Info Catalog elisp: Minibuffer History elisp: Minibuffers elisp: Completion

elisp: Initial Input

 
 19.5 Initial Input
 ==================
 
 Several of the functions for minibuffer input have an argument called
 INITIAL.  This is a mostly-deprecated feature for specifying that the
 minibuffer should start out with certain text, instead of empty as
 usual.
 
    If INITIAL is a string, the minibuffer starts out containing the text
 of the string, with point at the end, when the user starts to edit the
 text.  If the user simply types <RET> to exit the minibuffer, it will
 use the initial input string to determine the value to return.
 
    *We discourage use of a non-‘nil’ value for INITIAL*, because initial
 input is an intrusive interface.  History lists and default values
 provide a much more convenient method to offer useful default inputs to
 the user.
 
    There is just one situation where you should specify a string for an
 INITIAL argument.  This is when you specify a cons cell for the HISTORY
 argument.  Minibuffer History.
 
    INITIAL can also be a cons cell of the form ‘(STRING . POSITION)’.
 This means to insert STRING in the minibuffer but put point at POSITION
 within the string’s text.
 
    As a historical accident, POSITION was implemented inconsistently in
 different functions.  In ‘completing-read’, POSITION’s value is
 interpreted as origin-zero; that is, a value of 0 means the beginning of
 the string, 1 means after the first character, etc.  In
 ‘read-minibuffer’, and the other non-completion minibuffer input
 functions that support this argument, 1 means the beginning of the
 string, 2 means after the first character, etc.
 
    Use of a cons cell as the value for INITIAL arguments is deprecated.
 

Info Catalog elisp: Minibuffer History elisp: Minibuffers elisp: Completion