此元素为空

我正试图让一个自动完成表单工作,但我似乎不明白为什么我一直得到一个 this.element 是空错误。

以下是js:

    //autocomplete
function AutoComp() {
new Ajax.Autocompleter("autocomplete", "autocomplete_choices", "fin/autocomplete", {});
}
document.onLoad = AutoComp();

HTML:

            <input type="text" id="autocomplete" name="autocomplete_parameter"/>
        <span id="indicator1" style="display: none">
          <img src="/shared/img/loading.png" alt="Working..." />
        </span>
        <div id="autocomplete_choices" class="autocomplete"></div>

var Autocompleter = { };
Autocompleter.Base = Class.create({
  baseInitialize: function(element, update, options) {
    element          = $(element);
    this.element     = element;
    this.update      = $(update);
    this.hasFocus    = false;
    this.changed     = false;
    this.active      = false;
    this.index       = 0;
    this.entryCount  = 0;
    this.oldElementValue = this.element.value;

如果我通过value=“blah”手动设置textfield的值,我仍然会得到null。如果我尝试在controls.js中执行警报,它似乎在this.element=element;处失败;。e、 g.如果我提醒(元素),它会正确地提醒字段的id。如果我提醒(this.element)[在分配之后],它会提醒null。

如果我改变

  baseInitialize: function(element, update, options) {
    element          = $(element);
    this.element     = element;
    this.update      = $(update);
    this.hasFocus    = false;
    this.changed     = false;
    this.active      = false;
    this.index       = 0;
    this.entryCount  = 0;
    this.oldElementValue = this.element.value;

致:

  baseInitialize: function(element, update, options) {
    test          = $(element);
    this.test     = test;
    this.update      = $(update);
    this.hasFocus    = false;
    this.changed     = false;
    this.active      = false;
    this.index       = 0;
    this.entryCount  = 0;
    this.oldElementValue = this.test.value;

它不会抛出错误。“元素”是否保留?

我刚刚运行了scriptaculous单元测试,在自动完成测试中出现了一些失败:

failed  testAjaxAutocompleter   7 assertions, 1 failures, 1 errors
Failure: 'ac_update' was not visible. undefined
TypeError: $("ac_update").firstChild is null(TypeError: $("ac_update").firstChild is null)
failed  testAfterUpdateElement  2 assertions, 2 failures, 0 errors
Failure: 'ac2_update' was not visible. undefined
Failure: assertEqual: expected "'afterupdate:LI'", actual "'abcdefg'"
failed  testTokenizing  1 assertions, 3 failures, 0 errors
Failure: assertEqual: expected "'test1'", actual "'abc'"
Failure: assertEqual: expected "'test1,test2'", actual "'abc,abc'"
Failure: assertEqual: expected "'test3,test2'", actual "'test1b,test2'"
failed  testAjaxAutocompleterNoLinebreaksInResult   7 assertions, 1 failures, 1 errors
Failure: 'ac_update_br' was not visible. undefined
TypeError: $("ac_update_br").firstChild is null(TypeError: $("ac_update_br").firstChild is null)