solid-client


Javascript library for writing Solid
applications. (See Changelog for version history.)

Usage

The solid client can be used by solid applications that run in the browser or on
Node.js. A minified UMD bundle is provided along with the regular set of
CommonJS modules.

For example:

``html









`

Or, using a module loader:

`js
var solid = require('solid-client')
`

See the installation docs for more installation examples.

Take a look at the **solid-client demo
page** (source located in
demo/index.html) for usage examples.

Tutorials

If you would like to learn how to build Solid apps using solid-client, please see:

* solid introduction tutorial
* pastebin example tutorial
* using rdflib.js tutorial

Developing solid-client

Node version: 6.0+.

Install dev dependencies:

`
npm install
`

Building (uses Browserify, builds to solid-client.js and dist/solid-client-no-rdflib.js):

`
npm run build
`

Testing

To run the unit tests:

`
npm test
`

This runs the Tape unit test suite.

Releases

The following steps specify how to release solid-client:

Make sure you're at the HEAD of master.

`shell
$ git checkout master && git pull
`

Run npm version to bump the package version via git commit and git
tags.

`shell


refer to http://semver.org/ for which of (major, minor, patch) to use


$ npm version [major|minor|patch]
`

Next, push the commit and tags:

`shell
$ git push --follow-tags
`

Finally release the package to npmjs.

`shell
$ npm publish
`

Logging In and User Profiles

Before doing any sort of reading or
writing of
Solid resources, your app will likely need to authenticate a user and load their
profile, so let's start with those sections.

$3

Solid currently uses WebID-TLS
for authentication, which relies on a web browser's built-in key store to manage
certificates and prompt the user to select the correct certificate when
accessing a server.

Solid servers must always return a Solid-specific HTTP header called User,
which contains the WebID that
the user used to access this particular server. An empty header usually means
that the user is not authenticated.

#### Detecting the Current Logged-in User

Most of the WebID-TLS authentication process takes place before a web
page gets fully loaded and the javascript code has had a chance to run.
Since client-side Javascript code does not have access to most HTTP headers
(including the User header) of the page on which it runs, how does an app
discover if there is an already authenticated user that is accessing it?

The current best practice answer is -- the app should do an Ajax/XHR HEAD
request to the relevant resource:

1. either to the current page if it's a standalone app, or
2. to the requested resource (if it's an app that's acting as a viewer or
editor, and requires a resource URI as a parameter)

For the first case (standalone apps), solid-client provides a convenience
solid.currentUser() method (which does a HEAD request to the current page in
the background). Usage:

`js
solid.currentUser()
.then(function (currentWebId) {
if (currentWebId) {
console.log('Current WebID: %s', currentWebId)
} else {
console.log('You are not logged in')
}
})
`

For the second case (apps that are wrapping a resource as viewers or editors),
client apps can just use a solid.login(targetUrl) function to return the
current user's WebID. And if users are unable to log in, prompt the user
to create an account with solid.signup().

#### Login example

Here is a typical example of authenticating a user and returning their WebID.
The following login function, specific to your application, wraps the
solid.login() function. If the promise is resolved, then an application
will do something with the webId value. Otherwise, if the promise is rejected,
the application may choose to display an error message.

HTML:

`html
Login
`

Javascript:

`javascript
var solid = require('solid')
var login = function() {
// Get the current user
solid.login().then(function (webId){
// authentication succeeded; do something with the WebID string
console.log(webId)
}).catch(function (err) {
// authentication failed; display some error message
console.log(err)
})
}
`

$3

The signup function is very similar to the login function, wrapping the
solid.signup() function. It results in either a WebID or an error message
being returned.

HTML:

`html
Sign up
`

Javascript:

`javascript
var solid = require('solid')
// Signup for a WebID
var signup = function() {
solid.signup()
.then(function (webId) {
// authentication succeeded; do something with the WebID string
console.log(webId)
})
.catch(function (err) {
// authentication failed; display some error message
console.log(err)
})
}
`

$3

Once you have a user's WebID (say, from a login() call), it's often useful
to load the user profile:

`javascript
var profile = solid.login()
.then(function (webId) {
// have the webId, now load the profile
return solid.getProfile(webId)
})
`

The call to getProfile(url) loads the full extended
profile:
the profile document itself, any sameAs and seeAlso links it finds there,
as well as the Preferences file.

Once a profile is loaded, you can access the values of the profile's pre-defined
fields, or look for predicates in the profile's parsed graph using
profile.find() and profile.findAll():

`js
var ns = solid.vocab
solid.login()
.then(function (webId) {
return solid.getProfile(webId)
})
.then(function (profile) {
profile.name // -> 'Alice'
profile.picture // -> 'https://example.com/profile/icon.png'
profile.find(ns.solid('inbox')) // -> 'https://example.com/inbox/'
profile.findAll(ns.owl('sameAs')) // -> [ url1, url2 ]
})
.catch(function (err) {
console.log('Error accessing profile: ' + err)
})
`

#### Profile App Registry

The profile provides an interface to the user's App Registry.

`js
var ns = solid.vocab
solid.login()
.then(function (webId) {
return solid.getProfile(webId)
})
.then(function (profile) {
return profile.loadAppRegistry()
})
.then(function (profile) {
// The profile has been updated, app registry loaded. Now you can register
// apps with is.
var options = {
name: 'Contact Manager',
shortdesc: 'A reference contact manager',
redirectTemplateUri: 'https://solid.github.io/contacts/?uri={uri}'
}
var typesForApp = [ ns.vcard('AddressBook') ]
var isListed = true
var app = new AppRegistration(options, typesForApp, isListed)
return profile.registerApp(app)
})
.then(function (profile) {
// The app entry was created. You can now query the registry for it
return profile.appsForType(ns.vcard('AddressBook'))
})
.then(function (registrationResults) {
var app = registrationResults[0]
app.name // -> 'Contact Manager'
app.shortdesc // -> ...
app.redirectTemplateUri
})
`

#### User Type Registry Index

If your application needs to do data discovery, it can also call
loadTypeRegistry() after loading the profile:

`javascript
var profile = solid.login()
.then(function (webId) {
return solid.getProfile(webId)
})
.then(function (profile) {
return profile.loadTypeRegistry()
})
`

Now, both listed and unlisted type indexes are loaded, and you can look up
where the user keeps various types.

`js
var ns = solid.vocab
// .. load profile and load type registry

var addressBookRegistrations = solid.getProfile(webId)
.then(function (profile) {
return profile.loadTypeRegistry()
})
.then(function (profile) {
return profile.typeRegistryForClass(ns.vcard('AddressBook'))
})
/*
-->
[
an IndexRegistration(
locationUri: 'https://localhost:8443/public-contacts/AddressBook.ttl',
locationType: 'instance',
isListed: true
),
an IndexRegistration(
locationUri: 'https://localhost:8443/personal-address-books/',
locationType: 'container',
isListed: false
)
]
*/
`

You can then load the resources from the returned locations, as usual.

`js
addressBookRegistrations.forEach(function (registration) {
if (registration.isInstance()) {
// This is an instance (an individual resource)
} else if (registration.isContainer()) {
// This is a container with many address books
}
})
`

#### Registering (and un-registering) Types in the Type Registry

To register an RDF Class with a user's Type Registry (listed or unlisted),
use profile.registerType():

`js
var ns = solid.vocab
// .. load profile

var classToRegister = vocab.sioc('Post')
var locationToRegister = 'https://localhost:8443/new-posts-container/'
var isListed = true
profile.registerType(classToRegister, locationToRegister, 'container', isListed)
.then(function (profile) {
// Now the type is registered, and the profile's type registry is refreshed
// querying the registry now will include the new container
profile.typeRegistryForClass(ns.sioc('Post'))
})

// To remove the same class from registry:
var classToRemove = ns.sioc('Post')
profile.unregisterType(classToRemove, isListed)
.then(function (profile) {
// Type is removed
profile.typeRegistryForClass(ns.sioc('Post')) // --> []
})
`

Web operations

solid-client uses a mix of LDP and Solid-specific
functions to manipulate Web resources. Please see the
Solid spec for more details.

$3

Sometimes an application may need to get some useful meta data about a resource.
For instance, it may want to find out where the ACL resource is. Clients should
take notice to the fact that the solid.web.head() function will always
successfully complete, even for resources that don't exists, since that is
considered useful information. For instance, clients can use the
solidResponse.xhr.status value will indicate whether the resource exists or
not.

Here, for example, we can find out where the corresponding ACL resource is for
our new blog post hello-world.

`javascript
var solid = require('solid')
var url = 'https://example.org/blog/hello-world'
solid.web.head(url).then(
function(solidResponse) {
console.log(solidResponse.acl) // the ACL uri
if (!solidResponse.exists()) {
console.log("This resource doesn't exist")
} else if (solidResponse.xhr.status === 403) {
if (solidResponse.isLoggedIn()) {
console.log("You don't have access to the resource")
} else {
console.log("Please authenticate")
}
}
}
)
`

The SolidResponse object returned by most solid.web calls, including
head(), contains the following properties:

* url - the URL of the resource // https://example.org/blog/hello-world
* acl - the URL of the corresponding .acl resource //
https://example.org/blog/hello-world.acl
* meta - the URL of the corresponding .meta resource //
https://example.org/blog/hello-world.meta
* types - An array of LDP types for the resource, if applicable. For example:
[ 'http://www.w3.org/ns/ldp#LDPResource',
'http://www.w3.org/ns/ldp#Resource' ]
* user - the WebID of the authenticated user (if authenticated) //
https://user.example.org/profile#me
* websocket - the URI of the corresponding websocket instance //
wss://example.org/blog/hello-world
* method - the HTTP verb (get, put, etc) of the original request that
resulted in this response.
* xhr - the raw XMLHttpRequest object (e.g. xhr.status)

The response object also has some convenience methods:

* contentType() - returns the MIME type of the resource
* isContainer() - determines whether the resource is a Container or a regular
resource

$3

Assuming that a resource or a container exists (see
creating resources and
creating containers below), you can retrieve
it using web.get():

`js
solid.web.get(url)
.then(function (response) {
if (response.isContainer()) {
// This is an instance of SolidContainer, see Listing Containers below
for (resourceUrl in response.resources) {
// iterate over resources
}
for (subcontainerUrl in response.containers) {
// iterate over sub-containers
}
} else {
// Regular resource
console.log('Raw resource: %s', response.raw())

// You can access the parsed graph (parsed by RDFLib.js):
var parsedGraph = response.parsedGraph()
}
})
.catch(function (err) {
console.log(err) // error object
// ...
})
`

#### Fetching a Parsed Graph

Once a resource is retrieved, we can access it as a parsed graph (here, parsed
by rdflib.js). This graph can then be queried.

`js
var solid = require('solid')
var vocab = solid.vocab

var url = 'https://example.org/blog/hello-world'

solid.web.get(url)
.then(function(response) {
var graph = response.parsedGraph()
// Print all statements matching resources of type foaf:Post
console.log(graph.statementsMatching(undefined, vocab.rdf('type'),
vocab.sioc('Post')))
})
.catch(function(err) {
console.log(err) // error object
})
`

$3

The Solid client offers a function called solid.web.createContainer(),
which is used to create containers. The
function accepts the following parameters:

* parentDir (string) - the URL of the parent container in which the new
resource/container will be created.
* containerName (string) (optional) - the value for the Slug header -- i.e. the name
of the new resource to be created; this value is optional.
* options (object) - Optional hashmap of request options
* data (string) - Optional RDF data serialized as text/turtle; can also be an empty
string if no data will be sent.

In the example below we are also sending some meta data (semantics) about the
container, setting its type to sioc:Blog.

`javascript
// Assumes you've loaded rdflib.js and solid-client, see Dependences above
var solid = require('solid')
var parentUrl = 'https://example.org/'
var containerName = 'blog'
var options = {}
var data = '<#this> .'

solid.web.createContainer(parentUrl, containerName, options, data).then(
function(solidResponse) {
console.log(solidResponse)
// The resulting object has several useful properties.
// See lib/solid/response.js for details
// solidResponse.url - value of the Location header
// solidResponse.acl - url of acl resource
// solidResponse.meta - url of meta resource
}
).catch(function(err){
console.log(err) // error object
})
`

Note that the options and data parameters are optional, and you can simply
do solid.web.createContainer(url, name).

$3

To list the contents of a Solid container, just use solid.web.get().
This returns a promise that resolves to a SolidContainer instance,
which will contain various useful properties:

- A short name (.name) and absolute URI (.uri)
- A .parsedGraph property for further RDF queries
- A parsed list of links to all the contents (both containers and resources)
(.contentsUris)
- A list of RDF types to which the container belongs (.types)
- A hashmap of all sub-Containers within this container, keyed by absolute uri
(.containers)
- A hashmap of all non-container Resources within this container, also keyed by
absolute uri. (.resources)

Containers also have several convenience methods:

- container.isEmpty() will return true when there are no sub-containers or
resources inside it
- container.findByType(rdfClass) will return an array of resources or
containers that have the given rdfClass in their .types array

For example:

`js
var container = solid.web.get('/settings/')
.then(function (container) {
console.log(container)
// See below
})

// container is an instance of SolidContainer (see lib/solid/container.js)
container.uri // -> 'https://localhost:8443/settings/'
container.name // -> 'settings'
container.isEmpty() // -> false
container.types // ->
[
'http://www.w3.org/ns/ldp#BasicContainer',
'http://www.w3.org/ns/ldp#Container'
]
container.contentsUris // ->
[
'https://localhost:8443/settings/prefs.ttl',
'https://localhost:8443/settings/privateTypeIndex.ttl',
'https://localhost:8443/settings/testcontainer/'
]

var subContainer =
container.containers['https://localhost:8443/settings/testcontainer/']
subContainer.name // -> 'testcontainer'
subContainer.types // ->
[
'http://www.w3.org/ns/ldp#BasicContainer',
'http://www.w3.org/ns/ldp#Container',
'http://www.w3.org/ns/ldp#Resource'
]

var resource =
container.resources['https://localhost:8443/settings/privateTypeIndex.ttl']
// resource - SolidResource instance
resource.name // -> 'privateTypeIndex.ttl'
resource.types // ->
[
'http://www.w3.org/ns/ldp#Resource',
'http://www.w3.org/ns/solid/terms#TypeIndex',
'http://www.w3.org/ns/solid/terms#UnlistedDocument'
]
resource.isType('http://www.w3.org/ns/solid/terms#TypeIndex') // -> true

container.findByType('http://www.w3.org/ns/ldp#Resource') // ->
[
// a SolidContainer('testcontainer'),
// a SolidResource('privateTypeIndex.ttl'),
// a SolidResource('prefs.ttl')
]
`

$3

Creating a regular LDP resource is done using the web.post() method.

In this example we will create the resource hello-world under the newly
created blog/ container.

`javascript
var solid = require('solid')
var parentDir = 'https://example.org/blog/'
var slug = 'hello-world'
var data =
<> a ;
"First post" ;
"Hello world! This is my first post" .

solid.web.post(parentDir, data, slug)
.then(function (response) {
console.log(response.url) // URL of the newly created resource
})
.catch(function (err){
console.log(err) // error object
})
`

$3

Sometimes we need to update a resource after making a small change. For
instance, we sometimes need to delete a triple, or update the value of an object
(technically by replacing the triple with a new one). Luckily, Solid allows us
to use the HTTP PATCH operation to do very small changes.

Let's try to change the value of the title in our first post. To do so, we need
to indicate which triple we want to replace, and then the triple that will
replace it.

Let's create the statements and serialize them to Turtle before patching the
blog post resource:

`js
var rdf = require('rdflib')
var url = 'https://example.org/blog/hello-world'
var vocab = ns.vocab

var oldTitleTriple = rdf.triple(rdf.namedNode(url), ns.dct('title'),
rdf.literal("First post")).toCanonical()

var newTitleTriple = rdf.triple(rdf.namedNode(url), ns.dct('title'),
rdf.literal("Hello")).toCanonical()
`

Now we can actually patch the resource. The solid.web.patch() function (also
aliased to solid.web.update()) takes three arguments:

* url (string) - the URL of the resource to be overwritten.
* toDel (array) - an array of statements to be deleted, serialized as Turtle.
* toIns (array) - an array of statements to be inserted, serialized as Turtle.

`javascript
var solid = require('solid')
var toDel = [ oldTitleTriple ]
var toIns = [ newTitleTriple ]
solid.web.patch(url, toDel, toIns)
.then(function (response){
console.log(response.xhr.status) // HTTP 200 (OK)
})
.catch(function(err) {
console.log(err) // error object
})
`

$3

We can also completely replace (overwrite) existing resources with new content,
using the client's solid.web.put() function (also aliased to replace()). The
function accepts the following parameters:

* url (string) - the URL of the resource to be overwritten.
* data (string) - RDF data serialized as text/turtle; can also be an empty
string if no data will be sent.
* mime (string) (optional) - the mime type for this resource; this value is
optional and defaults to text/turtle.

Here is an example where we try to overwrite the existing resource
hello-world, giving it a bogus type - http://example.org/#Post.

`javascript
var solid = require('solid')
var url = 'https://example.org/blog/hello-world'
var data = '<> .'

solid.web.put(url, data)
.then(function (response) {
console.log(response.xhr.status) // HTTP 200 (OK)
})
.catch(function(err) {
console.log(err) // error object
})
`

$3

Delete an RDF resource from the Web. For example, we can delete the blog post
hello-world we created earlier, using the solid.web.del() function.

NOTE: while this function can also be used to delete containers, it will
only work for empty containers. For now, app developers should make sure to
empty a container by recursively calling calling this function on its contents.

`javascript
var solid = require('solid')
var url = 'https://example.org/blog/hello-world'

solid.web.del(url)
.then(function (response) {
console.log(response)
}).catch(function (err) {
console.log(err) // error object
})
`

$3

Each Solid resource has a set of permissions that determine which user
(identified by their WebID) has read and write access to it, called an
ACL resource.
(See the web-access-control-spec repo
for the exact details.)

solid-client has a set of convenience methods to help developers manage those
permissions.

#### Reading Permissions

To load the corresponding ACL resource, for a given file:

`js
var solid = require('solid')
var resourceUrl = 'https://example.org/blog/hello-world'

solid.getPermissions(resourceUrl)
.then(function (permissionSet) {
// Now the permission set, parsed from hello-world.acl is loaded,
// and you can iterate over the individual authorizations
permissionSet.forEach(function (auth) {
if (auth.isAgent()) {
console.log('agent webId: ' + auth.agent)
} else if (auth.isPublic()) {
// this permission is for everyone (acl:agentClass foaf:Agent)
} else if (auth.isGroup()) {
console.log('agentClass webId: ' + auth.group)
}
// You can also use auth.webId() for all cases:
console.log('agent/group webId: ' + auth.webId())
// You can check what sort of access modes are granted:
auth.allowsRead() // -> true if the authorization contains acl:Read mode
auth.allowsWrite()
auth.allowsAppend()
auth.allowsControl()
// Check to see if this Authorization is inherited (acl:default)
auth.isInherited() // -> false for a resource, usually true for container
// Check to see if access is allowed from a given Origin
auth.allowsOrigin('https://example.com')
})
})
`

Note: You can read the permissions for a given resource only if you have
acl:Control access mode for that resource. (You also need that access mode to
edit those permissions, as well.)

You can also access individual authorizations from a resource set:

`js
solid.getPermissions(resourceUrl)
.then(function (permissionSet) {
var auth = permissionSet.permissionFor(bobWebId)
auth.webId() // -> bob's web id
auth.allowsRead() // -> true if bob has acl:Read permission
auth.allModes() // -> array of access modes granted
auth.allOrigins() // -> array of allowed origin URLs
// If this is for the root container's ACL, you can also load a user's
// emails using the mailTo property. (Unofficial functionality)
auth.mailTo // -> ['bob@example.com', 'bob@gmail.com']
})
`

#### Editing Permissions

To manage the set of permissions for a given resource (provided the current
user has acl:Control access mode granted to them for that resource), use
the convenience methods provided by PermissionSet.

The example below adds 3 different permissions:

1. Allows Alice to Read, Write and Control the resource
2. Allows Public Read access (that's the solid.acl.EVERYONE)
3. Grants Bob Write access (in addition to the Read access he inherits from
the above permission, since he's a member of the Public).
Also, this Write access is only allowed from a particular origin.

`js
var solid = require('solid')
var resourceUrl = 'https://example.org/blog/hello-world'
var aliceWebId = 'https://alice.example.org/profile/card#me'
var bobWebId = 'https://bob.example.org/profile/card#me'
var allowedOrigin = 'https://example.org'

solid.getPermissions(resourceUrl)
.then(function (permissionSet) {
return permissionSet
.addPermission(aliceWebId, [solid.acl.READ, solid.acl.WRITE,
solid.acl.CONTROL])
.addPermission(solid.acl.EVERYONE, solid.acl.READ)
// see also .addGroupPermission()
.addPermission(bobWebId, solid.acl.WRITE, allowedOrigin)
.save()
})
.then(function (response) {
console.log('Permissions saved successfully')
})
.catch(function (err) {
console.log('Error saving permissions')
})
`

To delete all permissions associated with a resource, use
clearPermissions(). Keep in mind that permissions are inherited from a
resource's parent container, and if you delete an individual ACL resource,
this simply means that the permissions reset to that of the upstream container.
You can also clear the ACLs of the container, all the way up to the root storage
container's ACL, which cannot be deleted. Refer to the
ACL Inheritance Algorithm
section of the spec.

`js
// If you have an existing PermissionSet as a result of getPermissions():
solid.getPermissions('https://www.example.com/file1')
.then(function (permissionSet) {
return permissionSet.clear() // deletes the file1.acl resource
})
// Otherwise, use the helper function
// solid.clearPermissions(resourceUrl) instead
solid.clearPermissions('https://www.example.com/file1')
.then(function (response) {
// file1.acl is now deleted
})
``