![]() The browser provides a way for us to add a new entry into the browser’s history. This is a great feature that enables authors of SPA 3 frameworks to write wonderful things like the React router library. The browser’s history API 1 goes even further and allows us to add new entries or manipulate (to an extend) the entries that already exists. Going back and forth between existing entries in our browser’s history is exciting and useful. 2Ĭonveniently, calling history.go(0) will not go anywhere, and will instead just reload the page. If you provide the value 1 it will go forward one element, while calling history.go(-2) will go two elements back. We can even go multiple steps at a time (in either direction) using the history.go() function. The browser does not forget about the other elements, so that we can also go forward and make the next element the “current” one by simple calling the history.forward() method. ![]() This way, the previous element will now be marked as the “current” element. To go back to the previous page, we can simple call history.back() in our Javascript code and the browser will go “one element back” in our history. Imagine our browser’s history as a series of elements: There is always one element, that is our “current” element and it represents the page that we are currently seeing.įortunately for us, the functionality behind the back and forward buttons is provided to us by the browser’s history object. On the one hand we can move back and forth through the browser’s history and on the other hand we can even manipulate the current and future state. The Javascript API 1 to deal with the browser’s history is surprisingly easy to use. ![]() Whenever we find ourselves in a situation where we want to go back to the previous page (or even a few pages back) we can easily do this with the back button in our browser. When we navigate from one website to another website, we are creating basically a list of websites that we went to. The browser’s history feature is something that we use almost every day, without thinking about it too much. Working with history, pushState and replaceState in Javascript 22. You now need a handler function which runs when the window popstate event fires following the browser’s back or next button being clicked: ![]() History.replaceState() has identical arguments and is only used if you want to replace the current state with a new one. ?view=EMAILCONTENT&item=123 your application could analyze these values on start-up and return to the same place. In most cases, you’ll want to use parameters or a hash name, e.g. The URL can be anything - the browser won’t jump to that page, but could if the user reloaded the page or restarted their browser. You could use this to retain state information, e.g. Assume you’ve just displayed the result of an Ajax request: If you need to support IE9 and below, there are a number of shims including History.js and HTML5-History-API. The downside? Forget IE compatibility until v10 arrives. A handler function can retrieve the associated state and display the appropriate screen. When the user clicks back (or forward), the window.onpopstate event is fired.You can run history.pushState() as many times as necessary, or modify the current state using history.replaceState().This enables the back button but - importantly - does not move the user from the page. the user opens an email, history.pushState() is passed state information and executed. Try the history.pushState() demonstration page… It’s not perfect, but works in all browsers.įortunately, the problem has been addressed with the HTML5 history.pushState and history.replaceState methods in conjunction with the window.onpopstate event. Some involve changing the hash mark (#name) in the URL so the state can be retained. Our webmail client doesn’t support the one browser control most users understand. Or, if it’s a new browser tab, the back button is disabled and can’t be clicked. The application closes and returns to the page they were viewing prior to accessing the application. They now want to return to the email list what do they do?…īang. They click a title and the email content is retrieved using Ajax and displayed. The user loads the URL and is presented with a list of emails. In essence, it’s a complex JavaScript program running on a single HTML page. Consider a sophisticated application such as webmail client.
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