Description
Exports all rows or only the changed rows from all or specified buffers to a plain JSON string or DataWindow JSON string.
Applies to
|
DataWindow type |
Method applies to |
|---|---|
|
PowerBuilder |
DataWindow control, DataWindowChild object, and DataStore object, except for those with the Composite, Crosstab, OLE 2.0, or RichText presentation styles. |
Syntax
PowerBuilder
string dwcontrol.ExportJson( {DWBuffer dwbuffer,} boolean changedonly, boolean format )
|
Argument |
Description |
|---|---|
|
dwcontrol |
A reference to a DataWindow control, DataStore, or DataWindowChild. |
|
dwbuffer (optional) |
A value of the dwBuffer enumerated datatype identifying the DataWindow buffer from which you want to export the data. For a list of valid values, see DWBuffer. If not specified, all of the DataWindow buffers will be exported, however, the data for DataWindowChild will not be exported (even if changedonly is false). |
|
changedonly |
A boolean specifying the changing flag.
|
|
format |
A boolean specifying the JSON format.
See the section called “Supported JSON formats” in Application Techniques for details about the JSON format. |
Return value
String. Returns the JSON string if it succeeds. Returns the empty string ("") if an error occurs.
The method returns null if any of the following:
-
any argument's value is null
-
the DataWindow object (dataobject) is invalid
-
the DataWindow presentation style is unsupported, such as Composite, Crosstab, OLE 2.0, or RichText
Usage
The Number data type is handled as Double data type; 15 digits of precision is supported; and it will be written in scientific notation if it exceeds 15 digits.
The Decimal{0} data type is handled as Double data type; it has no fractional part, and the digits in the fractional part (if any) will be rounded to the integral part; 15 digits of precision is supported; and it will be written in scientific notation if it exceeds 15 digits.
The Decimal{n} data type is handled as Double data type; it can have n digits in the fractional part, and the following digits (if any) will be rounded; 15 digits of precision is supported; and it will be written in scientific notation if it exceeds 15 digits.
Examples
This example exports the changed rows from all buffers of the DataWindow to a DataWindow JSON string:
string ls_DWJson ls_DWJson = dw_1.ExportJson(true, true)
This example exports the changed rows from the primary buffer of the DataWindow to a plain JSON string:
string ls_PlainJson ls_PlainJson = dw_1.ExportJson(Primary!, true, false)
See also
