I am using Ajax and hash for navigation.
Is there a way to check if the window.location.hash changed like this?
http://example.com/blah#123 to http://example.com/blah#456
It works if I check it when the document loads.
But if I have #hash based navigation it doesn't work when I press the back button on the browser (so I jump from blah#456 to blah#123).
It shows inside the address box, but I can't catch it with JavaScript.
The only way to really do this (and is how the 'reallysimplehistory' does this), is by setting an interval that keeps checking the current hash, and comparing it against what it was before, we do this and let subscribers subscribe to a changed event that we fire if the hash changes.. its not perfect but browsers really don't support this event natively.
Update to keep this answer fresh:
If you are using jQuery (which today should be somewhat foundational for most) then a nice solution is to use the abstraction that jQuery gives you by using its events system to listen to hashchange events on the window object.
$(window).on('hashchange', function() {
//.. work ..
});
The nice thing here is you can write code that doesn't need to even worry about hashchange support, however you DO need to do some magic, in form of a somewhat lesser known jQuery feature jQuery special events.
With this feature you essentially get to run some setup code for any event, the first time somebody attempts to use the event in any way (such as binding to the event).
In this setup code you can check for native browser support and if the browser doesn't natively implement this, you can setup a single timer to poll for changes, and trigger the jQuery event.
This completely unbinds your code from needing to understand this support problem, the implementation of a special event of this kind is trivial (to get a simple 98% working version), but why do that when somebody else has already.
HTML5 specifies a hashchange event. This event is now supported by all modern browsers. Support was added in the following browser versions:
Internet Explorer 8
Firefox 3.6
Chrome 5
Safari 5
Opera 10.6
Note that in case of Internet Explorer 7 and Internet Explorer 9 the if statment will give true (for "onhashchange" in windows), but the window.onhashchange will never fire, so it's better to store hash and check it after every 100 millisecond whether it's changed or not for all versions of Internet Explorer.
if (("onhashchange" in window) && !($.browser.msie)) {
window.onhashchange = function () {
alert(window.location.hash);
}
// Or $(window).bind( 'hashchange',function(e) {
// alert(window.location.hash);
// });
}
else {
var prevHash = window.location.hash;
window.setInterval(function () {
if (window.location.hash != prevHash) {
prevHash = window.location.hash;
alert(window.location.hash);
}
}, 100);
}
EDIT -
Since jQuery 1.9, $.browser.msie is not supported. Source: http://api.jquery.com/jquery.browser/
There are a lot of tricks to deal with History and window.location.hash in IE browsers:
As original question said, if you go from page a.html#b to a.html#c, and then hit the back button, the browser doesn't know that page has changed. Let me say it with an example: window.location.href will be 'a.html#c', no matter if you are in a.html#b or a.html#c.
Actually, a.html#b and a.html#c are stored in history only if elements '<a name="#b">' and '<a name="#c">' exists previously in the page.
However, if you put an iframe inside a page, navigate from a.html#b to a.html#c in that iframe and then hit the back button, iframe.contentWindow.document.location.href changes as expected.
If you use 'document.domain=something' in your code, then you can't access to iframe.contentWindow.document.open()' (and many History Managers does that)
I know this isn't a real response, but maybe IE-History notes are useful to somebody.
Firefox has had an onhashchange event since 3.6. See window.onhashchange.
I was using this in a react application to make the URL display different parameters depending what view the user was on.
I watched the hash parameter using
window.addEventListener('hashchange', doSomethingWithChangeFunction);
Then
function doSomethingWithChangeFunction () {
let urlParam = window.location.hash; // Get new hash value
// ... Do something with new hash value
};
Worked a treat, works with forward and back browser buttons and also in browser history.
You could easily implement an observer (the "watch" method) on the "hash" property of "window.location" object.
Firefox has its own implementation for watching changes of object, but if you use some other implementation (such as Watch for object properties changes in JavaScript) - for other browsers, that will do the trick.
The code will look like this:
window.location.watch(
'hash',
function(id,oldVal,newVal){
console.log("the window's hash value has changed from "+oldval+" to "+newVal);
}
);
Then you can test it:
var myHashLink = "home";
window.location = window.location + "#" + myHashLink;
And of course that will trigger your observer function.
Another great implementation is jQuery History which will use the native onhashchange event if it is supported by the browser, if not it will use an iframe or interval appropriately for the browser to ensure all the expected functionality is successfully emulated. It also provides a nice interface to bind to certain states.
Another project worth noting as well is jQuery Ajaxy which is pretty much an extension for jQuery History to add ajax to the mix. As when you start using ajax with hashes it get's quite complicated!
var page_url = 'http://www.yoursite.com/'; // full path leading up to hash;
var current_url_w_hash = page_url + window.location.hash; // now you might have something like: http://www.yoursite.com/#123
function TrackHash() {
if (document.location != page_url + current_url_w_hash) {
window.location = document.location;
}
return false;
}
var RunTabs = setInterval(TrackHash, 200);
That's it... now, anytime you hit your back or forward buttons, the page will reload as per the new hash value.
I've been using path.js for my client side routing. I've found it to be quite succinct and lightweight (it's also been published to NPM too), and makes use of hash based navigation.
path.js NPM
path.js GitHub
SHORT and SIMPLE example
Click on buttons to change hash
window.onhashchange = () => console.log(`Hash changed -> ${window.location.hash}`)
<button onclick="window.location.hash=Math.random()">hash to Math.Random</button>
<button onclick="window.location.hash='ABC'">Hash to ABC</button>
<button onclick="window.location.hash='XYZ'">Hash to XYZ</button>
Related
This has probably been answered before but i don't understand al the difficult research online so i ask it here And hope for a easy answer
<script type="text/javascript"> // <![CDATA[
if ((navigator.userAgent.indexOf('iPad') != -1)) {
location.replace = "http://www.joey-games.byethost4.com/games/";
} // ]]>
This does not redirect me.
var isiPad = navigator.userAgent.match(/iPad/i) != null;
//or by using
var ua = navigator.userAgent;
var isiPad = /iPad/i.test(ua)
You can find other related information in the following links:
http://fellowtuts.com/jquery/ipadiphone-detection-using-javascript/
Detect iPad users using jQuery?
Instead of using location.replace use location.href
Your snippet becomes
if (navigator.userAgent.indexOf('iPad') > -1) {
location.href = 'http://www.joey-games.byethost4.com/games/';
}
I've made two changes to your code
!= to > in the if statement which is no biggie (nothing relevant)
changed method call from replace to href Taken from MDN
The Location.replace() method replaces the current resource with the one at the provided URL. The difference from the assign() method is that after using replace() the current page will not be saved in session History, meaning the user won't be able to use the back button to navigate to it.
This basically says that if you use replace you cannot use the browsers back button to get to this page anymore, basically reducing the users user-experience since they'll get confused about what the back button does when they use your website.
This will redirect your users on the iPad to a different website however, you shouldn't do this - it's bad for your users and your website. (as partially explained above)
Iam Not gonna use The redirecting to go to "Joey-games.byethost4.com/games/" I wil redirect iPad users to: Joey-games.byethost4.com/mobile/iPad/ for a mobile site since flash player is not supported in safari yet
I have a single page website and would like to achieve the following:
back button working as if it was a normal website
and instead of say,
www.mysite.com/index.php?p=#this-is-a-great-product
I'd like to have this url
www.mysite.com/this-is-a-great-product
while still having back button working properly.
Regarding 1.) I use the following code ive found which works great:
<!-- Getting BackButton to work properly -->
<script type="text/javascript">
var times = 0;
function doclick() {
times++;
}
function doclick() {
times++;
location.hash = times;
}
window.onhashchange = function() {
if (location.hash.length > 0) {
times = parseInt(location.hash.replace('#',''),10);
} else {
times = 0;
}
}
</script>
…but of course it just changes any anchors to /#1, then /#2 and so forth ro get the backbutton to work. But as I'm not a programmer I don't know how to change it… :(
Regarding 2.) i can add in htaccess this:
>RewriteEngine On
>RewriteRule ^([^/.]+)/?$ /index.php?page=$1
and this changes /index.php?p=products to /products.
So how do I change the above code (under 1.) so it doesn't change all anchors to #1, #2, etc. but instead references / uses the urls I achieved under 2, like
www.mysite.com/this-is-a-great-product
And (probably a very dumb question, but a very important one) -given I use only the new url links on my site- is there any danger that this still might result in duplicate content in any way?
Regarding this, should I (for that reason or any other) sefreferential my single page index.php to itself using rel canonical link=index.php?
Thanks so much in advance!
As mentioned, you will want to use the HTML5 History API. Please note, this API is relatively new and therefore browser support is a concern. At the time of writing, approximately 71% of global Internet users have support for it (see http://caniuse.com/#feat=history for browser support information). Therefore, you will want to ensure you have a fall-back solution for this. You will likely want to use the older #! solution that was popular before the HTML 5 History API was adopted.
If you use the history API to replace, for example, example.com/#!settings with example.com/settings and a user bookmarks that nicer URL, then when they go to visit it, their browser will make a request to the server for /settings (which doesn't actually exist in the web server's context). Therefore, you will need to make sure your web server has some redirection rules (i.e. RewriteEngine) such that it can take the pretty URLs and redirect them to the #! version (and then if the user's browser supports the history API it can replace that with the nice URL).
If you aren't very comfortable programming yourself, I'd recommend using a JavaScript library that does a lot of the work for you. I did some quick searching and discovered the following, though there might be better ones out there: https://github.com/browserstate/history.js
Basically i have created a small prototype on jsfiddle which tracks all the urls accessed via ajax calls.
Also contains navigation to access links back and forth .
How It Actually Works:
I have created a global array called history, which keeps track of all urls accessed via ajax in sequence.
also there a global index defined to keep track of the url being accessed when navigating back and forth the links in history array.
There is History section at the bottom of the jsfiddle, which shows the sequence in which the links are accessed by capturing the link names and posting them in the order in which they were accessed.
JS Code:
$(function () {
var history = [];
var index = 0;
$('.links').on('click', function () {
$('#history').append($(this).text());
var address = $(this).attr('data-ref');
index += 1;
history[index] = address;
$('.links').attr('disabled', 'disabled');
loadExternalPage(address);
console.log('list:' + history);
});
$('#back').on('click', function () {
console.log(index);
index -= 1;
console.log(index);
console.log(history[index]);
loadExternalPage(history[index]);
});
$('#forward').on('click', function () {
console.log(index);
index += 1;
console.log(index);
console.log(history[index]);
loadExternalPage(history[index]);
});
var loadExternalPage = function (address) {
console.log(history[index]);
$('#result-section').load(address, function () {
console.log('data-loaded');
$('.links').removeAttr('disabled');
});
};
});
Live Demo # JSFiddle:http://jsfiddle.net/dreamweiver/dpwmcu0b/8/
Note: This solution is far from being perfect, so dont consider it as final solution but rather use it as a base to build upon
On using BACK and FORWARD functions in the browser top-left button:
In principle, there is no great problem with this as long as you work with the existing storage object (a stack) for previously visited web pages on your browser. This object is the history object and you can see what is in it anytime by right-clicking and selecting "Inspect", then selecting the "Console" tab, then enter window.history and enter.
Check out the Browser Object Model (BOM) section of Pro Java For Web Developers (Frisbee) for the background to the history object. (Just a few pages, an easy read, don't worry.) Just remember that in this process you are storing the new page that you move to, not the old page that you are leaving !
For a simple SPA example, look at this example. codepen.io/tamjk/pen/NWxWOxL
In regard to the URL, the method that the history object uses to load a new page state into the history stack, i.e. pushState(...), has an optional third parameter for associating a dummy URL for each web page that is stored.
Personally, when I first sorted out the BACK & FORWARD functions, I did not use dummy URLs as the browser was being confused by them and I had enough to do sorting out the history sequence using just the first two parameters, i.e.
the state object - a JSON holding enough data to recreate the page stored
a title for the page I expect that you could also use a dummy URL but I will leave that to the student as an exercise, as they say.
But you can add the URL of the new page if you want to.
In the example above, for the state object I just used the IDs of the page's nav link and its content element.
For the title, I programmatically changed the HTML's page title element with each change of page. I did this after noticing that the browser listed the previous pages according to the title element in the HTML code.
Unfortunately, this title does not show up on CodePen when you right-click on the browser BACK and FORWARD buttons due to CodePen's system not allowing it. But it will show on your own sites.
It's important that whatever method you use to store current web page states when using the navbar links to navigate, you DO NOT ADD page states to the browser history when you arrive at them using BACK or FORWARD buttons. Otherwise your history stack will have repetitions of entries going back and deletion of entries going forward.
In the CodePen, this was achieved by having the addToHistory(..) function separate to and outside the scope of the switchPage(...) function. This allows you use of the switchPage function in both normal navbar navigation and browser BACK/FORWARD navigation. The third parameter of switchPage(...) is a boolean indicating if the page is to be stored in history or not.
Anyway, this is just something to get you started.
I am trying to start 3 applications from a browser by use of custom protocol names associated with these applications. This might look familiar to other threads started on stackoverflow, I believe that they do not help in resolving this issue so please dont close this thread just yet, it needs a different approach than those suggested in other threads.
example:
ts3server://a.b.c?property1=value1&property2=value2
...
...
to start these applications I would do
location.href = ts3server://a.b.c?property1=value1&property2=value2
location.href = ...
location.href = ...
which would work in FF but not in Chrome
I figured that it might by optimizing the number of writes when there will be effectively only the last change present.
So i did this:
function a ()
{
var apps = ['ts3server://...', 'anotherapp://...', '...'];
b(apps);
}
function b (apps)
{
if (apps.length == 0) return;
location.href = apps[0]; alert(apps[0]);
setTimeout(function (rest) {return function () {b(rest);};} (apps.slice(1)), 1);
}
But it didn't solve my problem (actually only the first location.href assignment is taken into account and even though the other calls happen long enough after the first one (thanks to changing the timeout delay to lets say 10000) the applications do not get started (the alerts are displayed).
If I try accessing each of the URIs separately the apps get started (first I call location.href = uri1 by clicking on one button, then I call location.href = uri2 by clicking again on another button).
Replacing:
location.href = ...
with:
var form = document.createElement('form');
form.action = ...
document.body.appendChild(form);
form.submit();
does not help either, nor does:
var frame = document.createElement('iframe');
frame.src = ...
document.body.appendChild(frame);
Is it possible to do what I am trying to do? How would it be done?
EDIT:
a reworded summary
i want to start MULTIPLE applications after one click on a link or a button like element. I want to achieve that with starting applications associated to custom protocols ... i would hold a list of links (in each link there is one protocol used) and i would try to do "location.src = link" for all items of the list. Which when used with 'for' does optimize to assigning only once (the last value) so i make the function something like recursive function with delay (which eliminates the optimization and really forces 3 distinct calls of location.src = list[head] when the list gets sliced before each call so that all the links are taken into account and they are assigned to the location.src. This all works just fine in Mozilla Firefox, but in google, after the first assignment the rest of the assignments lose effect (they are probably performed but dont trigger the associated application launch))
Are you having trouble looping through the elements? if so try the for..in statement here
Or are you having trouble navigating? if so try window.location.assign(new_location);
[edit]
You can also use window.location = "...";
[edit]
Ok so I did some work, and here is what I got. in the example I open a random ace of spades link. which is a custom protocol. click here and then click on the "click me". The comments show where the JSFiddle debugger found errors.
I'm afraid it might be impossible but is there a way to change the hash value of a URL without leaving an entry in the browser's history and without reloading? Or do the equivalent?
As far as specifics go, I was developing some basic hash navigation along the lines of:
//hash nav -- works with js-tabs
var getHash = window.location.hash;
var hashPref = "tab-";
function useHash(newHash) {
//set js-tab according to hash
newHash = newHash.replace('#'+hashPref, '');
$("#tabs li a[href='"+ newHash +"']").click();
}
function setHash(newHash) {
//set hash according to js-tab
window.location.hash = hashPref + newHash;
//THIS IS WHERE I would like to REPLACE the location.hash
//without a history entry
}
// ... a lot of irrelavent tabs js and then....
//make tabs work
$("#tabs.js-tabs a").live("click", function() {
var showMe = $(this).attr("href");
$(showMe).show();
setHash(showMe);
return false;
});
//hash nav on ready .. if hash exists, execute
if ( getHash ){
useHash(getHash);
}
Using jQuery, obviously. The idea is that in this specific instance 1) making the user go back over every tab change could effectively 'break the back button' by piling up needless references, and 2) not retaining which tab they're currently on if they hit refresh is an annoyance.
location.replace("#hash_value_here"); worked fine for me until I found that it doesn't work on IOS Chrome. In which case, use:
history.replaceState(undefined, undefined, "#hash_value")
history.replaceState() operates exactly like history.pushState() except that replaceState() modifies the current history entry instead of creating a new one.
Remember to keep the # or the last part of the url will be altered.
location.replace("#hash_value_here");
The above seems to do what you're after.
Edit: It's been a couple years now, and browsers have evolved.
#Luxiyalu's answer is the way to go
--Old Answer--
I too think it is impossible (at this time). But why do you need to change the hash value if you are not going to use it?
I believe the main reason why we use the hash value as programmers is to let the user bookmark our pages, or to save a state in the browser history. If you don't want to do any of this, then just save the state in a variable, and work from there.
I think that the reason to use a hash is to work with a value that is out of our control. If you don't need it, then it probably means you have everything under your control, so just store the state in a variable and work with it. (I like repeating myself)
I hope this helps you out. Maybe there's an easier solution to your problem.
UPDATE:
How about this:
Setup a first hash, and make sure it gets saved in the browser history.
When a new tab gets selected, do window.history.back(1), that will make the history go back from your first init hash.
Now you set the new hash, therefore the tabbing will only make one entry in the history.
You'll probably have to use some flags, to know if the current entry can be "deleted" by going back, or if you just skip the first step.
And to make sure, that your loading method for the "hash" doesn't execute, when you force the history.back.
You can always create an event listener to catch click events on the hyperlink and in the callback function put e.preventDefault(), that should prevent the browser from inserting it into the history.
I have a Ajax heavy application that may have a URL such as
http://example.com/myApp/#page=1
When a user manipulates the site, the address bar can change to something like
http://example.com/myApp/#page=5
without reloading the page.
My problem is the following sequence:
A user bookmarks the first URL.
The user manipulates the application such that the second URL is the current state.
The user clicks on the bookmark created in step 1.
The URL in the address bar changes from http://example.com/myApp/#page=5 to http://example.com/myApp/#page=1, but I don't know of a way to detect the change happened.
If I detect a change some JavaScript would act on it.
HTML5 introduces a hashchange event which allows you to register for notifications of url hash changes without polling for them with a timer.
It it supported by all major browsers (Firefox 3.6, IE8, Chrome, other Webkit-based browsers), but I'd still highly suggest to use a library which handles the event for you - i.e. by using a timer in browsers not supporting the HTML5 event and using the event otherwise.
window.onhashchange = function() {
alert("hashtag changed");
};
For further information on the event, see https://developer.mozilla.org/en/dom/window.onhashchange and http://msdn.microsoft.com/en-us/library/cc288209%28VS.85%29.aspx.
check the current address periodically using setTimeout/interval:
var oldLocation = location.href;
setInterval(function() {
if(location.href != oldLocation) {
// do your action
oldLocation = location.href
}
}, 1000); // check every second
You should extend the location object to expose an event that you can bind to.
ie:
window.location.prototype.changed = function(e){};
(function() //create a scope so 'location' is not global
{
var location = window.location.href;
setInterval(function()
{
if(location != window.location.href)
{
location = window.location.href;
window.location.changed(location);
}
}, 1000);
})();
window.location.changed = function(e)
{
console.log(e);//outputs http://newhref.com
//this is fired when the window changes location
}
SWFaddress is an excellent library for these types of things.