~~Title: Data API~~
~~NOTRANS~~
~~NOPDF~~

For managing the data of a screen, the **CustomScreen** provides a simple API which can be accessed via ''%%getDataApi('DATA_PROVIDER_NAME')%%'' from anywhere in it's extended classes.

This API provides following functions:

  * ''%%dynamic getValue(String columnName)%%''\\ Provides the value of a specific column
  * ''%%List getValues(List columnNames)%%''\\ Provides a list of values for the specified columns\\  
  * ''%%setValue(String columnName, dynamic value)%%''\\ Sets the value for a specific column
  * ''%%setValues(List columnNames, List values)%%''\\ Sets the values for a list of specified columns
  * ''%%insertRecord()%%''\\ Inserts a new record
  * ''%%deleteRecord(int index)%%''\\ Deletes the record at the specified index
  * ''%%selectRecord(int index)%%''\\ Selects the record at the specified index

The client persists those changes by itself. 

=== Examples ===

==Reading a value==

<file dart>
DataApi dataApi = getDataApi('JVxMobileDemo/Con-CG/contacts#4');
    
FlatButton(
    child: Text("Call"), onPressed: () {
        phone = dataApi.getValue("PHONE");
	launch("tel://$phone");
    })
</file>

==Setting a value==

<file dart>
DataApi dataApi = getDataApi('JVxMobileDemo/Con-CG/contacts#4');
    
FlatButton(
    child: Text("Set phone number"), onPressed: () {
        phone = dataApi.setValue("PHONE", '+43660123456');
    }
)
</file>
   
== Inserting a record ==

<file dart>
DataApi dataApi = getDataApi('JVxMobileDemo/Con-CG/contacts#4');
    
FlatButton(
    child: Text("Insert"), onPressed: () {
        phone = dataApi.insertRecord();
    }
)
</file>

More examples can be found [[https://github.com/sibvisions/flutterclient.example/blob/master/lib/screens/signature_custom_screen.dart|here]] and [[https://github.com/sibvisions/flutterclient.example/blob/master/lib/screens/contact_custom_screen.dart|here]].