我有一个基于jquery的单页web应用程序。它通过AJAX调用与基于rest的web服务通信。
我正在努力实现以下目标:
向REST url提交包含JSON数据的POST。
如果请求指定了JSON响应，则返回JSON。
如果请求指定PDF/XLS/etc响应，则返回可下载的二进制文件。
我有1和2工作现在，和客户端jquery应用程序通过创建基于JSON数据的DOM元素在网页中显示返回的数据。我还让#3从web服务的角度工作，这意味着如果给定正确的JSON参数，它将创建并返回二进制文件。但我不确定在客户端javascript代码中处理#3的最佳方法。
是否有可能从这样的ajax调用中获得一个可下载的文件?如何让浏览器下载并保存文件?
$.ajax({
type: "POST",
url: "/services/test",
contentType: "application/json",
data: JSON.stringify({category: 42, sort: 3, type: "pdf"}),
dataType: "json",
success: function(json, status){
if (status != "success") {
log("Error loading data");
return;
}
log("Data loaded!");
},
error: function(result, status, err) {
log("Error loading data");
return;
}
});
服务器响应以下报头:
Content-Disposition:attachment; filename=export-1282022272283.pdf
Content-Length:5120
Content-Type:application/pdf
Server:Jetty(6.1.11)
另一种想法是生成PDF并将其存储在服务器上，然后返回包含文件URL的JSON。然后，在ajax成功处理程序中发出另一个调用，执行如下操作:
success: function(json,status) {
window.location.href = json.url;
}
但这样做意味着我需要对服务器进行多次调用，我的服务器需要构建可下载的文件，将它们存储在某个地方，然后定期清理存储区域。
一定有更简单的方法。想法吗?
编辑:在检查文档$。ajax，我看到响应dataType只能是xml, html，脚本，json, jsonp，文本之一，所以我猜没有办法直接下载一个文件使用ajax请求，除非我嵌入二进制文件使用数据URI方案建议在@VinayC答案(这不是我想做的事情)。
所以我想我的选择是:
Not use ajax and instead submit a form post and embed my JSON data into the form values. Would probably need to mess with hidden iframes and such.
Not use ajax and instead convert my JSON data into a query string to build a standard GET request and set window.location.href to this URL. May need to use event.preventDefault() in my click handler to keep browser from changing from the application URL.
Use my other idea above, but enhanced with suggestions from the @naikus answer. Submit AJAX request with some parameter that lets web-service know this is being called via an ajax call. If the web service is called from an ajax call, simply return JSON with a URL to the generated resource. If the resource is called directly, then return the actual binary file.
我越想越喜欢最后一个选项。通过这种方式，我可以获得关于请求的信息(生成时间、文件大小、错误消息等)，并且可以在开始下载之前对这些信息采取行动。缺点是服务器上需要额外的文件管理。
还有其他方法吗?我应该知道这些方法的优缺点吗?
Letronje的解决方案只适用于非常简单的页面。document.body.innerHTML +=接受正文的HTML文本，追加iframe HTML，并将页面的innerHTML设置为该字符串。这将清除页面上的所有事件绑定。创建一个元素并使用appendChild。
$.post('/create_binary_file.php', postData, function(retData) {
var iframe = document.createElement("iframe");
iframe.setAttribute("src", retData.url);
iframe.setAttribute("style", "display: none");
document.body.appendChild(iframe);
});
或者使用jQuery
$.post('/create_binary_file.php', postData, function(retData) {
$("body").append("<iframe src='" + retData.url+ "' style='display: none;' ></iframe>");
});
What this actually does: perform a post to /create_binary_file.php with the data in the variable postData; if that post completes successfully, add a new iframe to the body of the page. The assumption is that the response from /create_binary_file.php will include a value 'url', which is the URL that the generated PDF/XLS/etc file can be downloaded from. Adding an iframe to the page that references that URL will result in the browser promoting the user to download the file, assuming that the web server has the appropriate mime type configuration.
我已经醒了两天了，现在试图弄清楚如何使用jquery和ajax调用下载文件。我得到的所有支持都无法帮助我，直到我尝试了这个。
客户端
function exportStaffCSV(t) {
var postData = { checkOne: t };
$.ajax({
type: "POST",
url: "/Admin/Staff/exportStaffAsCSV",
data: postData,
success: function (data) {
SuccessMessage("file download will start in few second..");
var url = '/Admin/Staff/DownloadCSV?data=' + data;
window.location = url;
},
traditional: true,
error: function (xhr, status, p3, p4) {
var err = "Error " + " " + status + " " + p3 + " " + p4;
if (xhr.responseText && xhr.responseText[0] == "{")
err = JSON.parse(xhr.responseText).Message;
ErrorMessage(err);
}
});
}
服务器端
[HttpPost]
public string exportStaffAsCSV(IEnumerable<string> checkOne)
{
StringWriter sw = new StringWriter();
try
{
var data = _db.staffInfoes.Where(t => checkOne.Contains(t.staffID)).ToList();
sw.WriteLine("\"First Name\",\"Last Name\",\"Other Name\",\"Phone Number\",\"Email Address\",\"Contact Address\",\"Date of Joining\"");
foreach (var item in data)
{
sw.WriteLine(string.Format("\"{0}\",\"{1}\",\"{2}\",\"{3}\",\"{4}\",\"{5}\",\"{6}\"",
item.firstName,
item.lastName,
item.otherName,
item.phone,
item.email,
item.contact_Address,
item.doj
));
}
}
catch (Exception e)
{
}
return sw.ToString();
}
//On ajax success request, it will be redirected to this method as a Get verb request with the returned date(string)
public FileContentResult DownloadCSV(string data)
{
return File(new System.Text.UTF8Encoding().GetBytes(data), System.Net.Mime.MediaTypeNames.Application.Octet, filename);
//this method will now return the file for download or open.
}
祝你好运。
