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Computing with ioLProgrammer's GuideLanguage Reference

abs tag   add tag   align field   and tag   array tag   audio tag   backgroundColor field   bold field   border field   borderBottom field   borderColor field   borderLeft field   borderRight field   borderStyle field   borderTop field   bottom field   box tag   button tag   carat field   checkBox tag   choiceBox tag   class tag   clear tag   clientFrame tag   color field   console tag   dialog tag   div tag   do field   ellipse tag   else field   eq tag   false tag   focus field   focusOrder field   font field   for tag   ge tag   gt tag   height field   hotKey field   if tag   img tag   inf tag   inline field   input tag   invalid tag   int tag   italic field   join tag   layer field   le tag   left field   limit field   line tag   lt tag   margin field   marginBottom field   marginLeft field   marginRight field   marginTop field   mod tag   mul tag   ne tag   neg tag   not tag   null tag   num tag   onClear field   onClick field   onCommit field   onContextClick field   onExit field   onFocus field   onGet field   onKeyDown field   onKeyPress field   onKeyUp field   onMouseDown field   onMouseIn field   onMouseMove field   onMouseOut field   onMouseUp field   onPull field   onPush field   onResize field   onTimer field   openLink tag   or tag   pivot field   playing field   put tag   putError tag   putLn tag   requestTransfer tag   right field   rotate field   scalar tag   scroll field   scrollPos field   selectable field   spacing field   spacingBottom field   spacingLeft field   spacingRight field   spacingTop field   span tag   split tag   sub tag   table tag   tabRow tag   then field   timer tag   top field   transfer tag   transferAbility tag   transition field   true tag   underline field   vector tag   video tag   visible field   void tag   width field   with field   xor tag


array tag

Category: presentation tag

Creates an arbitrary number of instances of a tag according to a definition.

Each instance within the array can then be referenced and manipulated independently using a unique index number.

Sample usage

<index:array size=10 *=
  <box {This is box</n>number <index>.}>
>

— Creates and presents 10 boxes on the screen, each containing predefined text with that box's number from 1 to 10.

This is box
number 1.
This is box
number 2.
This is box
number 3.
This is box
number 4.
This is box
number 5.
This is box
number 6.
This is box
number 7.
This is box
number 8.
This is box
number 9.
This is box
number 10.

Fields

Primary field

Category: scalar field

The array tag's primary field specifies the index number of the current element within the array.

Secondary fields

Behaviour

An array creates a specified number of presentation tags or persistent logic tags. All tags are created according to a common definition, but after creation each tag in the array can be accessed and manipulated using its numerical position (known as its array index) within the array.

Each tag within the array may be referred to as an array 'element'. The definition used to create array elements must be specified in the * field before the array tag is complete. Once it has been defined, this template definition cannot be altered during the lifetime of the array tag instance. An array element definition must consist of exactly one tag, defined with any fields desired. The primary and secondary fields of that tag may themselves contain other tags as required.

The size field specifies the total number of elements in the array. Array elements are allocated index numbers from 1 up to and including the value of the size field. After the array tag is complete, the value in the size field can be changed at any time thereafter in order to resize the array. If the size value is reduced, excess elements at the end of the array are deleted. If the size value is increased, new elements are created at the end of the array according to the initial definition.

The array tag's primary field is used for getting or setting the current array index in order to access an individual element in the array, which can then be accessed using the * field.

A reference to the current element can be obtained using *.&. This is useful in cases where continued access to a particular element is needed even after the array's current index has been changed.

In order to provide access to the primary field of an array tag, an array tag should always be given a name. Take care to ensure the name chosen does not conflict with an existing tag or field of the same name within the same scope.

Example

This example takes a list of colors provided in a vector, and then creates an array of checkBoxes on the screen containing the colors from the vector.

Afterwards, a new color is inserted into the list at position 3. First the array's primary field is set to 3, then the .insert operation is used to create a new element in that position. The array definition causes the new element to be created with the color {blue}, so the new checkBox's primary field is then changed to {Magenta}, as is the color field of the new array element.


<optionList:vector {Red},{Green},{Blue},{Yellow},{Cyan}>

<optIndex:array size=optionList.#
  *=<span color=<optionList.@ optIndex> {<opt:checkBox | optionList.@ optIndex></n>}>
>

<optIndex=3><optIndex.insert>
<optIndex.*.opt={Magenta}>
<optIndex.*.color={Magenta}>
Red
Green
Magenta
Blue
Yellow
Cyan