ListInsert (Function)

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List control with more than 10,000 elements
Visibility/Invisibility of elements in a List Box or Combo Box control
Customizing the elements found in a List Box or Combo Box control
Sorted/Unsorted List Box control
Tabulations: Multi-selection List Box control
Adding an element to the browser
Miscellaneous

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ListInsert (Function)

In french: ListeInsère

Inserts an element into a List Box, ListView or Combo Box control populated programmatically.

Remarks:

To add an element at the end of List Box (or Combo Box) control, use ListAdd.
ListInsert can be used on single-selection and multi-selection List Box controls
To manage the contents of a Combo Box control in a container column of a Table control, use the Content property.

Caution: The element will only be added to the page displayed in the browser. For more details, see Remarks.

Example

// Add "Clark" in 4th position to "LIST_CustomerList"
ListInsert(LIST_CustomerList, "Clark", 4)

// Add the "C:\MyImages\CoralReef.JPG" image in 5th position to "LSV_Diving"
// The caption of this image will be "Nice coral"
ListInsert(LSV_Diving, "Nice coral", "C:\MyImages\CoralReef.JPG", 4)

Syntax

<Result> = ListInsert(<List Box control> , <Element> [, <Image> [, <Element index>]])

<Result>: Boolean

True if the element was inserted,
False otherwise.
ListInsert returns no result.

<List Box control>: Control name

Name of List Box or Combo Box control populated programmatically.
If this parameter corresponds to an empty string (""), the element is inserted in the List Box or Combo Box control to which the current process belongs.
The name of List Box or Combo Box control to use must necessarily be specified.

<Element>: Character string

Element that must be inserted into the specified List Box (or Combo Box) control populated programmatically.
This parameter can contain:
Carriage Return characters (CR) to add several rows. In this case:
if <Element index> is not specified, the elements are added.
If <Element index> is specified, only the first element will be added.
tabs (TAB) to obtain a multi-element List Box control (see Notes).
For a ListView control, this parameter corresponds to the image caption. This parameter can contain Carriage Return characters (CR) to add several elements. In this case:
if <Image> and <Element index> are not specified, the added elements will be associated with the default image (defined in the "Details" tab of the control description window).
if <Image> and <Element index> are specified, only the first element will be added. This element will be associated with the default image (defined in the "Details" tab of the description window of control).
if <Image> is specified and if <Element index> is not specified, only the first element will be added. This element will be associated with the specified image.
The Carriage Return characters (CR) and the tabulations (TAB) are not supported.
To add several consecutive spaces, non-breakable space characters must be used: Charact(160).

<Image>: Optional character string

Name and path of image that will be added into a ListView control. This parameter is taken into account for ListView controls displayed in ListView mode only. If this parameter is not specified, the default image (defined in the "Details" tab in the description window of control) will be used.
This parameter is not available.

<Element index>: Optional integer

Index of the element to be inserted.
If this parameter:
is not specified, the element is inserted:
before the current element in a single-selection List Box control. If there is no current element, the element is inserted at the last position in the List Box (or Combo Box) control populated programmatically.
at the last position in the List Box (or Combo Box) control populated programmatically, in a multi-selection List Box control.
is greater than the number of elements in the List Box (or Combo Box) control, the element is inserted at the last position in the List Box (or Combo Box) control populated programmatically. The number of elements in a List Box (or Combo Box) control is returned by ListCount.
is equal to 0, the element is added at the first position in the List Box (or Combo Box) control populated programmatically.

Remarks

List control with more than 10,000 elements

The maximum number of elements in a List Box control is only limited by the available memory (theoretical maximum: 2 billion rows). Nevertheless, populating a List Box control with a large number of elements (more than 10,000) affects performance.
To add a large number of elements, it is recommended to use a List Box control based on an HFSQL data file.

Visibility/Invisibility of elements in a List Box or Combo Box control

To make an element invisible in a List Box or Combo Box control, use gStoredValue.

Customizing the elements found in a List Box or Combo Box control

To customize the elements in a List Box or Combo Box control (background color, image, drawing, etc.), use Graphic string management functions.

Sorted/Unsorted List Box control

If the List Box control is sorted, the new element is inserted at the current position without sorting the list box.
If the List Box control is not sorted, the new element is added:
- at <Element index> if <Element index> is specified.
- before the current element in a single-selection List Box control if the <Element index> parameter is not specified. If there is no current element, the element is inserted at the last position in the List Box (or Combo Box) control populated programmatically.
- at the last position of the List Box (or Combo Box) control populated programmatically in a multi-selection List Box control, if the <Element index> is not specified.

The type of the List Box control (sorted or not) is selected during the control description ("Details" tab).

Use ListAdd rather than ListInsert to add an element to a sorted List Box control.

The element is added at the end of control, no matter whether the List Box control is sorted or not.

Tabulations: Multi-selection List Box control

To manage the tabulations in a List Box control (alignment of columns), use the TAB constant. For example:

ListInsert(LIST_Customer, LastName + TAB + FirstName)

In this example, all the first names start at the same position and are aligned one under the other.

Remark: The first call to ListInsert defines the position of tabulations. These positions will be taken as reference for all values added thereafter. Similarly, if values have been typed entered in the editor, the positions of these values are taken as reference. During the first call to ListInsert, we advise you to define the width of columns with Complete. For example, to fix the width of columns found in "LIST_Customer" to 10 characters:

ListInsert(LIST_Customer, Complète(LastName, 10) + TAB + Complète(FirstName, 10))

Adding an element to the browser

When adding an element in browser code, this element is added to the page displayed in the browser only. In order for this element to be added onto the server, ListInsert must be run on the server.

Calling ListInsert in browser code is useful when using AJAX technology, in "Programmed AJAX" mode (via AJAXExecute or AJAXExecuteAsynchronous).

Reminder: In "Automatic and immediate AJAX" mode, all you have to do is switch the server process containing ListInsert to automatic AJAX mode. That's it! No additional programming is required. For more details, see AJAX.

Miscellaneous

To insert an element into a Table control, use TableInsert.
ListInsert can be used on a "Combo Box" column in a Table control .

Component: wd290obj.dll