Symbolic-Link header

[rimmartin]

Hi,

To further complete a solid server emulating a unix fie system it would need the equivalent of a symbolic link.

The server would respond to and make a container predicate a Container or Resource already predicated by some another container.

        solid.auth.fetch('https://roger.localhost:8443/public/', {
           method: 'POST'
           headers:{
            'Content-Type': 'text/turtle',
	    'Link': '<http://www.w3.org/ns/ldp#BasicContainer>; rel="type"',
            'Slug':  '<name-of-link>',
            'Symbolic-Link': '<path-to-existing-container-or-resource>'
	   }
           }).then((res) => {return res;})
        .then((response) => {callback(null);})
        .catch((error) => {callback('Error: '+JSON.stringify(error));});

The would be a resource path starting at the root or relative to the current resource.

When reading a glob back from the parent of the sym link container it would need to provide an indicator the child is a sym link.

Is there another way to do this?

[rimmartin]

ifpis object-valued, we create a directoryr/s/p, and the objectobe-comes a symbolic linkr/s/p/o→../../o, i.e., it links back to thatresource on the root level

RDF2FS – A Unix File System RDF Store

It sounds quite doable. Might need some code added to the ResourceMapper in nss

[TallTed]

For better readability --

if p is object-valued, we create a directory r/s/p, and the object o becomes a symbolic link r/s/p/o → ../../o, i.e., it links back to that resource on the root level

[elf-pavlik]

How it supposed to work with Web Access Control, especially if when it gets inherited from parent containers?

It seems to me that filesystems using tree hierarchy use symlinks to have multi parent. On the other hand linked data already has native graph structure without need to denote same resource with multiple IRIs. Also if IRIs stay opaque for the clients, what benefits have creating a symlink - another IRI denoting same resource ?

[megoth]

Although the file system analogy is useful in many cases, it can be a dangerous path to go down if you want the Solid server to be a facade for a Unix file system. I imagine many features will probably be problematic for servers that uses a triple store for persistent storage.

In this case, as @elf-pavlik says, how does the Symbolic Link work wrt WebACL?

[rimmartin]

@elf-pavlik

I'm trying to complete the glue (https://github.com/DataDriven-CAM/solid-fs#project-progress) to isomorphic-git https://isomorphic-git.org/docs/en/plugin_fs

https://forum.solidproject.org/t/can-a-resource-be-predicated-by-more-than-one-basic-container/219/8

@megoth
https://solid.inrupt.com/how-it-works

PODs are like secure USB sticks for the Web

now that would be really handy and open up many applications

[megoth]

PODs are like secure USB sticks for the Web

Important to include the whole quote when you quote something: "PODs are like secure USB sticks for the Web, that you can access from anywhere." I think the point they want to get across here is the portability of the Pod, that you can access it from anywhere. Not that Pods imitate features known from unix file systems.

[TallTed]

Not that Pods imitate features known from unix file systems

On the contrary. Everything I understand about Solid basics is that it is trying to port the Unix filesystem to the Web. I think this may need @timbl to add a few words, to set it straight for certain.

[acoburn]

Everything I understand about Solid basics is that it is trying to port the Unix filesystem to the Web.

I am not sure that this is accurate. Solid, at its core, is built on top of the Linked Data Platform. There are certainly many similarities between LDP and a UNIX filesystem (esp. if you focus on basic containment), but there are also many, many differences.

If the goal was to port the UNIX filesystem to the Web, then arguably, the better choice would have been WebDAV.

[rimmartin]

@acoburn @megoth @TallTed @elf-pavlik
Related topic in the forum giving insight although quite a different title:)
https://forum.solidproject.org/t/can-a-resource-be-predicated-by-more-than-one-basic-container/219

[rimmartin]

LDP can do it; link data, give meaning to the linkage instead of copying data around. Basically a sym link and graph edge with attributes

[TallTed]

@acoburn -

I should have said "trying to port the Unix filesystem to the Linked Data Web" which takes you beyond WebDAV.

Whether WebDAV or LDP would have been a better starting point may be arguable but Solid did start with LDP.

And yes, LDP is very different from the Unix filesystem. Also, Solid != LDP.

[acoburn]

Solid != LDP

Solid builds on LDP. Compare that to the very first normative statement in the Solid specification:

A Solid data pod MUST conform to the LDP specification

[rimmartin]

Solid builds on LDP.

nss is a limited subset of LDP. All I want is to move forward with LDP which would allow more than one container to predicate a resource.

an Oct 18 reply by @timbl
https://forum.solidproject.org/t/can-a-resource-be-predicated-by-more-than-one-basic-container/219/2?u=rimmartin

[acoburn]

@rimmartin I would suggest you look into direct containers. They provide a weaker sort of membership than basic containers do. NSS does not support direct containment, but it is also not terribly difficult to implement. Alternatively, you can just manage RDF properties manually:

</resource1> ex:hasSymlink </resource2> .

[rimmartin]

@acoburn yep been looking at Direct and Indirect
In nss there is te beginning of Direct
https://github.com/solid/node-solid-server/blob/master/lib/header.js#L39
a I'm trying to learn what to do at the ResourceMapper level
https://github.com/solid/node-solid-server/blob/master/lib/resource-mapper.js
where I believe the <=> fs is accomplished

[timbl]

I am undecided on this at the moment. From the acl point of view though I think the patent of the resource would be its container not thx symlink.

Questions: if the link can be to a resource on the same server — why not to any URI?

Should the server surface the link as an HTTp redirect instead of a 200?

Can we do it on the client side only by making a class of rdf object which is a soft link — and just store it in a normal file from the servers point of view?

[rimmartin]

isomorphic-git/isomorphic-git#583 (comment)

[rimmartin]

https://www.npmjs.com/package/isomorphic-git
gets nearly 13,000 downloads a week with recent new version published. I'm certain there would be goodly interest where the backend was solid

[namedgraph]

A fixed hierarchy is the wrong way to think about an RDF dataset.