{{tag>category:"presentation server" }}

====== The VALUES and VALUE properties ======

=== Published 04 OCT 2015 at 11:51:16PM ===

When working with ListBox and ComboBox controls it can sometimes be a chore to derive an "internal" value from list of visible items.  In many cases this involves creating an associated array of internal values, storing them in the **MISC** property (or a custom "@" property), and then extracting this array and the **SELPOS** property at runtime to arrive at the required data.

For example:

<code>
// Set up a LIST and internal items
colorNames = "Red"    : @fm : "Green"  : @fm : "Blue"
colorVals  = 0x0000FF : @fm : 0x00FF00 : @fm : 0xFF0000

call set_Property_Only( @window : ".LIST_1", "LIST", colorNames )
call set_Property_Only( @window : ".LIST_1", "MISC", colorVals )

... 

// Then at runtime to access the currently selected internal value
colorVals = get_Property( @window : ".LIST_1", "MISC" )
selPos    = get_Property( @window : ".LIST_1", "SELPOS" )

colorVal  = colorVals

...

// Or even more long-winded, find an internal value from the external one:
colorNames = get_Property( @window : ".LIST_1", "LIST" )
colorVals  = get_Property( @window : ".LIST_1", "MISC" )

locate "Green" in colorNames using @fm setting pos then
   greenVal = colorVals
end

...

// or perhaps setting the currently selected item from an internal code:
colorNames = get_Property( @window : ".LIST_1", "LIST" )
colorVals  = get_Property( @window : ".LIST_1", "MISC" )

locate 0x00FF00 in colorVals using @fm setting pos then
   greenName = colorNames
   call set_Property_Only( @window : ".LIST_1", "TEXT", greenName )
end
</code>

To make this style of coding somewhat cleaner, OpenInsight 10 introduces the new **VALUES** property, which allows you to set an "internal" value for each item in the control, along with [[https://revdevx.wordpress.com/2013/11/17/property-indexes/|property indexing]] support.  There is also a new **VALUE** property, which is the counterpart to the standard **TEXT** property, and provides access to the currently selected item via it's internal value.

Here's the above examples rewritten to use **VALUES** and **VALUE** instead:

<code>
// Set up a LIST and internal items
colorNames = "Red"    : @fm : "Green"  : @fm : "Blue"
colorVals  = 0x0000FF : @fm : 0x00FF00 : @fm : 0xFF0000

call set_Property_Only( @window : ".LIST_1", "LIST", colorNames )
call set_Property_Only( @window : ".LIST_1", "VALUES", colorVals )

... 

// Then at runtime to access the currently selected internal value
colorVal = get_Property( @window : ".LIST_1", "VALUE" )
...

// Find an internal value from the external one:
greenVal = get_Property( @window : ".LIST_1", "VALUES", "Green" )

// or by position
greenVal = get_Property( @window : ".LIST_1", "VALUES", 2 )

...

// or perhaps setting the currently selected item from an internal code:
call set_Property_Only( @window : ".LIST_1", "VALUE", 0x00FF00 )
</code>

**VALUES** and **VALUE** apply to both ListBox and ComboBox controls.

//(Disclaimer: This article is based on preliminary information and may be subject to change in the final release version of OpenInsight 10).//


=== Comments ===


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=== At 05 OCT 2015 01:29AM Don Bakke wrote:  ===

<QUOTE>This certainly seems like a helpful improvement. Another way to avoid the cumbersome approach is to create a UDC that displays one value and returns another.

</QUOTE>

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=== At 05 OCT 2015 01:11PM Craig Tildesley wrote:  ===

<QUOTE>I can't remember if you already said but is VALUE read only or can you set your listbox/combo using it?

</QUOTE>

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=== At 05 OCT 2015 01:55PM Captain C wrote:  ===

<QUOTE>Hi Craig - you can use it to set the current selection if you wish - look at the last statement in the second code example to see how it's done.

</QUOTE>





== Original ID: revdevx.wordpress.com/?p=1457 ==