1. A method of input control for text input boxes, comprising: at a device having one or more processors, memory, and a display: detecting selection of a text input box in a user interface; in response to detecting the selection of the text input box and prior to receiving input text for the text input box, obtaining a regular expression for acceptable input corresponding to text input box; for each character in the regular expression, determining whether the character belongs to a respective validation filter character set for a predetermined data type; and in response to a determination that all characters in the regular expression belongs to the respective validation filter character set for the predetermined data type, selectively presenting a respective character keyboard corresponding to the predetermined data type to a user for text entry.