我对JS / JQuery web dev一般都很陌生。
对于工作任务，我被要求提出一个解决方案，其中显示列表中的前3个基金，如果他们投资超过3个，那么将显示所有资金按钮并且一旦点击它将切换剩余的资金。
<!DOCTYPE html>
<html lang="en">
<head>
<title>Check your retirement plan demo</title>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="stylesheet" type="text/css" href="css/dropdown-component.css" />
<script src="js/modernizr.custom.63321.js"></script>
</head>
<body style="background-color:#eaeaea;">
<div class="container">
<h2> Dropdown Component</h2>
<!-- THIS BIT FUNDS START -->
<section class="main clearfix">
<select id="cd-dropdown" name="cd-dropdown" class="cd-select">
<option value="-1" selected>Funds in your portfolio (3)</option>
<option value="1">fund1 £60,000</option>
<option value="2">fund 2 £40,000</option>
<option value="3">fund 3 £24,000</option>
<option value="4">View all funds ></option>
<option value="5">Fund 5 £40,000</option>
</select>
</section>
<!-- THIS BIT FUNDS END -->
</div>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript" src="js/jquery.dropdown.js"></script>
<script type="text/javascript">
$(function () {
$('#cd-dropdown').dropdown({
gutter: 5
});
});
</script>
</body>
</html>`
我正在使用jquery下拉解决方案来帮助我获得资金，而不是隐藏超过3的资金的功能，并在看到更多资金被点击后切换它们。
/**
* jquery.dropdown.js v1.0.0
* http://www.codrops.com
*
* Licensed under the MIT license.
* http://www.opensource.org/licenses/mit-license.php
*
* Copyright 2012, Codrops
* http://www.codrops.com
*/
; (function ($, window, undefined) {
'use strict';
$.DropDown = function (options, element) {
this.$el = $(element);
this._init(options);
};
// the options
$.DropDown.defaults = {
speed: 300,
easing: 'ease',
gutter: 0,
// initial stack effect
stack: true,
// delay between each option animation
delay: 0,
// random angle and positions for the options
random: false,
// rotated [right||left||false] : the options will be rotated to thr right side or left side.
// make sure to tune the transform origin in the stylesheet
rotated: false,
// effect to slide in the options. value is the margin to start with
slidingIn: false,
onOptionSelect: function (opt) { return false; }
};
$.DropDown.prototype = {
_init: function (options) {
// options
this.options = $.extend(true, {}, $.DropDown.defaults, options);
this._layout();
this._initEvents();
},
_layout: function () {
var self = this;
this.minZIndex = 1000;
var value = this._transformSelect();
this.opts = this.listopts.children('li');
this.optsCount = this.opts.length;
this.size = { width: this.dd.width(), height: this.dd.height() };
var elName = this.$el.attr('name'), elId = this.$el.attr('id'),
inputName = elName !== undefined ? elName : elId !== undefined ? elId : 'cd-dropdown-' + (new Date()).getTime();
this.inputEl = $('<input type="hidden" name="' + inputName + '" value="' + value + '"></input>').insertAfter(this.selectlabel);
this.selectlabel.css('z-index', this.minZIndex + this.optsCount);
this._positionOpts();
if (Modernizr.csstransitions) {
setTimeout(function () { self.opts.css('transition', 'all ' + self.options.speed + 'ms ' + self.options.easing); }, 25);
}
},
_transformSelect: function () {
var optshtml = '', selectlabel = '', value = -1;
this.$el.children('option').each(function () {
var $this = $(this),
val = isNaN($this.attr('value')) ? $this.attr('value') : Number($this.attr('value')),
classes = $this.attr('class'),
selected = $this.attr('selected'),
label = $this.text();
if (val !== -1) {
optshtml +=
classes !== undefined ?
'<li data-value="' + val + '"id=fundID' + val + '><span class="' + classes + '">' + label + '</span></li>' :
'<li data-value="' + val + '"id=fundID' + val + '><span>' + label + '</span></li>';
}
if (val > 3) {}
if (selected) {
selectlabel = label;
value = val;
}
});
this.listopts = $('<ul/>').append(optshtml);
this.selectlabel = $('<span/>').append(selectlabel);
this.dd = $('<div class="cd-dropdown"/>').append(this.selectlabel, this.listopts).insertAfter(this.$el);
this.$el.remove();
return value;
},
_positionOpts: function (anim) {
var self = this;
this.listopts.css('height', 'auto');
this.opts
.each(function (i) {
$(this).css({
zIndex: self.minZIndex + self.optsCount - 1 - i,
top: self.options.slidingIn ? (i + 1) * (self.size.height + self.options.gutter) : 0,
left: 0,
marginLeft: self.options.slidingIn ? i % 2 === 0 ? self.options.slidingIn : - self.options.slidingIn : 0,
opacity: self.options.slidingIn ? 0 : 1,
transform: 'none'
});
});
if (!this.options.slidingIn) {
this.opts
.eq(this.optsCount - 1)
.css({ top: this.options.stack ? 9 : 0, left: this.options.stack ? 4 : 0, width: this.options.stack ? this.size.width - 8 : this.size.width, transform: 'none' })
.end()
.eq(this.optsCount - 2)
.css({ top: this.options.stack ? 6 : 0, left: this.options.stack ? 2 : 0, width: this.options.stack ? this.size.width - 4 : this.size.width, transform: 'none' })
.end()
.eq(this.optsCount - 3)
.css({ top: this.options.stack ? 3 : 0, left: 0, transform: 'none' });
}
},
_initEvents: function () {
var self = this;
this.selectlabel.on('mousedown.dropdown', function (event) {
self.opened ? self.close() : self.open();
return false;
});
this.opts.on('click.dropdown', function () {
if (self.opened) {
var opt = $(this);
self.options.onOptionSelect(opt);
self.inputEl.val(opt.data('value'));
self.selectlabel.html(opt.html());
self.close();
}
});
},
open: function () {
var self = this;
this.dd.toggleClass('cd-active');
this.listopts.css('height', (this.optsCount + 1) * (this.size.height + this.options.gutter));
this.opts.each(function (i) {
$(this).css({
opacity: 1,
top: self.options.rotated ? self.size.height + self.options.gutter : (i + 1) * (self.size.height + self.options.gutter),
left: self.options.random ? Math.floor(Math.random() * 11 - 5) : 0,
width: self.size.width,
marginLeft: 0,
transform: self.options.random ?
'rotate(' + Math.floor(Math.random() * 11 - 5) + 'deg)' :
self.options.rotated ?
self.options.rotated === 'right' ?
'rotate(-' + (i * 5) + 'deg)' :
'rotate(' + (i * 5) + 'deg)'
: 'none',
transitionDelay: self.options.delay && Modernizr.csstransitions ? self.options.slidingIn ? (i * self.options.delay) + 'ms' : ((self.optsCount - 1 - i) * self.options.delay) + 'ms' : 0
});
});
this.opened = true;
},
close: function () {
var self = this;
this.dd.toggleClass('cd-active');
if (this.options.delay && Modernizr.csstransitions) {
this.opts.each(function (i) {
$(this).css({ 'transition-delay': self.options.slidingIn ? ((self.optsCount - 1 - i) * self.options.delay) + 'ms' : (i * self.options.delay) + 'ms' });
});
}
this._positionOpts(true);
this.opened = false;
}
}
$.fn.dropdown = function (options) {
var instance = $.data(this, 'dropdown');
if (typeof options === 'string') {
var args = Array.prototype.slice.call(arguments, 1);
this.each(function () {
instance[options].apply(instance, args);
});
}
else {
this.each(function () {
instance ? instance._init() : instance = $.data(this, 'dropdown', new $.DropDown(options, this));
});
}
return instance;
};
})(jQuery, window);'
任何人都可以帮助我提出快速解决方案或指出正确的方向吗？感谢
答案 0 :(得分：1)
您希望在页面上创建一个隐藏元素，用于缓存或容纳您不希望看到的选项。然后，您将向该元素添加一些CSS并使用jQuery将选项放入其中。
<强> HTML
<select id="cd-dropdown" name="cd-dropdown" class="cd-select">
<option value="-1" selected>Funds in your portfolio (3)</option>
<option value="1">fund1 £60,000</option>
<option value="2">fund 2 £40,000</option>
<option value="3">fund 3 £24,000</option>
<option value="4">View all funds ></option>
<option value="5">Fund 5 £40,000</option>
</select>
<input type="button" value="View all" class='view_more_button' />
<input type="button" value="View less" class='view_less_button hide' />
<强> CSS
.hide {
left: -9999px !important;
position: absolute !important;
visibility: hidden;
z-index: -500;
top: -9999px;
}
<强>的JavaScript
//Create on DOM element dynamically that will house options greater than three.
var blank_input = $('<select>', {
class: 'hidden_input_field hide',
name: 'hidden_fields'
});
//This variable caches the master select element.
var master_select_menu = jQuery('#cd-dropdown');
//Put the blank select field in the DOM tree to be select via jQuery selectors.
blank_input.appendTo(jQuery('body'));
jQuery('.view_more_button').on('click', function(e) {
var place_holder_select_field = jQuery('.hidden_input_field');
if (place_holder_select_field.children('option').length) {
jQuery('.moved').each(function(index,element) {
jQuery(element).appendTo(master_select_menu);
});
jQuery(e.target).addClass('hide');
jQuery('.view_less_button').removeClass('hide');
}
master_select_menu.val(-1).change();
});
jQuery('.view_less_button').on('click', function(e) {
view_three();
jQuery(e.target).addClass('hide');
jQuery('.view_more_button').removeClass('hide');
master_select_menu.val(-1).change();
});
view_three();
//This function gets called as soon as the page loads, where it appends any option element greater than 3 to the hidden select field.
function view_three() {
jQuery('option').each(function(index, element) {
var place_holder_select_field = jQuery('.hidden_input_field');
if (index > 3) {
jQuery(element).addClass('moved').appendTo(place_holder_select_field);
}
});
}
//Create on DOM element dynamically that will house options greater than three.
var blank_input = $('<select>', {
class: 'hidden_input_field hide',
name: 'hidden_fields'
});
//This variable caches the master select element.
var master_select_menu = jQuery('#cd-dropdown');
//Put the blank select field in the DOM tree to be select via jQuery selectors.
blank_input.appendTo(jQuery('body'));
jQuery('.view_more_button').on('click', function(e) {
var place_holder_select_field = jQuery('.hidden_input_field');
if (place_holder_select_field.children('option').length) {
jQuery('.moved').each(function(index,element) {
jQuery(element).appendTo(master_select_menu);
});
jQuery(e.target).addClass('hide');
jQuery('.view_less_button').removeClass('hide');
}
master_select_menu.val(-1).change();
});
jQuery('.view_less_button').on('click', function(e) {
view_three();
jQuery(e.target).addClass('hide');
jQuery('.view_more_button').removeClass('hide');
master_select_menu.val(-1).change();
});
view_three();
//This function gets called as soon as the page loads, where it appends any option element greater than 3 to the hidden select field.
function view_three() {
jQuery('option').each(function(index, element) {
var place_holder_select_field = jQuery('.hidden_input_field');
if (index > 3) {
jQuery(element).addClass('moved').appendTo(place_holder_select_field);
}
});
}.hide {
left: -9999px !important;
position: absolute !important;
visibility: hidden;
z-index: -500;
top: -9999px;
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<select id="cd-dropdown" name="cd-dropdown" class="cd-select">
<option value="-1" selected>Funds in your portfolio (3)</option>
<option value="1">fund1 £60,000</option>
<option value="2">fund 2 £40,000</option>
<option value="3">fund 3 £24,000</option>
<option value="4">View all funds ></option>
<option value="5">Fund 5 £40,000</option>
</select>
<input type="button" value="View all" class='view_more_button' />
<input type="button" value="View less" class='view_less_button hide' />