util.js

实现自动刷新页面 本例实现页面自动刷新的效果

      // Some browsers match names when looking for ids, so check names anyway.
      if (nodes == null) nodes = document.getElementsByName(orig);
      if (nodes != null && nodes.length > 1) {
        for (i = 0; i < nodes.length; i++) {
          node = nodes.item(i);
          if (node.type == "radio") node.checked = (node.value == val);
        }
      }
      else ele.checked = (val == true);
    }
    else if (ele.type == "checkbox") ele.checked = val;
    else ele.value = val;

    return;
  }

  if (dwr.util._isHTMLElement(ele, "textarea")) {
    ele.value = val;
    return;
  }

  // If the value to be set is a DOM object then we try importing the node
  // rather than serializing it out
  if (val.nodeType) {
    if (val.nodeType == 9 /*Node.DOCUMENT_NODE*/) val = val.documentElement;
    val = dwr.util._importNode(ele.ownerDocument, val, true);
    ele.appendChild(val);
    return;
  }

  // Fall back to innerHTML
  ele.innerHTML = val;
};

/**
 * @private Find multiple items in a select list and select them. Used by setValue()
 * @param ele The select list item
 * @param val The array of values to select
 */
dwr.util._selectListItems = function(ele, val) {
  // We deal with select list elements by selecting the matching option
  // Begin by searching through the values
  var found  = false;
  var i;
  var j;
  for (i = 0; i < ele.options.length; i++) {
    ele.options[i].selected = false;
    for (j = 0; j < val.length; j++) {
      if (ele.options[i].value == val[j]) {
        ele.options[i].selected = true;
      }
    }
  }
  // If that fails then try searching through the visible text
  if (found) return;

  for (i = 0; i < ele.options.length; i++) {
    for (j = 0; j < val.length; j++) {
      if (ele.options[i].text == val[j]) {
        ele.options[i].selected = true;
      }
    }
  }
};

/**
 * @private Find an item in a select list and select it. Used by setValue()
 * @param ele The select list item
 * @param val The value to select
 */
dwr.util._selectListItem = function(ele, val) {
  // We deal with select list elements by selecting the matching option
  // Begin by searching through the values
  var found = false;
  var i;
  for (i = 0; i < ele.options.length; i++) {
    if (ele.options[i].value == val) {
      ele.options[i].selected = true;
      found = true;
    }
    else {
      ele.options[i].selected = false;
    }
  }

  // If that fails then try searching through the visible text
  if (found) return;

  for (i = 0; i < ele.options.length; i++) {
    if (ele.options[i].text == val) {
      ele.options[i].selected = true;
    }
    else {
      ele.options[i].selected = false;
    }
  }
};

/**
 * Read the current value for a given HTML element.
 * @see http://getahead.org/dwr/browser/util/getvalue
 */
dwr.util.getValue = function(ele, options) {
  if (options == null) options = {};
  var orig = ele;
  ele = dwr.util.byId(ele);
  // We can work with names and need to sometimes for radio buttons, and IE has
  // an annoying bug where
  var nodes = document.getElementsByName(orig);
  if (ele == null && nodes.length >= 1) {
    ele = nodes.item(0);
  }
  if (ele == null) {
    dwr.util._debug("getValue() can't find an element with id/name: " + orig + ".");
    return "";
  }

  if (dwr.util._isHTMLElement(ele, "select")) {
    // Using "type" property instead of "multiple" as "type" is an official 
    // client-side property since JS 1.1
    if (ele.type == "select-multiple") {
      var reply = new Array();
      for (i = 0; i < ele.options.length; i++) {
        var item = ele.options[i];
        if (item.selected) {
          if (item.value != null && item.value != "") {
            reply.push(item.value);
          }
          else {
            reply.push(item.text);
          }
        }
      }
      return reply;
    }
    else {
      var sel = ele.selectedIndex;
      if (sel != -1) {
        var item = ele.options[sel];
        if (item.value != null && item.value != "") {
          return item.value;
        }
        return item.text;
      }
      else {
        return "";
      }
    }
  }

  if (dwr.util._isHTMLElement(ele, "input")) {
    if (ele.type == "radio") {
      var node;
      for (i = 0; i < nodes.length; i++) {
        node = nodes.item(i);
        if (node.type == "radio") {
          if (node.checked) {
            if (nodes.length > 1) return node.value;
            else return true;
          }
        }
      }
    }
    switch (ele.type) {
    case "checkbox":
    case "check-box":
    case "radio":
      // if (ele.checked && ele.value != "") return ele.value;
      // else
      return ele.checked;
    default:
      return ele.value;
    }
  }

  if (dwr.util._isHTMLElement(ele, "textarea")) {
    return ele.value;
  }

  if (dwr.util._shouldEscapeHtml(options)) {
    if (ele.textContent) return ele.textContent;
    else if (ele.innerText) return ele.innerText;
  }
  return ele.innerHTML;
};

/**
 * getText() is like getValue() except that it reads the text (and not the value) from select elements
 * @see http://getahead.org/dwr/browser/util/gettext
 */
dwr.util.getText = function(ele) {
  ele = dwr.util._getElementById(ele, "getText()");
  if (ele == null) return null;
  if (!dwr.util._isHTMLElement(ele, "select")) {
    dwr.util._debug("getText() can only be used with select elements. Attempt to use: " + dwr.util._detailedTypeOf(ele) + " from  id: " + orig + ".");
    return "";
  }

  // This is a bit of a scam because it assumes single select
  // but I'm not sure how we should treat multi-select.
  var sel = ele.selectedIndex;
  if (sel != -1) {
    return ele.options[sel].text;
  }
  else {
    return "";
  }
};

/**
 * Given a map, or a recursive structure consisting of arrays and maps, call 
 * setValue() for all leaf entries and use intermediate levels to form nested
 * element ids.
 * @see http://getahead.org/dwr/browser/util/setvalues
 */
dwr.util.setValues = function(data, options) {
  var prefix = "";
  if (options && options.prefix) prefix = options.prefix;
  if (options && options.idPrefix) prefix = options.idPrefix;
  dwr.util._setValuesRecursive(data, prefix);
};

/**
 * @private Recursive helper for setValues()
 */
dwr.util._setValuesRecursive = function(data, idpath) {
  // Array containing objects -> add "[n]" to prefix and make recursive call
  // for each item object
  if (dwr.util._isArray(data) && data.length > 0 && dwr.util._isObject(data[0])) {
    for (var i = 0; i < data.length; i++) {
      dwr.util._setValuesRecursive(data[i], idpath+"["+i+"]");
    }
  }
  // Object (not array) -> handle nested object properties
  else if (dwr.util._isObject(data) && !dwr.util._isArray(data)) {
    for (var prop in data) {
      var subidpath = idpath ? idpath+"."+prop : prop;
      // Object (not array), or array containing objects -> call ourselves recursively
      if (dwr.util._isObject(data[prop]) && !dwr.util._isArray(data[prop]) 
          || dwr.util._isArray(data[prop]) && data[prop].length > 0 && dwr.util._isObject(data[prop][0])) {
        dwr.util._setValuesRecursive(data[prop], subidpath);
      }
      // Functions -> skip
      else if (typeof data[prop] == "function") {
        // NOP
      }
      // Only simple values left (or array of simple values, or empty array)
      // -> call setValue()
      else {
        // Are there any elements with that id or name
        if (dwr.util.byId(subidpath) != null || document.getElementsByName(subidpath).length >= 1) {
          dwr.util.setValue(subidpath, data[prop]);
        }
      }
    }
  }
};

/**
 * Given a map, or a recursive structure consisting of arrays and maps, call 
 * getValue() for all leaf entries and use intermediate levels to form nested
 * element ids.
 * Given a string or element that refers to a form, create an object from the 
 * elements of the form.
 * @see http://getahead.org/dwr/browser/util/getvalues
 */
dwr.util.getValues = function(data, options) {
  var ele;
  if (typeof data == "string") ele = dwr.util.byId(data);
  if (dwr.util._isHTMLElement(data)) ele = data;
  if (ele != null) {
    return dwr.util.getFormValues(ele);
  }
  else {
    var prefix = "";
    if (options != null && options.prefix) prefix = options.prefix;
    if (options != null && options.idPrefix) prefix = options.idPrefix;
    dwr.util._getValuesRecursive(data, prefix);
    return data;
  }
};

/**
 * Given a string or element that refers to a form, create an object from the 
 * elements of the form.
 * @see http://getahead.org/dwr/browser/util/getvalues
 */
dwr.util.getFormValues = function(ele) {
  ele = dwr.util.byId(ele);
  if (ele != null) {
    if (ele.elements == null) {
      alert("getFormValues() requires an object or reference to a form element.");
      return null;
    }
    var reply = {};
    var value;
    for (var i = 0; i < ele.elements.length; i++) {
      if (ele[i].type in {button:0,submit:0,reset:0,image:0,file:0}) continue;
      if (ele[i].id != null) value = ele[i].id;
      else if (ele[i].value != null) value = ele[i].value;
      else value = "element" + i;
      reply[value] = dwr.util.getValue(ele[i]);
    }
    return reply;
  }
};

/**
 * @private Recursive helper for getValues().
 */
dwr.util._getValuesRecursive = function(data, idpath) {
  // Array containing objects -> add "[n]" to idpath and make recursive call
  // for each item object
  if (dwr.util._isArray(data) && data.length > 0 && dwr.util._isObject(data[0])) {
    for (var i = 0; i < data.length; i++) {
      dwr.util._getValuesRecursive(data[i], idpath+"["+i+"]");
    }
  }
  // Object (not array) -> handle nested object properties
  else if (dwr.util._isObject(data) && !dwr.util._isArray(data)) {
    for (var prop in data) {
      var subidpath = idpath ? idpath+"."+prop : prop;
      // Object, or array containing objects -> call ourselves recursively
      if (dwr.util._isObject(data[prop]) && !dwr.util._isArray(data[prop])
          || dwr.util._isArray(data[prop]) && data[prop].length > 0 && dwr.util._isObject(data[prop][0])) {
        dwr.util._getValuesRecursive(data[prop], subidpath);
      }
      // Functions -> skip
      else if (typeof data[prop] == "function") {
        // NOP
      }
      // Only simple values left (or array of simple values, or empty array)
      // -> call getValue()
      else {
        // Are there any elements with that id or name
        if (dwr.util.byId(subidpath) != null || document.getElementsByName(subidpath).length >= 1) {
          data[prop] = dwr.util.getValue(subidpath);
        }
      }
    }
  }
};

/**
 * Add options to a list from an array or map.
 * @see http://getahead.org/dwr/browser/lists
 */
dwr.util.addOptions = function(ele, data/*, options*/) {
  ele = dwr.util._getElementById(ele, "addOptions()");
  if (ele == null) return;
  // TODO: Restructure so we handle arguments to get proper options handling
  // if (options == null) options = {};
  var useOptions = dwr.util._isHTMLElement(ele, "select");
  var useLi = dwr.util._isHTMLElement(ele, ["ul", "ol"]);
  if (!useOptions && !useLi) {
    dwr.util._debug("addOptions() can only be used with select/ul/ol elements. Attempt to use: " + dwr.util._detailedTypeOf(ele));
    return;
  }
  if (data == null) return;

  var text, value, li;
  if (dwr.util._isArray(data)) {
    // Loop through the data that we do have
    for (var i = 0; i < data.length; i++) {
      if (useOptions) {
        if (arguments[2] != null) {
          if (arguments[3] != null) {
            text = dwr.util._getValueFrom(data[i], arguments[3]);
            value = dwr.util._getValueFrom(data[i], arguments[2]);
          }
          else text = value = dwr.util._getValueFrom(data[i], arguments[2]);
        }
        else text = value = dwr.util._getValueFrom(data[i], arguments[3]);

        if (text != null || value) ele.options[ele.options.length] = new Option(text, value);
      }
      else {
        li = document.createElement("li");
        value = dwr.util._getValueFrom(data[i], arguments[2]);
        if (value != null) {
          li.innerHTML = value;
          ele.appendChild(li);
        }
      }
    }
  }
  else if (arguments[3] != null) {
    if (!useOptions) {
      alert("dwr.util.addOptions can only create select lists from objects.");
      return;
    }
    for (var prop in data) {
      value = dwr.util._getValueFrom(data[prop], arguments[2]);
      text = dwr.util._getValueFrom(data[prop], arguments[3]);

      if (text || value) ele.options[ele.options.length] = new Option(text, value);
    }
  }
  else {
    if (!useOptions) {
      dwr.util._debug("dwr.util.addOptions can only create select lists from objects.");
      return;
    }
    for (var prop in data) {
      if (typeof data[prop] != "function") {
        if (arguments[2]) ele.options[ele.options.length] = new Option(prop, data[prop]);
        else ele.options[ele.options.length] = new Option(data[prop], prop);
      }
    }
  }

  // All error routes through this function result in a return, so highlight now
  dwr.util.highlight(ele, null); // TODO: forward options instead of null 
};

/**
 * @private Get the data from an array function for dwr.util.addOptions
 */
dwr.util._getValueFrom = function(data, method) {
  if (method == null) return data;
  else if (typeof method == 'function') return method(data);
  else return data[method];
};

/**
 * Remove all the options from a select list (specified by id)
 * @see http://getahead.org/dwr/browser/lists
 */
dwr.util.removeAllOptions = function(ele) {
  ele = dwr.util._getElementById(ele, "removeAllOptions()");
  if (ele == null) return;
  var useOptions = dwr.util._isHTMLElement(ele, "select");
  var useLi = dwr.util._isHTMLElement(ele, ["ul", "ol"]);
  if (!useOptions && !useLi) {
    dwr.util._debug("removeAllOptions() can only be used with select, ol and ul elements. Attempt to use: " + dwr.util._detailedTypeOf(ele));
    return;
  }
  if (useOptions) {
    ele.options.length = 0;
  }
  else {
    while (ele.childNodes.length > 0) {
      ele.removeChild(ele.firstChild);
    }
  }
};

/**