jQuery 学习笔记(jQuery: The Return Flight)

第一课.

ajax：$.ajax(url[, settings])

练习代码：

$(document).ready(function() {$("#tour").on("click", "button", function() {$.ajax('/photos.html', {success: function(response) {$('.photos').html(response).fadeIn();}});});
});

<div id="tour" data-location="london"><button>Get Photos</button><ul class="photos"></ul>
</div>

ajax 调用简写：$.get(url, success)

$(document).ready(function() {$("#tour").on("click", "button", function() {$.get('/photos.html', function(response) {$('.photos').html(response).fadeIn();});});
});

ajax 传递参数：直接在 url 中拼接或使用 data 对象传递，data: { "confNum": 1234 }

练习代码：获取网页元素中的 data 属性值作为 ajax 参数值传递

$(document).ready(function() {$("#tour").on("click", "button", function() {$.ajax('/photos.html', {success: function(response) {$('.photos').html(response).fadeIn();},data: { "location": $("#tour").data("location")}});});
});

<div id="tour" data-location="london"><button>Get Photos</button><ul class="photos"></ul>
</div>

第二课.

ajax 异常处理：error: function(request, errorType, errorMessage) { }

ajax 超时设定：timeout: 3000

ajax 调用前（beforeSend: function() {}）完成后（complete: function() {}）执行方法：

练习代码：

$(document).ready(function() {var el = $("#tour");el.on("click", "button", function() {$.ajax('/photos.html', {data: {location: el.data('location')},success: function(response) {$('.photos').html(response).fadeIn();},error: function(request, errorType, errorMessage) {//var errmsg = $("<li>Error: " + errorType + " with message: " + errorMessage + "</li>");//$('.photos').append(errmsg);//alert('Error: ' + errorType + ' with message: ' + errorMessage);$('.photos').html('<li>There was a problem fetching the latest photos. Please try again.</li>');},timeout: 3000,beforeSend: function() {$("#tour").addClass("is-fetching")},complete: function() {$("#tour").removeClass("is-fetching")}});});
});

<div id="tour" data-location="london"><button>Get Photos</button><ul class="photos"></ul>
</div>

ajax 事件处理：处理 ajax 完成新增的标签元素的事件

练习代码：

$(document).ready(function() {function showPhotos() {$(this).find('span').slideToggle();}$('.photos').on('mouseenter', 'li', showPhotos).on('mouseleave', 'li', showPhotos);var el = $("#tour");el.on("click", "button", function() {$.ajax('/photos.html', {data: {location: el.data('location')},success: function(response) {$('.photos').html(response).fadeIn();},error: function() {$('.photos').html('<li>There was a problem fetching the latest photos. Please try again.</li>');},timeout: 3000,beforeSend: function() {$('#tour').addClass('is-fetching');},complete: function() {$('#tour').removeClass('is-fetching');}});});
});

HTML、AJAX Result

<div id="tour" data-location="london"><button>Get Photos</button><ul class="photos"></ul>
</div>

<li><img src="/assets/photos/paris1.jpg"><span style="display: none;">Arc de Triomphe</span>
</li>
<li><img src="/assets/photos/paris2.jpg"><span style="display: none;">The Eiffel Tower</span>
</li>
<li><img src="/assets/photos/london.jpg"><span style="display: none;">London</span>
</li>

第三课.

JavaScript Objects：

练习代码：

重构前：

$(document).ready(function() {$("#tour").on("click", "button", function() {$.ajax('/photos.html', {data: {location: $("#tour").data('location')},success: function(response) {$('.photos').html(response).fadeIn();},error: function() {$('.photos').html('<li>There was a problem fetching the latest photos. Please try again.</li>');},timeout: 3000,beforeSend: function() {$('#tour').addClass('is-fetching');},complete: function() {$('#tour').removeClass('is-fetching');}});});
});

重构为 JavaScript 对象 tour 后：

var tour = {init: function() {$("#tour").on("click", "button", this.fetchPhotos);},fetchPhotos: function() {$.ajax('/photos.html', {data: {location: $("#tour").data('location')},success: function(response) {$('.photos').html(response).fadeIn();},error: function() {$('.photos').html('<li>There was a problem fetching the latest photos. Please try again.</li>');},timeout: 3000,beforeSend: function() {$('#tour').addClass('is-fetching');},complete: function() {$('#tour').removeClass('is-fetching');}})}
}
$(document).ready(function() { tour.init();
});

第四课.

JavaScript Functions：重点理解 this 变量的作用域

ajax 回调函数中应用调用函数变量 this 时，需要首先在 ajax 的 context 参数中传入调用函数的 this 变量：

练习代码：

function Tour(el) {var tour = this;this.el = el;this.photos = this.el.find('.photos');this.fetchPhotos = function() { $.ajax('/photos.html', {data: {location: tour.el.data('location')},context: tour,success: function(response) {this.photos.html(response).fadeIn();},error: function() {this.photos.html('<li>There was a problem fetching the latest photos. Please try again.</li>');},timeout: 3000,beforeSend: function() {this.el.addClass('is-fetching');},complete: function() {this.el.removeClass('is-fetching');}});}this.el.on('click', 'button', this.fetchPhotos);
}$(document).ready(function() { var paris = new Tour($('#paris'));var london = new Tour($('#london'));
});

<div id="paris" data-location="paris"><button>Get Paris Photos</button><ul class="photos"></ul>
</div><div id="london" data-location="london"><button>Get London Photos</button><ul class="photos"></ul>
</div>

第五课.

Ajax Forms

$('form').on('submit', function(event) {}); //表单提交事件

event.preventDefault(); //阻止浏览器的默认表单提交行为

type: 'POST' // POST 方式提交

data:{ "destination": $('#destination').val(), "quantity": $('#quantity').val() } //获取表单中的元素值提交数据

data: $('form').serialize() //通过表单序列化，提交整张表单中的数据

练习代码：

$(document).ready(function() {$('form').on('submit', function(event) {event.preventDefault();$.ajax('/book', {type: 'POST',data: $('form').serialize(),success: function(response){$('.tour').html(response);}});});
});

<div class="tour" data-daily-price="357"><h2>Paris, France Tour</h2><p>$<span id="total">2,499</span> for <span id="nights-count">7</span> Nights</p><form action="/book" method="POST"><p><label for="nights">Number of Nights</label></p><p><input type="number" name="nights" id="nights" value="7"></p><input type="submit" value="book"></form>
</div>

第六课.

Ajax with JSON

dataType: 'json' // 通知服务器提交的数据类型为 json

contentType: 'application/json' //要求服务器返回的数据类型为 json

attr(<attribute>) //获取 html 对象的属性

attr(<attribute>, <value>) //给 html 对象的属性赋值

练习代码：

$(document).ready(function() {$('form').on('submit', function(event) {event.preventDefault();$.ajax($('form').attr('action'), {type: $('form').attr('method'),data: $('form').serialize(),dataType: 'json',success: function(response) {$('.tour').html('<p></p>').find('p').append('Trip to ' + response.description).append(' at $' + response.price).append(' for ' + response.nights + ' nights').append('. Confirmation: ' + response.confirmation);}});});
});

<div class="tour" data-daily-price="357"><h2>Paris, France Tour</h2><p>$<span id="total">2,499</span> for <span id="nights-count">7</span> Nights</p><form action="/book" method="POST"><p><label for="nights">Number of Nights</label></p><p><input type="number" name="nights" id="nights" value="7"></p><input type="submit" value="book"></form>
</div>

第七课.

Utility Methods

$.each(collection, function(<index>, <object>) {}) //iterate through the array

练习代码：

$('button').on('click', function() {$.ajax('/cities/deals', {contentType: 'application/json',dataType: 'json',success: function(result) {$.each(result, function(index, dealItem) {var dealElement = $('.deal-' + index);dealElement.find('.name').html(dealItem.name);dealElement.find('.price').html(dealItem.price);});}});
});

$.getJSON(url, success); //result will be an array of avaScript Objects

练习代码：

$('button').on('click', function() {$.getJSON('/cities/deals', function(result) {$.each(result, function(index, dealItem) {var dealElement = $('.deal-' + index);dealElement.find('.name').html(dealItem.name);dealElement.find('.price').html(dealItem.price);});});
});

$.map(collection, function(<item>, <index>){});

练习代码：

$('.update-available-flights').on('click', function() {$.getJSON('/flights/late', function(result) {var flightElements = $.map(result, function(flightItem, index){var liItem = $('<li></li>');liItem.append('<p>'+flightItem.flightNumber+'</p>');liItem.append('<p>'+flightItem.time+'</p>');return liItem;});$('.flight-times').html(flightElements);});
});

$.each vs $.map

.detach() //.detach() removes an element from the DOM, preserving all data and events.

detach() 方法移除被选元素，包括所有文本和子节点。

这个方法会保留 jQuery 对象中的匹配的元素，因而可以在将来再使用这些匹配的元素。

detach() 会保留所有绑定的事件、附加的数据，这一点与 remove() 不同。

练习代码：

$('.update-available-flights').on('click', function() {$.getJSON('/flights/late', function(result) {var flightElements = $.map(result, function(flightItem, index){var flightEl = $('<li>'+flightItem.flightNumber+'-'+flightItem.time+'</li>');return flightEl;});$('.flight-times').detach().html(flightElements).appendTo('.flights');});
});

第八课.

Managing Events：同一个元素同一个事件挂接多个事件处理程序，按顺序执行