {
            if (!(i in data) && data != "[object NodeList]") continue;
            var itemvalue = data[i];
            if (count > 0) strarr.push(", ");
            if (showLevels == 1) { // One-line format
              if (count == options.oneLineMaxItems) {
                strarr.push("...");
                break;
              }
            }
            else { // Multi-line format
              strarr.push(options.lineTerminator + indent(indentDepth+1, options));
            }
            if (i != count) {
              strarr.push(i);
              strarr.push(":");
            }
            strarr.push(recursive(itemvalue, showLevels-1, indentDepth+1, options));
            count++;
          }
          if (showLevels > 1) strarr.push(options.lineTerminator + indent(indentDepth, options));
          strarr.push("]");
          reply = strarr.join("");
        }
      }
      
      // Objects except Date
      else if (dwr.util._isObject(data) && !dwr.util._isDate(data)) {
        if (showLevels == 0) { // Short format (don't show properties)
          reply = dwr.util._detailedTypeOf(data);
        }
        else { // Long format (show properties)
          var strarr = [];
          if (dwr.util._detailedTypeOf(data) != "Object") {
            strarr.push(dwr.util._detailedTypeOf(data));
            if (typeof data.valueOf() != "object") {
              strarr.push(":");
              strarr.push(recursive(data.valueOf(), 1, indentDepth, options));
            }
            strarr.push(" ");
          }
          strarr.push("{");
          var isDomObject = dwr.util._isHTMLElement(data); 
          var count = 0;
          for (var prop in data) {
            var propvalue = data[prop];
            if (isDomObject) {
              if (!propvalue) continue;
              if (typeof propvalue == "function") continue;
              if (skipDomProperties[prop]) continue;
              if (prop.toUpperCase() == prop) continue;
            }
            if (count > 0) strarr.push(", ");
            if (showLevels == 1) { // One-line format
              if (count == options.oneLineMaxItems) {
                strarr.push("...");
                break;
              }
            }
            else { // Multi-line format
              strarr.push(options.lineTerminator + indent(indentDepth+1, options));
            }
            strarr.push(prop.length > options.propertyNameMaxLength ? prop.substring(0, options.propertyNameMaxLength-3) + "..." : prop);
            strarr.push(":");
            strarr.push(recursive(propvalue, showLevels-1, indentDepth+1, options));
            count++;
          }
          if (showLevels > 1 && count > 0) strarr.push(options.lineTerminator + indent(indentDepth, options));
          strarr.push("}");
          reply = strarr.join("");
        }
      }
  
      // undefined, null, number, boolean, Date
      else {
        reply = "" + data;
      }
  
      return reply;
    }
    catch(err) {
      return (err.message ? err.message : ""+err);
    }
  }

  function indent(count, options) {
    var strarr = [];
    strarr.push(options.baseIndent);
    for (var i=0; i<count; i++) {
      strarr.push(options.childIndent);
    }
    return strarr.join("");
  };
  
  return recursive(data, showLevels, 0, opt);
};

/**
 * 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%";
      // IE need a background color to block click. Use an invisible background.
      if (window.ActiveXObject) {
        disabledZone.style.background = "white";
        disabledZone.style.filter = "alpha(opacity=0)";
      }
      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";
      document.body.appendChild(messageZone);
      var text = document.createTextNode(loadingMessage);
      messageZone.appendChild(text);
      dwr.util._disabledZoneUseCount = 1;
    }
    else {
      dwr.util.byId('messageZone').innerHTML = loadingMessage;