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[英]How can it be that I can access and use event.currentTarget but when I print the event then currentTarget is null?
[英]JavaScript - How can I access the siblings of an event.currentTarget?
我为评论评分栏创建了一个基本的投票系统。 我正在尝试访问以前的兄弟元素以更新投票,但它无法正常工作。 你应该使用 event.currentTarget 还是 event.target? 我在哪里 go 错了? 谢谢你。
https://jsfiddle.net/donfontaine12/bm9njcLt/46/#&togetherjs=qocecyJqyy
HTML
<div id="comment_ratings_bar">
<div id="comment_rating_sign">+</div>
<div id="comment_rating_num">0</div>
<div id="comment_rating_percentage">[100.00%] </div>
<div class="green_up_arrow"></div>
<div class="red_down_arrow"></div>
</div>
<div id="comment_ratings_bar">
<div id="comment_rating_sign">+</div>
<div id="comment_rating_num">0</div>
<div id="comment_rating_percentage">[100.00%] </div>
<div class="green_up_arrow"></div>
<div class="red_down_arrow"></div>
</div>
<div id="comment_ratings_bar">
<div id="comment_rating_sign">+</div>
<div id="comment_rating_num">0</div>
<div id="comment_rating_percentage">[100.00%] </div>
<div class="green_up_arrow"></div>
<div class="red_down_arrow"></div>
</div>
<div id="comment_ratings_bar">
<div id="comment_rating_sign">+</div>
<div id="comment_rating_num">0</div>
<div id="comment_rating_percentage">[100.00%] </div>
<div class="green_up_arrow"></div>
<div class="red_down_arrow"></div>
</div>
CSS
#comment_ratings_bar {
width: 30%;
margin: 0px 20px;
padding: 0px 20px;
font-size: 110%;
font-weight: bolder;
font-family: 'B612 Mono', monospace;
color: lime;
background-color: black;
border: 0px solid black;
display: flex;
flex-direction: row;
justify-content: center;
}
.green_up_arrow {
display: flex;
flex-direction: row;
width: 0;
height: 0;
border-left: 5px solid transparent;
border-right: 5px solid transparent;
border-bottom: 10px solid lime;
cursor: pointer;
margin: 0em 0.25em;
}
.red_down_arrow {
display: flex;
flex-direction: row;
width: 0;
height: 0;
border-left: 5px solid transparent;
border-right: 5px solid transparent;
border-top: 10px solid red;
cursor: pointer;
margin: 0em 0.25em;
}
JavaScript
window.onload = function() {
let commentUpvotes = 0;
let commentDownvotes = 0;
let totalCommentVotes = commentUpvotes + commentDownvotes;
let commentRatingsBarAll = document.querySelectorAll("#comment_ratings_bar");
for (let c of commentRatingsBarAll) {
c.lastElementChild.previousElementSibling.addEventListener("click", updateCommentVotes);
c.lastElementChild.addEventListener("click", updateCommentVotes);
}
function updateCommentVotes(e) {
let siblings = getSiblings(e);
let sign = siblings[0].textContent;
let number = siblings[1].textContent;
let percentage = siblings[2].textContent;
if (sign && number && percentage) {
let actualNumber = parseFloat(number.replace(/,/g, ''));
if (e.target.className == "green_up_arrow") {
actualNumber++; commentUpvotes++; totalCommentVotes++;
} else {
actualNumber--; commentDownvotes++; totalCommentVotes++;
}
if (actualNumber < 0) { sign.replace("+", ""); }
percentage = "["
+ parseFloat((commentUpvotes / totalCommentVotes) * 100).toFixed(2) +"%]";
number = actualNumber.toLocaleString();
}
}
function getSiblings(element) {
if (element) {
let siblings = [];
let sibling = element.parentNode.firstElementChild;
while(sibling) {
if (sibling.nodeType === 1 && sibling !== element) {
siblings.push(sibling);
sibling = sibling.nextElementSibling;
}
}
return siblings;
}
}
}
一切正常,但在 updateCommentVotes function 中,我应该引用包含 textContent 而不是局部变量(符号、数字和百分比)的实际 div。
编辑:这是一个部分修复,我需要每个单独的评论栏引用它自己的符号、数字和百分比。 似乎它们都共享相同的数值。 任何提示表示赞赏。 虽然,我相信这是因为我对兄弟姐妹的值进行了硬编码。 谢谢你。
在此处查看代码: https://jsfiddle.net/donfontaine12/bm9njcLt/46/#
JavaScript
window.onload = function() {
let commentUpvotes = 0;
let commentDownvotes = 0;
let totalCommentVotes = commentUpvotes + commentDownvotes;
let commentRatingsBarAll = document.querySelectorAll("#comment_ratings_bar");
for (let c of commentRatingsBarAll) {
c.lastElementChild.previousElementSibling.addEventListener("click", updateCommentVotes);
c.lastElementChild.addEventListener("click", updateCommentVotes);
}
function updateCommentVotes(e) {
let siblings = getSiblings(e);
let sign = siblings[0].textContent;
let number = siblings[1].textContent;
let percentage = siblings[2].textContent;
if (sign && number && percentage) {
let actualNumber = parseFloat(number.replace(/,/g, ''));
if (e.target.className == "green_up_arrow") {
actualNumber++; commentUpvotes++; totalCommentVotes++;
} else {
actualNumber--; commentDownvotes++; totalCommentVotes++;
}
if (actualNumber < 0) { siblings[0].textContent.replace("+", ""); }
siblings[2].textContent = "["
+ parseFloat((commentUpvotes / totalCommentVotes) * 100).toFixed(2) +"%]";
siblings[1].textContent = actualNumber.toLocaleString();
}
}
function getSiblings(element) {
let siblings = [];
let sibling = element.target.parentNode.firstElementChild;
while(sibling) {
if (sibling.nodeType === 1 && sibling !== element) {
siblings.push(sibling);
sibling = sibling.nextElementSibling;
}
}
return siblings;
}
}
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