Singleton¶
The Data model type resource called data/Datamodel has an attribute
singleton that can take any of 3 values:
None (default): no singleton constraint
system: a system singleton that only allows one instance throughout the systemhierarchy: a hierarchy singleton that only allows one instance every hierarchy
For example, the snippet below shows a simple data/Datamodel instance
called LoginBanner that can itself only have one instance per hierarchy:
"data": {
"doc": "doc",
"Meta": {
"operations": [
"add",
"clone",
"export",
"export_bulkload_template",
"get",
"help",
"move",
"list",
"migration",
"transform",
"remove",
"tag",
"tag_version",
"update",
"field_display_policy"
],
"summary_attrs": [
"login_banner"
],
"singleton": "hierarchy",
"attr_props": [
{
"title": "Login Banner",
"required": true,
"type": "string",
"displayable": true,
"name": "login_banner"
}
]
},
"name": "LoginBanner"
}