INCLUDE

INCLUDE attribute specifies acceptable values for a field and causes Lycia to check at runtime before accepting an input value.

The element value should be placed within parentheses. Value can be one or more values, and/or ranges of values. If more than one value is used, the list must be comma separated.

Text Mode

Include fields will be rendered as normal text fields where the application verifies the contents of the field with the contents of the list.

GUI Clients

Include fields convert by default a normal text field to a combo list box. The contents of the include list will be used to populate the combo list. This behavior can be turned off by using the corresponding script option. It is also possible to specify a maximum range for the combo boxes; if the number of list values is larger than this number, no automatic combo box generation will take place.

Additionally, there is a fast range of combo list functions fgl_list_xxx() to manage, populate, search etc., the contents of the combo list box dynamically at runtime.

Usage

Each value specification is a restricted expression that cannot include the name of any 4GL variable or programmer-defined function. It can include literal values, built-in functions, operators, and the constants TRUE, FALSE, and NOTFOUND.

The same rules for DEFAULT attribute values also apply to INCLUDE values.  TEXT and BYTE fields cannot have the INCLUDE attribute.

If a field has the INCLUDE attribute, the user must enter an acceptable value (from the value list) before 4GL accepts a new row. If the value list does not include the default value, the INCLUDE attribute behaves like the REQUIRED attribute, and an acceptable entry is required. Include the NULL keyword in the value list to specify that it is acceptable for the user to press RETURN without entering any value.

f006 =       formomnly.terms,

             INCLUDE = (NULL, "Y", "N");

In this example, the NULL keyword allows the user to enter nothing. You cannot accomplish the same thing by substituting a string of blanks for the NULL keyword in the INCLUDE specification because for most data types a null value is different from ASCII 32, the blank character.

Including a COMMENTS attribute for the same field to describe acceptable values makes data entry easier because you can display a message to advise the user of whatever restrictions you have imposed on data entry:

i18 =        formonly.rating,

             INCLUDE = (1 TO 10),

             COMMENTS = "Enter your rating (1 lowest, 10 highest)";

If you include in the value list a character string that contains a blank space, a comma, or any special characters or a string that does not begin with a letter, you must enclose the entire string in quotation marks ( " ). (If you omit the quotation marks, any uppercase letters are down-shifted.)