Describe the Techniques for Using Visualforce to Perform Actions and Partial Page Refresh. PLATFORM-DEVELOPER-II Practice Questions (Page 2)

Questions 6–10

1. 6application · medium

   A Visualforce page has a search input field. When the user types a query and presses Enter, the page should refresh a results table without reloading the entire page. The search action should only process the input field and the search button. What should the developer do?

   • AUse actionPolling on the input field with a rerender attribute pointing to the results table.
   • BWrap the input field and search button in an actionRegion, and use actionSupport on the input field with a rerender attribute pointing to the results table.
   • CUse actionFunction to call the controller and manually refresh the results table with JavaScript.
   • DUse a commandButton with a rerender attribute pointing to the results table, and wrap the entire page in an actionRegion.
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2. 7foundation · easy

   A developer creates a Visualforce page with a command button. When the button is clicked, the page should execute a controller method that updates a record. How does the Visualforce framework invoke that controller method?

   • AThe button's onclick attribute must contain JavaScript that directly calls the Apex method.
   • BThe button's action attribute specifies the name of the controller method, and the framework calls it during the page's postback request.
   • CThe button's rerender attribute triggers the controller method after the page is fully rendered.
   • DThe button's value attribute is used to map to the controller method, and the framework invokes it automatically on page load.
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4. 8application · easy

   A Visualforce page has a command button that triggers a long-running Apex method. The developer wants to display a 'Processing...' message while the action is running and then hide it when the action completes. What should the developer use?

   • AactionPolling with a rerender attribute to update the message
   • BJavaScript remoting with a callback to show and hide the message
   • CactionFunction with a JavaScript callback to show and hide the message
   • DactionStatus with a rerender attribute on the command button
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5. 9expert · hard

   A Visualforce page uses actionPolling to refresh a list of records every 15 seconds. The developer notices that the page becomes unresponsive after a few minutes. What is the most likely cause and the best solution?

   • AThe actionPolling interval is too short, causing too many requests. Increase the interval to 60 seconds.
   • BThe action method is returning too much data. Change the action method to return null.
   • CThe actionPolling component is not compatible with rerender. Remove the rerender attribute.
   • DThe view state is growing because the entire page is being processed. Use an actionRegion to limit the scope of the polling action.
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6. 10foundation · easy

   A developer needs to invoke a controller method from a JavaScript function in a Visualforce page. Which component should be used?

   • AactionFunction
   • BactionPolling
   • CactionSupport
   • DactionStatus
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