Run JavaScript function when attempted to go to HTML anchor - javascript

Regardless of whether I'm trying to go to index.html#ExistingAnchor or index.html#NotExistingAnchor or any other anchor which might or might not exist on the page I'd like some javascript function to be run.
<html>
<body>
<a name="ExistingAnchor"></a>
</body>
</html>
What javascript code can I use to achieve it?
The page may already be loaded so I'd be just visiting HTML anchors on the same page from the browser address bar without reloading the page.
Also, having visited a number of anchors on the same page when I'm using the Back and Forward browser history buttons, I'd like some JavaScript function to be run as well so that I could identify what anchor I'm currently on - could you please advise this as well?

On modern browsers you can implement onHashChange event, on IE6/7 you're going to need to use some trickery involving iFrames and window.setTimeout.
The jQuery history plugin will achieve what you want if you use jQuery, if not you can study it and port it for your needs.
http://tkyk.github.com/jquery-history-plugin/

Related

How to reload part of a web page using iframe instead of ajax?

The reason I don't want to use ajax to do this is because the part I want to refresh is actually a commenting plugin implemented by other. I just put a snippet of script they provided in my html code and it shows a commenting part under my articles. As it's not a live commenting one, I want to add a refresh button next to it to enable users to just refresh the commenting part to get the latest comments without need for reloading the whole page.
Therefore, I think maybe iframe is an option for me. But the problem is I need to specify the src attribute of iframe. I don't know what value I should use because all I have is just a snippet of script. Can someone give me any idea on this?
By the way, the code snippet is as follows:
<div id="uyan_frame"></div>
<script type="text/javascript" id="UYScript" src="http://v1.uyan.cc/js/iframe.js?UYUserId=1674366" async=""></script>
Just create a html page with the script you talked inside about and use this file in the iframe src attribute.
You can put the snippet above in an html file like this
<!DOCTYPE html>
<html>
<body>
<div id="uyan_frame"></div>
<script type="text/javascript" id="UYScript" src="http://v1.uyan.cc/js/iframe.js?UYUserId=1674366" async=""></script>
</body>
</html>
And then use that file as the src of your iFrame, which you can refresh using javascript.
That said, just because you can do something doesn't mean you should do something. This is a really hacky way of doing what you're trying to do. A few alternative options:
Understand what the script you're using is doing, and work with it. Judging by the name of the script and div in the snippet, it may be creating an iframe to begin with. If thats the case, why not just figure out what that iFrame is called using your browsers debug it and refresh it manually, or modify the script to do so?
Use a live updating framework- This may not be possible for you, I don't know your constraints, but there are plenty of great commenting frameworks out there that do live updates. For instance Disqus comes to mind. Other examples are facebook comments or you could embed a reference to an external site like branch
Use Ajax - I'm a bit unclear on whether this is your script that you're writing, or a 3rd party script. If it is your script, then use the generally accepted methods for doing this type of work, unless you have a really great reason not too. You'll get better support from others, you'll gain more generally applicable experience, and for the most part, best practices gain that name for a reason. People use "ajax" methods for live updating pages because its effective and useful. Frames have become much less common on the web because they're clunky and make it difficult for different parts of the page to interact. If you don't have a great reason not to use the common practice, its usually your best bet.
You could do this :
var iframe = document.getElementById('your_frame_id');
iframe.src = iframe.src;
set the iframe src to its value again, this will cause the frame to refresh, and will work with cross domain frames

How to stop page load in html static page

Is there in HTML (javascript) or other static html tech
can:
Stop page loading (if browser does not download yet)
Stop page rendering (from where the code placed)
Stop javascript executed (from where the code placed)
Simply put, is there a code like
<script>window.StopWhateverBelow()</script>
To let browser totally ignore whatever below the code.
UPDATE
I understand the browser may already download the whole thing. What I want is, from the code, page should stopped, for example: if I put the code just after <body> visitor should see blank page, if I put the code in middle of the page, page should be just half like you pressed ESC
ANSWER
As bukko suggested, comments done the trick. But not full, just half
If you put <!-- in html page, the rest will be ignored. And in Javascript
document.write('<!--');
Done the trick.
For about make sense:
Here is how this code make sense: when you page load some offpage script, the script is dynamic. When the script code found something wrong (or match some condition), you have one more option to stop the page from rendering, loading, download...
You could do window.stop(); for most browsers besides Internet Explorer. For IE, I had to use document.execCommand('Stop');
If you already have html comments on your page, #bukko's solution doesn't fully work. Stuff after the html comment will get rendered normally.
Something else to try is:
document.write('<script type="text/undefined">')
The rest of the document gets interpreted as part of the script tag, and because the script isn't text/javascript, it gets ignored.
Worked for me, thought I'd share it.
Edit
I've seen the script trick not work in Chrome.
This does work, but I have not done extensive browser testing:
document.write('<style type="text/undefined">')
window.stop(); //works in all browsers but IE
if ($.browser.msie) {document.execCommand("Stop");}; //works in IE,
document.execCommand works in IE, however it does stop some of FF, NS and some other browsers' functions. Like displaying GIF's animation for example. Using "if browser is IE" makes these two codes work perfectly in all browsers.
Well, there is:
<!--
terminated by
-->
for HTML, but scripts will ignore this.
What you are asking makes no logical sense. Simply for two reasons:
Data is ALREADY sent to the user (HTML / JS) so even tho if you COULD hide content, the data would sitll be there for a user to see (if they view source for instance).
Why would you stop 'execution' of a page? It loads simple html structure and reults in a visual display, you should focus on the server site (php for instance) to hide or not send the content in the first place.
If you want to visually hide elements tho, you could use CSS styles (hide divs or the like) with simply adding style="display:none;" to a div like so:
<div style="display:none;">
This text will be downloaded by the user, but hidden from view due to CSS inline style
</div>
If you want to add commenting (thats just for your reference), then use comment formatting:
<!-- this is a comment and will not show up to a user -->
Reference for comments: http://htmlhelp.com/reference/wilbur/misc/comment.html
put window.Stop() wherever you want to stop the page from getting renderred
You could also hide the body like that:
var style = document.createElement("style");
style.innerHTML="body { display:none !important; }";
document.getElementsByTagName("HEAD")[0].appendChild(style);
HTML is static content so the server reads whatever you have written in the file unless you comment it out. For a dynamic file like what you are asking for you need to use php which can do this type of thing.
Just not much related to the question, but I thought it may be useful for some persons. If you want to jump to other page during page loading use window.location = "somepage.html"; or you can redirect users to the previous page: window.history.go(-1); Useful in JavaScript conditional statements
If you are using ASP or PHP, HTTP protocol automatically stops but HTTPS protocol don't stop automatically.
To stop it use:
In ASP:
dim r= accept.secure.protocol
r.onload=window.callback('c')
//to firefox,opera,safari
new clientObject(r).access()
// to chrome,ie
forEachElement(a==null);
PHP code:
$a.window ;
All this scripts sends the browserstring "elementcast" by post method
The stop methods can break things that have already started to load.
If you want to load everything above a certain point and skip everything below a certain point:
<p>Everything works above this point.</p>
<pre style="display: none !important;">
<p>As long as the PRE tag remains open,
nothing works below this point</p>
<script>document.write('Nope');

Showing a demo of my CSS on any website

I have developed a small component which can be put in to any website. Now, I want to develop a code that could demonstrate how would my component look like on any website.
So, the person would come to my page and put in his URL and then my code should embed my custom JS/CSS in to the downloaded HTML and display it. Something like this.
Here, like the feedback tab, I want to show my component any where on that page.
Try a bookmarklet.
Create a piece of javascript that adds your code into the page such as the following:
javascript:(function(){var%20script=document.createElement('script');script.src='http://www.example.org/js/example.js';document.getElementsByTagName('head')[0].appendChild(script);})()
Add it as the href of a link like so:
Link Text Here
Tell your users to drag the link to their bookmark toolbar and click on it on different websites to try your code out.
Some examples: http://www.reclaimprivacy.org/, http://www.readability.com/bookmarklets
In the example you linked, they are requesting the page specified in the url querystring parameter on the server, and then doing more or less the following steps:
In the <head> tag they are adding a <base href="url" /> tag to the document. The base tag will make any relative links in the document treat the value in the href attribute as their root. This is how they are getting around broken css / images. (The base tag is supported by all browsers)
At the end of the document (IE the </body> tag) they are injecting the javascript that runs their demos.
They serve the modified HTML requested to the browser.
All of this is pretty straight forward in implementation. You could use regular expressions to match the <head> and </body> tags for steps 1 and 2 respectively. Depending on the server platform how you actually request the page will vary, but here are some links to get you started:
C# - HttpWebRequest object documentation
PHP - HttpRequest::send
Nathan's answer is the closest to how we have done the demo feature at WebEngage. To make such a demo functional, you'll need to create a Javascript widget that can be embedded on third party sites. syserr0r's answer on creating a bookmarklet is the simplest approach to do so. Our's is a JAVA backend and we use HttpClient to fetch the responses. As Nathan suggested, we parse the response, sanitize it and add our widget Javascript to the response. The widget JS code takes it on from there to render the Feedback tab and load a demo short survey.
Disclosure: I am a co-founder and ceo at WebEngage.
You can not do this with JQuery due to cross site scripting restrictions.
I suggest you write a PHP script that downloads the URL specified by the user and includes your widget code and then echo it back to the user.
I recommend using bookmarklets. I've made a bookmarklet generator for adding jQuery-enabled bookmarklets to a page to make development easier.
There's a caliper bookmarklet on the page that you can mess around with just to show an example of it working.
Full disclosure, this is something I've made, I'm not trying to be spammy as I think it's relevant: zbooks
You could make an iframe page, which loads their page in the iframe, and uses javascript to inject your code into the iframe.
Here is my approach...
http://jsfiddle.net/L2kEf/
html
<iframe src="http://www.bing.com"></iframe>
<div>I am div</div>
css
div { background: red; position: absolute; top: 20px; width: 100px; left:20px;}
iframe{width: 100%; height: 500px;}
you can add javascript/jquery too, so you could do something like,
jQuery //not 100% sure it would work coz of cross browser thingy, but you know, worth a try.
$('div').click(function (){
$('iframe').contents().html('changed');///
});
if this can't change any of the contents, you can display a dialog, to say it would normally work if it was in your website, then use #syserr0r approach for bookmarked users, for better results, since you are offering this kinda services, to developers, im sure they would know about bookmarking, my approach would be rarely used :) so hope it helps.
I had a problem of a similiar nature, and the main obstacle is the cross-domain policy.
You have to ask the user to put your code in a <script src="..."> or create a proxy solution that would add your code for them.
I went for the proxy and here are my observations:
it's easy to create a basic proxy in php - there are some php proxies on sourceforge and Ben Alman has created a simple php proxy for AJAX. Based on those I was able to create a php proxy altering the content properly in one day.
after that I spent a lot of time making it work with more and more sites with issues. You can never create a perfect proxy.
As an alternative (sa long as you are non-commercial) you can use http://www.jmarshall.com/tools/cgiproxy/ and put the site in an iframe and then do whatever you want to do with the iframes document, as it's in your domain thanks to the proxy. You can access iframeDOMnode.contentWindow.document then, etc.
You can create a Crossrider extension which your users can download.
Then simply add this to your App/Extension code:
appAPI.dom.addRemoteJS("http://yourdomain.com/file.js")
Your users can then download the extension (it works cross-browser for Internet Explorer, Chrome and Firefox) and it will load your JS code on every page load.
You can get an approximation of what it will look like using a iframe. Take a look at that link for an example.
http://jsfiddle.net/jzaun/5PjRy/
The issue with this appoch is that you can't move your DIV(s) when the page scrolls, they are in effect just floating over the iframe. There is no way around this as cross-domain scripting wont let you access the iframe's document to monitor scroll events.
The only other option you have for a better fitting example would be to load the page from the server side in whatever scripting language you are using and load that into the iframe (or into a div, etc.) and you can use javascript all you want as the page is coming from your domain.
For your example of what will your widget look like I imagine floating your DIV(s) over an iframe would give enough of an idea.
Please note the example you gave is using the server side method, not the iframe method.
I agree with the bookmarklet strategy.
I'm a fan of http://bookmarklets.heroku.com/, which lets you generate bookmarklets easily, inject jQuery, etc.

Javascript to reload page with javascript disabled

I am interacting with a webpage that I need to have java scripting alternatively disabled and then enabled.
I can't change the scripting setting in the browser to disable scripting since some of the website requires scripting be enable to work properly.
The program I am using allows me to execute a javascript but I can't figure out how to code a script that load a page with javascript disabled.
Any ideas how I can run a javascript to disable scripts on the page?
Thanks for all the feedback - A little more background might help.
I am using a program to create a bot that automates some of my repetitive tasks. The problem is that my program doesn't recognize the links generated by java scripting on the first two pages of the process so I have to have scripting disabled in my browser. Unfortunately on the last and final page of the process scripting is required to render a menu.
I am have request with their development team to change this final page so its viewable without scripts but in the meantime I've still got this problem.
I believe I'll be able to make this work by opening a new browser window, executing the window onload script for the first two steps then going back to a regular window for the final step. I'll let you know if it works.
And yes this is for a personal project and the site owners are aware of my attempts to automate their pages with my software.
You can't disable scripts using javascript.
Disabling javascript is something that is done within the browser configuration.
If your script is run outside the browser, you may be able to point it at 2 different browsers, one that has javascript enabled and one that doesn't.
Alternatively, some browsers (Firefox) have the notion of "Profiles" that you can start directly - so you could have one profile with javascript enabled and one without it.
The only way you could force a reload without Javascript is via a meta-refresh in the page's <head> block:
<meta http-equiv="refresh" content="600;url=http://address.to.your/page" />
or output some text to tell people to "click here to refresh".
Basically you're asking "how can I drive my car somewhere after I remove the engine".
You could look into an add-on for your browser that disables scripts.
Particularly one that can disable them on only a few pages per website, and not the whole site.
...with great difficulty!
However, if you can put this right at the top of the document (preferably inside an if statement acting upon whatever trigger you're using to enable/disable JavaScript):
<script>
window.onload = function()
{
var contents = document.getElementsByTagName('XMP')[0].innerHTML;
contents = contents.replace(/<script/gi, '<xscript');
contents = contents.replace(/<\/script/gi, '</xscript');
contents = contents.replace(/ on([a-z]+=)/gi, ' *$1');
document.open();
document.write(contents);
document.close();
}
document.write("<xmp>");
</script>
That just might do the job. Except for JavaScript running in IFRAMES and things like that. And except for the unlikely scenario that you're actually using the lesser-spotted XMP element somewhere within your pages.
Not working in Safari. Is this just for your own personal use?

I need help with javascript

I have a javascipt code something like
<script type="text/javascript" src="http://ads..........." ></script>
this script shows a banner. i want to use onClick event with this script without disturbing the banner click. is that possible?
Yes if the banner is not wrapped in an iframe that is cross domain, but the question is...
onClick event on what? the banner? the page? another element?
use addEventListener/addEvent or a JS library to add the event. If this kills the banner be sure to take the banner's onclick property and add it as well to the banner.
Those scripts usually produce dynamic content via document.write. If you examine the resulting DOM (e.g., via Firebug in FireFox, or Dev Tools in Chrome, etc.), you can get an idea of what the resulting structure is. If there's a top-level image or link, you can hook it with a DOM2 handler (addEventListener is the standard form; IE uses attachEvent instead; Javascript libraries like Prototype or jQuery can help iron out the inconsistencies for you). That would let you see a click without disturbing its underlying action (provided you don't cancel the event, but you have to do that on purpose, so you should be okay.)
Process that click through the handler, e.g.
<!-- Banner image -->

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