Description
Gets the value of the key and inserts it into a DataWindow control, DataStore object, or DataWindowChild object.
If more than one key with the same name exists, then get the value of the first key. Notice that the IgnoreCase property (true by default) determines whether the key name will be matched in a case-sensitive manner.
This function will fail to import data properly, if the DataWindow is in query mode.
Applies to
Syntax
objectname.GetValueToDataWindow (string key, dwcontrol DWControl {, boolean resetflag} {, string error} {, DWBuffer dwbuffer {, long startrow {, long endrow } } } )
|
Argument |
Description |
|---|---|
|
objectname |
The name of the JSONPackage object |
|
Key |
A string specifying the key of the item of JsonStringItem type. The key value is the JSON-formatted data which is in the format described in the section called “Supported JSON formats” in Application Techniques. If it is DataWindow JSON, GetValueToDataWindow will ignore the mapping-method element of the JSON data. |
|
dwcontrol |
A reference to a DataWindow control, DataStore, or DataWindowChild. |
|
resetflag (optional) |
A boolean value specifying whether dwcontrol should automatically reset the update flag. The default is TRUE. |
|
error (optional) |
A variable into which the returned warning or error message will be placed. When there are a large amount of error messages, the error information will only display the total number of errors, and the detailed message of the first 10 errors. The import warning caused by data type mismatch will not affect the return value of ImportJsonByKey; although the data of the mismatched columns will not be imported, the rest columns (even only one column) that are matched will be imported successfully; and that row will be regarded as a successful import and counted into the return value. The import error caused by DW presentation style mismatch, invalid arguments, startrow value greater than the number of rows,etc. will be regarded as a failure, and represented by a negative return value of GetValueToDataWindow, instead of being placed into this variable. See the Return Value section for more. Most of the messages placed into this variable are warnings (such as data type mismatch) rather than errors. Developers can adjust the JSON data according to the message or simply ignore the message if the problematic column is not critical and the corresponding DataWindow column can be left blank. |
|
dwbuffer (optional) |
A value of the dwBuffer enumerated datatype identifying the DataWindow buffer from which you want to import the data. For a list of valid values, see the section called “DWBuffer” in DataWindow Reference. For plain JSON: If not specified, imports the JSON data to the Primary! buffer. If specified, imports the JSON data to the specified buffer. For DataWindow JSON: If not specified, imports data of all of the buffers from the JSON string to the corresponding buffers and, if any, imports the data for DataWindowChild. If specified, imports data of the specified buffer from the JSON string to the corresponding buffer. |
|
startrow (optional) |
The number of the first detail object in the JSON Array that you want to import. The default is 1. If it is 0 or negative, 1 is used. |
|
endrow (optional) |
The number of the last detail object in the JSON Array that you want to import. The default is the rest of the objects. If it is 0 or negative, it indicates the rest of rows. |
Return value
Long. Returns the number of rows that were imported if it succeeds and one of the following negative integers if an error occurs. The return value will count the rows imported into the primary, filter, and delete buffers, but not the rows imported into DataWindowChild.
0 -- When all of the data in the JSON string is null, or the JSON string only contains data for DataWindowChild, or no JSON key matches with the DataWindow column.
-1 -- General error.
-2 -- No row is supplied or the startrow value supplied is greater than the number of rows in the JSON data.
-3 -- Invalid argument.
-4 -- Invalid JSON.
-5 -- JSON format error.
-6 -- Unsupported DataWindow presentation style for import.
-7 -- Error resolving DataWindow nesting.
The method returns null if any of the following:
-
any argument's value is null
-
the DataWindow object (dataobject) is invalid
Usage
There is no forced conversion between strings and numbers. For example, the number 123 in JSON string will not be imported into the DataWindow column of char(10) type. For such case, a data type mismatch warning will be recorded in the error argument.
A boolean value (true or false) will be converted to 0 or 1 when imported from the JSON string to the DataWindow; however, 0 or 1 will not be converted to a boolean value (true or false) when exported from the DataWindow to the JSON string.
If the string length in JSON is larger than the string length in DataWindow, the string will be truncated when imported into the DataWindow. For example, JSON string [{"name":"TestForTrancate"}] is imported as "Test" when the data type of DataWindow column "name" is char(4).
When the number value is imported from the JSON string to the DataWindow column of number data type (with uncertain precision), the value will have uncertain decimals, for example, 6.78 becomes 6.78000020980835 after imported from the JSON string to the DataWindow.
Example 1
This example obtains the key value from the JSON string and sets the value to DataWindow.
// long GetValueToDataWindow ( string key, dwcontrol DWControl )
Integer li_Return
JsonPackage ljpk_Dept
ljpk_Dept = Create JsonPackage
// The DataWindow column name and type must match with that in the JSON string
dw_Dept.DataObject = "d_example_dept"
// Loads the DataWindow JSON string to the JsonPackage object
ljpk_Dept.LoadString('{"name":"Powerbuilder", "dept":{"identity":"70c86603-983b-4bd9-adbc-259436e43cbd", "version":1, "platform":"PowerBuilder", "mapping-method":0, "dataobject":{"name":"d_example_dept", "meta-columns":[{"name":"dept_id", "index":0, "datatype":"long", "nullable":1}, {"name":"dept_name", "index":1, "datatype":"string", "nullable":1}, {"name":"dept_head_id", "index":2, "datatype":"long", "nullable":1}], "primary-rows":[{"row-status":0, "columns":{"dept_id":[100], "dept_name":["R & D8"], "dept_head_id":[105]}}, {"row-status":0, "columns":{"dept_id":[200], "dept_name":["Sales"], "dept_head_id":[129]}}, {"row-status":0, "columns":{"dept_id":[300], "dept_name":["Finance"], "dept_head_id":[102]}}, {"row-status":0, "columns":{"dept_id":[400], "dept_name":["Marketing"], "dept_head_id":[1576]}}, {"row-status":0, "columns":{"dept_id":[500], "dept_name":["Shipping"], "dept_head_id":[703]}}, {"row-status":0, "columns":{"dept_id":[999], "dept_name":["test4"], "dept_head_id":[null]}}]}}}')
// Loads the data from the JSON string to DataWindow
li_Return = ljpk_Dept.GetValueToDatawindow ("dept", dw_Dept)
If li_Return <= 0 Then
// Prints the error message
End If
// Loads the plain JSON string to the JsonPackage object
ljpk_Dept.LoadString('{"dept2":[{"dept_id":100, "dept_name":"R & D8", "dept_head_id":105}, {"dept_id":200, "dept_name":"Sales", "dept_head_id":129}, {"dept_id":300, "dept_name":"Finance", "dept_head_id":102}, {"dept_id":400, "dept_name":"Marketing", "dept_head_id":1576}, {"dept_id":500, "dept_name":"Shipping", "dept_head_id":703}]}')
// Loads the data from the JSON string to DataWindow
li_Return = ljpk_Dept.GetValueToDatawindow ("dept2", dw_Dept)
If li_Return <= 0 Then
// Prints the error message
End If
Example 2
This example obtains the data in rows 2 through 4 from the JSON string and sets the data to DataWindow.
// long GetValueToDataWindow ( string key, dwcontrol DWControl, boolean resetflag, DWBuffer dwbuffer, long startrow, long endrow )
Integer li_Return
JsonPackage ljpk_Dept
ljpk_Dept = Create JsonPackage
// The DataWindow column name and type must match with that in the JSON string
dw_Dept.DataObject = "d_example_dept"
ljpk_Dept.LoadString('{"dept":[{"dept_id":100, "dept_name":"R & D8", "dept_head_id":105}, {"dept_id":200, "dept_name":"Sales", "dept_head_id":129}, {"dept_id":300, "dept_name":"Finance", "dept_head_id":102}, {"dept_id":400, "dept_name":"Marketing", "dept_head_id":1576}, {"dept_id":500, "dept_name":"Shipping", "dept_head_id":703}]}')
// Loads the data from the JSON string to DataWindow: startrow:2, endrow:4.
// GetValueToDataWindow returns 3, indicating 3 rows have been imported.
li_Return = ljpk_Dept.GetValueToDataWindow("dept", dw_Dept, False, Filter!, 2, 4 )
dw_Dept.SetFilter("") // Displays the data imported to the Filter buffer
dw_Dept.Filter()
Example 3
This example obtains the key value from the JSON string and imports the value to the specified DataWindow buffer.
// long GetValueToDataWindow ( string key, dwcontrol DWControl, string error, DWBuffer dwbuffer )
Integer li_Return
String ls_Error
JsonPackage ljpk_Dept
ljpk_Dept = Create JsonPackage
// The DataWindow column name and type must match with that in the JSON string
dw_Dept.DataObject = "d_example_dept"
ljpk_Dept.LoadString('{"dept1":[{"dept_id":500,"dept_name":"Shipping","dept_head_id":703}],"dept2":[{"dept_id":"100","dept_name":"R & D8","dept_head_id":"test"}]}') // 105
// Loads the data of dept1 from the JSON string to DataWindow
li_Return = ljpk_Dept.GetValueToDataWindow("dept1", dw_Dept, ls_Error, Primary! )
// Prints ls_error. It is an empty string.
// Loads the data of dept2 from the JSON string.
// The value type in the JSON string does not match with that in the DataWindow. Error is saved to ls_Error.
li_Return = ljpk_Dept.GetValueToDataWindow("dept2", dw_Dept, ls_Error, Primary! )
// Prints ls_Error.
// Total errors: 2
// Row 1, node "dept_id" in the JSON object has a different data type from column 1 in the Primary buffer.
// Row 1, node "dept_head_id" in the JSON object has a different data type from column 3 in the Primary buffer.
See also
