Handle form containing files and text

I have a simple form with a text input and multiple file input.

<form action="/posts" method="post" enctype="multipart/form-data">
  <input name="title"/>
  <input type="file" name="file" multiple/>
  <button>Post</button>
</form>

The problem is that I can’t get the value of "title" both from ctx.uploadedFiles() (which understandably returns only files) and from ctx.formParam()(which stopped returning data when I switched content-type to multipart). Of course, I can parse the request using FileUpload directly, but maybe there is already a simpler way to get text values?

[leveluptor]

sorry for the delay, it’s done, will push PR today when i get back to the computer

On Sat, Feb 24, 2018 at 2:03 AM, David [e-mail] wrote:

@leveluptor https://github.com/leveluptor are you still working on this?

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/tipsy/javalin/issues/124#issuecomment-368163866, or mute the thread https://github.com/notifications/unsubscribe-auth/ARXlStxQsPvVgd-D4-AAanUPTzFbisgTks5tX0PZgaJpZM4R_F6F .

[leveluptor]

I’ll describe how I see these two scenarios from a developer’s point of view.

1. Upload files: All uploaded files are processed together. E.g. “save all images to the disk”.

2. Upload both files and text fields: All uploaded files are processed together, text fields are processed separately from files. E.g. “save all images to the disk, extract post title and post text from text fields, write title and text to the database”.

Which means that we need following public “methods”:

• “give me all files”
• “give me all form fields and then let me access separately all files and all text fields”

Restrictions:

• No changes in existing public API - can’t touch Context#uploadedFiles or UploadUtil#getUploadedFiles
• No changes in existing logic - can’t make Context#formParamMap return parsed multipart form params instead of empty list

If it’s OK to keep things as simple as they are now, I can add Context#multipartFormFields (not the best name) which will act similar to UploadUtil#getUploadedFiles.

However, if client code calls “give me all files” and then “give me all text fields”, the form will be parsed twice. If we want to avoid this (and also group the closely related methods together), everything becomes a bit more complicated:

• Introduce one more entity, e.g. MultipartForm with two methods: getUploadedFiles : List<UploadedFile> and getTextFields : Map<String, Array<String>>
• Introduce new method: Context#multipartForm : MultipartForm, which parses the whole form and fills MultipartForm with all files and text fields
• For scenario 1, client code calls (as before)

 //delegates to ctx.multipartForm().getUploadedFiles(name)
  val files = ctx.uploadedFiles(name)

• For scenario 2, client code calls

  val multipartForm = ctx.multipartForm()
  val files = multipartForm.getUploadedFiles(name)
  val fields = multipartForm.getTextFields()

Honestly I’m not a fan of both these solutions. The first one looks clunky for me and the second one creates multiple ways to do the same thing.