Active Controls (AJAX enabled Controls)

Active controls extends standard PRADO controls adding the ability to automatically update themselves on callbacks without the need of ad-hoc javascript calls. See the Introduction for a quick overview of the concept behind active controls (AJAX enabled controls).

For a quick demo of active controls, try the TActiveButton control. See also the later part of the Currency Converter tutorial for a more in depth example.

Standard Active Controls

• TActiveButton represents a click button on a Web page. It can be used to trigger a callback request.
• TActiveCheckBox represents a checkbox on a Web page. It can be used to collect two-state user input and can trigger a callback request.
• TActiveCustomValidator validates a particular control using a callback request.
• TActiveDatePicker adds a date picker that permits the suer to choose a date.
• TActiveFileUpload displays a file upload field on a page and uses an iframe to permit handling of the file upload in a callback.
• TActiveHtmlArea represents a WYSIWYG text input field taking user input that are in HTML format allowing to change the content during callback.
• TActiveHtmlArea5 is the active counterpart of THtmlArea5 based on TinyMCE version 5.
• TActiveHiddenField displays a hidden input field that can be changed upon callback.
• TActiveHyperLink represents a hyperlink on a Web page.
• TActiveImage represents an image on a Web page.
• TActiveImageButton represents a click button that has an image as the background. It is can be used to trigger a callback request.
• TActiveLabel represents a label on a Web page. The label can be customized via various CSS attributes.
• TActiveLinkButton represents a hyperlink that can perform a callback request.
• TActiveMultiView represents a container for a group of TView controls, each of which is container for other controls. At any time, at most one TView is visible. It's the active counterpart of TMultiView.
• TActivePanel represents a container for other controls on a Web page. In HTML, it is displayed as a <div> element. The panel's contents can be replaced during a callback request.
• TActivePager generates UI that allows users to interactively specify which page of data to be displayed in a data-bound control.
• TActiveRadioButton represents a radiobutton on a Web page. It is mainly used in a group from which users make a choice. It can be used to perform a callback request.
• TActiveTextBox represents a text input field on a Web page. It can collect single-line, multi-line or password text input from users. It can be used to perform a callback request.

Active List Controls

• TActiveCheckBoxList displays a list of checkboxes on a Web page and each checkbox can trigger a callback request.
• TActiveDropDownList displays a dropdown list box that allows users to select a single option from a few prespecified ones. It can be used to perform a callback request.
• TActiveListBox displays a list box that allows single or multiple selection. It can be used to perform a callback request.
• TActiveRadioButtonList is similar to TActiveCheckBoxList in every aspect except that each TActiveRadioButtonList displays a group of radiobuttons. Each radio button can perform a callback request.
• TActiveRatingList is an EXPERIMENTAL class that displays clickable images that represent a TRadioButtonList.

Active Data Controls

• TActiveDataList is used to display or modify a list of data items. It is the active counterpart to the original TDataList control.
• TActiveDataGrid displays data in a tabular format with rows and columns. It is the active counterpart to the original TDataGrid control.
• TActiveRepeater displays its content defined in templates repeatedly based on the given data. It is the active counterpart to the original TRepeater control.

Extended Active Controls

• TCallback a generic control that can perform callback requests.
• TEventTriggeredCallback triggers a callback request based on HTML DOM events.
• TInPlaceTextBox represents a label that can be edited by clicked.
• TTimeTriggeredCallback triggers a callback request based on time elapsed.
• TValueTriggeredCallback monitors (using a timer) an attribute of an HTML element and triggers a callback request when the attribute value changes.

Active Control Abilities

The following table shows the Active Controls that can trigger a callback event and whether the control will raise a PostBack event if Javascript was disabled on the client's browser.

Control Name	Triggers Callback	Falls back to PostBack
TActiveButton	Yes	Yes
TActiveCheckBox	Yes	Yes
TActiveCustomValidator	Yes	Yes
TActiveHyperLink	No	Yes
TActiveImage	No	Yes
TActiveImageButton	Yes	Yes
TActiveLabel	No	Yes
TActiveLinkButton	Yes	No
TActivePanel	No	Yes
TActiveRadioButton	Yes	Yes
TActiveTextBox	Yes	Yes
TCallbackOptions	No	N/A
TActiveCheckBoxList	Yes	Yes
TActiveDropDownList	Yes	Yes
TActiveListBox	Yes	Yes
TActiveRadioButtonList	Yes	Yes
TCallback	Yes	No
TEventTriggeredCallback	Yes	No
TInPlaceTextBox	Yes	No
TTimeTriggeredCallback	Yes	No
TValueTriggeredCallback	Yes	No