source: trunk/lang/tcl/scripts/objects/choice/choice.rp @ 3177

# ----------------------------------------------------------------------
#  RAPPTURE OBJECT: choice
#
#  A set of mutually-exclusive choices, as in Model A or Model B.
#  Usually used as an input to a simulation.
#
# ======================================================================
#  AUTHOR:  Michael McLennan, Purdue University
#  Copyright (c) 2004-2012  HUBzero Foundation, LLC
#
#  See the file "license.terms" for information on usage and
#  redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
# ======================================================================

object choice -extends base {
    palettes "Inputs"

    help http://rappture.org/wiki/rp_xml_ele_choice

    attr options -title "Options" -type choices -path option -tooltip "List of choices that will appear on the drop-down menu in your program."

    attr default -title "Default Value" -type string -path default -only input -tooltip "Sets the value that this input has when the program first starts.  This value is used by default unless the user explicitly changes it."

    check options {
        if {[llength $attr(options)] < 2} {
            return [list warning "Should have at least two options for this choice, or it's not really a choice at all."]
        }
    }

    check default {
        if {[llength $attr(options)] > 0} {
            if {[string length [string trim $attr(default)]] == 0} {
                return [list error "Must have a default value for this choice."]
            }

            # make sure that the default is really a choice
            set defval [string trim $attr(default)]
            set found 0
            foreach rec $attr(options) {
                set label [string trim [lindex $rec 0]]
                set value [string trim [lindex $rec 1]]
                if {$defval eq $label || $defval eq $value} {
                    set found 1
                    break
                }
            }
            if {!$found} {
                return [list error "Default value must be a label or value for one of the current choices."]
            }
        }
    }

    storage {
        private variable _val   ;# current choice
    }

    import xml {xmlobj path} {
        attr import $xmlobj $path
        import_string [$xmlobj get $path.current]
    }

    export xml {xmlobj path} {
        $xmlobj put $path $_val
    }

    import string {val} {
        set _val $val
    }

    export string {var} {
        upvar $var v
        set v $_val
    }

    compare {
        return [string compare $_val $_val2]
    }
}