验证错误后保留表单文件 [英] Keep form files after validation error
问题描述
我有一个表单，我可以同时向后端发送几个(比如说 10 个)文件以及其他一些常规输入字段.
I have a form where I simultaneously send several (let's say 10) files to the backend, along with some other regular input fields.
当我在后端发现验证问题时，我再次显示表单并填写常规输入(下拉列表、文本输入等)，但我无法填写文件字段，迫使用户从文件中选择文件再次目录.
When I find a validation problem in the backend I display the form again and fill the regular inputs (dropdowns, text inputs, etc.), but I cannot fill the file fields, forcing the user to select the files from the file directory again.
我想到的解决方案是发送文件的base64编码表示，并将它们放回表单中以防出现验证错误，但我想知道是否有更简单的方法.
The solution I think of is sending the base64 encoded representation of the files, and put them back in the form in case there is a validation error, but I would like to know if there is a simpler way.
推荐答案
无论您做什么，都不能跳过服务器端验证.出于安全原因(例如，有人发送原始请求).至于在出现错误(或简单的重新加载)时显示文件，我会将其作为 Base64 发送，但如果文件很大，则通过 AJAX 发送.
No matter what you do, you can not skip server-side validation. For security reasons (someone sending raw requests for example). As far as showing the files in case of error (or simple reloading) I would send it as Base64, but via AJAX if the files are large.
- 客户端验证:大多数验证(如果不是全部)都可以使用普通 JS 完成.无论是文件大小、内容类型……还是根据文件类型(图像、文档……)进行更具体的验证
- 服务器端验证:发送后，对文件和内容进行全面验证.
- 发回文件:如果出现错误，如果文件小，则将文件连同请求一起发送.如果大文件通过 AJAX 发送以避免阻塞并保持快速页面加载时间.
- Client-side validation: most validations (if not all) can be done using plain JS. Be it filesize, content type... and more specific validations according to filetypes (image, document...)
- Server-side validation: Once sent, fully validate the file and content.
- Send files back:In case of error, send the files with the request if small. If big send them via AJAX to avoid blocking and keep page loading times fast.
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