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Closed 12 years ago.
For me iframes are pure evil (well, maybe not so pure). They seems to make a lot of troubles. Yes, your whole site will load once and then you can just load single pages. But people invented AJAX for this purpose.
One of the biggest issues I found with iframe was that I couldn't paste a link to one of the subpages, because the URL never changed (yes, I know there is a workaround for this). Second thing, web search engines may have problems indexing such pages.
Sometimes the accessibility of this sites are worse and some browser can even display them improperly.
There are better ways to design layouts without iframes. Everyday I can see some one asking at SO questions, like "How to access iframe with jQuery?".
So what are the benefits of iframes? What reason can it be to still use them? I just would like to know why.
I can think of 2 reasons (at the moment) why people would still use iframes instead of AJAX:
1) Iframes circumvent the cross domain origin policy (images, scripts, and styles do not). This can be useful for pulling in sites / content from other domain names relatively safely. Basically, this allows the advantage of being able to visually show data from other domains without letting them stomp all over your page with unlimited access (like something like JSONP would be able to do).
2) You can load multiple types of resources from within an iframe, not just certain mime-types (you're relatively limited to application/javascript, application/x-javascript, text/css, text/xml, image/png, image/jpeg, image/gif with scripts, XHR, images, and sources). For instance, if I want to show you a PDF, I can open an iframe and let the Adobe Reader plugin show you that file. Additionally, in the same domain, if I want to pipeline a script, style, and image all together (inline on the page, image would have to be data URI), I can accomplish this with an iframe (and if it's in the same domain, port, and protocol I can access it with JavaScript as well).
Did you know that Gmail is a set of iframes? The visible part is just clever positioning. Additionally, many OAuth implementation (Twitter, Facebook, Google, Yahoo!) usually use iframes to associate a user on their domain with a successful authentication URL (for after the user logs in).
IFRAMEs are used to embed and isolate third-party content into a website.
Most of web advertising solutions are based on iframes - because they give security (cross-domain policy) and isolated rectangle on screen which can be fully managed by third party content and scripting (a common use case is advertisments).
Another modern use of IFRAMES is a management of history (common back button workaround) of AJAX applications.
FRAMEs are poor version of IFRAMES. Their use is declining.
If a user has javascript disabled, iframes will work when ajax doesn't. This is not out of the question, considering that people use things like NoScript.
I use them on ajax websites, when I need to upload files without reloading the page.
I still see iframes being used in large corporations where they provide a single sign on which injects header information about the authenticated user which is then passed, via an iframe, towards the actual application(s). Since the "portal" surrounding the iframe handles all the specific authentication details those applications behind it don't need to have each an implementation for it, making things easier to make for the development team and having a single place to monitor and adjust authentication details of users.
There are plenty of technical reasons to use them (especially the security issue mentioned by Dan Beam).
What you shouldn't do is use iframes “like frames”, doing navigation to new pages by updating the iframe only. As you say, this prevents the navigation from being bookmarkable/linkable, responding to the normal navigation buttons, and providing useful link affordances like open-in-new-tab.
But that's not peculiar to iframes. You can see more and more pages where the navigation is done by fetching new content with XMLHttpRequest and writing it to the main content div's innerHTML. Often this is done with jQuery load() and clever-clever slidey animations. This breaks navigation just as badly as iframe-used-as-frame, or indeed old-school framesets. It's a shame so many web authors are using this tactic believing it to be a super-modern web design methodology, when really it's just a new skin on yesterday's despised framesets.
You can work around it in both cases, but it means you have to store a viewstate in the # fragment identifier part and support proper hash-navigation, which isn't trivial. Even then you've still got problems with non-JS agents like search engines; you end up having to have a parallel ?-based and #-based navigation to support both. It's a pain and most don't bother.
Framesets are outdated as of HTML 5, and sometimes you need to have a frame with another site within a site.
Also AJAX can only do so much. Try uploading a file to a site on another domain through https without an iframe. AJAX won't help you there.
In addition to others reasons, I have one specific usage of iframe in my application. Unfortunately, the target browser in my case is Internet Explorer 6. I need to have a footer and a header that are fixed in my web pages. The main part of this page is scrollable.
However, there is a bug in IE6 where I cannot display a div element on top of select elements using the z-index CSS property. Thus, I need to create an iframe that will be used as a hack to avoid this problem.
Of course, this is a really specific usage of iframe and only concern IE6...
Javascript WYSIWYG Editors use iframes, because that is easiest and best way to make it. For example TinyMCE uses it:
http://tinymce.moxiecode.com/
I was building a social network and i see iframes being useful for widgets to put on other peoples website to show like a mini profile or integrate with the content on a remote server. Seems like the most simple way to build this. I know some widgets use JavaScript. Also with the iframe method the session is the same as visiting the site like normal, so great for like buttons.
Many Formatted Text Editors (e.g. TinyMCE, HTMLArea) are implemented as iframe.
iFrames are okay for some cases, as X-domain-requests, or posting data to a source via parameters. But when I want to access data across domains, I prefer using CSS-files - they can accept params, set cookies, add content to the page (:before & :after) and give a visual feedback.
Related
I would like to use iframe html5 tag in my web project (ASP.NET MVC5). But I am wonder the browsers not allowed display content. So is using iframe dead?
My goal is wrap the payment gate window to iframe tag and place to my web page.
Iframe is not dead. It is still widely used, mostly for advertisement (third parties can serve content without intervention from the site admin). This answer mentions some valid points.
You can separate websites and domains easily without security concerns (cross-domain policy). That makes it unique and irreplaceable.
It works?
Yes.
But...
It was deprecated in HTML5, tough some browsers still support it I do not recommend you to use it in your projects.
The problems
1) It was removed from web standards, you maybe get some problems while trying to access your page from newer browsers.
2) It's SEO unfriendly. A webpage was supposed to only have one URL, but if you use frames your page will have multiple URLs (one for each frame).
3) If the frame source isn't reliable you can get security problems.
Sites that use it
JS Bin, JS Fiddle and Codepen are good examples.
I am about to develop a web site for data entry. It will have hundreds of data entry pages. Previously i have made extensive use of iFrames from the menuing system.
Is this now best practice, i number of developers i have mentioned this to have questioned the use of iFrames saying there are better techniques now. However no one could give me a reason not to use the iFrame.
Does anyone have some opinions on the use of iFrames and the reason i should not use them? If not an iFrame then what?
An iFrame is to embed foreign content, another site or another page of your site. Web is not only about what you see but about semantic meanings.
Using iFrames is the most effective way to kill your ranking in search engines and also to difficult web browsing since a browser cannot tell what part of the content represents what or how they are related to each other.
For instance, navigate into an iFrame based page and bookmark an internal page, then come back through the bookmark and see the results.
Do a search in Internet and there are many more explanations about this.
I understand that frames are a lot more typing work to implement than Iframes, and that they require a lot more styling than Iframes. I am currently working on a website which must download some content (in fact, an entire set of webpages) from another website, one - by - one of course depending on the user's action on the main website. Iframes seem to be a short and rowdy way to implement this requirement, but what I am worried about is performance and integrity.
I would like some advice on what I would rather use when the following criteria is met:
The pages that must be downloaded onto my webpage are quite large (width and height)
Contains multiple images
Experiences occasional downtimes (maintainence)
any ideas for a man in wonder?
At this point, go with iFrames:
iFrame is HTML5. Frameset is obsolete in HTML5.
You have to load pages into each Frameset. iFrames can be embedded anywhere in a document.
You can style, hide, resize either, but iFrames are much easier to work with in this regard.
I've seen cases where the developer went with Frameset because he couldn't get the iFrame to size properly, but this isn't too big a deal with a little Javascript (if even that). The only reason to use a Frameset is if you don't fear it's eventual deprecation with modern browsers, and/or if you can't get iFrames to size the way you want based on the content you're integrating and need a quick solution.
If this is about display of 3rd party data in your site, you could use data feeds from the other sites if they're available, or use a screen scraper to extract the information you need, then display it in your own way on the page.
Unless it needs to look exactly like to other page.
Check out this link on screen scraping for ASP.NET
As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance.
Closed 9 years ago.
I have asp.net website name http://www.go4sharepoint.com
I have tried almost all ways to improve performance of this site, I have even check firebug and page speed addon on Firefox, but somehow i am not pleased with the result.
I also tried like removing whitespace, remove viewstate, optimizing code which renders it, applied GZip, I have also no heavy session variables used, but still when i compare with other popular websites it is not upto the mark.
I have check CodeProject website and was surprise that even though they have lot of stuff displayed there website is loading fast and they also have good loading rate.
To all experts, Please suggest me where i am going wrong in my development.
Thank you.
First of all I see now your pages and they not gZipped.
You make the question for the gzip, but its seems that at the end they are not gzipped.
Second your pages come very fast, they are small, and the lag time is slow, that means that your call to sql is good.
I only see a problem on "banner.php" page that for some reason this is seams that make the delay. A Javascript make this call to banner.php and waits until get return, render it and continue.
Check this 2 issues to fix your slow load.
About the banner.php
Here is one of the calls that you page make
http://sharepointads.com/members/scripts/banner.php?a_aid=go4sharepoint&a_bid=ac43d413
and you make at least 9 of them !. in first page.
This page have 400ms lag x 10, plus delay to load and reder is the delay that you search for. and is not comming direct from you. You need to find some other way to load them...
I can suggest some other way but not I must go... maybe tomorrow
gzip
An external test to prove that your pages are not gzip. Just see the report.
When optimizing the html visible to the client, the server side is sometimes neglected. What about:
Server side Caching - from entire page to data caching
Reduce number of database queries executed. And once retrieved from the database, cache it.
Is your server hardware up to it? Memory, cpu?
EDIT:
And for completeness, here's the list from the performance section of the popular question What should a developer know before building a public web site?
Implement caching if necessary, understand and use HTTP caching properly
Optimize images - don't use a 20 KB image for a repeating background
Learn how to gzip/deflate content (deflate is better)
Combine/concatenate multiple stylesheets or multiple script files to reduce number of browser connections and improve gzip ability to compress duplications between files
Take a look at the Yahoo Exceptional Performance site, lots of great guidelines including improving front-end performance and their YSlow tool. Google page speed is another tool for performance profiling. Both require Firebug installed.
Use CSS Image Sprites for small related images like toolbars (see the "minimize http requests" point)
Busy web sites should consider splitting components across domains. Specifically...
Static content (ie, images, CSS, JavaScript, and generally content that doesn't need access to cookies) should go in a separate domain that does not use cookies, because all cookies for a domain and it's subdomains are sent with every request to the domain and its subdomains.
Minimize the total number of HTTP requests required for a browser to render the page.
Utilize Google Closure Compiler for JavaScript and other minification tools
Are you using JavaScript, and are these JavaScript files loaded at the very beginning? Sometimes that slows the page down... Minifying JS files helps reduce size, and if you can, load scripts dynamically after the page loads.
Using an approach like http://www.pageflakes.com can also help too, where the content is loaded after the fact.
Lastly, is it speed related to your machine or hosting? Doing a tracert in the command window can help identify the network traffic.
HTH.
Have you identified any slow running queries? You might consider running profiler against your DB and see if anything if running long...
Before you do anything to change the code, you need to figure out where the problem actually is.
Which component is it that is "slow"?
The browser?
The server?
The network?
A stackoverflow user actually has a good book on this subject:
http://www.amazon.com/gp/product/1430223839?ie=UTF8&tag=mfgn21-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=1430223839
A couple of recommendations after looking at your site:
Put some of your static files (images, js, etc.) on different domains so that they can be downloaded at the same time. (also turn off cookies for those domains)
Use image sprites instead of separate images.
Move around when things are loaded. It looks like the script files for the ads are holding up content. You should make content of the site load first by putting it in the HTML before the ads. Also, make sure that the height and width of things are specified such that the layout doesn't change as things are downloaded, this makes the site feel slow. Use Google Chrome's developer tools to look at the download order and timeline of all your object downloads.
Most of the slowness looks like it's coming from downloading items from sharepointads.com. Perhaps fewer adds, or have them use space already reserved for them by specifying height and width.
Add a far future expires time to the header for all static content.
Serve scaled images. Currently the browser is resizing the images. You could save tons of bandwidth by serving the images already the proper size.
Also, download YSlow (from yahoo) and Page Speed (from google)
Another good post for performance.
Just check
http://howto-improveknowledge.blogspot.com/2011/11/performance-improvement-tips.html
which explain the how to find bottleneck for performance.
are there any reasons not to use iframes at all? I currently use it to load a page from a different server (a sign up page - part of a distributed application) to provide a seamless experience. Is using iframes considered bad practice or is its use OK?
The iframe is a great tool. It enjoys near-universal browser support, it's easy to implement and has a number of useful functions. As with any other HTML element, it can be abused, but wielded intelligently it can play a part in a solid UI.
Some developers might argue to use AJAX instead, and in some situations that may be the more appropriate approach, but AJAX is not a panacea and iframes can be a far simpler implementation which has the same end-result for your users. Do whatever is simplest first, and only change that when you can verify how and why that is not working.
Keep using iframes. Here's an example of why:
The whole Verified By Visa thing really annoys me. I'm happily shopping at some site that I trust, when I'm redirected to some site I've never heard of (not visa.com) and I have to fill in some other form and hope that I get redirected correctly back to the shopping site.
Then recently I was shopping at the John Lewis website, and they brought up the Verified By Visa page in an iframe - wonderful! I'm still looking at the John Lewis site, and all that's happening is I'm being asked for my Verified By Visa password - no problem.
Although as a web developer I know that there's no technical difference between that and a plain old redirect-there-redirect-back, the user experience is so much better!
Pros:
Helps with slow third-party content like badges and ads
Security sandbox
Download scripts in parallel
Cons:
Costly even if blank
Blocks page onload
Non-semantic
Source: Best Practices for Speeding Up Your Web Site
iframes have access to certain properties of the parent document, e.g. redirect the parent frame to a new location using parent.location.href or parent.window.location (IE allows to restrict that).
This is great for phishing attacks when embedding content from other servers (even if you trust that server it might be compromised).
iframes can also be used for a variety of other attacks: IFrames security summary.
With HTML 5 you'll be able to use the cross document messaging API to send messages from window to window, but for now the iFrame is the most viable alternative to any sort of AJAX that requires styling and scripting to load with the data.
If you're looking to just use text data in the iFrame, use AJAX instead. If you want external CSS or JavaScript to work in a protected environment, want styling to start from scratch, or need to access cross domain documents, use the iFrame.
Cons are that the accessibility of iFrames generally sucks, although you can prevent this by making sure that you proceed the iFrame with a notice of external content for screenreaders. Also check the HTML specifications for other ways to make the iFrame more accessible. Other than that and the obvious limitations scripting wise, the iFrame is a great tool is used responsibly and sparsely.
One last note, piling a page full of iFrames is definitely not a good idea, as remember that for each loaded iFrame, a DOM is created, HTML requests are made and document wrappers are instantiated, eating memory and bandwidth in the process. Keep iFrame's to a minimum on the page, and you'll avoid misuing a powerful tool in the HTML aresenal.
IFrames are a great way to "include" external content in a web page. However, there are a couple of (small) drawbacks:
Security sandboxing will cause problems with JavaScript if the IFrame does not originate from the same domain.
You cannot get CSS to co-operate between the IFrame and the parent page, unless you control the stylesheets themselves.
From an indexing point of view, the IFrame's content doesn't exist.
Screen readers might not like the IFrame, for the same reason. Or they won't be able to properly indicate the relative meaning of an IFrame's contents.
Apart from that, they're great! The points I mentioned might even be considered advantages, if you think about it (except the screen reader one): in principle, an IFrame can't influence its parent page's layout, and it isn't influenced itself by its parent either.
As a general rule, iframes are a bad experience for SEO reasons. So, you ask is there any reason not to use iframes? Yes, if you use iframes you are losing some organic placement in the search engines.
Of course, there are usability concerns which can (and should) trump SEO value of pages.