如何使用dotdotdot实现Read More和Read less？

Question

使用jQuery dotdotdot插件,我想有一个更多和更少的按钮来显示和隐藏<div>当有很多文本要显示时的整个内容." 更多"按钮工作正常,但我还没有找到一种方法来返回<div>它的原始显示.请注意,这不仅仅是关于如何使用dotdotdot扩展截断的字符串,因为它包含Less按钮重新截断长字符串.

这是我的代码:

$(function() {
    $("div.ellipsis-text").dotdotdot({
        after: 'a.more',
        callback: dotdotdotCallback
    });
    $("div.ellipsis-text").find("a").click(function() {
        if ($(this).text() == "More") {
            var div = $(this).closest('div.ellipsis-text');
            div.trigger('destroy').find('a.more').hide();
            div.css('max-height', '');
            $("a.less", div).show();
        }
        else {
            $(this).text("More");
            $(this).closest('div.ellipsis-text').css("max-height", "50px").dotdotdot({ after: "a", callback: dotdotdotCallback });
        }
    });

    function dotdotdotCallback(isTruncated, originalContent) {
        if (!isTruncated) {
         $("a", this).remove();   
        }
    }
});

看来,click事件处理程序<div>的锚标记是越来越删除,我从来没有能够在后到达事件处理程序的更多按钮被点击.

解决方案:

更新的代码:

$(function() {
    $("div.ellipsis-text").dotdotdot({
        after: 'a.more',
        callback: dotdotdotCallback
    });
    $("div.ellipsis-text").on('click','a',function() {
        if ($(this).text() == "More") {
            var div = $(this).closest('div.ellipsis-text');
            div.trigger('destroy').find('a.more').hide();
            div.css('max-height', '');
            $("a.less", div).show();
        }
        else {
            $(this).hide();
            $(this).closest('div.ellipsis-text').css("max-height", "50px").dotdotdot({ after: "a.more", callback: dotdotdotCallback });
        }
    });

    function dotdotdotCallback(isTruncated, originalContent) {
        if (!isTruncated) {
         $("a", this).remove();   
        }
    }
});

多谢你们!

Answer 1

改变这个:

$("div.ellipsis-text").find("a").click(function() {

对此:

$("div.ellipsis-text").on('click','a',function() {

更新的代码:

$(function () {
    $("div.ellipsis-text").dotdotdot({
        after: 'a.more',
        callback: dotdotdotCallback
    });
    $("div.ellipsis-text").on('click', 'a', function () {

        if ($(this).text() == "More") {
            var div = $(this).closest('div.ellipsis-text');
            div.trigger('destroy').find('a.more').hide();
            div.css('max-height', '');
            $("a.less", div).show();
        } else {

            $(this).closest('div.ellipsis-text').css("max-height", "50px").dotdotdot({
                after: "a",
                callback: dotdotdotCallback
            });
        }
    });

    function dotdotdotCallback(isTruncated, originalContent) {
        if (!isTruncated) {
            $("a", this).remove();
        }
    }
});

第二个方法是使用单一的一个标签,只是切换的文字是这样的:

HTML:

    <div class='ellipsis-text'>"But I must explain to you how all this mistaken idea of denouncing pleasure and praising pain was born and I will give you a complete account of the system, and expound the actual teachings of the great explorer of the truth, the master-builder of human happiness. No one rejects, dislikes, or avoids pleasure itself, because it is pleasure, but because those who do not know how to pursue pleasure rationally encounter consequences that are extremely painful. Nor again is there anyone who loves or pursues or desires to obtain pain of itself, because it is pain, but because occasionally circumstances occur in which toil and pain can procure him some great pleasure. To take a trivial example, which of us ever undertakes laborious physical exercise, except to obtain some advantage from it? But who has any right to find fault with a man who chooses to enjoy a pleasure that has no annoying consequences, or one who avoids a pain that produces no resultant pleasure?" 

<a class='more' href='#'>More</a>

 </div>

JQUERY:

$(function () {
    $("div.ellipsis-text").dotdotdot({
        after: 'a.more',
        callback: dotdotdotCallback
    });
    $("div.ellipsis-text").on('click', 'a', function () {

        if ($(this).text() == "More") {
            var div = $(this).closest('div.ellipsis-text');
            div.trigger('destroy')
            div.css('max-height', '');
            $(this).text("Less");

        } else {
            $(this).text("More")
            $(this).closest('div.ellipsis-text').css("max-height", "50px").dotdotdot({
                after: "a",
                callback: dotdotdotCallback
            });
        }
    });

    function dotdotdotCallback(isTruncated, originalContent) {
        if (!isTruncated) {
            $("a", this).remove();
        }
    }
});

Answer 2

我参加这个派对有点晚了,但我觉得你可能喜欢这个代码.

也在jsfiddle.net/fo4z05qp上

var bindReadMore = function(){
    $('.read-more').on('click', function(e) {
        e.preventDefault();
        var parent = $(this).parent();
        parent.trigger("destroy");
        parent.removeClass('truncable-txt--is-truncated');
        parent.addClass('truncable-txt--is-not-truncated');
        bindReadLess(); // bind click on "less"
    });
};

var bindReadLess = function(){
    $('.read-less').on('click', function(e) {
        e.preventDefault();
        var parent = $(this).parent();
        truncateIfNeeded(parent); // Re-initialize ellipsis
    });
};

var truncateIfNeeded = function(jqueryTag){
    var $selectionToTruncate = jqueryTag || $('.truncable-txt');
    
    $selectionToTruncate.dotdotdot({
        ellipsis: '...',
        watch   : true,
        wrap    : 'letter',
        height  : 20 * 3, // max number of lines
        after   : '.read-more',
        callback: function( isTruncated, orgContent ) {
            var $currentReadMore = $(this).find('.read-more');
            var $currentReadLess = $(this).find('.read-less');
            
            if( isTruncated ){
                $(this).addClass('truncable-txt--is-truncated');
            }
            bindReadMore(); // bind click on "read more"
        },
    });
};

$(function() {
    truncateIfNeeded(); // Initialize ellipsis
});

.trigger-js {
    cursor: pointer;
    cursor: hand;
}
.read-less,
.read-more {
    display: none;
}

.read-more__txt,
.read-less__txt {
    text-decoration: underline;
}

/* [1] downwards arrow, fileformat.info/info/unicode/char/2193/index.htm */
.read-more::after {
    margin-left: 4px;
    content: '\2193'; /* [1] */
}
/* [2] upwards arrow, fileformat.info/info/unicode/char/2191/index.htm */
.read-less::after {
    margin-left: 4px;
    content: '\2191'; /* [2] */
}

.truncable-txt--is-truncated .read-more,
.truncable-txt--is-not-truncated .read-less {
    display: inline-block;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script src="https://rawgit.com/BeSite/jQuery.dotdotdot/master/src/js/jquery.dotdotdot.min.js"></script>
<p class="truncable-txt">Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum
    <span class="read-more trigger-js">&nbsp;<a class="read-more__txt">more</a></span>
    <span class="read-less trigger-js">&nbsp;<a class="read-less__txt">less</a></span>
</p>

<p class="truncable-txt">Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum
    <span class="read-more trigger-js">&nbsp;<a class="read-more__txt">more</a></span>
    <span class="read-less trigger-js">&nbsp;<a class="read-less__txt">less</a></span>
</p>

资源

• dotdotdot.frebsite.nl&github.com/BeSite/jQuery.dotdotdot
• 如何使用dotdotdot扩展截断文本？
• https://gist.github.com/chiragparekh/c7e33dc749ed25544bde以及jsfiddle.net/sTe5P/5