xmlhttprequest

YES or NO: Can a server send an HTTP response, while still uploading the file from the correlative HTTP request?

由 梦想与她 提交于 2020-01-21 15:25:03
问题 If a website user submits an HTML form with: (1) a post method; (2) a multipart/form-data enctype; and, (3) a large attached file, can the server upload a posted file, and send a server generated HTTP response before the file upload is completed, without using AJAX? That's pretty dense. So, I wrote an example to illustrate what I mean. Let's say there is an image upload form with a caption field. <form action="upload-with-caption/" method="post" enctype="multipart/form-data"> <input type=

YES or NO: Can a server send an HTTP response, while still uploading the file from the correlative HTTP request?

由 点点圈 提交于 2020-01-21 15:22:27
问题 If a website user submits an HTML form with: (1) a post method; (2) a multipart/form-data enctype; and, (3) a large attached file, can the server upload a posted file, and send a server generated HTTP response before the file upload is completed, without using AJAX? That's pretty dense. So, I wrote an example to illustrate what I mean. Let's say there is an image upload form with a caption field. <form action="upload-with-caption/" method="post" enctype="multipart/form-data"> <input type=

小白浅谈Ajax基础

由 空扰寡人 提交于 2020-01-21 14:22:55
小白浅谈Ajax Ajax的全称是Asynchronous Javascript and XML,意思是 异步JavaScript和XML Ajax是使用XMLHttpRequest对象与服务器端通信的脚本语言。 可以发送及接收各种格式的信息，包括JSON、XML、HTML和文本文件。 Ajax可以无需刷新页面而与服务器端进行通信。 允许你根据用户事件来更新来更新部分页面内容。 1、Ajax的工作原理 Ajax的工作原理相当于 在用户和服务器之间加了一个中间层（Ajax引擎），使用户操作与服务器响应式异步化。 只有确定需要从服务器读取新数据时再由Ajax引擎代为向服务器提交请求。 把这些交给了Ajax引擎，用户操作起来也就更加流畅了。 2、Ajax的优点 页面无刷新，用户体验好 异步通信，更加快的响应能力 减少允余请求，减轻了服务器的负担 基于标准化的并被广泛支持的技术，不需要下载插件或者小程序 界面与应用分离 3、Ajax应用场景 举个例子，用户在填写一个网上表单，当用户将所有的表单信息都填完之后，点击提交，然后有一个文本框提示所填文本格式不正确，然后页面表单里面的所有信息都要重新填。这时，用户是不是会有砸电脑的冲动。（哈哈哈。。。）但在Ajax出来之后，用户可以在不用刷新页面的情况下进行表单验证。提示表单所填格式的正确与否。这样是不是给用户带来很好的用户体验。 按需获取数据

Request header field X-CSRFToken is not allowed by Access-Control-Allow-Headers in preflight response

由 别说谁变了你拦得住时间么 提交于 2020-01-21 10:59:30
问题 I'm trying to make an API call to the GroupMe API to fetch a JSON response but have been getting the following error: XMLHttpRequest cannot load ...(call url)... Request header field X-CSRFToken is not allowed by Access-Control-Allow-Headers in preflight response. My Javascript looks like this: var xmlhttp = new XMLHttpRequest(); var url = (call url) xmlhttp.onreadystatechange = function() { if (xmlhttp.readyState == 4 && xmlhttp.status == 200) { xmlhttp.open("GET", url, true); xmlhttp

Passing “#” hash symbol in request parameter of url not working in Firefox

由 你。 提交于 2020-01-21 04:30:07
问题 I am hitting a struts action using AJAX, everything is fine but there is problem with Firefox , when i am passing the parameter in URL as a request parameter and if that parameter, contains hash(#) symbol in the end, then firefox strips everything after that symbol and send that parameter to action without it. For example, if im passing test123#abcd in Firefox, then i am getting only test123 in action class as opposed to test123#abcd which is undesirable for my requirement.For IE it is

HTML5 FormData returns null in Java Servlet request.getParameter()

由 我只是一个虾纸丫 提交于 2020-01-21 03:21:04
问题 My view is HTML 5. I'm using FormData to make a AJAX 2 POST to a Servlet. Inside the servlet i'm trying to read request parameters. I can't see any parameters. However, Google Chrome Dev console shows the request payload. How can I get the same in Servlet code? Any help will be appreciated. Here's the code. JS code var xhr = new XMLHttpRequest(); var formData = new FormData(); formData.append('firstName', 'ABC'); formData.append('lastName', 'XYZ'); xhr.open("POST", targetLocation, true); xhr

XMLHttpRequest() & net::ERR_NAME_NOT_RESOLVED

由 落花浮王杯 提交于 2020-01-19 14:12:26
问题 I am writing a javascript app that makes an HTTP request of a remote server. The user will enter the host name. I want to offer a diagnostic message if they enter a DNS name that cannot resolve. Here's the current code: var req, t, url; url = 'http://definitelydoesntexist0x314159.com'; req = new XMLHttpRequest(); req.open('GET', url, true); req.onreadystatechange = function() { if (req.readyState == 4) { t = req.statusText; } }; req.send(); In the onreadystatechange function, the req has

XMLHttpRequest() & net::ERR_NAME_NOT_RESOLVED

由 拥有回忆 提交于 2020-01-19 14:11:59
问题 I am writing a javascript app that makes an HTTP request of a remote server. The user will enter the host name. I want to offer a diagnostic message if they enter a DNS name that cannot resolve. Here's the current code: var req, t, url; url = 'http://definitelydoesntexist0x314159.com'; req = new XMLHttpRequest(); req.open('GET', url, true); req.onreadystatechange = function() { if (req.readyState == 4) { t = req.statusText; } }; req.send(); In the onreadystatechange function, the req has

XMLHttpRequest status 0 on second load

由 て烟熏妆下的殇ゞ 提交于 2020-01-17 11:14:12
问题 I am experiencing an interesting issue when I am trying to load some data in .txt format from the same domain using XMLHttpRequest. I am trying to load the data, parse it and then store it in localStorage var xmlhttp; // code for IE7+, Firefox, Chrome, Opera, Safari if (window.XMLHttpRequest){ xmlhttp=new XMLHttpRequest(); }else{ // code for IE6, IE5 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); } var temp; xmlhttp.onreadystatechange=function(){ if (xmlhttp.readyState==4 && xmlhttp.status=

XMLHttpRequest status 0 on second load

由 那年仲夏 提交于 2020-01-17 11:14:07
问题 I am experiencing an interesting issue when I am trying to load some data in .txt format from the same domain using XMLHttpRequest. I am trying to load the data, parse it and then store it in localStorage var xmlhttp; // code for IE7+, Firefox, Chrome, Opera, Safari if (window.XMLHttpRequest){ xmlhttp=new XMLHttpRequest(); }else{ // code for IE6, IE5 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); } var temp; xmlhttp.onreadystatechange=function(){ if (xmlhttp.readyState==4 && xmlhttp.status=
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