title: "links"
...
+{% comment %}
+Copyright (C) The Arvados Authors. All rights reserved.
-See "REST methods for working with Arvados resources":{{site.baseurl}}/api/methods.html
+SPDX-License-Identifier: CC-BY-SA-3.0
+{% endcomment %}
API endpoint base: @https://{{ site.arvados_api_host }}/arvados/v1/links@
-UUID type: @o0j2j@
+Object type: @o0j2j@
-Required arguments are displayed in %{background:#ccffcc}green%.
+Example UUID: @zzzzz-o0j2j-0123456789abcde@
h2. Resource
Links are an extensible way to describe relationships between Arvados objects and metadata about individual objects.
-Each link has, in addition to the usual "attributes of Arvados resources":{{site.baseurl}}/api/resources.html:
+Each link has, in addition to the "Common resource fields":{{site.baseurl}}/api/resources.html:
table(table table-bordered table-condensed).
|_. Attribute|_. Type|_. Description|
-|tail_uuid|string|Object UUID at the tail (start, source, origin) of this link|
-|link_class|string|Class (see below)|
-|name|string|Link type (see below)|
-|head_uuid|string|Object UUID at the head (end, destination, target) of this link|
+|head_uuid|string|The object being described or acted on.|
+|tail_uuid|string|The origin or actor in the description or action (may be null).|
+|link_class|string|Type of link|
+|name|string|Primary value of the link.|
|properties|hash|Additional information, expressed as a key→value hash. Key: string. Value: string, number, array, or hash.|
h2. Link classes
Some classes are pre-defined by convention and have standard meanings attached to names.
-h3. provenance
-
-table(table table-bordered table-condensed).
-|_. tail_type→head_type|_. name→head_uuid {properties}|_. Notes|
-|→Collection |provided → _collection uuid_
-{url→http://example.com/foo.tgz, retrieved_at→1352616640.000}||
-|Job→Collection |provided → _collection uuid_||
-|Specimen→Collection|provided → _collection uuid_||
-|Human→Specimen |provided → _specimen uuid_||
-|Human→Collection |provided → _collection uuid_||
-
h3. permission
-table(table table-bordered table-condensed).
-|_. tail_type→head_type|_. name→head_uuid {properties}|_. Notes|
-|User→Group |{white-space:nowrap}. can_manage → _group uuid_|The User can read, write, and control permissions on the Group itself, every object owned by the Group, and every object on which the Group has _can_manage_ permission.|
-|User→Group |can_read → _group uuid_ |The User can retrieve the Group itself and every object that is readable by the Group.|
-|User→Job|can_write → _job uuid_ |The User can read and update the Job. (This works for all objects, not just jobs.)|
-|User→Job|can_manage → _job uuid_ |The User can read, update, and change permissions for the Job. (This works for all objects, not just jobs.)|
-|Group→Job|can_manage → _job uuid_ |Anyone with _can_manage_ permission on the Group can also read, update, and change permissions for the Job. Anyone with _can_read_ permission on the Group can read the Job. (This works for all objects, not just jobs.)|
-
-h3. resources
-
-table(table table-bordered table-condensed).
-|_. tail_type→head_type|_. name→head_uuid {properties}|_. Notes|
-|User→Collection|wants → _collection uuid_ |Determines whether data can be deleted|
-|User→Job |wants → _job uuid_ |Determines whether a job can be cancelled|
+See "permission links":{{site.baseurl}}/api/permission-model.html#links section of the permission model.
h3. tag
|→Collection | _tag name_ → _collection uuid_|
|→Job | _tag name_ → _job uuid_|
-h3. human_trait
-
-table(table table-bordered table-condensed).
-|_. tail_type→head_type|_. name→head_uuid {properties}|_. Notes|
-|Human→Trait |measured → _trait uuid_ {value→1.83, unit→metre, measured_at→1352616640.000}||
-
-h3. identifier
-
-table(table table-bordered table-condensed).
-|_. tail_type→head_type|_. name→head_uuid {properties}|_. Notes|
-|→Human |hu123456 → _human uuid_||
+h2. Methods
+See "Common resource methods":{{site.baseurl}}/api/methods.html for more information about @create@, @delete@, @get@, @list@, and @update@.
-h2. Methods
+Required arguments are displayed in %{background:#ccffcc}green%.
h3. create
List links.
-Arguments:
-
-table(table table-bordered table-condensed).
-|_. Argument |_. Type |_. Description |_. Location |_. Example |
-|limit|integer (default 100)|Maximum number of links to return.|query||
-|order|string|Order in which to return matching links.|query||
-|filters|array|Conditions for filtering links.|query||
-
-h3. render_not_found
-
-render_not_found links
-
-Arguments:
-
-table(table table-bordered table-condensed).
-|_. Argument |_. Type |_. Description |_. Location |_. Example |
-{background:#ccffcc}.|a|string||path||
+See "common resource list method.":{{site.baseurl}}/api/methods.html#index
h3. update