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Text item

The purpose of a text item is to provide a way to capture and manipulate the object position in statements.

The allowed values for the object position are steered by providing certain restrictions on the text item. In the editing view the user typically provides the value by typing in one or several input fields.

Text item reference

Key Explanation
type Must be "text" for text items
id Identifier for the item
property A leading property required to be matched for this text item. For example, http://purl.org/dc/terms/title corresponding to the predicate of a RDF statement where the object is specified to be a language controlled literal via the nodeType. The property must always be specified for text items, except when used in the group URI special case.
pattern A regular expression to match the provided value against.
valueTemplate Will be used when updating the statement where any occurence of $1 is replaced with the value provided by the user (if no $1 is provided the user provided value is added at the end).
cardinality See separate section on cardinality.
nodetype Allowed values are ONLY_LITERAL, LANGUAGE_LITERAL, DATATYPE_LITERAL, and URI, see separate section on nodetypes.
datatype A single datatype or an array of datatypes. May be namespaced. Only used if nodeType is DATATYPE_LITERAL.
deps Dependency path that determines if the statement will be expressed. See separate section on dependency paths.
value A hardcoded value that will be used to create a statement if no matching statement is found.
language A language value that will be used to create a statement if no matching statement is found, only used if nodetype is LANGUAGE_LITERAL.
label A multi-language label for the text item.
editLabel A multi-language edit label for the text item, has higher priority than label in edit view (if provided).
description A multi-language description for the text item.
editDescription A multi-language edit description for the text item, has higher priority than label in edit view (if provided).
placeholder A multi-language text that will be shown in input fields before user starts to type.
help A multi-language help text that will be shown if the provided value does not fit the pattern.
text A set of multi-language texts, parametrized by keys. The keys are typically something like "title", "purpose", "usagenote", "mapping", "example" etc.
styles An open-ended list of attributes that is used by the different views to control behaviour. See separate section of well supported attributes.
cls An array of css classes that will be inserted in the DOM structure for this text item when renderered in a view.
uriValueLabelProperties An array of properties to be used to detect a suitable label if the nodetype is a URI.

Example

Below a text item for presenting / validating / editing a single statement with property foaf:firstName is examplified, no language or datatype is proscribed.

{
    "id": "foaf::firstname",
    "type": "text",
    "property": "http://xmlns.com/foaf/0.1/firstName",
    "label": { "en":"First name", "sv": "Förnamn" },
    "cardinality": { "min": 1, "max": 1},
    "nodetype": "ONLY_LITERAL"
}

Binding mechanism

A text item can be used to bind existing statements as well as create new statements. The binding step is performed by the RDForms engine that takes an RDF graph a template and a staring node as input and produces a binding tree as output. Below we describe both the matching and the creation step for statements.

Matching statements

A binding is created for every statements that matches:

  • the subject from the surrounding group
  • the given property
  • the given nodetype
  • the pattern (if any)
  • one of the given datatypes (if any)
  • one of the given languages (if any)

Creating statements

A text item can be used to create a statement based on the user input, the restrictions from the matching step and the following rules applies:

  • Any pattern provided in the item will prohibit creation of statement until it is fullfilled.
  • If the nodetype is set to RESOURCE a URI will be created, not a blank node.
  • If the nodetype is set to ANY_LITERAL or PLAIN_LITERAL a literal will be created without a language or datatype.
  • If the nodetype is set to DATATYPE_LITERAL and the datatype contains a list of datatypes to be accepted the first will be used by default.