Files Upload and Handling - Rust SDK Documentation

Overview

BosBase allows you to upload and manage files through file fields in your collections. Files are stored with sanitized names and a random suffix for security (e.g., test_52iwbgds7l.png).

Key Features:

Upload multiple files per field
Maximum file size: ~8GB (2^53-1 bytes)
Automatic filename sanitization and random suffix
Image thumbnails support
Protected files with token-based access
File modifiers for append/prepend/delete operations

Backend Endpoints:

POST /api/files/token - Get file access token for protected files
GET /api/files/{collection}/{recordId}/{filename} - Download file

File Field Configuration

Before uploading files, you must add a file field to your collection:

use bosbase::BosBase;
use serde_json::json;
use std::collections::HashMap;

let pb = BosBase::new("http://localhost:8090");
pb.admins().auth_with_password("admin@example.com", "password").await?;

let mut collection = pb.collections.get_one(
    "example",
    HashMap::new(),
    HashMap::new(),
    None,
    None
).await?;

// Add file field
if let Some(fields) = collection.get_mut("fields").and_then(|f| f.as_array_mut()) {
    fields.push(json!({
        "name": "documents",
        "type": "file",
        "maxSelect": 5,        // Maximum number of files (1 for single file)
        "maxSize": 5242880,    // 5MB in bytes (optional, default: 5MB)
        "mimeTypes": ["image/jpeg", "image/png", "application/pdf"],
        "thumbs": ["100x100", "300x300"],  // Thumbnail sizes for images
        "protected": false     // Require token for access
    }));
}

pb.collections.update(
    "example",
    json!({
        "fields": collection["fields"]
    }),
    HashMap::new(),
    HashMap::new(),
    None,
    None
).await?;

Uploading Files

Basic Upload with Create

When creating a new record, you can upload files directly:

use bosbase::{BosBase, FileAttachment};
use serde_json::json;
use std::collections::HashMap;

let pb = BosBase::new("http://localhost:8090");

// Prepare files
let mut files = Vec::new();
files.push(FileAttachment {
    field: "documents".to_string(),
    filename: "file1.txt".to_string(),
    content_type: "text/plain".to_string(),
    data: b"content 1...".to_vec(),
});

files.push(FileAttachment {
    field: "documents".to_string(),
    filename: "file2.txt".to_string(),
    content_type: "text/plain".to_string(),
    data: b"content 2...".to_vec(),
});

// Create record with files
let created_record = pb.collection("example").create(
    json!({
        "title": "Hello world!"
    }),
    HashMap::new(),
    files,
    HashMap::new(),
    None,
    None
).await?;

Upload with Update

// Update record and upload new files
let mut files = Vec::new();
files.push(FileAttachment {
    field: "documents".to_string(),
    filename: "file3.txt".to_string(),
    content_type: "text/plain".to_string(),
    data: b"content 3...".to_vec(),
});

let updated_record = pb.collection("example").update(
    "RECORD_ID",
    json!({
        "title": "Updated title"
    }),
    HashMap::new(),
    files,
    HashMap::new(),
    None,
    None
).await?;

Append Files (Using + Modifier)

For multiple file fields, use the + modifier to append files:

// Append files to existing ones
let mut files = Vec::new();
files.push(FileAttachment {
    field: "documents+".to_string(),  // Note: + modifier in field name
    filename: "file4.txt".to_string(),
    content_type: "text/plain".to_string(),
    data: b"content 4...".to_vec(),
});

pb.collection("example").update(
    "RECORD_ID",
    json!({}),
    HashMap::new(),
    files,
    HashMap::new(),
    None,
    None
).await?;

Deleting Files

Delete All Files

// Delete all files in a field (set to empty array)
pb.collection("example").update(
    "RECORD_ID",
    json!({
        "documents": []
    }),
    HashMap::new(),
    Vec::new(),
    HashMap::new(),
    None,
    None
).await?;

Delete Specific Files (Using - Modifier)

// Delete individual files by filename
pb.collection("example").update(
    "RECORD_ID",
    json!({
        "documents-": ["file1.pdf", "file2.txt"]
    }),
    HashMap::new(),
    Vec::new(),
    HashMap::new(),
    None,
    None
).await?;

File URLs

Get File URL

Each uploaded file can be accessed via its URL:

http://localhost:8090/api/files/COLLECTION_ID_OR_NAME/RECORD_ID/FILENAME

Using SDK:

let record = pb.collection("example").get_one(
    "RECORD_ID",
    HashMap::new(),
    HashMap::new(),
    None,
    None
).await?;

// Single file field (returns string)
if let Some(filename) = record.get("documents").and_then(|f| f.as_str()) {
    let url = pb.get_file_url(
        record.clone(),
        filename,
        None,      // thumb
        None,      // token
        None,      // download
        HashMap::new()
    );
    println!("File URL: {}", url);
}

// Multiple file field (returns array)
if let Some(files) = record.get("documents").and_then(|f| f.as_array()) {
    if let Some(first_file) = files.first().and_then(|f| f.as_str()) {
        let url = pb.get_file_url(
            record.clone(),
            first_file,
            None,
            None,
            None,
            HashMap::new()
        );
        println!("First file URL: {}", url);
    }
}

Image Thumbnails

If your file field has thumbnail sizes configured, you can request thumbnails:

let record = pb.collection("example").get_one(
    "RECORD_ID",
    HashMap::new(),
    HashMap::new(),
    None,
    None
).await?;

if let Some(filename) = record.get("avatar").and_then(|f| f.as_str()) {
    // Get thumbnail with specific size
    let thumb_url = pb.get_file_url(
        record.clone(),
        filename,
        Some("100x300".to_string()),  // Width x Height
        None,
        None,
        HashMap::new()
    );
    println!("Thumbnail URL: {}", thumb_url);
}

Thumbnail Formats:

WxH (e.g., 100x300) - Crop to WxH viewbox from center
WxHt (e.g., 100x300t) - Crop to WxH viewbox from top
WxHb (e.g., 100x300b) - Crop to WxH viewbox from bottom
WxHf (e.g., 100x300f) - Fit inside WxH viewbox (no cropping)
0xH (e.g., 0x300) - Resize to H height, preserve aspect ratio
Wx0 (e.g., 100x0) - Resize to W width, preserve aspect ratio

Supported Image Formats:

JPEG (.jpg, .jpeg)
PNG (.png)
GIF (.gif - first frame only)
WebP (.webp - stored as PNG)

Example:

let record = pb.collection("products").get_one(
    "PRODUCT_ID",
    HashMap::new(),
    HashMap::new(),
    None,
    None
).await?;

if let Some(image) = record.get("image").and_then(|i| i.as_str()) {
    // Different thumbnail sizes
    let thumb_small = pb.get_file_url(
        record.clone(),
        image,
        Some("100x100".to_string()),
        None,
        None,
        HashMap::new()
    );
    
    let thumb_medium = pb.get_file_url(
        record.clone(),
        image,
        Some("300x300f".to_string()),
        None,
        None,
        HashMap::new()
    );
    
    let thumb_large = pb.get_file_url(
        record.clone(),
        image,
        Some("800x600".to_string()),
        None,
        None,
        HashMap::new()
    );
}

Force Download

To force browser download instead of preview:

let url = pb.get_file_url(
    record.clone(),
    filename,
    None,
    None,
    Some(true),  // Force download
    HashMap::new()
);

Protected Files

By default, all files are publicly accessible if you know the full URL. For sensitive files, you can mark the field as “Protected” in the collection settings.

Setting Up Protected Files

let mut collection = pb.collections.get_one(
    "example",
    HashMap::new(),
    HashMap::new(),
    None,
    None
).await?;

// Find and update file field
if let Some(fields) = collection.get_mut("fields").and_then(|f| f.as_array_mut()) {
    if let Some(file_field) = fields.iter_mut().find(|f| {
        f.get("name").and_then(|n| n.as_str()) == Some("documents")
    }) {
        file_field["protected"] = json!(true);
    }
}

pb.collections.update(
    "example",
    json!({
        "fields": collection["fields"]
    }),
    HashMap::new(),
    HashMap::new(),
    None,
    None
).await?;

Accessing Protected Files

Protected files require authentication and a file token:

// Step 1: Authenticate
pb.collection("users").auth_with_password(
    "user@example.com",
    "password123",
    HashMap::new(),
    HashMap::new(),
    None
).await?;

// Step 2: Get file token (valid for ~2 minutes)
let token_result = pb.files.get_token(
    HashMap::new(),
    HashMap::new()
).await?;
let file_token = token_result["token"].as_str().unwrap();

// Step 3: Get protected file URL with token
let record = pb.collection("example").get_one(
    "RECORD_ID",
    HashMap::new(),
    HashMap::new(),
    None,
    None
).await?;

if let Some(filename) = record.get("privateDocument").and_then(|f| f.as_str()) {
    let url = pb.get_file_url(
        record.clone(),
        filename,
        None,
        Some(file_token.to_string()),
        None,
        HashMap::new()
    );
    println!("Protected file URL: {}", url);
}

Important:

File tokens are short-lived (~2 minutes)
Only authenticated users satisfying the collection’s viewRule can access protected files
Tokens must be regenerated when they expire

Complete Protected File Example

async fn load_protected_image(
    pb: &BosBase,
    record_id: &str,
    filename: &str,
) -> Result<String, Box<dyn std::error::Error>> {
    // Check if authenticated
    if !pb.auth_store().is_valid() {
        return Err("Not authenticated".into());
    }

    // Get fresh token
    let token_result = pb.files.get_token(
        HashMap::new(),
        HashMap::new()
    ).await?;
    let token = token_result["token"].as_str().unwrap();

    // Get file URL
    let record = pb.collection("example").get_one(
        record_id,
        HashMap::new(),
        HashMap::new(),
        None,
        None
    ).await?;

    let url = pb.get_file_url(
        record,
        filename,
        None,
        Some(token.to_string()),
        None,
        HashMap::new()
    );

    Ok(url)
}

Complete Examples

Example 1: Image Upload with Thumbnails

use bosbase::{BosBase, FileAttachment};
use serde_json::json;
use std::collections::HashMap;

let pb = BosBase::new("http://localhost:8090");
pb.admins().auth_with_password("admin@example.com", "password").await?;

// Create collection with image field and thumbnails
let collection = pb.collections.create_base(
    "products",
    json!({
        "fields": [
            {
                "name": "name",
                "type": "text",
                "required": true
            },
            {
                "name": "image",
                "type": "file",
                "maxSelect": 1,
                "mimeTypes": ["image/jpeg", "image/png"],
                "thumbs": ["100x100", "300x300", "800x600f"]  // Thumbnail sizes
            }
        ]
    }),
    HashMap::new(),
    HashMap::new()
).await?;

// Upload product with image
let mut files = Vec::new();
files.push(FileAttachment {
    field: "image".to_string(),
    filename: "product.jpg".to_string(),
    content_type: "image/jpeg".to_string(),
    data: image_bytes,  // Your image bytes
});

let product = pb.collection("products").create(
    json!({
        "name": "My Product"
    }),
    HashMap::new(),
    files,
    HashMap::new(),
    None,
    None
).await?;

// Display thumbnail
if let Some(image) = product.get("image").and_then(|i| i.as_str()) {
    let thumbnail_url = pb.get_file_url(
        product.clone(),
        image,
        Some("300x300".to_string()),
        None,
        None,
        HashMap::new()
    );
    println!("Thumbnail URL: {}", thumbnail_url);
}

Example 2: File Management

struct FileManager {
    pb: BosBase,
    collection_id: String,
    record_id: String,
}

impl FileManager {
    async fn load(&self) -> Result<serde_json::Value, Box<dyn std::error::Error>> {
        Ok(self.pb.collection(&self.collection_id).get_one(
            &self.record_id,
            HashMap::new(),
            HashMap::new(),
            None,
            None
        ).await?)
    }

    async fn delete_file(&self, filename: &str) -> Result<(), Box<dyn std::error::Error>> {
        self.pb.collection(&self.collection_id).update(
            &self.record_id,
            json!({
                "documents-": [filename]
            }),
            HashMap::new(),
            Vec::new(),
            HashMap::new(),
            None,
            None
        ).await?;
        Ok(())
    }

    async fn add_files(&self, files: Vec<FileAttachment>) -> Result<(), Box<dyn std::error::Error>> {
        self.pb.collection(&self.collection_id).update(
            &self.record_id,
            json!({}),
            HashMap::new(),
            files,
            HashMap::new(),
            None,
            None
        ).await?;
        Ok(())
    }
}

File Field Modifiers

Summary

No modifier - Replace all files: documents: []
+ suffix - Append files: Use "documents+" as field name in FileAttachment
- suffix - Delete files: "documents-": ["file1.pdf"]

Best Practices

File Size Limits: Always validate file sizes on the client before upload
MIME Types: Configure allowed MIME types in collection field settings
Thumbnails: Pre-generate common thumbnail sizes for better performance
Protected Files: Use protected files for sensitive documents (ID cards, contracts)
Token Refresh: Refresh file tokens before they expire for protected files
Error Handling: Handle 404 errors for missing files and 401 for protected file access
Filename Sanitization: Files are automatically sanitized, but validate on client side too

Error Handling

use bosbase::errors::ClientResponseError;

match pb.collection("example").create(
    json!({
        "title": "Test"
    }),
    HashMap::new(),
    vec![FileAttachment {
        field: "documents".to_string(),
        filename: "test.txt".to_string(),
        content_type: "text/plain".to_string(),
        data: b"content".to_vec(),
    }],
    HashMap::new(),
    None,
    None
).await {
    Ok(record) => {
        println!("Upload successful: {:?}", record);
    }
    Err(err) => {
        match err.status() {
            413 => {
                eprintln!("File too large");
            }
            400 => {
                eprintln!("Invalid file type or field validation failed");
            }
            403 => {
                eprintln!("Insufficient permissions");
            }
            _ => {
                eprintln!("Upload failed: {:?}", err);
            }
        }
    }
}

Storage Options

By default, BosBase stores files in pb_data/storage on the local filesystem. For production, you can configure S3-compatible storage (AWS S3, MinIO, Wasabi, DigitalOcean Spaces, etc.) from: Dashboard > Settings > Files storage

This is configured server-side and doesn’t require SDK changes.

Collections - Collection and field configuration
Authentication - Required for protected files
File API - File download and access