This chapter describes the various ways that data can be entered at the pc and stored into variables.

FORMAT:

[line] input var, var... [key] [line] input [ ['Prompt_text'] [, prompt str_expr] [, erase] [, at row, column] [, length num_expr] [, default str_expr] [, VALID str_expr] [, timeout time_limit] [, elapsed num_var] [, area num_expr, num_expr, num_expr, num_expr] [, attributes attr_list] [, screen '[text] <format>...'] [, dialogbox str_exp,] [, menu str_expr: str_var] :] var [,var. . .]

EXAMPLE:

Example 8-1 INPUT statement

input 'Please enter your first name': first$ input 'Now, enter your last name': last$ line input 'Where do you live': city$ print print 'Hello '; first$; ' '; last$ print 'From '; city$ end Please enter your first name? Sunny Now, enter your last name? Day Where do you live? San Diego, California Hello Sunny Day From San Diego, California

PURPOSE:

The INPUT statement is used to ask questions from the user and store the answers for use in a program.

DESCRIPTION:

The INPUT statement reads data typed by the user and assigns it to variables. var is a variable that the data is being assigned to. When SheerPower executes an INPUT statement, it prints any prompt given and waits for the user's response. The user's response is then assigned to the variable(s) specified.

For information on INPUT from a text file, see Chapter 14, File Handling.

The user enters data in response to the INPUT statement. The input data must be the same data type as the variable, or SheerPower generates an exception. If, in response to the INPUT statement, the user presses the [Enter] key and:

• the variable is numeric, SheerPower assigns it a 0
• the variable is a string, SheerPower assigns it a null string ("")

There are three types of INPUT statements:

• INPUT
  The INPUT statement reads one or more comma-separated data items.
  
• LINE INPUT
  The LINE INPUT statement reads an entire line of data.
  
• KEY INPUT
  The KEY INPUT statement reads a single keystroke.

There are four input styles:

1. Simple input

   Example 8-2 Simple input style

   input 'Please enter your name': name$ print 'Hello '; name$ end Please enter your name? Toby Hello Toby

   
   
   

2. Formatted data entry screens (see Section 8.17, SCREEN Option)

   Example 8-3 Formatted data entry screens

   input 'Please enter your name': name$ input screen 'Soc. sec.: <DIGITS: ###-##-####>': ssn print name$, 'Social security number:'; ssn end Please enter your name? Fred Soc. sec.: ___-__-____ (before input) Soc. sec.: 324-11-4533 (after input) Fred Social security number: 324114533

   
   
   

3. Free format multi-line text input (see Section 8.15, AREA Option)

   Example 8-4 Free format multi-line text input

   line input area 5, 10, 8, 60: text$ print at 10, 1: 'Rewrapped text' wt$ = wrap$(text$, 1, 30) print wt$ end This is an example of wrapped text. The text is wrapping.__________________________________________ ___________________________________________________ ___________________________________________________ Rewrapped text This is an example of wrapped text. The text is wrapping.

   
   
   

4. Pop-up menus (see Section 8.18, MENU Option)

   Example 8-5 Pop-up menus

   sample_menu$ = '%title "Options",' & + 'Add, Change, Delete, Inquire' line input menu sample_menu$: selection$ print 'Menu option was '; selection$ end +--Options---+ | ADD | | CHANGE | | DELETE | | INQUIRE | +------------+ Menu option was CHANGE

The INPUT statement has the following options, which are described in detail in following sections of this chapter:

PROMPT	displays the prompt text
AT row, col	positions the cursor on the desired row and column
LENGTH nn	limits the number of characters that a user can type
DEFAULT	lets you provide defaults for INPUT statements
VALID	validates user responses
TIMEOUT	limits the time the user has to respond to the INPUT prompt
AREA	does free format multi-line text input from an area on the screen
SCREEN	creates formatted data entry screens
MENU	displays and receives input from "pop-up" menus
ELAPSED	keeps track of the time it takes the user to respond to an INPUT prompt
ATTRIBUTES	displays in BOLD, BLINK, REVERSE
ERASE	clears the input line prior to accepting input and after the input has been completed
DIALOGBOX	presents the end user with simple to complex input forms. See Chapter 9, Input Dialogbox - Creating GUI Forms with SheerPower

At an input prompt, there are several commands and keystrokes that the user can enter instead of an answer to the prompt. These are:

EXIT or [Ctrl/Z]

Type the word EXIT or press [Ctrl/Z] to exit from a prompt or procedure. If one of these options is entered, SheerPower sets the internal variable _EXIT to TRUE (1).

[esc] or UP-arrow

If [esc] or the Up-arrow key is entered, the internal variable _BACK will be set to TRUE (1).

HELP or [Help]

Get help for an input item by typing the word HELP or by pressing the [Help] button in the toolbar. If one of these options is input, SheerPower sets the internal variable _HELP to TRUE (1).

_HELP should be checked before _BACK and/or _EXIT because, in some cases, all three are set on. For example, if "EXIT" is the default and the [Help] key is pressed, both _HELP and _EXIT are set on.

The internal variables _BACK, _EXIT and _HELP can be examined within a program and appropriate action can be taken.

The following keys allow the user to edit input:

Left-arrow	move left
Right-arrow	move right
Delete key	delete character(s) to the left of the cursor
TAB	move to next input field or terminate input
[CTRL/A]	toggle between insert and overstrike mode
[CTRL/E]	move to end of line
[CTRL/H]	move to beginning of line
[CTRL/J]	delete the word to the left of the cursor.
[CTRL/U]	delete all the characters on a line.
[Enter]	terminate the input; [Enter] can be pressed anywhere in the line, not only at the end of the line.

If the INPUT is to a string variable, the user can enter an unquoted or a quoted string. If the user enters an unquoted string, SheerPower ignores any leading spaces, trailing spaces, or tabs. An unquoted string cannot contain commas.

If the user enters a quoted string, SheerPower removes the quotes, and includes any leading or trailing spaces and tabs.

Example 8-6 Inputting Strings

input 'Enter your name': name1$ input 'Enter your name in quotes': name2$ input 'Enter your name in quotes with spaces': name3$ input 'Enter last name, comma, space, first name in quotes': name4$ print print name1$ print name2$ print name3$ print name4$ end Enter your name? Tony Enter your name in quotes? 'Tony' Enter your name in quotes with spaces? ' Tony ' Enter last name, comma, space, first name in quotes? 'Smith, Tony' Tony Tony Tony Smith, Tony