xmlhttprequest

原生XMLHttpRequest学习日志

由 老子叫甜甜 提交于 2019-12-25 11:02:07
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 今天决定学习一下Ajax异步的XMLHttpRequest对象，平时一直使用jQuery.ajax()就万事大吉， 当自己要实现一套时才发现当中的细节事情!jQuery源码真的博大精深优美得很; 先从w3cschool看一下基本的使用方式，参考的jQ版本是v1.11.1 http://www.w3school.com.cn/xml/xml_http.asp 基本流程是先做简单 XMLHttpRequest 兼容处理,提交请求,最后是回调处理结果； setup1 配置 开始时候在想怎样才能写出优美的参数传值，看jQ源码发现是使用jQuery.extend，而且这函数在很多地方都在应用，看来分量很重噢； 手册介绍是用一个或多个其他对象来扩展一个对象，返回被扩展的对象；如果不指定target，则给jQuery命名空间本身进行扩展。 jQ是先定义了基本参数对象ajaxSettings#8830行开始；然后调用ajaxSetup方法，其实这货还是调用了 jQuery.extend去合并对象；只是判断是否是扩展配置对象； 自己太赖了只做最简参数单合并和获取回调方法事情； function ajaxSetup(opations) { if (typeof opations == 'object') { for (key in

XMLHttpRequest对象如何兼容各浏览器使用？

由 吃可爱长大的小学妹 提交于 2019-12-25 10:55:08
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 什么是 XMLHttpRequest 对象？ XMLHttpRequest 对象用于在后台与服务器交换数据。 XMLHttpRequest 对象是开发者的梦想，因为您能够： 在不重新加载页面的情况下更新网页 在页面已加载后从服务器请求数据 在页面已加载后从服务器接收数据 在后台向服务器发送数据 所有现代的浏览器都支持 XMLHttpRequest 对象。 1、如何创建兼容良好的XMLHttpRequest 对象： function createXmlRequest(){ var xmlHttp; try{ xmlHttp=new ActiveXObject("Msxml2.XMLHTTP"); }catch(e){ xmlHttp=new ActiveXObjec("Microsoft.XMLHTTP"); // 老版本的 Internet Explorer （IE5 和 IE6） }if(!xmlHttp && typeof XMLHttpRequest!='undefined'){ try{ xmlHttp=new XMLHttpRequest(); }catch(e){ xmlHttp=false; } } return xmlHttp; } 2、如何使用？以Struts为例： var xhr =

XMLHttpRequest对象

由 ╄→尐↘猪︶ㄣ 提交于 2019-12-25 10:37:17
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> XMLHttpRequest 对象用于在后台与服务器交换数据。 创建 XMLHttpRequest 对象 所有现代浏览器 (IE7+、Firefox、Chrome、Safari 以及 Opera) 都内建了 XMLHttpRequest 对象。 创建 XMLHttpRequest 对象的语法： xmlhttp=new XMLHttpRequest(); 老版本的 Internet Explorer （IE5 和 IE6）使用 ActiveX 对象： xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); <script type="text/javascript"> var xmlhttp; function loadXMLDoc(url) { xmlhttp=null; if (window.XMLHttpRequest) {// code for all new browsers xmlhttp=new XMLHttpRequest(); } else if (window.ActiveXObject) {// code for IE5 and IE6 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); } if

Abort/cancel/abandon a http request in angular js and retry it again

由 試著忘記壹切 提交于 2019-12-25 09:43:28
问题 I am working on an application in which i have to stop listening to a request if certain time is passed like if there is no response from a request in 60 secs then i have to abort that request and also there are multiple requests are going at a time. I don't know know how to keep track of each request with abort time(60 secs) . I mean how would i know which request is to abort. I want to implement this functionality in my AngularJS interceptor. I have tried many blogs and post that claims to

How does ajax call terminate when window closed or refreshed too fast as example at stackoverflow voting calls?

由 守給你的承諾、 提交于 2019-12-25 09:35:12
问题 As I asked in this meta question: https://meta.stackexchange.com/questions/119259/voting-is-lost-due-to-ajax-call-latency I wonder about issue, how it occurs? Is it because browser sends a notification that it says I gave up or is it because it is really fast action by user that browser even could not send the xhr request? 回答1: I'd guess that the request is sent, but that browsers cancel XHR pending requests when a page is unloaded. XHR requests can be canceled manually via the .abort()

AjaxChat: Image Upload code hangs, freezes browser, crashes server

由 a 夏天 提交于 2019-12-25 09:14:00
问题 This is a tangent from the question here: Returning value to Javascript from PHP called from XMLHttpRequest I am adding an "image upload" button to my AjaxChat. I am using an XMLHttpRequest to send the image to the server, where I run a PHP script to move it to my images folder. Below is the Javascript function in charge of opening the XMLHttpRequest connection and sending the file: function uploadImage() { var form = document.getElementById('fileSelectForm'); var photo = document

Angular 2 XMLHttpRequest

由 有些话、适合烂在心里 提交于 2019-12-25 08:57:41
问题 I'm trying to make a POST request to an API and I'm receiving this error: XMLHttpRequest cannot load http://*. Response for preflight has invalid HTTP status code 400 However, when I try to make a GET request, it works. My get method: getMethod() { return this.http.get<PerfilModel[]>(globals.BASE_URL + 'perfis'); } My post method: updateMethod(changePass: ChangePassModel) { let h = new Headers(); h.append('Content-Type', 'application/json'); return this.http2.post(globals.BASE_URL + 'users

Data Processing, how to approach

由 柔情痞子 提交于 2019-12-25 07:00:06
问题 I have the following Problem, given this XML Datastructure: <level1> <level2ElementTypeA></level2ElementTypeA> <level2ElementTypeB> <level3ElementTypeA>String1Ineed<level3ElementTypeB> </level2ElementTypeB> ... <level2ElementTypeC> <level3ElementTypeB attribute1> <level4ElementTypeA>String2Ineed<level4ElementTypeA> <level3ElementTypeB> <level2ElementTypeC> ... <level2ElementTypeD></level2ElementTypeD> </level1> <level1>...</level1> I need to create an Entity which contain: String1Ineed and

How fix cross origin error in extjs6?

由 …衆ロ難τιáo~ 提交于 2019-12-25 06:58:51
问题 I'm developing an application using Extjs-6.0.0 in client side. I run client side application in port 80 . My server side application running in port 8084 . When I submit a form with form.submit , the follow errors are occur. XMLHttpRequest cannot load localhost:8084/GeoAd/ad/add. Cross origin requests > are only supported for protocol schemes: http, data, chrome, chrome-extension, > https, chrome-extension-resource. chrome-extension, https, chrome-extension-resource. Uncaught NetworkError:

How do I append a file to FormData()?

由 浪尽此生 提交于 2019-12-25 06:33:45
问题 fd.append("upload", file) yields, ------WebKitFormBoundaryJnjpATRkxe2Duwwu Content-Disposition: form-data; name="userid" 8022171621665209152 ------WebKitFormBoundaryJnjpATRkxe2Duwwu Content-Disposition: form-data; name="upload"; filename="sample.csv" Content-Type: text/csv ------WebKitFormBoundaryJnjpATRkxe2Duwwu-- fd.append("upload", evt.target.result) yields, ------WebKitFormBoundaryITfVxS7FbNWfk3Ty Content-Disposition: form-data; name="userid" 8022171621665209152 -----
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