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737 lines
34 KiB
XML
737 lines
34 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
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<fpdoc-descriptions>
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<package name="lcl">
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<!--
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====================================================================
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DBActns
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====================================================================
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-->
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<module name="DBActns">
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<short>
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Standard actions used to navigate and manipulate a dataset in a datasource.
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</short>
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<descr>
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<p>
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<file>dbactns.pp</file> contains classes used to implement <var>TDataSetAction</var> and its descendants. They are dataset-aware actions used to navigate and manipulate a dataset in a datasource.
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</p>
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<p>
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This file is part of the Lazarus Component Library (<b>LCL</b>).
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</p>
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<p>
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The following components are registered but not displayed on the Lazarus IDE component palette:
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</p>
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<ul>
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<li>TDataSetFirst</li>
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<li>TDataSetLast</li>
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<li>TDataSetNext</li>
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<li>TDataSetPrior</li>
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<li>TDataSetRefresh</li>
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<li>TDataSetCancel</li>
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<li>TDataSetDelete</li>
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<li>TDataSetEdit</li>
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<li>TDataSetInsert</li>
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<li>TDataSetPost</li>
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</ul>
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</descr>
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<element name="Classes"/>
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<element name="DB"/>
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<element name="ActnList"/>
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<element name="TDataSetAction">
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<short>
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<var>TDataSetAction</var> is the base class for all other standard <var>TDataSet</var> actions.
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</short>
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<descr>
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<p>
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<var>TDataSetAction</var> is a <var>TAction</var> descendant that is the base class for all other standard <var>TDataSet</var> actions. TDataSetAction provides properties and methods which enables an action to be applied to a DataSource and its associated dataset.
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</p>
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<p>
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<var>TDataSetAction</var> provides an overridden Notification method to perform component notifications when the <var>DataSource</var> is removed for the action. A virtual <var>GetDataSet</var> method is implemented to ensure that a <var>DataSource</var> is cast to a <var>TDataSource</var> class instance prior to accessing its dataset. The <var>HandlesTarget</var> method is overridden to determine if the class includes both a valid datasource and a dataset for a specified target.
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</p>
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<p>
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Applications do not use instances of <var>TDataSetAction</var>; use one of the descendent classes that perform a specific action for a dataset.
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</p>
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</descr>
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<seealso>
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<link id="TDataSetFirst"/>
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<link id="TDataSetLast"/>
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<link id="TDataSetNext"/>
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<link id="TDataSetPrior"/>
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<link id="TDataSetRefresh"/>
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<link id="TDataSetCancel"/>
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<link id="TDataSetDelete"/>
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<link id="TDataSetEdit"/>
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<link id="TDataSetInsert"/>
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<link id="TDataSetPost"/>
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<link id="#lcl.actnlist.TAction">TAction</link>
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</seealso>
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</element>
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<element name="TDataSetAction.FDataSource" link="#lcl.dbactns.TDataSetAction.DataSource"/>
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<element name="TDataSetAction.SetDataSource">
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<short>Sets the value for the DataSource property.</short>
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<seealso>
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<link id="TDataSetAction.DataSource"/>
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</seealso>
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</element>
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<element name="TDataSetAction.SetDataSource.Value">
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<short>New value for the property.</short>
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</element>
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<element name="TDataSetAction.Notification">
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<short>
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Performs a notification when the datasource for the component is removed.
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</short>
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<descr>
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<p>
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<var>Notification</var> is an overridden procedure used to perform a notification message when the specified component is removed. <var>AComponent</var> contains the component for the notification message. <var>Operation</var> contains the operation for the notification message.
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</p>
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<p>
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<var>Notification</var> calls the inherited method. When <var>Operation</var> contains the value <var>opRemove</var> and <var>AComponent</var> contains the same class instance as the <var>DataSource</var> property, the <var>DataSource</var> property is set to <b>Nil</b>.
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</p>
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</descr>
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<seealso>
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<link id="TDataSetAction.DataSource"/>
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</seealso>
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</element>
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<element name="TDataSetAction.Notification.AComponent">
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<short>Component for the notification.</short>
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</element>
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<element name="TDataSetAction.Notification.Operation">
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<short>Operation for the notification.</short>
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</element>
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<element name="TDataSetAction.GetDataSet">
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<short>Gets the Dataset assigned to the specified target datasource.</short>
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<descr/>
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<seealso/>
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</element>
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<element name="TDataSetAction.GetDataSet.Result">
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<short>TDataSet assigned to the specified target datasource.</short>
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</element>
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<element name="TDataSetAction.GetDataSet.Target">
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<short>DataSource object examined in the method.</short>
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</element>
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<element name="TDataSetAction.HandlesTarget">
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<short>Indicates if the action is handled for the specified target.</short>
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<descr/>
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<seealso/>
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</element>
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<element name="TDataSetAction.HandlesTarget.Result">
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<short>True when a valid DataSource and DataSet exist in the Target.</short>
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</element>
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<element name="TDataSetAction.HandlesTarget.Target">
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<short>Object instance examined in the method.</short>
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</element>
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<element name="TDataSetAction.DataSource">
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<short>
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DataSource with the dataset for the action.
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</short>
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<descr>
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<p>
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<var>DataSource</var> is a <var>TDataSource</var> property which provides access to properties, methods, and events for the <var>TDataSet</var> used in the data source. Changing the value for <var>DataSource</var> causes a free notification message to be performed for the new class instance used as the value for the property.
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</p>
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</descr>
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<seealso/>
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</element>
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<element name="TDataSetFirst">
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<short>
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<var>TDataSetFirst</var> moves to first record in the <var>DataSet</var>.
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</short>
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<descr>
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<p>
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<var>TDataSetFirst</var> is a <var>TDataSetAction</var> descendant which moves to the first record in the dataset for a DataSource. TDataSetFirst can be added to an action list and assigned to controls which perform the corresponding action.
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</p>
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<p>
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<var>TDataSetFirst</var> publishes the <var>DataSource</var> property which explicitly declares the target for the database action. The DataSource may be determined by examining a data-aware control which used the database action, and passed an an argument to the UpdateTarget and HandlesTarget methods.
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</p>
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</descr>
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<seealso>
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<link id="TDataSetLast"/>
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<link id="TDataSetNext"/>
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<link id="TDataSetPrior"/>
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<link id="TDataSetRefresh"/>
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<link id="TDataSetCancel"/>
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<link id="TDataSetDelete"/>
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<link id="TDataSetEdit"/>
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<link id="TDataSetInsert"/>
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<link id="TDataSetPost"/>
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<link id="TDataSetAction"/>
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</seealso>
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</element>
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<element name="TDataSetFirst.ExecuteTarget">
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<short>
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Retrieves the dataset for the target datasource and calls its First method.
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</short>
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<descr/>
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<seealso/>
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</element>
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<element name="TDataSetFirst.ExecuteTarget.Target">
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<short>Target where the action is performed in the method.</short>
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</element>
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<element name="TDataSetFirst.UpdateTarget">
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<short>
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Enables or disables the action based on the state of the dataset in the target.
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</short>
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<descr>
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<p>
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<var>UpdateTarget</var> is an overridden method which enables or disables the database action based on the state of the dataset in the Target object. <var>UpdateTarget</var> calls the <var>GetDataSet</var> method to retrieve the dataset in the Target datasource. The action is Enabled when the dataset is active and not already positioned at its beginning (or first record). This ensures that the action cannot be performed for a dataset that has not been opened, or does not require repositioning.
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</p>
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</descr>
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<seealso/>
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</element>
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<element name="TDataSetFirst.UpdateTarget.Target">
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<short>Target datasource examined in the method.</short>
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</element>
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<element name="TDataSetFirst.DataSource" link="#lcl.dbactns.TDataSetAction.DataSource"/>
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<element name="TDataSetLast">
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<short>
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<var>TDataSetLast</var> moves to last record in the <var>DataSet</var>.
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</short>
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<descr>
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<p>
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<var>TDataSetLast</var> is a <var>TDataSetAction</var> descendant which moves to the last record in the dataset for a DataSource. TDataSetLast can be added to an action list and assigned to controls which perform the corresponding action.
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</p>
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<p>
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<var>TDataSetLast</var> publishes the DataSource property which explicitly declares the target for the database action. The DataSource may be determined by examining a data-aware control which used the database action, and passed an an argument to the UpdateTarget and HandlesTarget methods.
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</p>
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</descr>
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<seealso>
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<link id="TDataSetFirst"/>
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<link id="TDataSetNext"/>
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<link id="TDataSetPrior"/>
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<link id="TDataSetRefresh"/>
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<link id="TDataSetCancel"/>
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<link id="TDataSetDelete"/>
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<link id="TDataSetEdit"/>
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<link id="TDataSetInsert"/>
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<link id="TDataSetPost"/>
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<link id="TDataSetAction"/>
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</seealso>
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</element>
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<element name="TDataSetLast.ExecuteTarget">
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<short>
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Retrieves the dataset for the target datasource and calls its Last method.
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</short>
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<descr/>
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<seealso/>
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</element>
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<element name="TDataSetLast.ExecuteTarget.Target">
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<short>Target datasource examined in the method.</short>
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</element>
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<element name="TDataSetLast.UpdateTarget">
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<short>
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Enables or disables the action based on the state of the dataset in the target.
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</short>
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<descr>
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<p>
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<var>UpdateTarget</var> is an overridden method which enables or disables the database action based on the state of the dataset in the Target object.
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</p>
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<p>
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<var>UpdateTarget</var> calls the <var>GetDataSet</var> method to retrieve the dataset in the Target datasource. The action is Enabled when the dataset is active and not already positioned at end-of-file (last record). This ensures that the action cannot be performed for a dataset that has not been opened, or does not require repositioning.
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</p>
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</descr>
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<seealso/>
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</element>
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<element name="TDataSetLast.UpdateTarget.Target">
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<short>Target datasource examined in the method.</short>
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</element>
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<element name="TDataSetLast.DataSource" link="#lcl.dbactns.TDataSetAction.DataSource"/>
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<element name="TDataSetNext">
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<short>
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<var>TDataSetNext</var> moves to next record in the <var>DataSet</var>.
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</short>
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<descr>
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<p>
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<var>TDataSetNext</var> is a <var>TDataSetAction</var> descendant which moves to the next record in the dataset for a DataSource. TDataSetNext can be added to an action list and assigned to controls which perform the corresponding action.
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</p>
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<p>
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<var>TDataSetNext</var> publishes the DataSource property which explicitly declares the target for the database action. The DataSource may be determined by examining a data-aware control which uses the database action, and passed an an argument to the UpdateTarget and HandlesTarget methods.
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</p>
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</descr>
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<seealso>
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<link id="TDataSetFirst"/>
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<link id="TDataSetLast"/>
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<link id="TDataSetPrior"/>
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<link id="TDataSetRefresh"/>
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<link id="TDataSetCancel"/>
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<link id="TDataSetDelete"/>
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<link id="TDataSetEdit"/>
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<link id="TDataSetInsert"/>
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<link id="TDataSetPost"/>
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<link id="TDataSetAction"/>
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</seealso>
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</element>
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<element name="TDataSetNext.ExecuteTarget">
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<short>
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Retrieves the dataset for the target datasource and calls its Next method.
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</short>
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<descr/>
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<seealso/>
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</element>
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<element name="TDataSetNext.ExecuteTarget.Target">
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<short>DataSource object examined in the method.</short>
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</element>
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<element name="TDataSetNext.UpdateTarget">
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<short>
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Enables or disables the action based on the state of the dataset in the target.
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</short>
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<descr>
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<p>
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<var>UpdateTarget</var> is an overridden method which enables or disables the database action based on the state of the dataset in the Target object.
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</p>
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<p>
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<var>UpdateTarget</var> calls the <var>GetDataSet</var> method to retrieve the dataset in the Target datasource. The action is Enabled when the dataset is active and not already positioned at end-of-file (or last record). This ensures that the action cannot be performed for a dataset that has not been opened, or does not require repositioning.
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</p>
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</descr>
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<seealso/>
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</element>
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<element name="TDataSetNext.UpdateTarget.Target">
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<short>DataSource object examined in the method.</short>
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</element>
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<element name="TDataSetNext.DataSource" link="#lcl.dbactns.TDataSetAction.DataSource"/>
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<element name="TDataSetPrior">
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<short>
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<var>TDataSetPrior</var> moves to previous record in the <var>DataSet</var>.
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</short>
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<descr>
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<p>
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<var>TDataSetPrior</var> is a <var>TDataSetAction</var> descendant which moves to the previous record in the dataset for a DataSource. TDataSetPrior can be added to an action list and assigned to controls which perform the corresponding action.
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</p>
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<p>
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<var>TDataSetPrior</var> publishes the DataSource property which explicitly declares the target for the database action. The DataSource may be determined by examining a data-aware control which used the database action, and passed an an argument to the UpdateTarget and HandlesTarget methods.
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</p>
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</descr>
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<seealso>
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<link id="TDataSetFirst"/>
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<link id="TDataSetLast"/>
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<link id="TDataSetNext"/>
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<link id="TDataSetRefresh"/>
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<link id="TDataSetCancel"/>
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<link id="TDataSetDelete"/>
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<link id="TDataSetEdit"/>
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<link id="TDataSetInsert"/>
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<link id="TDataSetPost"/>
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<link id="TDataSetAction"/>
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</seealso>
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</element>
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<element name="TDataSetPrior.ExecuteTarget">
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<short>
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Retrieves the dataset for the target datasource and calls its Prior method.
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</short>
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<descr/>
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<seealso/>
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</element>
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<element name="TDataSetPrior.ExecuteTarget.Target">
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<short>DataSource object examined in the method.</short>
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</element>
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<element name="TDataSetPrior.UpdateTarget">
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<short>
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Enables or disables the action based on the state of the dataset in the target.
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</short>
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<descr>
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<p>
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<var>UpdateTarget</var> is an overridden method which enables or disables the database action based on the state of the dataset in the Target object.
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</p>
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<p>
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<var>UpdateTarget</var> calls the <var>GetDataSet</var> method to retrieve the dataset in the Target datasource. The action is Enabled when the dataset is active and not already positioned at its beginning (or first record). This ensures that the action cannot be performed for a dataset that has not been opened, or does not require repositioning.
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</p>
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</descr>
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<seealso/>
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</element>
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<element name="TDataSetPrior.UpdateTarget.Target">
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<short>DataSource object examined in the method.</short>
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</element>
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<element name="TDataSetPrior.DataSource" link="#lcl.dbactns.TDataSetAction.DataSource"/>
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<element name="TDataSetRefresh">
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<short>
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<var>TDataSetRefresh</var> refreshes the <var>DataSet</var>.
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</short>
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<descr>
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<p>
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<var>TDataSetRefresh</var> is a <var>TDataSetAction</var> descendant which refreshes the record content in the dataset for a DataSource. TDataSetRefresh can be added to an action list and assigned to controls which perform the corresponding action.
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</p>
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<p>
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<var>TDataSetRefresh</var> publishes the DataSource property which explicitly declares the target for the database action. The DataSource may be determined by examining a data-aware control which used the database action, and passed an an argument to the UpdateTarget and HandlesTarget methods.
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</p>
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</descr>
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<seealso>
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<link id="TDataSetFirst"/>
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<link id="TDataSetLast"/>
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<link id="TDataSetNext"/>
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<link id="TDataSetPrior"/>
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<link id="TDataSetCancel"/>
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<link id="TDataSetDelete"/>
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<link id="TDataSetEdit"/>
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<link id="TDataSetInsert"/>
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<link id="TDataSetPost"/>
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<link id="TDataSetAction"/>
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</seealso>
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</element>
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<element name="TDataSetRefresh.ExecuteTarget">
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<short>
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Retrieves the dataset for the target datasource and calls its Refresh method.
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</short>
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<descr/>
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<seealso/>
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</element>
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<element name="TDataSetRefresh.ExecuteTarget.Target">
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<short>DataSource object examined in the method.</short>
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</element>
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<element name="TDataSetRefresh.UpdateTarget">
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<short>
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Enables or disables the action based on the state of the dataset in the target.
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</short>
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<descr>
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<p>
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<var>UpdateTarget</var> is an overridden method which enables or disables the database action based on the state of the dataset in the <var>Target</var> object.
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</p>
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<p>
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<var>UpdateTarget</var> calls the <var>GetDataSet</var> method to retrieve the dataset in the Target datasource. The action is Enabled when the dataset is active. This ensures that the action cannot be performed for a dataset that has not been opened.
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</p>
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</descr>
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<seealso/>
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</element>
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<element name="TDataSetRefresh.UpdateTarget.Target">
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<short>DataSource object examined in the method.</short>
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</element>
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<element name="TDataSetRefresh.DataSource" link="#lcl.dbactns.TDataSetAction.DataSource"/>
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<element name="TDataSetCancel">
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<short>
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<var>TDataSetCancel</var> cancels the current edit mode for a <var>DataSet</var>.
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</short>
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<descr>
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<p>
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<var>TDataSetCancel</var> is a <var>TDataSetAction</var> descendant which cancels the current edit mode for a dataset record in its DataSource. This includes restoring the values in records to their pre-editing content, updating the record display, and removing any edit mode(s) assigned to the State property in the dataset. TDataSetCancel can be added to an action list and assigned to controls which perform the corresponding action.
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</p>
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<p>
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<var>TDataSetCancel</var> publishes the DataSource property which explicitly declares the target for the database action. The DataSource may be determined by examining a data-aware control which used the database action, and passed an an argument to the UpdateTarget and HandlesTarget methods.
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</p>
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</descr>
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<seealso>
|
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<link id="TDataSetFirst"/>
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<link id="TDataSetLast"/>
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<link id="TDataSetNext"/>
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<link id="TDataSetPrior"/>
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<link id="TDataSetRefresh"/>
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<link id="TDataSetDelete"/>
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<link id="TDataSetEdit"/>
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<link id="TDataSetInsert"/>
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<link id="TDataSetPost"/>
|
|
<link id="TDataSetAction"/>
|
|
</seealso>
|
|
</element>
|
|
|
|
<element name="TDataSetCancel.ExecuteTarget">
|
|
<short>
|
|
Retrieves the dataset for the target datasource and calls its Cancel method.
|
|
</short>
|
|
<descr/>
|
|
<seealso/>
|
|
</element>
|
|
<element name="TDataSetCancel.ExecuteTarget.Target">
|
|
<short>DataSource object examined in the method.</short>
|
|
</element>
|
|
|
|
<element name="TDataSetCancel.UpdateTarget">
|
|
<short>
|
|
Enables or disables the action based on the state of the dataset in the target.
|
|
</short>
|
|
<descr>
|
|
<p>
|
|
<var>UpdateTarget</var> is an overridden method which enables or disables the database action based on the state of the dataset in the <var>Target</var> object.
|
|
</p>
|
|
<p>
|
|
<var>UpdateTarget</var> calls the <var>GetDataSet</var> method to retrieve the dataset in the Target datasource. The action is <var>Enabled</var> when the dataset is active, and the value in its <var>State</var> property is in the <var>dsEditModes</var> set. This ensures that the action cannot be performed for a dataset that has not been opened, or has not been placed in edit mode.
|
|
</p>
|
|
</descr>
|
|
<seealso/>
|
|
</element>
|
|
<element name="TDataSetCancel.UpdateTarget.Target">
|
|
<short>DataSource object examined in the method.</short>
|
|
</element>
|
|
|
|
<element name="TDataSetCancel.DataSource" link="#lcl.dbactns.TDataSetAction.DataSource"/>
|
|
|
|
<element name="TDataSetDelete">
|
|
<short>
|
|
<var>TDataSetDelete</var> deletes the current record in the <var>DataSet</var>.
|
|
</short>
|
|
<descr>
|
|
<p>
|
|
<var>TDataSetDelete</var> is a <var>TDataSetAction</var> descendant which deletes the current record in the dataset for the target DataSource.
|
|
</p>
|
|
<p>
|
|
Delete behavior is dependent on the underlying database engine. Datasets using the DBF engine simply mark a record for deletion; it is not physically removed until the database engine packs the storage structure. Other datasets, such SQL-based ones, may require that changes be committed before they are flushed to the database engine.
|
|
</p>
|
|
<p>
|
|
<var>TDataSetDelete</var> publishes the <var>DataSource</var> property which explicitly declares the target for the database action. The DataSource may be determined by examining a data-aware control which used the database action, and passed an an argument to the <var>UpdateTarget</var> and <var>HandlesTarget</var> methods.
|
|
</p>
|
|
</descr>
|
|
<seealso>
|
|
<link id="TDataSetFirst"/>
|
|
<link id="TDataSetLast"/>
|
|
<link id="TDataSetNext"/>
|
|
<link id="TDataSetPrior"/>
|
|
<link id="TDataSetRefresh"/>
|
|
<link id="TDataSetCancel"/>
|
|
<link id="TDataSetEdit"/>
|
|
<link id="TDataSetInsert"/>
|
|
<link id="TDataSetPost"/>
|
|
<link id="TDataSetAction"/>
|
|
</seealso>
|
|
</element>
|
|
|
|
<element name="TDataSetDelete.ExecuteTarget">
|
|
<short>
|
|
Retrieves the dataset for the target datasource and calls its Delete method.
|
|
</short>
|
|
<descr/>
|
|
<seealso/>
|
|
</element>
|
|
<element name="TDataSetDelete.ExecuteTarget.Target">
|
|
<short>DataSource object examined in the method.</short>
|
|
</element>
|
|
|
|
<element name="TDataSetDelete.UpdateTarget">
|
|
<short>
|
|
Enables or disables the action based on the state of the dataset in the target.
|
|
</short>
|
|
<descr>
|
|
<p>
|
|
<var>UpdateTarget</var> is an overridden method which enables or disables the database action based on the state of the dataset in the Target object.
|
|
</p>
|
|
<p>
|
|
<var>UpdateTarget</var> calls the <var>GetDataSet</var> method to retrieve the dataset in the Target datasource. The action is Enabled when the dataset is active, is not positioned at the beginning- or end-of-file, and contains <b>True</b> in its <var>CanModify</var> property. This ensures that the action cannot be performed for a dataset that has not been opened, or when the current record cannot be modified.
|
|
</p>
|
|
</descr>
|
|
<seealso/>
|
|
</element>
|
|
<element name="TDataSetDelete.UpdateTarget.Target">
|
|
<short>DataSource object examined in the method.</short>
|
|
</element>
|
|
|
|
<element name="TDataSetDelete.DataSource" link="#lcl.dbactns.TDataSetAction.DataSource"/>
|
|
|
|
<element name="TDataSetEdit">
|
|
<short>
|
|
<var>TDataSetEdit</var> edits the current record in the <var>DataSet</var>.
|
|
</short>
|
|
<descr>
|
|
<p>
|
|
<var>TDataSetEdit</var> is a <var>TDataSetAction</var> descendant which edits the current record in the dataset for the target DataSource. TDataSetEdit ensures that the dataset is placed in edit mode (when available) by calling the Edit method for the dataset. Edit behavior is dependent on the underlying database engine.
|
|
</p>
|
|
<p>
|
|
<var>TDataSetEdit</var> publishes the DataSource property which explicitly declares the target for the database action. The DataSource may be determined by examining a data-aware control which used the database action, and passed an an argument to the UpdateTarget and HandlesTarget methods.
|
|
</p>
|
|
</descr>
|
|
<seealso>
|
|
<link id="TDataSetFirst"/>
|
|
<link id="TDataSetLast"/>
|
|
<link id="TDataSetNext"/>
|
|
<link id="TDataSetPrior"/>
|
|
<link id="TDataSetRefresh"/>
|
|
<link id="TDataSetCancel"/>
|
|
<link id="TDataSetDelete"/>
|
|
<link id="TDataSetInsert"/>
|
|
<link id="TDataSetPost"/>
|
|
</seealso>
|
|
</element>
|
|
|
|
<element name="TDataSetEdit.ExecuteTarget">
|
|
<short>
|
|
Retrieves the dataset for the target datasource and calls its Edit method.
|
|
</short>
|
|
<descr/>
|
|
<seealso/>
|
|
</element>
|
|
<element name="TDataSetEdit.ExecuteTarget.Target">
|
|
<short>DataSource object examined in the method.</short>
|
|
</element>
|
|
|
|
<element name="TDataSetEdit.UpdateTarget">
|
|
<short>
|
|
Enables or disables the action based on the state of the dataset in the target.
|
|
</short>
|
|
<descr>
|
|
<p>
|
|
<var>UpdateTarget</var> is an overridden method which enables or disables the database action based on the state of the dataset in the Target object.
|
|
</p>
|
|
<p>
|
|
<var>UpdateTarget</var> calls the <var>GetDataSet</var> method to retrieve the dataset in the Target datasource. The action is Enabled when the dataset is active, contains <b>True</b> in its <var>CanModify</var> property, and the value in its <var>State</var> property is in the <var>dsEditModes</var> set. This ensures that the action cannot be performed for a dataset that has not been opened, has not been placed in edit mode, or the current record cannot be modified.
|
|
</p>
|
|
</descr>
|
|
<seealso/>
|
|
</element>
|
|
<element name="TDataSetEdit.UpdateTarget.Target">
|
|
<short>DataSource object examined in the method.</short>
|
|
</element>
|
|
|
|
<element name="TDataSetEdit.DataSource" link="#lcl.dbactns.TDataSetAction.DataSource"/>
|
|
|
|
<element name="TDataSetInsert">
|
|
<short>
|
|
<var>TDataSetInsert</var> inserts (appends) a new record into the <var>DataSet</var>.
|
|
</short>
|
|
<descr>
|
|
<p>
|
|
<var>TDataSetInsert</var> is a <var>TDataSetAction</var> descendant which inserts a new record into the dataset for the target DataSource. The new record has blank values in each of its fields, and allows editing of the field values.
|
|
</p>
|
|
<p>
|
|
Positioning of the inserted record is actually determined using the facilities for the underlying database engine. In most cases, the record is simply appended to its data store and ordered using the indexing facilities for the database engine. Some database engines require an additional step to make the record insertion and/or field editing permanent; i.e. SQL databases require use of a COMMIT statement to flush the changes to the database engine.
|
|
</p>
|
|
<p>
|
|
TDataSetInsert calls the <var>Insert</var> method for the target dataset to perform the databse action.
|
|
</p>
|
|
</descr>
|
|
<seealso>
|
|
<link id="TDataSetFirst"/>
|
|
<link id="TDataSetLast"/>
|
|
<link id="TDataSetNext"/>
|
|
<link id="TDataSetPrior"/>
|
|
<link id="TDataSetRefresh"/>
|
|
<link id="TDataSetCancel"/>
|
|
<link id="TDataSetDelete"/>
|
|
<link id="TDataSetEdit"/>
|
|
<link id="TDataSetPost"/>
|
|
<link id="TDataSetAction"/>
|
|
</seealso>
|
|
</element>
|
|
|
|
<element name="TDataSetInsert.ExecuteTarget">
|
|
<short>
|
|
Retrieves the dataset for the target datasource and calls its Insert method.
|
|
</short>
|
|
<descr/>
|
|
<seealso/>
|
|
</element>
|
|
<element name="TDataSetInsert.ExecuteTarget.Target">
|
|
<short>DataSource object examined in the method.</short>
|
|
</element>
|
|
|
|
<element name="TDataSetInsert.UpdateTarget">
|
|
<short>
|
|
Enables or disables the action based on the state of the dataset in the target.
|
|
</short>
|
|
<descr>
|
|
<p>
|
|
<var>UpdateTarget</var> is an overridden method which enables or disables the database action based on the state of the dataset in the Target object. <var>UpdateTarget</var> calls the <var>GetDataSet</var> method to retrieve the dataset in the Target datasource. The action is Enabled when the dataset is active. No other conditions are checked for the dataset. This ensures that the action cannot be performed for a dataset that has not been opened.
|
|
</p>
|
|
</descr>
|
|
<seealso/>
|
|
</element>
|
|
<element name="TDataSetInsert.UpdateTarget.Target">
|
|
<short>DataSource object examined in the method.</short>
|
|
</element>
|
|
|
|
<element name="TDataSetInsert.DataSource" link="#lcl.dbactns.TDataSetAction.DataSource"/>
|
|
|
|
<element name="TDataSetPost">
|
|
<short>
|
|
<var>TDataSetPost</var> posts changes for the current record to the <var>DataSet</var>.
|
|
</short>
|
|
<descr>
|
|
<p>
|
|
<var>TDataSetPost</var> posts editing changes for the current record into the <var>DataSet</var>. Some datasets may require additional actions for editing changes to become permanent; i.e. SQL databases use transactions that require a <b>COMMIT</b> statement to be executed before changes are written to the database engine.
|
|
</p>
|
|
</descr>
|
|
<seealso>
|
|
<link id="TDataSetFirst"/>
|
|
<link id="TDataSetLast"/>
|
|
<link id="TDataSetNext"/>
|
|
<link id="TDataSetPrior"/>
|
|
<link id="TDataSetRefresh"/>
|
|
<link id="TDataSetCancel"/>
|
|
<link id="TDataSetDelete"/>
|
|
<link id="TDataSetEdit"/>
|
|
<link id="TDataSetInsert"/>
|
|
</seealso>
|
|
</element>
|
|
|
|
<element name="TDataSetPost.ExecuteTarget">
|
|
<short>
|
|
Retrieves the dataset for the target datasource and calls its Post method.
|
|
</short>
|
|
<descr/>
|
|
<seealso/>
|
|
</element>
|
|
<element name="TDataSetPost.ExecuteTarget.Target">
|
|
<short>DataSource object examined in the method.</short>
|
|
</element>
|
|
|
|
<element name="TDataSetPost.UpdateTarget">
|
|
<short>
|
|
Enables or disables the action based on the state of the dataset in the target.
|
|
</short>
|
|
<descr>
|
|
<p>
|
|
<var>UpdateTarget</var> is an overridden method which enables or disables the database action based on the state of the dataset in the Target object.
|
|
</p>
|
|
<p>
|
|
<var>UpdateTarget</var> calls the <var>GetDataSet</var> method to retrieve the dataset in the Target datasource. The action is Enabled when the dataset is active, and its State contains a value in the dsEditModes set. This ensures that the action cannot be performed for a dataset that has not been opened, or has not been placed in edit mode.
|
|
</p>
|
|
<p>
|
|
Please note that UpdateTarget does not check the values for fields in the current record to determine if they have actually been altered.
|
|
</p>
|
|
</descr>
|
|
<seealso/>
|
|
</element>
|
|
<element name="TDataSetPost.UpdateTarget.Target">
|
|
<short>DataSource object examined in the method.</short>
|
|
</element>
|
|
|
|
<element name="TDataSetPost.DataSource" link="#lcl.dbactns.TDataSetAction.DataSource"/>
|
|
|
|
<element name="Register">
|
|
<short>
|
|
Registers components for use in the Lazarus IDE.
|
|
</short>
|
|
<descr>
|
|
<p>
|
|
The following components are registered but not displayed on the Lazarus IDE component palette:
|
|
</p>
|
|
<ul>
|
|
<li>TDataSetFirst</li>
|
|
<li>TDataSetLast</li>
|
|
<li>TDataSetNext</li>
|
|
<li>TDataSetPrior</li>
|
|
<li>TDataSetRefresh</li>
|
|
<li>TDataSetCancel</li>
|
|
<li>TDataSetDelete</li>
|
|
<li>TDataSetEdit</li>
|
|
<li>TDataSetInsert</li>
|
|
<li>TDataSetPost</li>
|
|
</ul>
|
|
</descr>
|
|
<seealso/>
|
|
</element>
|
|
|
|
</module>
|
|
<!-- DBActns -->
|
|
</package>
|
|
</fpdoc-descriptions>
|