Lesson plan
Postback
In web development, a postback is the exchange of information between servers to report a user's action on a website, network, or app. Technically speaking, a postback is an HTTP POST to the same page that the form is on. In other words, the contents of the form are POSTed back to the same URL as the form. Postbacks are commonly seen in edit forms, where the user introduces information in a form and hits "save" or "submit", causing a postback. The server then refreshes the same page using the information it has just received. Postbacks are most commonly discussed in relation to JSF and ASP or ASP.NET. In ASP, a form and its POST action have to be created as two separate pages, resulting in the need for an intermediate page and a redirect if one simply wants to perform a postback. This problem was addressed in ASP.NET with the __doPostBack() function and an application model that allows a page to perform validation and processing on its own form data. In JSF, postbacks trigger the full JSF life-cycle, which just like ASP.NET performs conversion and validation of the form data that was included in the postback. Various utility methods are present in the JSF API to programmatically check if a given request is a postback or not.
Article summary
In web development, a postback is the exchange of information between servers to report a user's action on a website, network, or app. Technically speaking, a postback is an HTTP POST to the same page that the form is on. In other words, the contents of the form are POSTed back to the same URL as the form. Postbacks are commonly seen in edit forms, where the user introduces information in a form and hits "save" or "submit", causing a postback. The server then refreshes the same page using the information it has just received. Postbacks are most commonly discussed in relation to JSF and ASP or ASP.NET. In ASP, a form and its POST action have to be created as two separate pages, resulting in the need for an intermediate page and a redirect if one simply wants to perform a postback. This problem was addressed in ASP.NET with the __doPostBack() function and an application model that allows a page to perform validation and processing on its own form data. In JSF, postbacks trigger the full JSF life-cycle, which just like ASP.NET performs conversion and validation of the form data that was included in the postback. Various utility methods are present in the JSF API to programmatically check if a given request is a postback or not.
Key claims
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Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
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Key claims and bibliography are generated from the same tracked claims and sources as the article page.