5.1.1 Array Properties

These Array properties hold an array of one or more objects, which are usually description objects .

For example, the resources tables property is an array property. A table group description might contain:

"tables": [{
  "url": "https://example.org/countries.csv",
  "tableSchema": "https://example.org/countries.json"
}, {
  "url": "https://example.org/country_slice.csv",
  "tableSchema": "https://example.org/country_slice.json"
}]

in which case the resources tables property has a value that is an array of two table description objects.

Any items within an array that are not valid objects of the type expected are ignored. If the supplied value of an array property is not an array (eg if it is an integer), compliant applications MUST issue a warning and proceed as if the property had been supplied with an empty array.

link properties 5.1.2 Link Properties

These Link properties hold one or more references a single reference to other resources another resource by URL. Their values may be: value is a strings string — resolved as URLs a URL against the base URL arrays — lists . If the supplied value of strings which are resolved a link property is not a string (eg if it is an integer), compliant applications MUST issue a warning and proceed as URLs against if the base URL property had been supplied with an empty string.

For example, the dc:hasVersion url property is a link property. A table description might contain:

"dc:hasVersion"

"url"


:




"example-2014-01-03.csv"

in which case the dc:hasVersion url property on the table would have a single value, a link to example-2014-01-03.csv . Alternatively, , resolved against the base URL of the metadata document might contain: in which this was located. For example if the metadata document contained:

"@context"
:


]

[

"http://www.w3.org/ns/csvw"
,
{

"@base"
:
"http://example.org/"

}]

in which case the dc:hasVersion property on the table would be an array of three values, links this is equivalent to other versions of the table. specifying:

"url"
:
"http://example.org/example-2014-01-03.csv"

5.1.3 URI template properties Template Properties

A URI template property contains properties contain a [ URI-TEMPLATE ] which can be used to generate a URI. These URI templates are expanded in the context of each row by combining the template with a set of variables with values. values as defined in [ URI-TEMPLATE ]. The variables that are set are:

column names

a variable is set for each column within the schema ; the name of the variable is the column name of the column from the annotated table and the value is derived from the value of the cell in that column in the row that is currently being processed, namely one of:

• _row null
• the canonical representation of the value of the cell, based on its datatype as defined in [ xmlschema11-2 ], if it has a single value
• a list of canonical representations of the values of the cell, if it has a sequence value

Note

The languages of cell values are ignored.

_column

_row _column is set to the row column number of the row column from the annotated table that is currently being processed

_sourceColumn Issue 32

_sourceColumn is set to the source number of the column that is currently being processed; this usually varies from _column by skip columns

Where does row numbering begin? _row

_row is set to the row number of the row from the annotated table that is currently being processed

column names _sourceRow

a variable _sourceRow is set for each column within the schema; to the name source number of the variable row that is currently being processed; this usually varies from _row by skip rows and header rows

_name

_name is set to the percent-encoded URI decoded column name of annotation, as defined in [ tabular-data-model ], for the column and the that is currently being processed. (Percent-decoding is necessary as name may have been encoded if taken from titles ; this prevents double percent-encoding.)

The annotation value is the canonical representation of result of:

1. applying the value of template against the cell in that column in the row that is currently being processed
2. expanding any prefixes as if the value were the name of a common property , as described in section 5.8 Common Properties
3. resolving the resulting URL against the base URL of the table url if not null

If the supplied value of a URI template property is not a string (eg if it is an integer), compliant applications MUST issue a warning and proceed as if the property had been supplied with an empty string.

For example, the urlTemplate aboutUrl property holds a URI template that is used to generate a URL identifier for each row, which might look like:

"urlTemplate"

"aboutUrl"


:




"http://example.org/example.csv#row={_row}"

"http://example.org/example.csv#row.{_row}"

The identifiers about URL annotations that are generated and used as identifiers for the rows would then look like http://example.org/example.csv#row=1 http://example.org/example.csv#row.1 , http://example.org/example.csv#row=2 http://example.org/example.csv#row.2 and so on.

Alternatively, with the CSV and metadata in the section 1. Introduction , the urlTemplate aboutUrl might look like:

"urlTemplate"

"aboutUrl"


:




"http://example.org/tree/{on%2Dstreet}/{GID}"

"http://example.org/tree/{on_street}/{GID}"

This would generate URIs such as http://example.org/tree/ADDISON%20AV/1 and http://example.org/tree/EMERSON%20ST/2 .

If the value of the on_street or GID column were null , the URL would still be generated with the null value generating an empty string in the URL. For example if on_street were null and GID were 3 , the generated URL would be http://example.org/tree//3 .

Once the URI has been generated, it is resolved against the location url of the resource table (eg the CSV file) to create an absolute URI. For example, given a urlTemplate aboutUrl within a schema such as:

"aboutUrl"
:
"#row.{_row}"

and given a CSV file at http://example.com/temp.csv , the URL for the first row will be http://example.com/temp.csv#row=1 http://example.com/temp.csv#row.1 .

The propertyUrl property might be defined as "{#_name}" , meaning that it resolves as a fragment identifier relative to the URL of the source of the table. For example, accessing it from a column with the column name GID would look like:

"http://example.org/example.csv#GID"

A value defined within the data is also subject to expansion. For example, consider the following table:

project_name,project_type,keywords

CSVW,foaf:Project,table;data;conversion

The project_type column might have a valueUrl specified as "{project_type}" . In the first row the cell value is "foaf:Project" . The foaf prefix is understood, as described in section 5.8 Common Properties , to expand to http://xmlns.com/foaf/0.1/Project .

Similarly, the keywords column might have a valueUrl specified as "https://duckduckgo.com/?q={keywords}" . If the column also specifies "separator": ";" , then the cell value of the keywords column would be an array of the three values table , data , and conversion . This is set as the value of the keywords variable within the URI template, which means the result would be https://duckduckgo.com/?q=table,data,conversion .

If the value in the keywords column were an empty sequence (created from an empty cell in the original data), the reference properties to that column would be expanded to an empty string, generating https://duckduckgo.com/?q= .

When a cell's value is not a string, the canonical representation of that value is used within the expanded URL. For example, the data may include dates such as those in:

GID,On Street,Species,Trim Cycle,Inventory Date

1,ADDISON AV,Celtis australis,Large Tree Routine Prune,10/18/2010
2,EMERSON
ST,Liquidambar
styraciflua,Large
Tree
Routine
Prune,6/2/2010

These The Inventory Date column description would indicate that these were dates with the format M/d/yyyy :

{
  "name": "inventory_date",
  "titles": "Inventory Date",
  "datatype": {
    "base": "date",
    "format": "M/d/yyyy"
  }

}

The string value of the inventory_date column in the first row is parsed to create the date 18th October 2010. When the inventory_date column is referenced within a URI template such as http://example.org/event/{inventory_date} , the canonical representation of that date, as defined in [ xmlschema11-2 ] is used within the URL, giving the result http://example.org/event/2010-10-18 .

5.1.4 Column Reference Properties

Column reference properties hold one or more references to other column description objects. The referenced description object must have an a name property. Column reference properties can then reference column description objects through values that are:

• strings — which MUST match the name on a column description object within the metadata document
• arrays — lists of strings as above

If the supplied value of a column reference property is not a string or array (eg if it is an integer), or if any of the values in the supplied array are not strings, or if any of the supplied strings do not reference one or more columns, compliant applications MUST issue a warning and proceed as if the property had been specified (which may mean that an error is issued, if the property was required).

For example, the primaryKey property is an a column reference property on the schema. It has to hold references to columns defined elsewhere in the schema, and the descriptions of those columns must have name properties. It can hold a single reference, like this:

"tableSchema": {
  "columns": [{
    "name": "GID"
  }, ... ],
  "primaryKey": "GID"


}

or it can contain an array of references, like this:

"tableSchema": {
  "columns": [{
    "name": "givenName"
  }, {
    "name": "familyName"
  }, ... ],
  "primaryKey": [ "givenName", "familyName" ]


}

object properties 5.1.5 Object Properties

These Object properties hold one or more objects either a single object or references a reference to objects an object by URL. Their values may be:

• strings — resolved as URLs against the base URL
• objects — interpreted as structured objects
arrays — lists

If the supplied value of strings and/or objects, interpreted as URLs an object property is not a string or structured objects object (eg if it is an integer), compliant applications MUST issue a warning and proceed as if the property had been specified as an object with no properties.

Object properties are often used when the values can be or should be values within controlled vocabularies, or structured information which may be held elsewhere. For example, the dc:creator dialect of a table should be is an object property. It could be provided as a URL that indicates the creator, a commonly used dialect, like this:

"dc:creator"

"dialect"


:




"http://ons.gov.uk"

"http://example.org/tab-separated-values"

or a structured object, like this:

"dialect": {
  "delimiter": "\t",
  "encoding": "utf-8"


}

or an array of URLs, like this: Example 12 "dc:creator" : [ "http://ons.gov.uk" , When specified as a string, the resolved URL is used to fetch the referenced object during normalization as described in section 6.1 "https://www.gov.uk/government/organisations/department-for-transport" Normalization . For example, if http://example.org/tab-separated-values resolved to:

{
  "@context": "http://www.w3.org/ns/csvw",
  "quoteChar": null,
  "header": true,
  "delimiter": "\t"


]

}

or an array Following normalization , the value of structured objects: the dialect property would then be:

"dialect": {
  "@id": "http://example.org/tab-separated-values",
  "quoteChar": null,
  "header": true,
  "delimiter": "\t"


}]

}

"https://www.gov.uk/government/organisations/department-for-transport" 5.1.6 ] Natural Language Properties natural

Natural language properties These hold natural language strings. Their values may be:

• strings — interpreted as natural language strings in the default language
• arrays — interpreted as alternative natural language strings in the default language
• objects whose properties MUST be language codes as defined by [ BCP47 ] and whose values are either strings or arrays, providing natural language strings in that language

Natural language properties are used for things like descriptions and titles. For example, the title titles property on a column description provides a natural language label for a column. If it's a plain string like this:

"title"

"titles"


:




"Project
title"

then that string is assumed to be in the default language provided through the @language property of the nearest @context (or have no assumed an undefined language, und , if there is no such property). Multiple alternative values can be given in an array:

"titles": [
  "Project title",
  "Project"


]

It's also possible to provide multiple values in different languages, using an object structure. For example:

"titles": {
  "en": "Project title",
  "fr": "Titre du projet"


}

and within such an object, the values of the properties can themselves be arrays:

"titles": {
  "en": [ "Project title", "Project" ],
  "fr": "Titre du projet"


}

The annotation value of a natural language property is an object whose properties are language codes and where the values of those properties are an array of strings (see Language Maps in [ JSON-LD ]).

If the supplied value of a natural language property is not a string, array or object (eg if it is an integer), compliant applications MUST issue a warning and proceed as if the property had been specified as an empty array. If the supplied value is an array, any items in that array that they are interpreted not strings MUST be ignored. If the supplied value is an object, any properties that are not valid language codes as HTML defined by [ BCP47 ] MUST be ignored, as must any properties whose value is not a string or Markdown. an array, and any items that are not strings within array values of these properties.

atomic properties 5.1.7 Atomic Properties

These Atomic properties hold atomic values. values . Their values may be:

• numbers — interpreted as integers or doubles
• booleans — interpreted as booleans ( true or false )
• strings — interpreted as defined by the property
• objects — interpreted as defined by the property
• arrays — lists of numbers, booleans booleans, strings, or strings objects

The annotation value of a boolean atomic property takes is false if unset; otherwise, the annotation value of an atomic property is normalized value of that property, or the defined default value or null , if unset. Processors MUST issue a date warning if a property is set to an invalid value type, such as a value, this MUST be boolean atomic property being set to the number 1 or a string in numeric atomic property being set to the format string YYYY-MM-DD . "3.1415" , and act as if the property had not been specified (which may mean using the default value for the property, or may mean raising an error and halting processing if the property is a required property).

3.4.1 5.3.1 Required Properties

resources tables

An array property of table descriptions for the tables in the group. group, namely those listed in the tables annotation on the group of tables being described. Compliant application MUST raise an error if this array does not contain one or more table descriptions.

When an array of table descriptions B is imported merged into an original array of table descriptions A, A , each table description within B is combined into the original array A by:

• if there is a table description with the same @id url in A, A , the table description from B is imported merged into the matching table description in A .
• otherwise, the table description from B is appended to the array of table descriptions A .

3.4.2 5.3.2 Optional Properties

The description of a group of tables MAY also contain:

schema dialect

An object property that provides a single schema dialect description as described in section 3.8 Schemas , . If provided, dialect provides hints to processors about how to parse the referenced files to create tabular data models for all the tables in the group. This may be provided as an embedded object within the JSON metadata or as a URL reference reference. See section 5.9 Dialect Descriptions for more details.

notes

An array property that provides an array of objects representing arbitrary annotations on the annotated group of tables . The value of this property becomes the value of the notes annotation for the group of tables . The properties on these objects are interpreted equivalently to common properties as described in section 5.8 Common Properties . When an array of note objects B is merged into an original array of note objects A , each note object from B is appended into the array A .

Note

The Web Annotation Working Group is developing a separate JSON schema document. vocabulary for expressing annotations. In future versions of this specification, we anticipate referencing that vocabulary.

table-direction tableDirection

An atomic property that MUST have a single string value that is one of "rtl" , "ltr" or "default" . Indicates whether the tables in the group should be displayed with the first column on the right, on the left, or based on the first character in the table that has a specific direction. The value of this property becomes the value of the direction annotation for all the tables in the table group. See section 4.1.1 Bidirectional Tables for more details. Issue 51 in [ tabular-data-model This should be a defined controlled vocabulary in JSON-LD, so that the values map on to URIs in the RDF version rather than strings. We invite comment on how to configure the JSON-LD context to enable these values to be interpreted in ] for details. The default value for this way. property is "default" .

dialect tableSchema

An object property that provides a single dialect schema description . If provided, dialect provides hints to processors about how to parse as described in section 5.5 Schemas , used as the referenced files for to create tabular data models default for all the tables in the group. This may be provided as an embedded object within the JSON metadata or as a URL reference. See section 3.6 Dialect Descriptions for more details. reference to a separate JSON object that is a schema description .

templates transformations

An array property of template specifications transformation definitions that provide mechanisms to transform the tabular data into other formats. See section 3.7 Template Specifications The value of this property becomes the value of the transformations annotation for more details. all the tables in the table group.

When an array of template specifications transformation definitions B is imported merged into an original array of template specifications A, transformation definitions A , each template specification transformation definition within B is combined into the original array A by:

• if there is a template specification transformation definition with the same targetFormat and templateFormat url in A, A , the template specification transformation definition from B is imported merged into the matching template specification transformation definition in A .
• otherwise, the template specification transformation definition from B is appended to the array of template specifications transformation definitions A .

@id

If included, @id is a link property that identifies the group of tables , as defined by [ tabular-data-model ], described by this table group description . It MUST NOT start with _: . The value of this property becomes the value of the id annotation for the group of tables .

@type

If included, @type is an atomic property that MUST be set to "TableGroup" . Publishers MAY include this to provide additional information to JSON-LD based toolchains.

The description MAY contain any common properties as defined in section 3.3 Common Properties to provide extra metadata about the set group of tables as a whole.

The description MAY contain any of the inherited properties defined in section 2.2 Inherited Properties to describe cells within the tables.

3.5.1 5.4.1 Required Properties

@id url

This link property gives the single URL of the CSV file that the table is held in, relative to the location of the metadata document. The value of this property is the value of the url annotation for the annotated table this table description describes.

3.5.2 5.4.2 Optional Properties

The description of a table MAY also contain:

schema dialect

An object property that provides a single schema description as described in section 3.8 Schemas

As defined for table groups . This may be provided as an embedded object within the JSON metadata or as a URL reference to a separate JSON schema document.

notes

An object array property that provides an array of objects representing annotations. This specification does not place any constraints arbitrary annotations on the structure annotated tabular data model . The value of this property becomes the value of the notes annotation for the table . The properties on these objects. objects are interpreted equivalently to common properties as described in section 5.8 Common Properties . When an array of note objects B is merged into an original array of note objects A , each note object from B is appended into the array A .

Note

The Web Annotation Working Group is developing a vocabulary for expressing annotations. In future versions of this specification, we anticipate referencing that vocabulary.

Issue 70 Should there be column or level notes as well? Issue 71 The Annotation Model can indeed become very complex. table-direction As defined for table groups . templates As defined for table groups .

dialect suppressOutput

As defined for table groups

A boolean atomic property . @type If included, @type MUST true , suppresses any output that would be set to "Table" . Publishers MAY include generated when converting this to provide additional information to JSON-LD based toolchains. Issue We invite comment on whether we should include properties that help in checking the integrity of the file: datapackage includes bytes and hash . We could reuse the Subresource Integrity work here. table. The description MAY contain any common properties as defined in section 3.3 Common Properties to provide extra metadata about value of this property becomes the table as a whole. The description MAY contain any value of the properties defined in section 2.2 Inherited Properties suppress output to describe cells within the annotation for this table. 3.6 Dialect Descriptions Much of the tabular data that is published on the web The default is messy, and CSV parsers frequently need to be configured in order to correctly read in CSV. A dialect description provides hints to parsers about how to parse the file linked to from the @id property. It can have any of the following properties, which relate to the flags described in Section 5 Parsing Tabular Data within [ tabular-data-model ]: false .

encoding An atomic property that sets the encoding flag to the single provided string value, which MUST be a defined [ encoding ].

lineTerminator tableDirection

An atomic property that sets the line terminator flag to the single provided string value. quoteChar An atomic

As defined for table groups . The value of this property that sets the quote character flag to becomes the single provided value, which MUST be a single character. doubleQuote A single boolean atomic property that, if true , sets value of the escape character direction flag to " . If false , to \ . skipRows annotation for this table.

An atomic property that sets the skip rows flag to the single provided numeric value, which MUST be a non-negative integer.

commentPrefix tableSchema

An atomic object property that sets the comment prefix flag to the single provided value, which MUST be provides a single character string. header A single boolean atomic property that, if true , sets the header row count flag to 1 , and if false to 0 , unless headerRowCount schema description is provided, as described in which case the value provided for the header property is ignored. headerRowCount section 5.5 Schemas An atomic property that sets the header row count flag to the single provided value, which MUST . This may be a non-negative integer. delimiter An atomic property that sets the delimiter flag to the single provided value, which MUST be a single character string. skipColumns An atomic property that sets the skip columns flag to as an embedded object within the single provided numeric value, which MUST be JSON metadata or as a non-negative integer. headerColumnCount An atomic property that sets the header column count flag URL reference to a separate JSON schema document. If a table description is within a table group description , the single provided value, which MUST be non-negative integer. skipBlankRows tableSchema An atomic property from that sets the skip blank rows flag to the single provided boolean value. skipInitialSpace A single boolean atomic property that, if true , sets table group acts as the trim flag to "start" . If false , to false . default for this property.

If the a trim tableSchema property is provided, not declared in table description , it may be declared on the skipInitialSpace property table group description , which is ignored. then used as the schema for this table description .

The trim @id A single atomic property that, if of the boolean true tableSchema , sets the trim flag to true and if the boolean false to false . If the value provided there is a string, sets the trim flag to one, becomes the provided value, which MUST be one of "true" , "false" , "start" or "end" . @type If included, @type MUST be set to "Dialect" . Publishers MAY include this to provide additional information to JSON-LD based toolchains. The default dialect description for CSV files is: { "encoding": "utf-8", "lineTerminator": "\r\n", "quoteChar": "\"", "doubleQuote": true, "skipRows": 0, "header": true, "headerRowCount": 1, "delimiter": ",", "skipColumns": 0, "headerColumnCount": 0, "skipBlankRows": false, "skipInitialSpace": false, "trim": false } 3.7 Template Specifications A template specification is a definition value of how tabular data can be transformed into another format. It has the following properties: 3.7.1 Required Properties Template specifications MUST have the following properties: targetFormat A URL schema annotation for the format that will be created through the transformation. If one has been defined, this should be a URL for a media type, in the form http://www.iana.org/assignments/media-types/ media-type such as http://www.iana.org/assignments/media-types/text/calendar . Otherwise, it can be any URL that describes the target format. table.

Note

The When a schema is referenced by URL, this URL becomes the value of the targetFormat @id URL is intended as an informative identifier for property in the target format, normalized schema description, and applications MAY NOT access thus the URL. value of the schema annotation on the table.

templateFormat transformations

A URL As defined for the format that is used by the template. If one has been defined, table groups . The value of this should be a URL for a media type, in property becomes the form http://www.iana.org/assignments/media-types/ media-type such as http://www.iana.org/assignments/media-types/application/javascript . Otherwise, it can be any URL that describes value of the template format. Note The templateFormat URL is intended as an informative identifier transformations annotation for the template format, and applications MAY NOT access the URL. The template formats that an application supports are implementation defined. this table.

3.7.2 Optional Properties Template specifications MAY have the following properties:

title @id

A natural language property that describes the format that will be generated from the transformation. This is useful if the target format is a generic format (such as

If included, application/json @id ) and the transformation is creating a specific profile of that format. source A single string atomic link property that provides, if included, the format to which the tabular data should be transformed prior to the transformation using the template. If the value is "json" , the tabular data should first be transformed first to JSON based on the simple mapping defined in Generating JSON from Tabular Data on the Web . If the value is "rdf" , it should similarly first be transformed to XML based on identifies the simple mapping table , as defined in Generating RDF from Tabular Data on the Web [ tabular-data-model ], described by this table description . If the It MUST NOT start with source _: . The value of this property is missing or null then becomes the source value of the transformation is the annotated tabular data model. id annotation for this table.

@type

If included, @type is an atomic property that MUST be set to "Template" "Table" . Publishers MAY include this to provide additional information to JSON-LD based toolchains.

The template specification description MAY contain any common properties as defined in section 3.3 Common Properties to provide extra metadata about the transformation. table as a whole.

The following template specification will enable a processor that supports it to generate an iCalendar document using a Mustache template description MAY contain inherited properties based on the JSON created from the simple mapping to JSON. describe cells within the table.

5.8.1 Names of Common Properties

The names of common properties are prefixed names , in the syntax prefix : name .

Prefixed names that contains can be expanded to provide a single string URI, by replacing the prefix and following colon with the URI that the prefix is associated with. Expansion is intended to be entirely consistent with Section 6.3 IRI Expansion in [ JSON-LD-API ] and implementations MAY use a JSON-LD processor for performing prefixed name and IRI expansion.

The prefixes that are recognized are those defined for [ rdfa-core ] within the main datatype of RDFa 1.1 Initial Context and other prefixes defined within [ csvw-context ] and these MUST NOT be overridden. These prefixes are periodically extended; refer to [ csvw-context ] for details. Properties from other vocabularies MUST be named using absolute URLs.

This specification does not define how common properties are interpreted by implementations. Implementations SHOULD treat the cell. If prefixed names for common properties and the URLs that they expand into in the same way. For example, if an implementation recognises and displays the value of the cell contains a list (ie separator dc:description is specified property, it should also recognise and not display the value of the null http://purl.org/dc/terms/description ) then this is property in the datatype same way.

5.8.2 Values of each value Common Properties

Common properties can take any JSON value, so long as any objects within the list. Conversion specifications value (for example as items of an array or values of properties on other objects) adhere to the following restrictions, which are designed to ensure compatibility between JSON-LD-aware and non-JSON-LD-aware processors:

• If a @value property is used on an object, that object MUST NOT use the datatype have any other properties aside from either @type or @language , and MUST NOT have both @type and @language as properties. The value of the @value property MUST be a string, number, or boolean value.

  If @type is also used, its value to determine the conversion of MUST be one of:

  • a cell into the target format. See built-in datatype, as defined in section 3.11 5.11.1 Built-in Datatypes .
  • a prefixed name for more details. using any of the pre-defined prefixes as described in section 5.8.1 Names of Common Properties .
  • a string, which MUST be interpreted as an absolute URL.

  If a length @language An atomic property that contains is used, it MUST have a single integer string value that adheres to the syntax defined in [ BCP47 ], or be null .

• If a @type property is used on an object without a @value property, its value MUST be one of:

  • one of the exact length legitimate values for @type as defined for any of the value description objects in this specification.
  • a prefixed name using any of the cell. See pre-defined prefixes as described in section 3.11.1 5.8.1 Length Constraints Names of Common Properties for details. .
  • a string, which MUST be interpreted as an absolute URL.

  A minLength @type An atomic property that contains can also have a single integer value that is the minimum length an array of the value such values.

• The values of the cell. See @id properties are link properties and are treated as URLs. During normalization , as described in section 3.11.1 6.1 Length Constraints Normalization , they will have any prefix expanded for details. and the result resolved against the base URL . Therefore, if an maxLength @id An atomic property that contains is used on an object, it MUST have a single integer value that is a string and that string MUST NOT start with _: .

• A @language property MUST NOT be used on an object unless it also has a @value property.

• Aside from @value , @type , @language , and @id , the maximum length of properties used on an object MUST NOT start with @ .

These restrictions are also described in section A. JSON-LD Dialect , from the value perspective of a processor that otherwise supports JSON-LD. Examples of common property values and the cell. See impact of normalization are given in section 3.11.1 6.1.1 Length Constraints Examples .

5.10.1 Required Properties

Transformation definitions MUST have the following properties:

nonNegativeInteger url

A link property giving the single URL of the file that the script or template is held in, relative to the location of the metadata document.

unsignedInt scriptFormat ;

A link property giving the single URL for the format that is used by the script or template. If one has been defined, this should be a sub-value of URL for a media type, in the form unsignedLong http://www.iana.org/assignments/media-types/ media-type such as http://www.iana.org/assignments/media-types/application/javascript . Otherwise, it can be any URL that describes the script or template format.

Note

The unsignedShort ; a sub-value of unsignedInt scriptFormat URL is intended as an informative identifier for the template format, and applications SHOULD NOT access the URL. The template formats that an application supports are implementation defined.

unsignedByte targetFormat ;

A link property giving the single URL for the format that will be created through the transformation. If one has been defined, this should be a sub-value of URL for a media type, in the form unsignedShort http://www.iana.org/assignments/media-types/ media-type such as http://www.iana.org/assignments/media-types/text/calendar . Otherwise, it can be any URL that describes the target format.

Note

The positiveInteger ; a sub-value of nonNegativeInteger targetFormat URL is intended as an informative identifier for the target format, and applications SHOULD NOT access the URL.

5.10.2 Optional Properties

Transformation definitions MAY have the following properties:

float source ; a sub-value of

A single string atomic property that provides, if specified, the format to which the tabular data should be transformed prior to the transformation using the script or template. If the value is anySimpleType json , the tabular data MUST first be transformed to JSON as defined by [ csv2json ] using standard mode . If the value is double ; a sub-value of anySimpleType rdf , the tabular data MUST first be transformed to an RDF graph as defined by [ csv2rdf ] using standard mode . If the duration source ; a sub-value of property is missing or anySimpleType null (the default) then the source of the transformation is the annotated tabular data model . No other values are valid.

titles

A natural language property that describes the format that will be generated from the transformation. This is useful if the target format is a generic format (such as dateTime application/json ; ) and the transformation is creating a sub-value specific profile of that format.

anySimpleType @id

If included, time @id ; is a sub-value of link property that identifies the transformation described by this transformation definition . It MUST NOT start with anySimpleType _: .

date @type ; a sub-value of

If included, anySimpleType @type is an atomic property that MUST be set to "Template" . Publishers MAY include this to provide additional information to JSON-LD based toolchains.

The transformation definition MAY contain any common properties to provide extra metadata about the transformation.

5.10.3 Processing Transformation Definitions

Implementations MAY present users with options for transformations based on the available transformation definitions and their properties. Implementations SHOULD filter this list to only include those transformations whose gYearMonth ; a sub-value of anySimpleType scriptFormat they understand and can apply, and whose gYear source ; property, if present, specifies a sub-value of format that the implementation can convert to. Users may find the anySimpleType targetFormat and gMonthDay titles ; properties useful in deciding which transformation to apply.

When directed by a sub-value of user to transform a table using a transformation definition , implementations MUST :

1. Convert the table to the format specified by the anySimpleType source property, if this is specified and not null .
2. Fetch the script or template from the location specified by the gDay ; a sub-value of anySimpleType url property and raise an error if this does not exist.
3. Use the gMonth ; a sub-value of anySimpleType scriptFormat property to determine how to interpret that script or template, and apply it to the table (or the result of converting the table).

5.11.1 Built-in Datatypes

The possible built-in datatypes, as shown on the diagram , are:

• the datatypes defined in [ xmlschema11-2 ] as derived from and including anyURI ; a sub-value of anySimpleType anyAtomicType
• the datatype number which is exactly equivalent mapped to double in the data model
• the datatype binary which is exactly equivalent mapped to base64Binary in the data model
• the datatype datetime which is exactly equivalent mapped to dateTime in the data model
• the datatype any which is exactly equivalent mapped to anySimpleType anyAtomicType in the data model
• the datatype xml , a sub-type of string , which indicates the cell contains value is an XML fragment
• the datatype html , a sub-type of string , which indicates the cell contains value is an HTML fragment
• the datatype json , a sub-type of string , which indicates the cell contains value is serialized JSON

3.11.1 5.11.2 Length Constraints Derived Datatypes

More specialised datatypes can be defined through a datatype description . A datatype description may have any of the following properties, all of which are optional.

base

An atomic property that contains a single string: a term defined in the default context representing a built-in datatype URL, as listed above. Its default is string . All values of the datatype MUST be valid values of the base datatype. The value of this property becomes the base annotation for the described datatype .

format

An atomic property that contains either a single string or an object that defines the format of a value of this type, used when parsing a string value as described in Parsing Cells in [ tabular-data-model ]. The value of this property becomes the format annotation for the described datatype .

length ,

A numeric atomic property that contains a single integer that is the exact length of the value. The value of this property becomes the length annotation for the described datatype . See Length Constraints in [ tabular-data-model ] for details.

minLength and

An atomic property that contains a single integer that is the minimum length of the value. The value of this property becomes the minimum length annotation for the described datatype . See Length Constraints in [ tabular-data-model ] for details.

maxLength properties indicate

A numeric atomic property that contains a single integer that is the exact, maximum length of the value. The value of this property becomes the maximum length annotation for the described datatype . See Length Constraints in [ tabular-data-model ] for details.

minimum and

An atomic property that contains a single number or string that is the minimum valid value (inclusive); equivalent to minInclusive . The value of this property becomes the minimum annotation for the described datatype . See Value Constraints in [ tabular-data-model ] for details.

maximum lengths

An atomic property that contains a single number or string that is the maximum valid value (inclusive); equivalent to maxInclusive . The value of this property becomes the values maximum annotation for the described datatype . See Value Constraints in [ tabular-data-model ] for details.

minInclusive

An atomic property that contains a single number or string that is the minimum valid value (inclusive). The value of cells. this property becomes the minimum annotation for the described datatype . See Value Constraints in [ tabular-data-model ] for details.

maxInclusive

An atomic property that contains a single number or string that is the maximum valid value (inclusive). The value of this property becomes the maximum annotation for the described datatype . See Value Constraints in [ tabular-data-model ] for details.

minExclusive

An atomic property that contains a single number or string that is the minimum valid value (exclusive). The value of this property becomes the minimum exclusive annotation for the described datatype . See Value Constraints in [ tabular-data-model ] for details.

maxExclusive

An atomic property that contains a single number or string that is the maximum valid value (exclusive). The value of this property becomes the maximum exclusive annotation for the described datatype . See Value Constraints in [ tabular-data-model ] for details.