今天开始说非常简单的bootstrap-button组件。
button设计得非常smart，只有一个调用接口，你可以在$().button(str)中传入不同的字符串，来切换它的文本，其中有三个是框架占用的——toggle, reset, loading。
button的文本切换是通过data-xxx-text自定义属性控制。$().button("xxx")，就是取data-aaa-text的值作为新文本。如果要还原最初状态，使用$().button("reset")。loading参数会在这基础上添加disabled类名与disabled属性，目的是不让人家修改。
button的类型是通过data-toggle自定义属性决定，目前有三种。普通的单个按钮，checked类型的按钮组，radio类型的按钮组，分别对应button, buttons-checked, buttons-radio。
要使用bootstrap的样式，必须加btn类名。皮肤在通用样式名前加个btn-前缀，即.btn-primary, .btn-warning, .btn-danger, .btn-success, .btn-info, .btn-inverse
除了切换文本需要你动手外，切换状态的点击事件组件已经为你做好了，你只要引入它就能用了。
!function ($) {
"use strict"; // jshint ;_;
/* BUTTON PUBLIC CLASS DEFINITION
* ============================== */
var Button = function (element, options) {
this.$element = $(element)
this.options = $.extend({}, $.fn.button.defaults, options)
}
Button.prototype.setState = function (state) {
var d = 'disabled'
, $el = this.$element
, data = $el.data()
, val = $el.is('input') ? 'val' : 'html'//如果是button标签，使用html方法
state = state + 'Text'
//如果是reset，则变成resetText保留起来，换言之reset对框架而言是个保留字
data.resetText || $el.data('resetText', $el[val]())
//切换文本
$el[val](data[state] || this.options[state])
//如果是loading，那么它就添加一个disabled类名与disabled属性，换言之reset对框架而言是个保留字
setTimeout(function () {
state == 'loadingText' ?
$el.addClass(d).attr(d, d) :
$el.removeClass(d).removeAttr(d)
}, 0)
}
//这个用于按钮组，通过$().button('toggle')调用
Button.prototype.toggle = function () {
var $parent = this.$element.closest('[data-toggle="buttons-radio"]')
//radio具有排他性，只有一个按钮组只有一个按钮存在激活状态
$parent && $parent
.find('.active')
.removeClass('active')
this.$element.toggleClass('active')
}
var old = $.fn.button
/* BUTTON PLUGIN DEFINITION
* ======================== */
$.fn.button = function (option) {
return this.each(function () {
var $this = $(this)
, data = $this.data('button')
, options = typeof option == 'object' && option
//重复利用之前的实例
if (!data) $this.data('button', (data = new Button(this, options)))
if (option == 'toggle') data.toggle()
else if (option) data.setState(option)
})
}
$.fn.button.defaults = {
loadingText: 'loading...'
}
$.fn.button.Constructor = Button
/* BUTTON NO CONFLICT
* ================== */
$.fn.button.noConflict = function () {
$.fn.button = old
return this
}
/* BUTTON DATA-API
* =============== */
//为存在data-toggle属性，并且其值以button开头的按钮绑定点击事件
$(document).on('click.button.data-api', '[data-toggle^=button]', function (e) {
var $btn = $(e.target)
if (!$btn.hasClass('btn')) $btn = $btn.closest('.btn')
$btn.button('toggle')
})
}(window.jQuery);
以下是它对应的less，生成的CSS大概是它的五倍以上。
//
// Buttons
// --------------------------------------------------
// Base styles
// --------------------------------------------------
// Core
.btn {
display: inline-block;
.ie7-inline-block();
padding: 4px 12px;
margin-bottom: 0; // For input.btn
font-size: @baseFontSize;
line-height: @baseLineHeight;
text-align: center;
vertical-align: middle;
cursor: pointer;
.buttonBackground(@btnBackground, @btnBackgroundHighlight, @grayDark, 0 1px 1px rgba(255,255,255,.75));
border: 1px solid @btnBorder;
*border: 0; // Remove the border to prevent IE7's black border on input:focus
border-bottom-color: darken(@btnBorder, 10%);
.border-radius(@baseBorderRadius);
.ie7-restore-left-whitespace(); // Give IE7 some love
.box-shadow(~"inset 0 1px 0 rgba(255,255,255,.2), 0 1px 2px rgba(0,0,0,.05)");
// Hover state
&:hover {
color: @grayDark;
text-decoration: none;
background-position: 0 -15px;
// transition is only when going to hover, otherwise the background
// behind the gradient (there for IE<=9 fallback) gets mismatched
.transition(background-position .1s linear);
}
// Focus state for keyboard and accessibility
&:focus {
.tab-focus();
}
// Active state
&.active,
&:active {
background-image: none;
outline: 0;
.box-shadow(~"inset 0 2px 4px rgba(0,0,0,.15), 0 1px 2px rgba(0,0,0,.05)");
}
// Disabled state
&.disabled,
&[disabled] {
cursor: default;
background-image: none;
.opacity(65);
.box-shadow(none);
}
}
// Button Sizes
// --------------------------------------------------
// Large
.btn-large {
padding: @paddingLarge;
font-size: @fontSizeLarge;
.border-radius(@borderRadiusLarge);
}
.btn-large [class^="icon-"],
.btn-large [class*=" icon-"] {
margin-top: 4px;
}
// Small
.btn-small {
padding: @paddingSmall;
font-size: @fontSizeSmall;
.border-radius(@borderRadiusSmall);
}
.btn-small [class^="icon-"],
.btn-small [class*=" icon-"] {
margin-top: 0;
}
.btn-mini [class^="icon-"],
.btn-mini [class*=" icon-"] {
margin-top: -1px;
}
// Mini
.btn-mini {
padding: @paddingMini;
font-size: @fontSizeMini;
.border-radius(@borderRadiusSmall);
}
// Block button
// -------------------------
.btn-block {
display: block;
100%;
padding-left: 0;
padding-right: 0;
.box-sizing(border-box);
}
// Vertically space out multiple block buttons
.btn-block + .btn-block {
margin-top: 5px;
}
// Specificity overrides
input[type="submit"],
input[type="reset"],
input[type="button"] {
&.btn-block {
100%;
}
}
// Alternate buttons
// --------------------------------------------------
// Provide *some* extra contrast for those who can get it
.btn-primary.active,
.btn-warning.active,
.btn-danger.active,
.btn-success.active,
.btn-info.active,
.btn-inverse.active {
color: rgba(255,255,255,.75);
}
// Set the backgrounds
// -------------------------
.btn {
// reset here as of 2.0.3 due to Recess property order
border-color: #c5c5c5;
border-color: rgba(0,0,0,.15) rgba(0,0,0,.15) rgba(0,0,0,.25);
}
.btn-primary {
.buttonBackground(@btnPrimaryBackground, @btnPrimaryBackgroundHighlight);
}
// Warning appears are orange
.btn-warning {
.buttonBackground(@btnWarningBackground, @btnWarningBackgroundHighlight);
}
// Danger and error appear as red
.btn-danger {
.buttonBackground(@btnDangerBackground, @btnDangerBackgroundHighlight);
}
// Success appears as green
.btn-success {
.buttonBackground(@btnSuccessBackground, @btnSuccessBackgroundHighlight);
}
// Info appears as a neutral blue
.btn-info {
.buttonBackground(@btnInfoBackground, @btnInfoBackgroundHighlight);
}
// Inverse appears as dark gray
.btn-inverse {
.buttonBackground(@btnInverseBackground, @btnInverseBackgroundHighlight);
}
// Cross-browser Jank
// --------------------------------------------------
button.btn,
input[type="submit"].btn {
// Firefox 3.6 only I believe
&::-moz-focus-inner {
padding: 0;
border: 0;
}
// IE7 has some default padding on button controls
*padding-top: 3px;
*padding-bottom: 3px;
&.btn-large {
*padding-top: 7px;
*padding-bottom: 7px;
}
&.btn-small {
*padding-top: 3px;
*padding-bottom: 3px;
}
&.btn-mini {
*padding-top: 1px;
*padding-bottom: 1px;
}
}
// Link buttons
// --------------------------------------------------
// Make a button look and behave like a link
.btn-link,
.btn-link:active,
.btn-link[disabled] {
background-color: transparent;
background-image: none;
.box-shadow(none);
}
.btn-link {
border-color: transparent;
cursor: pointer;
color: @linkColor;
.border-radius(0);
}
.btn-link:hover {
color: @linkColorHover;
text-decoration: underline;
background-color: transparent;
}
.btn-link[disabled]:hover {
color: @grayDark;
text-decoration: none;
}