util.js

基于ajax的dwr框架开发详细实例

    // but I'm not sure how we should treat multi-select.
    var sel = ele.selectedIndex;
    if (sel != -1) {
      var reply = ele.options[sel].value;
      if (reply == null || reply == "") {
        reply = ele.options[sel].text;
      }

      return reply;
    }
    else {
      return "";
    }
  }

  if (DWRUtil._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":
      return ele.checked;
    default:
      return ele.value;
    }
  }

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

  if (options.textContent) {
    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.ltd.uk/dwr/browser/util/gettext
 */
DWRUtil.getText = function(ele) {
  var orig = ele;
  ele = $(ele);
  if (ele == null) {
    DWRUtil.debug("getText() can't find an element with id: " + orig + ".");
    return "";
  }

  if (!DWRUtil._isHTMLElement(ele, "select")) {
    DWRUtil.debug("getText() can only be used with select elements. Attempt to use: " + DWRUtil._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, call setValue() for all the entries in the map using the entry key as an element id
 * @see http://getahead.ltd.uk/dwr/browser/util/setvalues
 */
DWRUtil.setValues = function(map) {
  for (var property in map) {
    // Are there any elements with that id or name
    if ($(property) != null || document.getElementsByName(property).length >= 1) {
      DWRUtil.setValue(property, map[property]);
    }
  }
};

/**
 * Given a map, call getValue() for all the entries in the map using the entry key as an element id.
 * Given a string or element that refers to a form, create an object from the elements of the form.
 * @see http://getahead.ltd.uk/dwr/browser/util/getvalues
 */
DWRUtil.getValues = function(data) {
  var ele;
  if (typeof data == "string") ele = $(data);
  if (DWRUtil._isHTMLElement(data)) ele = data;
  if (ele != null) {
    if (ele.elements == null) {
      alert("getValues() requires an object or reference to a form element.");
      return null;
    }
    var reply = {};
    var value;
    for (var i = 0; i < ele.elements.length; i++) {
      if (ele[i].id != null) value = ele[i].id;
      else if (ele[i].value != null) value = ele[i].value;
      else value = "element" + i;
      reply[value] = DWRUtil.getValue(ele[i]);
    }
    return reply;
  }
  else {
    for (var property in data) {
      // Are there any elements with that id or name
      if ($(property) != null || document.getElementsByName(property).length >= 1) {
        data[property] = DWRUtil.getValue(property);
      }
    }
    return data;
  }
};

/**
 * Add options to a list from an array or map.
 * @see http://getahead.ltd.uk/dwr/browser/lists
 */
DWRUtil.addOptions = function(ele, data) {
  var orig = ele;
  ele = $(ele);
  if (ele == null) {
    DWRUtil.debug("addOptions() can't find an element with id: " + orig + ".");
    return;
  }
  var useOptions = DWRUtil._isHTMLElement(ele, "select");
  var useLi = DWRUtil._isHTMLElement(ele, ["ul", "ol"]);
  if (!useOptions && !useLi) {
    DWRUtil.debug("addOptions() can only be used with select/ul/ol elements. Attempt to use: " + DWRUtil._detailedTypeOf(ele));
    return;
  }
  if (data == null) return;

  var text;
  var value;
  var opt;
  var li;
  if (DWRUtil._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 = DWRUtil._getValueFrom(data[i], arguments[3]);
            value = DWRUtil._getValueFrom(data[i], arguments[2]);
          }
          else {
            value = DWRUtil._getValueFrom(data[i], arguments[2]);
            text = value;
          }
        }
        else
        {
          text = DWRUtil._getValueFrom(data[i], arguments[3]);
          value = text;
        }
        if (text || value) {
          opt = new Option(text, value);
          ele.options[ele.options.length] = opt;
        }
      }
      else {
        li = document.createElement("li");
        value = DWRUtil._getValueFrom(data[i], arguments[2]);
        if (value != null) {
          li.innerHTML = value;
          ele.appendChild(li);
        }
      }
    }
  }
  else if (arguments[3] != null) {
    for (var prop in data) {
      if (!useOptions) {
        alert("DWRUtil.addOptions can only create select lists from objects.");
        return;
      }
      value = DWRUtil._getValueFrom(data[prop], arguments[2]);
      text = DWRUtil._getValueFrom(data[prop], arguments[3]);
      if (text || value) {
        opt = new Option(text, value);
        ele.options[ele.options.length] = opt;
      }
    }
  }
  else {
    for (var prop in data) {
      if (!useOptions) {
        DWRUtil.debug("DWRUtil.addOptions can only create select lists from objects.");
        return;
      }
      if (typeof data[prop] == "function") {
        // Skip this one it's a function.
        text = null;
        value = null;
      }
      else if (arguments[2]) {
        text = prop;
        value = data[prop];
      }
      else {
        text = data[prop];
        value = prop;
      }
      if (text || value) {
        opt = new Option(text, value);
        ele.options[ele.options.length] = opt;
      }
    }
  }
};

/**
 * @private Get the data from an array function for DWRUtil.addOptions
 */
DWRUtil._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.ltd.uk/dwr/browser/lists
 */
DWRUtil.removeAllOptions = function(ele) {
  var orig = ele;
  ele = $(ele);
  if (ele == null) {
    DWRUtil.debug("removeAllOptions() can't find an element with id: " + orig + ".");
    return;
  }
  var useOptions = DWRUtil._isHTMLElement(ele, "select");
  var useLi = DWRUtil._isHTMLElement(ele, ["ul", "ol"]);
  if (!useOptions && !useLi) {
    DWRUtil.debug("removeAllOptions() can only be used with select, ol and ul elements. Attempt to use: " + DWRUtil._detailedTypeOf(ele));
    return;
  }
  if (useOptions) {
    ele.options.length = 0;
  }
  else {
    while (ele.childNodes.length > 0) {
      ele.removeChild(ele.firstChild);
    }
  }
};

/**
 * Create rows inside a the table, tbody, thead or tfoot element (given by id).
 * @see http://getahead.ltd.uk/dwr/browser/tables
 */
DWRUtil.addRows = function(ele, data, cellFuncs, options) {
  var orig = ele;
  ele = $(ele);
  if (ele == null) {
    DWRUtil.debug("addRows() can't find an element with id: " + orig + ".");
    return;
  }
  if (!DWRUtil._isHTMLElement(ele, ["table", "tbody", "thead", "tfoot"])) {
    DWRUtil.debug("addRows() can only be used with table, tbody, thead and tfoot elements. Attempt to use: " + DWRUtil._detailedTypeOf(ele));
    return;
  }
  if (!options) options = {};
  if (!options.rowCreator) options.rowCreator = DWRUtil._defaultRowCreator;
  if (!options.cellCreator) options.cellCreator = DWRUtil._defaultCellCreator;
  var tr, rowNum;
  if (DWRUtil._isArray(data)) {
    for (rowNum = 0; rowNum < data.length; rowNum++) {
      options.rowData = data[rowNum];
      options.rowIndex = rowNum;
      options.rowNum = rowNum;
      options.data = null;
      options.cellNum = -1;
      tr = DWRUtil._addRowInner(cellFuncs, options);
      if (tr != null) ele.appendChild(tr);
    }
  }
  else if (typeof data == "object") {
    rowNum = 0;
    for (var rowIndex in data) {
      options.rowData = data[rowIndex];
      options.rowIndex = rowIndex;
      options.rowNum = rowNum;
      options.data = null;
      options.cellNum = -1;
      tr = DWRUtil._addRowInner(cellFuncs, options);
      if (tr != null) ele.appendChild(tr);
      rowNum++;
    }
  }
};

/**
 * @private Internal function to draw a single row of a table.
 */
DWRUtil._addRowInner = function(cellFuncs, options) {
  var tr = options.rowCreator(options);
  if (tr == null) return null;
  for (var cellNum = 0; cellNum < cellFuncs.length; cellNum++) {
    var func = cellFuncs[cellNum];
    var reply = func(options.rowData, options);
    options.data = reply;
    options.cellNum = cellNum;
    var td = options.cellCreator(options);
    if (td != null) {
      if (reply != null) {
        if (DWRUtil._isHTMLElement(reply)) td.appendChild(reply);
        else td.innerHTML = reply;
      }
      tr.appendChild(td);
    }
  }
  return tr;
};

/**
 * @private Default row creation function
 */
DWRUtil._defaultRowCreator = function(options) {
  return document.createElement("tr");
};

/**
 * @private Default cell creation function
 */
DWRUtil._defaultCellCreator = function(options) {
  return document.createElement("td");
};

/**
 * Remove all the children of a given node.
 * @see http://getahead.ltd.uk/dwr/browser/tables
 */
DWRUtil.removeAllRows = function(ele) {
  var orig = ele;
  ele = $(ele);
  if (ele == null) {
    DWRUtil.debug("removeAllRows() can't find an element with id: " + orig + ".");
    return;
  }
  if (!DWRUtil._isHTMLElement(ele, ["table", "tbody", "thead", "tfoot"])) {
    DWRUtil.debug("removeAllRows() can only be used with table, tbody, thead and tfoot elements. Attempt to use: " + DWRUtil._detailedTypeOf(ele));
    return;
  }
  while (ele.childNodes.length > 0) {
    ele.removeChild(ele.firstChild);
  }
};

/**
 * @private Is the given node an HTML element (optionally of a given type)?
 * @param ele The element to test
 * @param nodeName eg "input", "textarea" - check for node name (optional)
 *         if nodeName is an array then check all for a match.
 */
DWRUtil._isHTMLElement = function(ele, nodeName) {
  if (ele == null || typeof ele != "object" || ele.nodeName == null) {
    return false;
  }

  if (nodeName != null) {
    var test = ele.nodeName.toLowerCase();

    if (typeof nodeName == "string") {
      return test == nodeName.toLowerCase();
    }

    if (DWRUtil._isArray(nodeName)) {
      var match = false;
      for (var i = 0; i < nodeName.length && !match; i++) {
        if (test == nodeName[i].toLowerCase()) {
          match =  true;
        }
      }
      return match;
    }

    DWRUtil.debug("DWRUtil._isHTMLElement was passed test node name that is neither a string or array of strings");
    return false;
  }

  return true;
};

/**
 * @private Like typeOf except that more information for an object is returned other than "object"
 */
DWRUtil._detailedTypeOf = function(x) {
  var reply = typeof x;
  if (reply == "object") {
    reply = Object.prototype.toString.apply(x);  // Returns "[object class]"
    reply = reply.substring(8, reply.length-1);  // Just get the class bit
  }
  return reply;
};

/**
 * @private Array detector. Work around the lack of instanceof in some browsers.
 */
DWRUtil._isArray = function(data) {
  return (data && data.join) ? true : false;
};

/**
 * @private Date detector. Work around the lack of instanceof in some browsers.
 */
DWRUtil._isDate = function(data) {
  return (data && data.toUTCString) ? true : false;
};

/**
 * @private Used by setValue. Gets around the missing functionallity in IE.
 */
DWRUtil._importNode = function(doc, importedNode, deep) {
  var newNode;

  if (importedNode.nodeType == 1 /*Node.ELEMENT_NODE*/) {
    newNode = doc.createElement(importedNode.nodeName);

    for (var i = 0; i < importedNode.attributes.length; i++) {
      var attr = importedNode.attributes[i];
      if (attr.nodeValue != null && attr.nodeValue != '') {
        newNode.setAttribute(attr.name, attr.nodeValue);
      }
    }

    if (typeof importedNode.style != "undefined") {
      newNode.style.cssText = importedNode.style.cssText;
    }
  }
  else if (importedNode.nodeType == 3 /*Node.TEXT_NODE*/) {
    newNode = doc.createTextNode(importedNode.nodeValue);
  }

  if (deep && importedNode.hasChildNodes()) {
    for (i = 0; i < importedNode.childNodes.length; i++) {
      newNode.appendChild(DWRUtil._importNode(doc, importedNode.childNodes[i], true));
    }
  }

  return newNode;
}

/**
 * Used internally when some message needs to get to the programmer
 */
DWRUtil.debug = function(message) {
  alert(message);
}