jquery优化02

缓存变量:DOM遍历是昂贵的,所以尽量将会重用的元素缓存。

$element = $('#element');
h = $element.height(); //缓存
$element.css('height',h-20);

如果你打算对DOM元素做大量操作(连续设置多个属性或css样式),建议首先分离元素然后在添加。

使用var与匈牙利命名法,且避免全局变量 ;  

优化选择符;避免多个ID选择符

ajax:

  • 使用相关函数:
    $("#file").on("click","button",function() {
    $.ajax("confirmation.html",{
    data: {"confNum":1234},
    success: function(res) {},
    error: function(req,errorType,errorMessage) {},
    timeout:3000,
    beforeSend: function() {
    $(".confirmation").addClass('is-loading');
    },
    complete: function() {
    $(".confirmation").removeClass("is-loading");
    }
    })
    });
  • 提交表单:
    $("form").on("submit",function(event) {
    event.preventDefault(); //submit will reflash the page
    var form = $(this);
    $.ajax("/book", {
    type: "POST",
    data: form.serialize(), //use this;
    success: function(result) {
    form.remove();
    $("#vacation").hide().html(result).fadeIn();
    }
    });
    });
  • 优化操作:
    $.ajax('/test.html')
    .done(function(res) {console.log(res,'done1');})
    .fail(function(res) {console.log(res,'fail');})
  • 要多个ajax共同使用的时候
    $.when($.ajax("test1.html"),$.ajax("test2.html"))
    .done(function(res) {console.log(res,'done');})
    .fail(function(res) {console.log(res,'fail');}); //都成功才会执行done;返回第一个ajax的res;

写插件:

  • html:
    <div class="container">
    <div class="col-sm-12 top">
    <button id="all" class="btn btn-primary col-sm-offset-10 show-price">show all</button>
    </div>
    <div class="jumbotron col-sm-3 vacation" data-price="110">
    <h4>Hawaiian Vaction</h4>
    <button class="click btn btn-info">SHOE PRICE</button>
    <p class="no-hide"><a href="#" class="remove-vacation">no thanks!</a></p>
    </div> <div class="jumbotron col-sm-3 col-sm-offset-1 vacation" data-price="150">
    <h4>European Getaway</h4>
    <button class="click btn btn-info">SHOE PRICE</button>
    <p class="no-hide"><a href="#" class="remove-vacation">no thanks!</a></p>
    </div> <div class="jumbotron col-sm-3 col-sm-offset-1 vacation" data-price="90">
    <h4>Visit Japan</h4>
    <button class="click btn btn-info">SHOE PRICE</button>
    <p class="no-hide"><a href="#" class="remove-vacation">no thanks!</a></p>
    </div>
    </div>
  • js:
    $.fn.pricefy = function(options) {
    this.each(function() {
    //使用$.extend添加属性;setting为要操作的数据集合
    var settings = $.extend({
    days: 3,
    vacation: $(this),
    price: $(this).data("price")
    },options);
    var show = function() {
    var details = $("<p>Book" + settings.days +"days for $" + (settings.days * settings.price)+ "</p>");
    settings.vacation.find(".click").hide();
    settings.vacation.append(details);
    };
    var remove = function() {
    settings.vacation.hide().off(".pricefy");
    };
    settings.vacation.on("click.pricefy","button",show);
    settings.vacation.on("show.pricefy",show);
    settings.vacation.on("click.pricefy",".remove-vacation",remove);
    })
    }; $(function() {
    $(".vacation").pricefy();
    $(".show-price").on("click",function(event) {
    event.preventDefault();
    $(".vacation").trigger('show.pricefy');
    });
    });

      

      

  

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