Well met!
I am working on a project similar to the Windows 8 tile-interface, only for Websites.
The idea is that, when a tile is clicked, it grows to fill the site (leaving a menu-bar on the top free) and the user can reguarly browse the loaded site. When he clicks a button on the menu-bar, the tile grows back.
My approach was to use IFrames. But those can be disabled through a HTTP-option by the visited site, or by using some javascript to test window toplevel.
Therefore I need some kind of alternative to IFrames. The best thing I was able to find was the JQuery .load(url), which only displays the content of the site, not making it regulary useable. It was very slow in my tests, too.
Is there something I can use, or do I have to drop the idea?
Thanks in advance!
Loading resources from different origins is very limited on the client side. Your best bet is probably a proxy on the server side (which isn't a perfect solution as it's used by scammers, read about it carefully) - I remember this iPad simulator has a fake Mobile Safari browser which uses php simple proxy.
Using Client Side Technology ...
jQuery's .load() will fetch the resource using AJAX and is constrained by the same-domain origin policy (security sandbox) that is inherent to the XMLHttpRequest object.
an iFrame will load the resource but as you pointed out it has drawbacks.
Using Server Side Technology ...
if you have only a few websites in the tiles that will need to be opened, you could preload them using a server side technology (php, jsp, asp) and hide them in a container object (like a div element) and then programmatically show them when the user activates the tile though a hover or click event.
Using java for example, you could use the java.net library to open a string buffer, read and save the contents of the website, and then add the variable to the servlet response. Using JSTL you would output the variable from the response object.
Related
I'm trying to create a secure Darknet with WebRTC DataChannels in pure HTML, so I'm not interested about to know when an iframe has been fully loaded, but instead I'm interested to capture the iframe elements (inline images and so) using a custom scheme so I can be able from the parent page (the one connected to the Darknet) to do the real request and response with the actual data. With FirefoxOS mozbrowserlocationchange event of the Browser API objects (an extension to iframes) I could be able to capture the user navigation, cancel it, do the real request on the Darknet and later inject the iframe with the real content fetched by the parent page, but how could I be able to do the same with inline images and scripts on this loaded page? Or is this not currently possible and should I ask to them about add this functionality?
Obviously, I don't have any control about the iframes content pages, so they would be created by whatever and in any way, and also the usage of Browser API is just because seems to be the most useful to whan I'm trying to do, ideally it would be perfect if this is possible to achieve with plain iframes... :-)
Update:
A half-solution I have thinking about would be since I could be able to capture the mozbrowserlocationchange event to do the real content request of the HTML page and before fill the iframe with it do the request of their linked images and scripts and set them inline to prevent the iframe from doing more request. This would only lead to somewhat very simple web pages compared to current web standards (no AJAX, no async loading of script tags...) but definitely it would be usable up to some point :-)
Anyway, is there any other better alternative?
That sounds like something, that would be possible (straightforward, even) as soon as Service Controllers (previously known as NavigationControllers) are implemented, but I do not know any way to accomplish this via any currently available method.
No wonder you didn't find info about this - the proposal is called "Service workers" (though, previously this was called Event workers, and even before that, they were called - guess what - navigation controllers). This is a lively spec! ;) Find the working draft on GitHub: https://github.com/slightlyoff/ServiceWorker/ with a lengthy explainer document that should get you going.
Also, there is a document with the current Chrome (blink) implementation plans.
I have seen this excellent firefox extension, Screengrab!. It takes a "picture" of the web page and copies it to the clipboard or saves it to a png file. I need to do so, but with a new web page, from an url I have in javascript. I can open the web page in a new window, but then I have to call the extension -not to press the control- and saves the page once the page is fully loaded.
Is it possible?
I am pretty certain that it is not possible to access any Firefox add-on through web page content. This could create privacy and/or security issues within the Firefox browser (as the user has never given you permission to access such content on their machine). For this reason, I believe Firefox add-ons run in an entirely different JavaScript context, thereby making this entirely impossible.
However, as Dmitriy's answer states, there are server-side workarounds that can be performed.
Does not look like ScreenGrab has any javascript API.
There is a PHP solution for Saving Web Page as Image.
If you need to do it from JavaScript (from client side) - you can:
Step 1: Create a PHP server app that does the trick (see the link), and that accepts JSONP call.
Step 2: Create a client side page (JavaScript) that will send a JSONP request to that PHP script. See my answer here, that will help you to create such request.
I apologize if this has been asked before. I searched but did not find anything. It is a well-known limitation of AJAX requests (such as jQuery $.get) that they have to be within the same domain for security reasons. And it is a well-known workaround for this problem to use iframes to pull down some arbitrary HTML from another website and then you can inspect the contents of this HTML using javascript which communicates between the iframe and the parent page.
However, this doesn't work on the iPhone. In some tests I have found that iframes in the Safari iPhone browser only show content if it is content from the same site. Otherwise, they show a blank content area.
Is there any way around this? Are there other alternatives to using iframes that would allow me to pull the HTML from a different domain's page into javascript on my page?
Edit:
One answer mentioned JSONP. This doesn't help me because from what I understand JSONP requires support on the server I'm requesting data from, which isn't the case.
That same answer mentioned creating a proxy script on my server and loading data through there. Unfortunately this also doesn't work in my case. The site I'm trying to request data from requires user login. And I don't want my server to have to know the user's credentials. I was hoping to use something client-side so that my app wouldn't have to know the user's credentials at the other site.
I'm prepared to accept that there is no way to accomplish what I want to do on the iPhone. I just wanted to confirm it.
You generally can NOT inspect the contents of an iframe from another domain via JavaScript. The most common answers are to use JSONP or have your original server host a proxy script to retrieve the inner contents for you.
Given your revisions, without modification or support from the secondary site, you are definitely not going to be able to do what you want via the iPhone's browser.
"In some tests I have found that iframes in the Safari iPhone browser only show content if it is content from the same site"
I found the same thing. Is this documented somewhere? Is there a workaround? This sounds like broken web standards to me, and I am wondering if there is a solution.
I'm just looking for clarification on this.
Say I have a small web form, a 'widget' if you will, that gets data, does some client side verification on it or other AJAX-y nonsense, and on clicking a button would direct to another page.
If I wanted this to be an 'embeddable' component, so other people could stick this on their sites, am I limited to basically encapsulating it within an iframe?
And are there any limitations on what I can and can't do in that iframe?
For example, the button that would take you to another page - this would load the content in the iframe? So it would need to exist outwith the iframe?
And finally, if the button the user clicked were to take them to an https page to verify credit-card details, are there any specific security no-nos that would stop this happening?
EDIT: For an example of what I'm on about, think about embedding either googlemaps or multimap on a page.
EDIT EDIT: Okay, I think I get it.
There are Two ways.
One - embed in an IFrame, but this is limited.
Two - create a Javascript API, and ask the consumer to link to this. But this is a lot more complex for both the consumer and the creator.
Have I got that right?
Thanks
Duncan
There's plus points for both methods. I for one, wouldn't use another person's Javascript on my page unless I was absolutely certain I could trust the source. It's not hard to make a malicious script that submits the values of all input boxes on a page. If you don't need access to the contents of the page, then using an iframe would be the best option.
Buttons and links can be "told" to navigate the top or parent frame using the target attribute, like so:
This is a link
<form action="http://some.url/with/a/page" target="_parent"><button type="submit">This is a button</button></form>
In this situation, since you're navigating away from the hosting page, the same-origin-policy wouldn't apply.
In similar situations, widgets are generally iframes placed on your page. iGoogle and Windows Live Gadgets (to my knowlege) are hosted in iframes, and for very good reason - security.
If you are using AJAX I assume you have a server written in C# or Java or some OO language.
It doesn't really matter what language only the syntax will vary.
Either way I would advise against the iFrame methods.
It will open up way way too many holes or problems like Http with Https (or vice-versa) in an iFrame will show a mixed content warning.
So what do you do?
Do a server-side call to the remote site
Parse the response appropriately on the server
Return via AJAX what you need
Display returned content to the user
You know how to do the AJAX just add a server-side call to the remote site.
Java:
URL url = new URL("http://www.WEBSITE.com");
URLConnection conn = url.openConnection();
or
C#:
HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create("http://www.WEBSITE.com");
WebResponse res = req.GetResponse();
I think you want to get away from using inline frames if possible. Although they are sometimes useful, they can cause issues with navigation and bookmarking. Generally, if you can do it some other way than an iframe, that is the better method.
Given that you make an AJAX reference, a Javascript pointer would probably be the best bet i.e. embed what you need to do in script tags. Note that this is how Google embed things such as Google Analytics and Google Ads. It also has the benefit of also being pullable from a url hosted by you, thus you can update the code and 'voila' it is active in all the web pages that use this. (Google usually use version numbers as well so they don't switch everyone when they make changes).
Re the credit card scenario, Javascript is bound by the 'same origin policy'. For a clarification, see http://en.wikipedia.org/wiki/Same_origin_policy
Added: Google Maps works in the same way and with some caveats such as a user/site key that explicitly identify who is using the code.
Look into using something like jQuery, create a "plugin" for your component, just one way, and just a thought but if you want to share the component with other folks to use this is one of the things that can be done.
I'm having a few problems with an application that integrates sharepoint, SQL reporting services and a bunch of custom forms that are built using ASP.NET MVC.
Assuming my servers are as follows;
MOSS
SSRS
Custom forms
In MOSS, my portal has need on occassion to popup a custom form to capture user input. I've done this by using a jQuery dialog (using Boxy), which iframes the custom form in and passes the url of the portal into it. When the custom form is finished, it navigates the parent window (the MOSS portal) to the URL passed in, which effectively refreshes the page.
This was working fine until we threw in the complexity of SSRS.
Now in MOSS, I have a report that lists some data, but the SSRS report viewer web part seems to iframe it's report content in, which means the hyperlinks from the report can't ask the parent to overlay the same dialogs (as it's cross domain) and if it were to perform the overlay itself, it would just overlay the iframe.
Sorry for the long post, getting to the point - this is an internal intranet application only. Is it possible to allow cross domain scripting somehow so that the popup dialogs can all be controlled from javascript within the sharepoint portal and SSRS and my custom forms can just invoke javascript methods on the parent?
Preferably I wouldn't want to have to do configuration in the client browser to allow this to happen, as I'd have to roll that change out to all the machines within the estate - which is a significant number.
Thanks in advance, beer available to anyone who can solve my woes ;)
Cheers,
Tony
IE8, Firefox 3, recent Opera and Safari/Chrome support postMessage which allows cooperating pages on different domains to talk to each other:
http://ajaxian.com/archives/cross-window-messaging-with-html-5-postmessage
If you are stuck with older browsers, you have few options. The cleanest is to send everything that needs to communicate with each other through the same proxy, although in the OP's situation it looks like this isn't possible.
The next cleanest is to use Flash's cross-domain facility.
Another option is xssinterface, which wraps postMessage where available and uses some voodoo involving cookies and polling where it isn't.
The only other option is to use hidden iframes - to send a message to a page, change the iframe's location to one on the destination page's domain and poll in the destination page - but again I think the proxying in the OP's case makes this unworkable.
There is another option in addition to those Andrew provides. You can dynamically inject script tags into the DOM, wherein the src attribute can point to a javascript file on any domain.
In jQuery you accomplish this by specifying "jsonp" as the datatype for the ajax request. You can read more about this approach here:
http://blog.ropardo.ro/2009/09/23/cross-domain-ajax-calls/
I finally got around these issues by using hidden iframes as suggested. I posted an article on my blog with more details and pushed the code onto codeplex:
http://www.deepcode.co.uk/2009/11/overcoming-cross-domain-issues-between.html