I believe you can use ports without native code to pass the event reference as Value to JS and call the FileReader API, returning file as String back to Elm. But that was more convoluted than I wanted to deal with.
On Saturday, May 6, 2017 at 5:12:23 PM UTC-5, Kasey Speakman wrote: > > I tried using both: > > import Json.Decode as Json > > -- the first JS File > Json.at [ "target", "files" ] (Json.index 0 Json.value) > > -- the JS FileList > Json.at [ "target", "files" ] Json.value > > Both of which came back as undefined after decoding. Maybe I was doing > something else wrong? > > Even one of these came through as Value, you can't do anything with it in > Elm. The Http module has no mechanism to send Value, only Strings > (multi-part also takes only Strings). For security reasons, the only way to > access the JS File contents (AFAIK) is through another JS API like XHR (to > send) or FileReader (to read the contents). There has to be some native > code involved to either get the contents or convert the file reference to > something that Elm can use. > > On Saturday, May 6, 2017 at 2:45:29 PM UTC-5, Witold Szczerba wrote: >> >> > I did actually try using decoders first to pull in the >> "e.target.files" property as a Value, but Elm just fails to decode it. >> >> How did you try to decode the "files"? There is a special function: >> value -> Decoder Value >> it does leave the structure "as is". I was wandering if it could work? >> The original "files" could be then assigned to the body, so Elm would not >> touch it at all. Would it possibly work? >> >> Regards, >> Witold Szczerba >> >> 05.05.2017 7:32 PM "Kasey Speakman" <[email protected]> napisał(a): >> >>> After a bit of research on file uploads, I pared it down to the simplest >>> method I could find. Here is the recipe I came up with. >>> >>> https://gist.github.com/kspeakman/20708d5ff58b6ea75f9c3a82f6c793c3 >>> >>> The FileUtils module essentially wraps the JS File object in Http.Body >>> as well as exposing common file info (name, size, contentType). Using >>> Http.Body makes it quite easy to send files with normal Http calls. >>> Unfortunately this does use native/kernel code, but this made it far easier >>> to work with in Elm than if I used ports. I did actually try using decoders >>> first to pull in the "e.target.files" property as a Value, but Elm just >>> fails to decode it. >>> >>> I also thought something like this could be a path forward to introduce >>> basic file uploads into Elm's core. It is not a general solution for all >>> binary formats. But it is a straightforward way to handle File objects from >>> JS. >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Elm Discuss" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> For more options, visit https://groups.google.com/d/optout. >>> >> -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
