ScreenToSource (Function)

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Binding between a control and a WLanguage variable or between a control and a data file item
Updating the items: Special cases

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WEBDEV

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See also

ScreenToSource (Function)

In french: EcranVersSource

Not available with this kind of connection

Automatically initializes:

the values of a data file's items in memory with the values from the controls in the window. The data file items bound to the window controls are automatically updated with the values of these controls.
the value of the WLanguage variables with the value of the window controls. The WLanguage variables bound to the window controls are automatically updated with the values of these controls.

This operation is performed regardless of the state of the controls (grayed, inactive or invisible).

Remarks:

ScreenToSource cannot be used to write to the data file: the variables of the data file items can only be updated (i.e variables of the record loaded in memory). To modify the records, use HAdd, HModify, HWrite, etc.
This function is also available for WEBDEV pages. It is equivalent to PageToSource.
Only the binding to the data file items is supported. Bindings to WLanguage variables are not supported in this version.

Example

// Click on "BTN_Add"
ScreenToSource()
HAdd(Customer)
IF HErrorDuplicates() = True THEN Error("This number already exists")

Syntax

ScreenToSource([<Window> [, <Source>]])

<Window>: Window name

Name of the window that contains the controls.
Summary: Called when a control gains focus.
If this parameter is specified, it must correspond to the name of the current page. Otherwise, an error occurs.
If this parameter is specified, it must correspond to the name of the current window. Otherwise, an error occurs.

<Source>: Optional character string

Name of the source containing the data to update. This source can be:
The name of a data file: only the controls bound to the items of the data file are taken into account.
The name of a WLanguage variable: only the controls bound to the WLanguage variable are taken into account.
Remarks:
If the name of the variable is enclosed in quotes, the control will be bound to the specified variable.
If the name of the variable is not enclosed in quotes, the control will be bound to the variable data (e.g., a variable containing the name of another variable).
If this name is not specified, all the window or page controls that are bound to a data file described in the data model editor or to a WLanguage variable will be taken into account.

Remarks

Binding between a control and a WLanguage variable or between a control and a data file item

The binding between a control and a WLanguage variable or between a control and a data file item can be determined:

In the editor, in the control description window ("Binding" tab).
Programmatically, with the DataBinding property.

Updating the items: Special cases

To automatically assign the NULL value to an item with ScreenToSource:
1. Check "Support NULL values" in the data file description.
2. Check "Allow NULL values" for the item in the data model editor.
3. Check "Return NULL if empty" in the "Details" tab of the Edit control bound to the item.
The items of the data file that are not bound to a control are not updated by ScreenToSource.
If multiple controls in the window or page are bound to the same data file item, ScreenToSource may not update the bound item properly. It is not recommended to bind multiple controls of a window or page to the same item.
ScreenToSource does not update the items with the values from Image controls. Use the HLinkMemo function.
ScreenToSource is not available on views.
Binding with "Secure Password" items: The value of the "Password" item cannot be modified until the user changes the value in the control bound to the item.

Component: wd300obj.dll