Methods and attributes

To use the JSON read and write features described in this chapter, use the handle to a temp-table, temp-table buffer, or ProDataSet to access methods and attributes of the object. The following table describes the available methods.

Table 4. JSON methods for temp-tables and ProDataSets
Method	Description
READ-JSON( )	Reads a specified JSON string, JsonArray object, or JsonObject object into a corresponding ProDataSet, a temp-table, or a temp-table buffer object.
WRITE-JSON( )	Writes a specified JSON string, JsonArray object, or JsonObject object from a corresponding ProDataSet, a temp-table, or a temp-table buffer object. In the case of the temp-table buffer object, all the records of the temp-table associated with the buffer object are written to the JSON string, JsonArray object, or JsonObject object—not just the one record in the buffer.
SERIALIZE-ROW ( )	Serializes a temp-table buffer's current row either to a JSON or XML string or to a JsonObject object.

Table 5. JSON related attributes for temp-tables and ProDataSets
Attribute	Data type	Applies to	Description
FOREIGN-KEY-HIDDEN¹ (Readable and writeable)	LOGICAL	Data-relation	Specifies whether the WRITE-JSON( ) method should hide foreign key fields in the child records of a nested data-relation in a ProDataSet.
NESTED (Readable and writeable)	LOGICAL	Data-relation	Specifies whether the AVM embeds child rows within a parent row in the JSON. This affects both the data and schema.
SERIALIZE-HIDDEN (Readable and writeable)	LOGICAL	Buffer-field	Indicates whether this field is written when the temp-table is serialized, for example into JSON or XML. This attribute als interacts with the XML-NODE-TYPE attribute.
SERIALIZE-NAME (Readable and writeable)	CHARACTER	ProDataSet temp-table temp-table buffer temp-table buffer field	Optionally specifies the name of a ProDataSet, a temp-table, a temp-table buffer, or a temp-table buffer-field object as it should appear when serialized, for example into JSON or XML. This attribute also interacts with the XML-NODE-NAME attribute.

¹ See Minimizingthe size of JSON data for more information.

Note: The SERIALIZE-HIDDEN and SERIALIZE-NAME attributes provide generalized support for serializing data objects to either JSON or XML. These attributes interact with the XML-specific attributes in ABL. For more information, see the descriptions of these attributes in OpenEdge Development: ABL Reference.