Input Field selection (caret position)

Is there any possibility to get current selected text inside Input Field or current caret position?
Something like selectionBegin, selectionEnd.
I need it to change text value from on-screen buttons (keyboard)

 

I don't think so, but you can check through the InputField source for how it manages the Caret position.

 

And where do you get that source code?

 

Here is the link to the scripting API for "InputField":

http://docs.unity3d.com/ScriptReference/UI.InputField.html

Specific to your Needs:

http://docs.unity3d.com/ScriptReference/UI.InputField-caretPosition.html
http://docs.unity3d.com/ScriptReference/UI.InputField-selectionAnchorPosition.html

This should have any answers you need for the basic stuff.

Code (CSharp):

1.  
2.                 InputField temp = gameObject.GetComponent<InputField> ();
3.  
4.                 temp.text = "1";
5.        
6.                 string stuff = temp.text;

Everything you mentioned wanting to do is explained in the API. The Code sample above is a basic method to 'get' or 'set' the text for a 'InputField'