javascript 无法读取 null 的属性“offsetHeight”
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时间：2020-10-28 12:40:00 来源:igfitidea点击:
Cannot read property 'offsetHeight' of null
提问by Digital site
I have strange issue showed up recently on my script and not sure what causes this issue to happen. It is popping up on Chrome browser mainly and I guess this function 'offsetHeight'is either deprecated or invalid. here is the full code:
我最近在我的脚本中出现了奇怪的问题，但不确定是什么导致了这个问题的发生。它主要在 Chrome 浏览器上弹出，我猜这个函数'offsetHeight'已被弃用或无效。这是完整的代码：
var Rep_Templates = {
// array of pre-defined reasons
answers: null,
// popup container
context_menu: null,
// popup copntiner height
menu_height: 0,
error_msg: null,
// ajax form and its param values
pseudoform: null,
url: null,
postid: 0,
// information phrases to display to user
thanks_phrase: '',
description_msg: '',
timer_id: null,
/**
* inits the popup
* @param answers array of pre-defined reasons
* @param error_msg to display in case of empty message
* @param url of current page
* @param thanks_phrase diaplyed after successful submission
*/
init: function(answers, url, phrases) {
if (AJAX_Compatible)
{
this.answers = answers;
this.error_msg = phrases['error'];
this.thanks_phrase = phrases['thanks'];
this.description_msg = phrases['description'];
this.context_menu = new YAHOO.widget.Menu("rep_tmpl_popup",
{clicktohide: false,
effect: {
effect: YAHOO.widget.ContainerEffect.FADE,
duration: 0.25
}});
// Fix for IE7 z-index bug
if (YAHOO.env.ua.ie && YAHOO.env.ua.ie < 8)
{
this.context_menu.cfg.setProperty("position", "dynamic");
this.context_menu.cfg.setProperty("iframe", true);
this.context_menu.cfg.setProperty("zindex", 10100);
}
this.context_menu.render(document.body);
var menu_object = fetch_object("rep_tmpl_menu_inner");
this.menu_height = menu_object.offsetHeight;
var links = YAHOO.util.Dom.getElementsByClassName("report", "a", document.body);
for ( var i = 0; i < links .length; i++ ) {
var index = links[i].href.indexOf("p=");
if (index > 0)
{
var postid = links[i].href.substr(index+2);
YAHOO.util.Event.on(links[i], "click", this.show_popup, postid);
}
}
this.pseudoform = new vB_Hidden_Form('ajax.php');
this.pseudoform.add_variable('ajax', 1);
this.pseudoform.add_variable('s', fetch_sessionhash());
this.pseudoform.add_variable('securitytoken', SECURITYTOKEN);
this.pseudoform.add_variable('do', 'email_report');
this.url = url;
}
},
/**
* inserts pre-defined reason into textarea
* @param id of selected reason
*/
set_answer: function(id) {
var textarea = fetch_object('rep_tmpl_message');
textarea.value = '';
if (id > 0 && id <= this.answers.length)
{
textarea.value = this.answers[id-1];
var error_msg = fetch_object('rep_tmpl_error');
error_msg.innerHTML = "";
}
},
/**
* show popup to the user
* @param event click event
* @param postid id of the post
*/
show_popup: function(event,postid) {
Rep_Templates.reset_data();
YAHOO.util.Event.stopEvent(event);
var elem = event.srcElement? event.srcElement : event.target;
Rep_Templates.postid = postid;
var xy = [0,0];
xy[0] = YAHOO.util.Dom.getX(elem) + 25;
xy[1] = YAHOO.util.Dom.getY(elem) - Rep_Templates.menu_height;
if (xy[1] < 0)
{
xy[1] = 0;
}
Rep_Templates.context_menu.moveTo(xy[0],xy[1]);
Rep_Templates.context_menu.show();
fetch_object('rep_tmpl_message').focus();
YAHOO.util.Event.on(document.body, "click", Rep_Templates.hide_menu);
},
/**
* hides the menu when users click Hide button or click outside of the popup. Resets data
* @param optional event. If specified, then user clicked outside.
*/
hide_menu: function(event) {
var is_inside = false;
if (event)
{
// check if click was inside or outside popup
var obj = event.srcElement? event.srcElement : event.target;
do {
if (obj.id == 'rep_tmpl_popup') {
is_inside = true;
break;
}
} while (obj = obj.parentNode);
if (!is_inside)
{
YAHOO.util.Event.removeListener(document.body, "click", Rep_Templates.hide_menu);
}
}
if (!event || !is_inside)
{
Rep_Templates.context_menu.hide();
Rep_Templates.postid = 0;
}
},
/**
* reset all fields with default values
*/
reset_data: function() {
var error_msg = fetch_object('rep_tmpl_error');
error_msg.innerHTML = "";
var phrase = fetch_object('rep_tmpl_phrase');
phrase.innerHTML = this.description_msg;
YAHOO.util.Dom.removeClass(phrase, 'rep_tmpl_thanks_message');
var button = fetch_object('rep_tmpl_submit');
YAHOO.util.Dom.removeClass(button, 'disabled');
button.disabled = false;
var image = fetch_object('rep_tmpl_progress');
image.style.display = 'none';
},
/**
* sends AJAX request
* @param event click event
*/
send_data: function(event) {
var textarea = fetch_object('rep_tmpl_message');
if (textarea && textarea.value.replace(/^\s\s*/, '').replace(/\s\s*$/, '') != '')
{
this.pseudoform.add_variable('postid', this.postid);
this.pseudoform.add_variable('url',this.url + "&p="+ this.postid + "#post" + this.postid);
var button = event.srcElement? event.srcElement : event.target;
button.disabled = true;
YAHOO.util.Dom.addClass(button, 'disabled');
var image = fetch_object('rep_tmpl_progress');
image.style.display = '';
YAHOO.util.Connect.asyncRequest("POST", 'ajax.php', {
success: this.handle_ajax_response,
failure: vBulletin_AJAX_Error_Handler,
timeout: vB_Default_Timeout,
scope: this
}, this.pseudoform.build_query_string() + '&reason=' + textarea.value);
}
else
{
var error_msg = fetch_object('rep_tmpl_error');
error_msg.innerHTML = this.error_msg;
}
return false;
},
/**
* handles AJAX request
* @param ajax data returned
*/
handle_ajax_response: function(ajax) {
if (ajax.responseXML)
{
// check for error first
var error = ajax.responseXML.getElementsByTagName('error');
if (error.length)
{
this.reset_data();
var error_msg = fetch_object('rep_tmpl_error');
error_msg.innerHTML = error[0].firstChild.nodeValue;
}
else
{
var result = ajax.responseXML.getElementsByTagName('result');
if (result.length)
{
var image = fetch_object('rep_tmpl_progress');
image.style.display = 'none';
var phrase = fetch_object('rep_tmpl_phrase');
phrase.innerHTML = this.thanks_phrase;
YAHOO.util.Dom.addClass(phrase, 'rep_tmpl_thanks_message');
this.timer_id = setTimeout('Rep_Templates.handle_timer_expiration()',1000);
}
}
}
},
/**
* hides popup on timer expiration
*/
handle_timer_expiration: function() {
clearTimeout(this.timer_id);
this.hide_menu();
}
}
any idea how to solve this issue!!
任何想法如何解决这个问题！
Thanks
谢谢
回答by KJ Price
Your problem is that the object menu_objectis null. My guess is that the element that you are looking for does not exist. Check out your element and make sure that it has the correct identifier (class or id) to match fetch_object("rep_tmpl_menu_inner")
您的问题是该对象menu_object为空。我的猜测是您要查找的元素不存在。检查您的元素并确保它具有匹配的正确标识符（类或 ID） fetch_object("rep_tmpl_menu_inner")
