Draft 2 states:
5.1.8. Property: logo [0..1]
A property to link an organisation to its logo. The value of this property is the URL
of the logo online, irrespective of the serialisation of the data.
In the RDF release of the CPOV, this property is bound to schema:logo.
That makes it difficult or impossible to specify logos of different sizes.
Proposal 1: Change "1" to "n"
AND EITHER
Proposal 2a: Use the Activity Streams 2.0 "icon" property instead of "schema:logo". Example:
"icon": [
{
"type": "Image",
"name": "Note (16x16)",
"url": "http://example.org/note1.png",
"width": 16,
"height": 16
},
{
"type": "Image",
"name": "Note (32x32)",
"url": "http://example.org/note2.png",
"width": 32,
"height": 32
}
]
http://jasnell.github.io/w3c-socialwg-activitystreams/activitystreams-v…
A minor issue is that AS2 is not yet a W3C Recommendation.
OR
Proposal 2b: Allow the full range of schema:logo. That includes schema:ImageObject in addition to schema:URL:
https://schema.org/ImageObject
Comments
Thanks Andreas,
That's helpful, I'll look into this in detail. Both solutions looks workable to me.
Thanks again, Andreas,
I've looked at the AS spec and schema.org. The like the AS approach but the icon is specifified as having equal width and height. The broader image object doesn't appear to include dimensions. Yes, they can be added, but the examples don't show that, suggesting that they're not expected. For that reason, more than the status of the spec, I'm minded to go for schema:ImageObject.
Just to be sure I'm not missing the context of this issue:
Is there any specific requirement about using schema:logo instead of other terms? (e.g., foaf:logo, as I mentioned in a comment on a different issue).
@Andrea http://xmlns.com/foaf/spec/#term_logo contains this sentence: "It is probably underspecified..." (and I agree that it is).
@Phil AS2 is very open. Only a few properties are required. That is intended. The range of the icon property includes "Link" and that class has properties "width" and "height". (I will try to find out why they are not defined for "Image".) The note regarding icons currently says that they "should have an aspect ratio of one (horizontal) to one (vertical)". But that this is a small should, not a SHOULD. Only the latter one is to be interpreted as described in RFC2119.
Draft 3 binds the logo property to schema:ImageObject, which is an RDF class. It should be bound to schema:logo as in Draft 2, which is an RDF property.
@Andreas, @James, thanks for your explanations.
So, if I correctly understand, the use case includes the need / ability to specify some information about the logo - as in the AS-based example provided by Andreas, and as schema:ImageObject allows. In other words, being able to specify the logo just with its URI/URL is not enough.
If we want to restrict the range of schema:logo to only allow schema:ImageObject as values, then we would have to create a new property that is a subproperty of schema:logo, since schema:logo allows either schema:ImageObject or URL as values.
We cannot simply make schema:ImageObject the property, because schema:ImageObject is a class, not a property, so it's just broken/incorrect/impossible to use schema:ImageObject as the property.
@Andrea It would be great to be able to specify "the logo just with its URI/URL". But that would also require using a scalable format like SVG. The CPOV spec can suggest to use SVG but it should not require it.
Bitmaps have a specific size and therefore several sizes should be offered so that one of them can be selected depending on the context. One context might be the use as a "favicon" (often 16x16 or 32x32). Another one might be for a large flag or for high-resolution printing.
Thanks for all the pointers (and for correcting my sloppiness). Taking on board what has been said here I propose this as the text for this section:
Property: logo
A property to link an organization to its logo. The value of this property can simply be the URL of the logo but it is better for developers if it links to an object that provides the URL of the image and essential metadata about it, notably its dimensions.
In the RDF release of the CPOV, this property is bound to schema:logo which takes either a URL or a schema:ImageObject as its value.
Proposed text accepted during WG meeting 2016-04-14