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TCustomDataSetAdapterField.ImplGetNeedPrevValue Method
TCustomDataSetAdapterField Class | TCustomDataSetAdapterField Members | DBAdapt Namespace | Description | See Also
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Provides the underlying implementation for the GetNeedPrevValue method.

Pascal
function ImplGetNeedPrevValue: Boolean; virtual;
C++
virtual __fastcall Boolean ImplGetNeedPrevValue();
Description

GetNeedPrevValue calls ImplGetNeedPrevValue to determine whether an HTML form should include a hidden field that stores this field's value. This method returns true if the parent dataset adapter is in edit mode and this field's FieldFlags property includes ffInOrigValues. Otherwise, ImplGetNeedPrevValue returns false. 

By including the current field value as a hidden field when the dataset adapter is in edit mode, this field ensures that update requests from the HTML form include sufficient information for locating the record that should be updated. When the dataset adapter is in any other mode, there is no need to locate a particular record in the dataset. 

 

See Also
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