Upload and Download
Uploading your data to Swarm is easy with bee-js. Based on your needs you can either upload directly unstructured data, single file or even complex directories. Let's walk through the options one by one.
Postage stamps
Uploading to Swarm network require to have Postage stamps for every write operation. To understand better what does it mean see Bee docs - Keep your data alive.
Data
You can upload and retrieve any string or Uint8Array data with uploadData and downloadData functions.
When you download data the return type is Data interface which extends Uint8Array with convenience functions like:
text()that converts the bytes into UTF-8 encoded stringhex()that converts the bytes into non-prefixed hex stringjson()that converts the bytes into JSON object
const postageBatchId = await bee.createPostageBatch("100", 17)
const result = await bee.uploadData(postageBatchId, "Bee is awesome!")
// prints Swarm hash of the file with which it can be retrieved
// here it is fd79d5e0ebd8407e422f53ce1d7c4c41ebf403be55143900f8d1490560294780
console.log(result.reference)
const retrievedData = await bee.downloadData(result.reference)
console.log(retrievedData.text()) // prints 'Bee is awesome!'
Tip
Swarm reference or hash is a 64 characters long hex string which is the address of the uploaded data, file or directory.
Single file
You can also upload files and include a filename. When you download the file, bee-js will return additional information like contentType or name of the file.
const postageBatchId = await bee.createPostageBatch("100", 17)
const result = await bee.uploadFile(postageBatchId, "Bee is awesome!", "textfile.txt")
const retrievedFile = await bee.downloadFile(result.reference)
console.log(retrievedFile.name) // prints 'textfile.txt'
console.log(retrievedFile.contentType) // prints 'application/octet-stream'
console.log(retrievedFile.data.text()) // prints 'Bee is awesome!'
In browsers, you can upload directly File type. The filename is taken from the file object itself, but can be overwritten through the second argument of the uploadFile function (see the API docs)
const file = new File(["foo"], "foo.txt", { type: "text/plain" })
const postageBatchId = await bee.createPostageBatch("100", 17)
const result = await bee.uploadFile(postageBatchId, file)
const retrievedFile = await bee.downloadFile(result.reference)
console.log(retrievedFile.name) // prints 'foo.txt'
console.log(retrievedFile.contentType) // prints 'text/plain'
console.log(retrievedFile.data.text()) // prints 'foo'
Files and Directories
The last supported mode is upload of files and directories. In browsers, you can easily upload an array of File comming from your form directly as well as FileList. If the files uploaded through uploadFiles have a relative path, they are added relative to this filepath. Otherwise, the whole structure is flattened into single directory.
const foo = new File(["foo"], "foo.txt", { type: "text/plain" })
const bar = new File(["bar"], "bar.txt", { type: "text/plain" })
const postageBatchId = await bee.createPostageBatch("100", 17)
const result = await bee.uploadFiles(postageBatchId, [ foo, bar ]) // upload
const rFoo = await bee.downloadFile(result.reference, './foo.txt') // download foo
const rBar = await bee.downloadFile(result.reference, './bar.txt') // download bar
console.log(rFoo.data.text()) // prints 'foo'
console.log(rBar.data.text()) // prints 'bar'
In nodejs, you may utilise the uploadFilesFromDirectory function, which takes directory path as input and upload all files in that directory. Lets assum we have following data structure:
.
+-- foo.txt
+-- dir
| +-- bar.txt
const postageBatchId = await bee.createPostageBatch("100", 17)
const result = await bee.uploadFilesFromDirectory(postageBatchId, './') // upload recursively current folder
const rFoo = await bee.downloadFile(result.reference, './foo.txt') // download foo
const rBar = await bee.downloadFile(result.reference, './dir/bar.txt') // download bar
console.log(rFoo.data.text()) // prints 'foo'
console.log(rBar.data.text()) // prints 'bar'
Retrieve file from node or gateway
You can always retrieve your files and data directly from the bee node through browser as well. For example, if you want to retrieve the "Bee is awesome!" text uploaded to Swarm in section upload data, you can directly access it with: http://localhost:1633/files/fd79d5...294780
To share files with someone who isn't running a Bee node yet, simply change the host in the link to be one of our public gateways. Send the link to your friends, and they will be able to download the file too!