postback

This method is called by a control when it receives a postback event notification, to check whether the event is adapter-specific.

Properties and methods that enable you to determine in client script whether the page is processing an asynchronous postback .

It is possible for a malicious user to use the postback script to send arbitrary post events to server controls.

Just as @Out is used to push variables out to the view, @In can be used to recapture them on a postback.

A string constant used in postback event arguments to indicate whether the user should be returned to the list view.

The PageRequestManager class enables you to give precedence to a specific postback and cancel others that are underway.

If the ID matches the ID of a button that cancels the postback, the abortPostBack method of the PageRequestManager class is called.

The browser performs an HTTP POST method, which in ASP. NET is referred to as a postback.

Saves any user control view-state changes that have occurred since the last page postback.

RegisterScripts will be called during an asynchronous postback as well (due to the else clause shown in Figure 11).

The reference string is defined by the specified control that handles the postback and a string argument of additional event information .

Without the hidden field (see Figure 1), the refresh machinery has no way to detect if the next postback is a refresh or a submit.

If the ID matches the ID of a button that cancels the postback, the abortPostBack method is called.

Access the underlying request and response objects that are used for the asynchronous postback.

As with the button text, the message displayed in the alert dialog box is set to a localized string value without a postback to the server.

In particular, the response includes only the markup for the updatable regions that have been modified during the postback.

A string constant used in postback event arguments to indicate that the browser should jump to a specific item in the list.

If the Text value were not stored in view state, the value would be set to its default, Empty, on each postback.

In general, postbacks occur in one of two ways: through a Submit button or through a script.

Although dressed like a pure AJAX remote call, an AJAX postback looks like a regular postback request to the ASP. NET runtime components.

You can still configure a panel to refresh when a state-changed event occurs on the server during an AJAX postback.

Gets or sets a value indicating whether the page scroll position should be maintained upon returning from a postback from the server.

Creates a link on the current page to enable postback on devices that do not support postback events.

The response of an AJAX postback is a text stream that can be seen as a table of records with Size, Type, ID, and Content columns.

Contains a page number delimiter used to ensure proper page numbering in a postback .

The ScriptManager control checks an HTTP header in the request to determine whether the request is an AJAX postback.

If a postback does not require form data to be submitted, the adapter can call the same methods as the HTML adapters.

The presence of the page hidden fields VIEWSTATE and EVENTTARGET is used to help determine whether a postback event has occurred .

If the page is not undergoing a partial postback, a globalization script block is registered, along with all your scripts and services.

Data is injected into a component either on postback or when the component is initialized.

Method is called after all postback data returned from the user is loaded.

Used to maintain the path of the menu when a postback event is raised.

Property to specify whether clicking the hot spot results in going to another page or in a postback .

Is a number, and if present in the postback arguments, indicates that the browser should jump to a specific item in the list.

Method if the markup for the browser supported by the adapter requires a different format for the postback form reference.

Hence, an AJAX postback uploads a bit more information than a regular ASP. NET postback.

This phase of the lifecycle presents three view instances: new view, initial view, and postback, with each one being handled differently.

NET mobile controls, the page adapter must persist this string to the client and ensure that it is available on a subsequent postback.

This is true even after a postback, because the page is being re-created on the server and the browser considers it a new page.

Controls in a zone, based on the changes that have occurred since the most recent postback event.

Raised after all content on the page is refreshed as a result of either a synchronous or an asynchronous postback.

Note that although the cache is updated, the time displayed on the page does not change until a postback event occurs.

In this example, a handler for the initializeRequest event enables an asynchronous postback to be canceled.

Determines whether the given target requires a postback and returns the required postback argument.

By default, ASP. NET pages check pages on postback to guarantee that user input does not include script or HTML elements.

This event is called on the server if a postback event is generated by some other control and the selection has changed.

Renders hidden postback variables for child controls that are not visible due to pagination or secondary UI.

To programmatically control the actions performed when a postback HotSpot is clicked, provide an event handler for the Click event.

Renders a postback event into the response stream as a link, including all required arguments.

Raised during the initialization of the asynchronous postback.

Screen readers and other assistive devices read aloud the text in a navigation control during every visit to a page and on every postback.

The code checks whether the request is an asynchronous postback.

Some of the controls and techniques from Web Forms can be still be used, but only if they don't rely on post backs.

Renders a reference to a postback event appropriately for the target device.

In the beginRequest event handler the postBackElement property is used to access the name of the element that caused the postback.

Returns the options required for a postback script for a specified button control.

True if the postback event should return the page to the current scroll position and return focus to the target control; otherwise.

View state is a repository in an ASP. NET page that can store values that need to be retained during postback.

Gets or sets a value indicating whether the Button control uses the client browser's submit mechanism or the ASP. NET postback mechanism.

The user is returned to the top of the page on a postback.

Notifies the server control that caused the postback that it should handle an incoming postback event.

Property indicates whether the postback event should occur from client-side script.

Method to provide target-specific handling of the postback variables collection.

When the page is posted back, the contents of view state are sent as part of the page postback information.

Because some devices handle postback differently than others, this method allows the adapter to modify the collection.

The button controls trigger an event in server code that you can handle to respond to the postback.

So far the ScriptManager control recognizes that a partial postback is occurring and has identified the controls that caused the postback.

Property is set to the page that the button is currently on, a normal postback event cycle occurs.

Gets or sets a value indicating whether the postback event should occur from client-side script.

Even worse, the situation continues to degrade upon postback, at which time additional redundant database calls may be made.

Gets or sets a value indicating whether the page validates postback and callback events.

In this scenario, client script sends a request to the server to execute a page without performing a complete postback cycle.

Select a product name to be sure that the list performs a postback.

On the server, an AJAX postback differs from a classic ASP. NET postback only in the algorithm it uses to render the final markup.

Registration for control state is not carried over from request to request during a postback.

Select a category to be sure that the list performs a postback.

In the code under "Example" above, the control is bound only the first time the page runs, not on every postback.

Once on the server, the request goes through the typical lifecycle of postback requests and raises such events as Init, Load, and PreRender.

Handles an exception caused by an expired view state on postback.

Renders a postback event as a link with the specified argument, text, and access key.

This time, the time displayed in the UpdatePanel control does not change, because the asynchronous postback was canceled.

Raised before the processing of an asynchronous postback starts and the postback request is sent to the server.

Object that represents the postback behavior of the specified button control.

Raised after an asynchronous postback is finished and control has been returned to the browser.

Property, which determines the group of controls that should be validated when the control causes a postback.

It tests first to see if this is a postback; if not, this is the first time the page has run.

If the postback data is not recognized in the adapter, it must call back on the control to process it.

Returns a value that indicates whether the PageRequestManager object is processing a postback.

In this scenario, the GetPostBackEventReference method returns the client postback event for the Button control.

Unless the action is coded in the Page_Load event, there's no way an ASP. NET page can execute sensitive code outside a postback event.

Gets a value indicating whether the browser supports WML cards for postback.

Defines methods that ASP. NET server controls must implement to automatically load postback data.

Indicates whether the adapter handles the postback event.

Information about which UpdatePanel controls were deleted, updated, or created during an asynchronous postback.

Gets or sets the target URL for the postback of a Web Forms page.

For a postback event to take place, the view state field is mandatory.

Overridden. Registers client script for generating postback prior to rendering on the client if.

Event occurs after all postback data and view-state data is loaded into the page and all controls on the page.

He goes on to discuss the problems with ViewState, event management, and post-backs in detail.

Changing the selection on the client does not generate a postback event.

By default, a Timer control inside the panel will cause just the panel to refresh during an asynchronous postback.

Gets or sets a value indicating whether to return the user to the same position in the client browser after postback.

Returns a string that can be used in a client event to cause postback to the server.

Load event. There is a second attempt to load postback data before the.

A delta node identifies a possible change that occurred during the AJAX postback.

Gets or sets a value that indicates whether an automatic postback to the server occurs when the TextBox control loses focus.

Specifies whether pages and controls validate postback and callback events.

In that case, the UpdateProgress control displays a message only when a postback originates inside the associated UpdatePanel control.

Contains the source identifier to use to render the hidden field for the postback source.

Thus, each postback and round trip results in a new instance of the page.

The next phase after a postback is apply request values.

Adding these controls to a page eliminates the need to refresh the whole page with each postback.

In ASP. NET pages, a single form can post to itself, and the model provides for generalized control state management and postback events.

Registers a control as one that requires postback handling when the page is posted back to the server.

The endRequest event is raised after an asynchronous postback is finished and control has been returned to the browser.

True if a postback to the server automatically occurs whenever the user changes the selection of the list; otherwise, false.

For more information about postback processing, see ASP. NET Web Server Control Event Model.

If an unexpected error occurs during an asynchronous postback, you can handle the error in client script.

The beginRequest event is raised before the processing of an asynchronous postback starts and the postback is sent to the server.

You will start by creating ECMAScript (JavaScript) code that manages the asynchronous postback in the browser.

During postback, Seam automatically detects the pairing.

The UpdatePanel control removes the requirement to refresh the whole page with each postback, which improves the user experience.

Raises the PreLoad event after postback data is loaded into the page server controls but before the OnLoad event.

The identity of the control that caused the postback event is tucked away for later use.

Returns a string to use in a client event to cause postback to the server.

This property works just like IsPostBack but returns true when a cross-page postback has occurred.

A postback action occurs each time you navigate to a page or reload a page.

However, to enable a postback to send form data to the server, the adapter must render a submit button.

The SelectUrl property returns the JavaScript that is normally rendered for that day to cause a postback indicating date selection.

When a postback event originates from an UpdatePanel control, any associated UpdateProgress controls are displayed.

Contains the identifier to use to for the hidden field for the postback argument.

Notifies the Image object of a postback event.

Indicates whether to return the user to the same position in the client browser after postback.

Other postback controls inside the panel are defined as triggers for the panel.

Defines the method ASP. NET server controls must implement to handle postback events.

In cases where the HTTP request is a postback and view state is enabled but the data-bound control has not yet been bound.

Notifies the Form object of a postback event.

In the initializeRequest event, you can determine which element caused the postback and whether a postback is already underway.

Property and is used to store additional data about the navigation node, such as the data that is used for handling postback events.

Property is used to store any additional data about the node, such as data used for handling postback events.

The code checks whether the current request is a postback.

However, in some situations, it is useful to run server code from the client without performing a postback.

Specifies how client-side JavaScript is generated to initiate a postback event.

For browsers that support script, this includes a script block to perform postback.

In that case, the UpdateProgress control cannot determine automatically that an asynchronous postback has been triggered.

NET to validate only those events that can be raised in the control during a postback request or callback.

The following example shows how to determine whether the PageRequestManager is currently processing a postback.

Registers client script for generating postback events prior to rendering on the client, if AutoPostBack is true.

If the postback used the GET command, the query string information is returned.

Gets or sets a value indicating whether client-side validation is required before the postback event occurs.

Additionally, by using the page postback model instead of cross-page posting all input elements of the wizard are accessible continuously.

A string of optional arguments to pass to the control that processes the postback.

Control state is used to recreate the page and reestablish previous settings on each postback.

Processes postback data for the TreeView control.

In addition, this should not be done through a postback or a refresh meta-tag so as to avoid the full refresh of the page.

Renders a postback event with the control as a target.

The client script displays a pop-up window requesting the user to confirm the postback.

A string that, when treated as script on the client, initiates the client postback.

Defines a Button control that causes an asynchronous postback.

NET controls create client-side scripts to raise postback events on the server.

Event and registers the control as one that requires postback handling.

But using ClientScriptManager will not work during a partial postback.

Methods for rendering control postback events.

That represents the control that receives the postback event.

Gets the request object that represents the current postback.

Calling server code from client script without postback.

On each postback, the page is recreated and values are restored from view state.

A string that, when treated as script on the client, initiates the postback.

Control is set to validate when a postback occurs.

Method to ensure that the user action completes before the postback occurs.

On postback, recreates child controls and binds them to data stored in view state during a preceding DataBind call.

Processes the postback data for this control.

Figure 3 shows the modified lifecycle of an AJAX postback request.

The following example shows how to use the initializeRequest event to allow an asynchronous postback to be canceled.

After outjecting the course to the view that renders the course editor form, you need to capture the updated object on postback.

The default behavior is that the last postback takes precedence.

Determines the postback event options for the FormView control.

Control values passed on postback (HTTP POST values).

Method returns the client postback event for the.

The PreLoad event is raised after all postback data processing and before the Load event.

Server events occur after postback, and they are handled in the server-side code that you write for the page.

The server Control that processes the postback on the server.

Method provides a DHTML reference to the postback form.

The LinkButton control renders a link (a element) that uses client script to perform a postback.

Collection of postback data from the request object.

Control that the postback data has changed.

Changes to the ListView control will not require a full postback.

The form must contain a Command to initiate a postback event that raises the TextChanged event.

Browsers, by default, will postback if the form doesn't contain an action attribute.

Renders a postback event as a link on the page.

Control to also use client script to perform the postback.

Provides event data for the endRequest event, which is raised after an asynchronous postback has finished.

This code will cause the control, Button1, to do a full postback of the page, even if Button1 exists within an UpdatePanel.

Enables the HtmlInputImage control to raise events on postback.

Returns a collection of postback values.

Items are displayed as links that perform a postback.

The HotSpot generates a postback to the server.

If the request is a postback, the values of the controls have not yet been restored from view state.

Property, the page generates a postback to the server when the.

Objects generate a postback to the server.

Property specifies an optional argument that is transferred in a postback event .

Method to render text or an image inside the postback.

A postback occurs only when the user presses the ENTER or the TAB key while in the TextBox control.

Client script is used to support postback events.

For instance, you might want to read information from a database the first time a page is displayed, but not on every postback.

Method to define a client postback event.

The control in the example is set to perform a postback.

Tag and generates a postback when the user clicks the link.

No full postback will occur and the end result will be absolutely seamless.

The page still needs a button, or an auto-postback control, to trigger the postback in order to update the label.

In 2. 0, we already provide support for auto-detecting and invoking model validators on postback, so the foundation is there.

This tutorial shows how to write JavaScript code that cancels an asynchronous postback.

The following example shows how to use the initializeRequest event to cancel an asynchronous postback.

It also shows how to use the Rows property on postback to expand the list.

You can also give the user the option to cancel the postback.

Interface so that it can respond to and raise specific events during postback.

The beginRequest event is raised just before the postback request is made.

This is because the page is not performing a postback and updating the whole page every time.

For example, a client script function cannot pass a value directly to server code during a postback event.

This indicates that it is the first time the page has run; that is, it is not a postback.

If, on the other hand, a partial postback is underway, only scripts are registered.

For example, if you are binding controls to data, when you disable view state, you must rebind the controls to data on each postback.

Property indicates whether the postback event should return the page to the current scroll position and return focus to the

Giving Precedence to a Specific Asynchronous Postback

Control is in selection mode, each time a user clicks a node, a postback to the server occurs and the

Determine whether the request comes as a postback

True if the page is being loaded in response to a client postback; otherwise,

After a postback but before your event methods are called, the page calls the validator controls and aggregates their results into the

True if the adapter handles loading the postback data; otherwise,

In days of old you would have added script to the page as a result of a full postback such as this

At this stage, the page also determines whether the request is a postback or a new request and sets the

If required to support auto-postback behavior, controls will render a

Gets a value indicating whether postback data sent by the browser will be

Execute any code associated with the postback event

Event after postback data is loaded into the page server controls but before the

Server controls that can perform a postback must be inside the

during a postback event , the control adapter sets the

Event is raised after all postback data processing and before the

To create JavaScript code to cancel a postback

To create a page where users can cancel a postback