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h1. Linked Objects in Free Text
Various RS objects can be linked into free text (annotation text or forum post). The user can paste any [Data Basket|Data Basket Model] item using the editor toolbar, and we want to track all [Item Types|Data Basket Model#Item Types] except:
- Forum: forum post linking is handled by jForum
- Image: We currently don't have a display of image alone
- Text Snippet which: pasted itself, has no URI
- Web Link: represented as a normal URL in the text, doesn't need to be tracked

h2. Link Types
Links are represented in the text like this:
<a class="rslink linkMO" href="">
RFI41407 Chromolithograph pictorial label used for...</a>
<a class="rslink linkStatement" href="">
amulet YCA70788 Glass two-finger amulet: this moulded funerary...: dimension</a>

||Link Class||Item Type||Sample URL||Note||
|linkMO|rso:FC70_Thing|[]|Museum Object|
|linkStatement|rdf:Statement|[]|[Annotation Point|Annotation Design#Annotation Point]|
|linkDataAnnotation|rso:DataAnnotation|TODO| |
|linkImageAnnotation|rso:ImageAnnotation|]| |
|linkSearch|rso:Search|TODO| |

h2. Related Object to Annotation/Post
In the first tab of a Museum Object (Object Details), we want to show all related annotations and forum posts. Related annotations/posts for an object are the ones that mention it or its fields.

An annotation/post is related to an object ?obj iff: there is an ?uri in the free-text such that:
||Link to||Conditions||Notes||
|object itself|?uri a rso:FC70_Thing. ?uri=?obj||
|annotation point|{nf}?uri a rdf:Statement; dcterms:isPartOf ?obj{nf}|See [Open Annotation Collaboration (OAC)#Annotation with OAC and Reification]|
|data annotation|{nf}{?uri a rso:DataAnnotation; oac:hasTarget ?obj}
UNION {?uri a rso:DataAnnotation; oac:hasTarget ?st. ?st a rdf:Statement; dcterms:isPartOf ?obj}{nf}|See same|

h1. Link Data Model
Since Links are pasted from the Data Basket, they are similar to the [Bookmark Data Model|Data Basket Model#Bookmark]
| *Property* | *Notes* |
| rdf:type | rso:Link (new class) |
| oac:hasBody | oac:Body (for annotations) or rso:Forum (for a post). See note below |
| oac:hasTarget | ?uri pointing to one of the [#Link Item Types] |
| rso:root | if ?uri matches one of the conditions above, the respective rso:FC70_Thing |
Note about hasBody:
- For annotation: points to the oac:Body of the annotation. The annotation text is stored in oac:hasBody/rso:P3_has_description.
- For forum post: they are stored in jForum, not OWLIM. We generate URIs like [] (where 123 is the forum ID), and mark the URI with rso:Forum (new class)

h2. Link Data Example
Here is a comprehensive example:
# Data annotation <object/123/annot/23> mentions <object/456>
# Forum post 321 mentions data annotation <object/456/annot/45> of <object/456>
# Image annotation <pic.tif/annot/67> mentions annotation point <st/56> of <object/456>

<link/1> a rso:Link;
oac:hasBody <object/123/annot/23/body>;
oac:hasTarget <object/456>;
rso:root <object/456>.

<forum/123> a rso:Forum;
<link/2> a rso:Link;
oac:hasBody <forum/123>;
oac:hasTarget <object/456/annot/45/body>;
rso:root <object/456>.

<link/3> a rso:Link;
oac:hasBody <pic.tif/annot/67/body>;
oac:hasTarget <st/56>;
rso:root <object/456>;

All of these statements (incl "a rso:Forum") need to be created, except the last line.

h2. Link Data Illustration
The figure above shows the same example, plus the extra statements that make the link to <object/456>.

digraph g {
ranksep=2.5 concentrate=0
node [shape=box margin=0]
edge [labelangle=0]
{rank=same "<link/1>" "<link/2>" "<link/3>"}

"<link/1>" [label="<link/1>\na rso:Link"]
"<link/1>" -> "<object/123/annot/23/body>" [taillabel="oac:hasBody" labeldistance=2]
"<link/1>" -> "<object/456>" [taillabel="oac:hasTarget" labeldistance=3]
"<link/1>" -> "<object/456>" [taillabel="rso:root" labeldistance=5]

"<object/123/annot/23/body>" [label=<
rso:P3_has_description "...<u>object 456</u>..."

"<forum/123>" [label=<
a rso:Forum<br/>
"...<u>data annotation 45</u>..."

"<link/2>" [label="<link/2>\na rso:Link"]
"<link/2>" -> "<forum/123>" [taillabel="oac:hasBody" labeldistance=3]
"<link/2>" -> "<object/456/annot/45/body>" [taillabel="oac:hasTarget" labeldistance=5]
"<link/2>" -> "<object/456>" [taillabel="rso:root" labeldistance=2]

"<object/456/annot/45>" -> "<object/456/annot/45/body>" [taillabel="oac:hasBody" labeldistance=2]
"<object/456/annot/45>" -> "<object/456>" [taillabel="oac:hasTarget" labeldistance=4]

"<pic.tif/annot/67/body>" [label=<
rso:P3_has_description "...<u>statement 56</u>..."

"<link/3>" [label="<link/3>\na rso:Link"]
"<link/3>" -> "<pic.tif/annot/67/body>" [taillabel="oac:hasBody" labeldistance=3]
"<link/3>" -> "<st/56>" [taillabel="oac:hasTarget" labeldistance=5]
"<link/3>" -> "<object/456>" [taillabel="rso:root" labeldistance=2]

"<st/56>" [label="<st/56>\na rdf:Statement"]
"<st/56>" -> "<object/456>" [label="dcterms:isPartOf"]

h1. Link API
Annotation's content is stored as text and we need to parse it and find out if any links to objects are present. We will do that when saving annotation/post.

If any linked objects are present in text, we need to refresh the list of related objects for the annotation/post in OWLIM. That is, each time annotation/post is edited we need to parse and recreate the list per annotation/post.

When an, we need to parse the text and extract linked objects. We search for links like:

h3. Storing related objects

We collect the URIs of the MO/AP. If it is Annotation Point, then we load it and get URI if the object it belongs to. (See APLink class and APLink.annotationPoint.main)

After annotation is saved (so that we have the annotation's URI for new annotations), we recreate the list of related objects for this annotation. That is, we delete all related objects and create a new list that contains the latest ones.

Same goes for the forum posts.

Related objects are stored using a method in the&nbsp;DMS2RDF class.

h3. Retrieving related objects
There will be 2 methods in&nbsp;DMS2RDF:
URI[] getReferringAnnotations(URI uri):
// returns all annotations' URIs that mention the MO with this uri or its data fields (annotation points);
String[] getReferringForumPosts(URI uri):
// returns all forum posts that mention the MO with this uri or its data fields (annotation points);
// IDs for the forum posts are returned as Strings.

{warn}Jana, don't you also need to list the data annotations of the object even if they don't mention the object?{warn}