Allow loading entities by any field.

[e0ipso]

I've found need this several times already. I need to be able to load an entity by a unique field or property attached to that particular entity.

This is the URL schema I'm looking for:

https://www.example.org/[resource-name]/[non-standard-id-value]?loadById=[non-standard-id-name]

At the same time we need to communicate to the API consumer that the canonical resource for what RESTful is returning is different. We should do that with a Link header and a rel="canonical" in the response. That is one of the REST principles that is really useful to normalize caches –among other things–.

Real scenario

There's a Segment content type that has a unique field. We want to be able to load by that ID.

https://www.example.org/segments/asdf-asdf-asdf-asdf?loadById=unique

Returns:

HTTP/1.1 200 OK
Date: Mon, 22 Dec 2014 08:08:53 GMT
Expires: -1
Cache-Control: private, max-age=0
Content-Type: text/html; charset=ISO-8859-1
X-XSS-Protection: 1; mode=block
X-Frame-Options: SAMEORIGIN
Alternate-Protocol: 80:quic,p=0.02
Transfer-Encoding: chunked
Link: https://www.example.org/segments/12; rel="canonical" <----

[RESPONSE BODY]

[amitaibu]

👍

I wonder if loadById is the correct term - maybe loadByFieldName?

[amitaibu]

(as, we expose the term "field" regardless is the internal is a property or a configurable field)

[e0ipso]

Only missing tests.

[e0ipso]

@amitaibu this is ready to be reviewed.

[amitaibu]

entity ID. => entity ID, for example a unique ID title

[amitaibu]

seems we are loosing an important validation here, although I'm not sure how smart we want to be about it. Any ideas? (anyway this isn't a blocker)

[e0ipso]

I don't think it's a big deal, since there's still validation when trying to load the entity.

[amitaibu]

Looks promising :) Some comments added.

[e0ipso]

@amitaibu feedback implemented.

[amitaibu]

go ahead - merge it :)

[e0ipso]

w00t! My first PR for a work related project :-)

[amitaibu]

mazal tov dude :)