solid-file-fns

solid-file-client

A library for creating and managing files and folders in Solid data stores

This library provides a simple interface for logging in and out of a Solid data store and for creating, reading, updating, and deleting files and folders on it. It may be used either directly in the browser or with node/require. The library is based on solid-auth-client, providing an error-handling interface and some convenient shortcuts on top of solid-auth-client's methods.

Installation

Just download it.

Invocation

In a node/require context

// rdflib and solid-auth-client must be available
// but will be required automatically by the library

const fileClient = require('solid-file-client');

In the browser

<script src="somepath/rdflib.js"></script>
<script src="somepath/solid-auth-client.js"></script>
<script src="somepath/solid-file-client.js"></script>
<script>
  const fileClient = new SolidFileClient();
</script>

Error reporting

All methods are asynchronous, return false on error, and put the error in the fileClient.err variable. For example

fileClient.delete(url).then(response => {
  if (!response) alert("Couldn't delete " + url + ' ' + fileClient.err);
  else alert(url + ' successfully deleted');
});

Content-types

Many methods take and/or return content-type parameters. The library can handle text/_ types (e.g. text/turtle, text/html) and text-based application/_ types (e.g. application/json). A special content-type "folder" is used for ldp:BasicContainer resources. In cases where the content type is omitted, the type will be guessed from the file extension or a trailing slash to indicate a folder.

Connection Methods

popupLogin()

fileClient.popupLogin().then(webId => {
  if (!webId) console.log(fileClient.err);
  else console.log(`Logged in as ${webId}.`);
});

Opens a popup window that prompts for an IDP then lets you login.

login(IDP)

fileClient.login(idp).then(webId => {
  if (!webId) console.log(fileClient.err);
  else console.log(`Logged in as ${webId}.`);
});

Logs in to the specified IDP (Identity Provider, e.g. 'https://solid.community') on a redirected page and returns to wherever it was called from.

logout()

fileClient.logout().then( console.log( `Bye now!` )

checkSession()

fileClient.checkSession().then(session => {
  if (!session) console.log('Not logged in.');
  else console.log('Logged in as ' + session.webId);
});

File Methods

createFile(URL,contentType)

fileClient.createFile(newFile).then(success => {
  if (!success) console.log(fileClient.err);
  else console.log(`Created file ${newFile}.`);
});

This method creates a new empty file. The contentType should be specified either in the URL's extension or in the contentType parameter, but not both.

NOTE : if the file already exists, the solid.community server (and others) will create an additional file with a prepended numerical ID so if you don't want that to happen, use updateFile() which will first delete the file if it exists, and then add the new file.

readFile(URL)

fileClient.readFile(newFile).then(response => {
  if (!response) console.log(fileClient.err);
  else console.log(`File content is : ${response.value}.`);
});

In the case of a successful fetch of an empty file, the response will be true but the response.value will be empty. This means that any true response can be interpreted as "this file exists" and you need to check response.value for its content, if any.

updateFile(URL,content)

fileClient.updateFile(url, newContent).then(success => {
  if (!success) console.log(fileClient.err);
  else console.log(`Updated ${url}.`);
});

NOTE : this is a file-level update, it replaces the file with the new content by removing the old version of the file and adding the new one.

deleteFile(URL)

fileClient.deleteFile(url).then(success => {
  if (!success) console.log(fileClient.err);
  else console.log(`Deleted ${url}.`);
});

fetchAndParse(URL,contentType)

Results will be empty on either a failure to fetch or a failure to parse and the relevant error will be in fileClient.err. If the content-type is omitted, it will be guessed from the file extension. If the content-type is or is guessed to be 'text/turtle' or any other format that rdflib can parse, the response will be parsed by rdflib and returned as an rdflib graph object. If the content-type is 'application/json' the response will be a JSON object.

fileClient.fetchAndParse(url, 'text/turtle').then(graph => {
  if (!graph) alert("Couldn't fetch or parse : " + fileClient.err);
  else {
    let something = graph.any(someSubject, somePredicate);
  }
});

Folder Methods

createFolder(URL)

fileClient.createFolder(url).then(success => {
  if (!success) console.log(fileClient.err);
  else console.log(`Created folder ${url}.`);
});

deleteFolder(URL)

fileClient.deleteFolder(url).then(success => {
  if (!success) console.log(fileClient.err);
  else console.log(`Deleted ${url}.`);
});

Attempting to delete a non-empty folder will fail with a "409 Conflict" error.

readFolder(URL)

fileClient.readFolder(url).then(folder => {
  if (!folder) console.log(fileClient.err);
  else console.log(`Read ${folder.name}, it has ${folder.files.length} files.`);
});

On success, the readFolder() method returns a folder object in this format:

{
     type : "folder",
     name : // folder name (without path),
      url : // full URL of the resource,
 modified : // dcterms:modified date
    mtime : // stat:mtime
     size : // stat:size
   parent : // parentFolder or undef if none,
  content : // raw content of the folder's turtle representation,
    files : // an array of files in the folder
  folders : // an array of sub-folders in the folder,
}

Each item in the arrays of files and sub-folders will be a file object which is the same as a folder object except it does not have the last two fields (files,folders). The content-type in this case is not guessed, it is read from the folder's triples, i.e. what the server sends.

A General Fetch Method

fetch(URL,request)

Results will be empty on failure to fetch and on sucess results.value will hold the raw text of the resource. It may be called with a simple URL parameter or with a full request object which specifies method, headers, etc. This is a pass-through to solid-auth-client.fetch providing some error trapping to make it consistent with the solid-file-client interface but otherwise, see the solid-auth-client docs and the Solid REST spec for details.

fileClient.fetch( url ).then( results => {
    if(!results) alert("Could not fetch "+url+" "+fileClient.err)
     else // do something with results.value
 })

copyright (c) 2018 Jeff Zucker