nova_forms/components/

file_upload.rs

use std::{fmt::Display, str::FromStr};

use leptos::*;
use serde::{Deserialize, Serialize};
use uuid::Uuid;

use crate::{Group, GroupContext, Icon, QueryStringPart};
use serde::de::Error;
use server_fn::codec::{MultipartData, MultipartFormData};
use web_sys::{wasm_bindgen::JsCast, FormData, HtmlInputElement};


// See this for reference: https://github.com/leptos-rs/leptos/blob/96e2b5cba10d2296f262820be19cac9b615b0d23/examples/server_fns_axum/src/app.rs

/// A component that allows users to upload files.
/// The files are automatically uploaded to the server and stored in the `FileStore`.
#[component]
pub fn FileUpload(
    /// The query string to bind to a list of `FileId`s.
    #[prop(into)] bind: QueryStringPart
) -> impl IntoView {
    let (file_info, set_file_info) = create_signal(Vec::new());

    let on_input = move |ev: web_sys::Event| {
        let target = ev
            .target()
            .expect("target must exist")
            .unchecked_into::<HtmlInputElement>();

        if let Some(files) = target.files() {
            let form_data: FormData = FormData::new().expect("can create form data");

            for i in 0..files.length() {
                let file = files.get(i).expect("file must exist");
                let file_name = file.name();

                form_data
                    .append_with_blob_and_filename(&file_name, &file, &file_name)
                    .expect("appending file to form data must be successful");
            }

            spawn_local(async move {
                let mut new_file_infos = upload_file(form_data.into())
                    .await
                    .expect("couldn't upload file");

                set_file_info.update(|file_info| {
                    file_info.append(&mut new_file_infos);
                });
            });
        }
    };

    view! {
        <Group bind=bind>
            {
                let group = expect_context::<GroupContext>();
                let qs = group.qs();

                view! {
                    <label class="button icon-button" for=qs.to_string()>
                        <input id=qs.to_string() type="file" class="sr-hidden" on:input=on_input disabled=cfg!(feature = "csr") />
                        <Icon label="Upload" icon="upload" />
                    </label>
                    <ul>
                        <For
                            each=move || file_info.get().into_iter().enumerate()
                            key=|(_, (file_id, _))| file_id.clone()
                            // renders each item to a view
                            children=move |(i, (file_id, file_info))| {
                                let qs = qs.add_index(i);
        
                                view! {
                                    <li>
                                        {format!("{}", file_info.file_name)}
                                        <input type="hidden" name=qs value=file_id.to_string() />
                                    </li>
                                }
                            }
                        />
                    </ul>
                }
            }
        </Group>
        
    }
}

/// A unique identifier for a file.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct FileId(Uuid);

#[cfg(feature = "ssr")]
impl FileId {
    pub(crate) fn new() -> Self {
        FileId(Uuid::new_v4())
    }
}

impl Display for FileId {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "file_id_{}", self.0)
    }
}

impl Serialize for FileId {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: serde::Serializer,
    {
        serializer.serialize_str(&format!("file_id_{}", self.0))
    }
}

impl<'de> Deserialize<'de> for FileId {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        let mut value = String::deserialize(deserializer)?;
        if !value.starts_with("file_id_") {
            return Err(D::Error::custom("prefix mismatch"));
        }
        match Uuid::from_str(&value.split_off(8)) {
            Ok(uuid) => Ok(FileId(uuid)),
            Err(_) => Err(D::Error::custom("invalid uuid")),
        }
    }
}

/// Contains information about a file, but not the file contents itself.
#[derive(Clone, Serialize, Deserialize, Debug)]
pub struct FileInfo {
    file_name: String,
    content_type: Option<String>,
}

impl FileInfo {
    pub fn new(file_name: String, content_type: Option<String>) -> Self {
        FileInfo {
            file_name,
            content_type,
        }
    }

    pub fn file_name(&self) -> &str {
        &self.file_name
    }

    pub fn content_type(&self) -> Option<&str> {
        self.content_type.as_ref().map(|s| s.as_str())
    }
}

#[server(input = MultipartFormData)]
async fn upload_file(data: MultipartData) -> Result<Vec<(FileId, FileInfo)>, ServerFnError> {
    use crate::FileStore;

    let mut data = data.into_inner().unwrap();
    let mut file_infos = Vec::new();

    while let Ok(Some(mut field)) = data.next_field().await {
        let content_type = field.content_type().map(|mime| mime.to_string());
        let file_name = field.file_name().expect("no filename on field").to_string();
        let file_info = FileInfo::new(file_name, content_type);

        let mut data = Vec::new();

        while let Ok(Some(chunk)) = field.chunk().await {
            data.extend_from_slice(&chunk);
            //let len = chunk.len();
            //println!("[{file_name}]\t{len}");
            //progress::add_chunk(&name, len).await;
            // in a real server function, you'd do something like saving the file here
        }

        let file_store = expect_context::<FileStore>();
        let file_id = file_store.insert(file_info.clone(), data).await?;

        println!(
            "inserted file {} into database with id {}",
            file_info.file_name(),
            file_id
        );

        file_infos.push((file_id, file_info));
    }

    Ok(file_infos)
}