different CSS stylesheet for iPad and iPhone in universal application - javascript

I have what is essentially an offline web site embedded in a UIWebView. I've created a stylesheet to format everything nicely on the iPhone screen, but I need different formatting to take better advantage of the iPad's screen.
I tried using code to simply copy a different stylesheet into place, but this involves modifying the application bundle which is either discouraged or, in this case, just doesn't work.
Can anyone think of a way to have a different stylesheet loaded based on whether the app is running on the iPhone or iPad? I have thousands of HTML files which are synchronized with a web site so I can't very easily modify all of them. I need some way to change the stylesheet that gets loaded using javascript or by moving the css file into a certain location.
I should also mention that this is a universal application with almost the exact same code (and slightly different nib files) running on both.

Can you use a CSS media query? You could inject it into your pages using stringByEvaluatingJavaScriptFromString:.

Via your server side code, you could detect the iPad User Agent and write out a link tag to a different stylesheet. I would probably go with server side logic rather than Javascript, simply because I don't like the possibility of a "flicker" of doing this with Javascript.

Why dont you have a look at 960 Grid System http://960.gs . It helps to use different CSS formats based on the device it encounters

Related

how to read text from input file in javascript?

I have a text file i want to read in my html page,both are in the same directory and i am not running a server. I intend that my users use the script offline(basically text manipulation based on expressions and preserving new line characters) .
I tried ajax call but mostly cross domain origin problem occured and i know most of the users will have this security tighened up in many browsers , so its not of use to circumvent this in only in my browser.
I want to support many browsers including old browsers as in IE7,8 etc which do not support HTML5 filereader.for the same reason reading using filesystemobject or activex is not good.
Reading the file after user select it as input , is this possible?Otherwise i would have no option then using other technologies like php,java etc which may expect my user to setup these.
Please excuse me if i am repeating this but i am a beginner web developer. I know that reading local files via javascript is not possible but is there any other way?
If you can't support FileReader, then the answer is pretty much no (at least, if you want to support a large range of browsers rather than rely on convenient feature x of browser y). Unless : you indeed increase the requirements for running the application and get some sort of local server going (for instance node.js, Apache, TomCat, etc. but like you said this will greatly increase the requirements and become cumbersome for users).
You could also rethink what it is you're trying to achieve. What are the contents of the file you want to read ? Can't these contents be part of the HTML file you're serving to your users (i.e. a large JSON Object inside a script-tag ?)
On possibility of using node.js:
Node.js is quite easy to install and assuming you are requiring from your users to install it, you can use it as a local server, which is a nodejs script of about two lines in size :). Running it locally would also omit the need to upload anything anywhere as you can directly read from the file system using the fs-object (see sitepoint.com/accessing-the-file-system-in-node-js).
STILL: from both a design and ease-of-use-point of view you might want to resort to using either another technology, or include the text file content inside the HMTL file

Converting a web app into an embeddable <script> tag

I just did a proof of concept/demo for a web app idea I had but that idea needs to be embedded on pages to work properly.
I'm now done with the development of the demo but now I have to tweak it so it works within a tag on any websites.
The question here is:
How do I achieve this without breaking up the main website's stylesheets and javascript?
It's a node.js/socket.io/angularjs/bootstrap based app for your information.
I basically have a small HTML file, a few css and js files and that's all. Any idea or suggestions?
If all you have is a script tag, and you want to inject UI/HTML/etc. into the host page, that means that an iframe approach may not be what you want (although you could possibly do a hybrid approach). So, there are a number of things that you'd need to do.
For one, I'd suggest you look into the general concept of a bookmarklet. While it's not exactly what you want, it's very similar. The problems of creating a bookmarklet will be very similar:
You'll need to isolate your JavaScript dependencies. For example, you can't load a version of a library that breaks the host page. jQuery for example, can be loaded without it taking over the $ symbol globally. But, not all libraries support that.
Any styles you use would also need to be carefully managed so as to not cause issues on the host page. You can load styles dynamically, but loading something like Bootstrap is likely going to cause problems on most pages that aren't using the exact same version you need.
You'll want your core Javascript file to load quickly and do as much async work as possible as to not affect the overall page load time (unless your functionality is necessary). You'll want to review content like this from Steve Souders.
You could load your UI via a web service or you could construct it locally.
If you don't want to use JSONP style requests, you'll need to investigate enabling CORS.
You could use an iframe and PostMessage to show some UI without needing to do complex wrapping/remapping of the various application dependencies that you have. PostMessage would allow you to send messages to tell the listening iFrame "what to do" at any given point, while the code that is running in the host page could move/manipulate the iframe into position. A number of popular embedded APIs have used this technique over the years. I think DropBox was using it for example.

How to get the associated icon of a file in HTA (HTML/Javascript/VBScript)

I'm building an HTA application in which I need to display a list of file with their associated system icon.
I'm using FileSystemObject to list the file but there seem to have no way to get the icon...
I've found a script in VBS that can save the icon of a file into a .ico .
It read the file (PE resource file, .exe or dll) and parse the icon data.
I modified that script to return the icon's bytes, convert it to base64 and use embed base64 images in HTML.
Here's the original script: http://gilpin.us/IconSiphon/
Issue
) In most case the .ico contains multiple icons (many sizes and color depth) but there's no way I can specify which one to use (as I need 16x16 icons).
) Not all icons are displayed
) Could be slow with many file as it read exe and dll (but I'm ok with that, I can cache already fetched icon)
I've also tried some ActiveX control but none seem to work properly. Even those provided by microsoft (ShellFolderView or ListView) are very buggy.
Requirements
Must display 16x16 icon
Must allow multiple file selection
Everything must be embed in hta (if possible). No external .exe
Does anyone know a way to achieve that?
Thanks!
Use SHGetFileInfo() with the SHGFI_ICON flag.
http://msdn.microsoft.com/en-us/library/windows/desktop/bb762179(v=vs.85).aspx
The filesystemobject will provide you the necessary functions for enumerating files on the local filesystem. However to get the icon image you will need to use the win32 api per #seanchase's response or an external exe.
However you can access the win32api via javascript in the hta using the wshApiToolkit activex object - http://www.google.com/search?q=wshAPIToolkit.ucATO%2F&rls=com.microsoft:en-us&ie=UTF-8&oe=UTF-8&startIndex=&startPage=1
Find a copy of that and you're close to being done. It does require distributing the activex object with your code and shell executing the registration process from within the HTA so that might violate your third constraint. Though I believe you can base64 encode the exe into the hta in a dataurl and write that back out to the file system so it would at least be bundled into a single file. If you support that option then maybe embedding an exe that does the same would meet your requriements.
Definitely some hacky stuff that may be unstable on future OS versions - heck I'm not even sure the wshApiToolkit works on windows 7, and 8 is just around the corner. Good luck!
You indicated you're opened to installing ActiveX components and using them in your HTA.
If I had the time, I would approach this for myself by creating ActiveX components using Visual Studio to call FindResource, LoadResource and LockResource. These will enable access to the Group Icon resource for which I would then provide rich interfaces to iterate through the Icons offering the ability to extract BMPs (or PNGs).
This is "how" I would go about achieving this short of actually going off doing it.
Once I build a similar HTA interface and I faced the same problem. I solved the problem by creating a custom icon gallery and converting the images using base64. You may achieve the same by either converting or using sprite. Many UI does it, even java.swing has its own collection embbebed. As you noticed, reading from *.dll can speed down the application

Accessing Local Files with jQuery

I believe that this question has been asked in a few different forms, but I've read quite a few different responses.
At first, I had a web-application written with mostly jQuery that would make use of servlets to retrieve information from various locations JavaScript could not access (ie. Feeds, images from a server, etc.). Now, however, I've been told to do away with the servlets and application configuration classes so that this project of mine contains only HTML, CSS, and JavaScript/jQuery. Rather than pulling the images off of the server, I need to retrieve them from a local file on the computer. I know that allowing this might seem like terrible design, but it's what I've been asked to do. At any rate, what I really need to do is count the number of image files in a directory and then perhaps compile an array of the filenames themselves. I could do this fine in Java when using the servlets, but without them, I'm not sure how or even if this can be done.
I'm basically trying to use the jQuery Cycle plug-in to cycle through these images like a slideshow. I inject (or $("#div").append()) these images into the div by using a loop based on the number of images present.
So, is there a way I can do this with using JavaScript, HTML, jQuery plug-in, etc? I'd like to avoid using PHP and Java at this point...
You can't just read a directory with JavaScript; however, there appears to be a way to "exploit" how browsers function using http://www.irt.org/articles/js014/. It may not be pretty, but the demo works in the latest Chrome and IE7-9 for me. I'm sure some of the techniques could be updated to use cleaner code if you'd like to improve upon it.
EDIT:
Another technique you could use can be found in Javascript read files in folder
It definitely looks to be a cleaner solution. What I'd recommend is extracting the body contents to inject into a hidden div or using the path for an iframe that you can read from.

newbie question about javascript embed code?

I am a javascript newbie. I am trying to write a requirements document, and need some help describing what I am looking for. We want our application to generate a javascript snippet like this:
<script src="http://www.jotform.com/jsform/10511502633"></script>
This will load a web form.
So my question is:
- How does a single script load an entire web form? Is this a JSON?
- What is this called? Is this a cross browser javascript?
- Can anyone point me in the direction of learning more about what this is?
Thank you for your help!
The javascript file is just hosted on an external site. It appears to be dynamically generated, so feel free to use some fancy words ;) But basically, you just include it here, as if it was on your own site.
You could say "The application will generate the required script-tags to include dynamically generated javascript file from an external, third-party site".
Offcourse you need to take special cautions for cases when the include won't work, because the other site is not reachable (site is down, DNS does not work, file is moved on other webserver, your application is on an intranet/behind a proxy/firewall...). Why can't you copy their file and mirror it locally? Or use a reliable Content Delivery Network, like Google or Amazon.
There are many names for this type of inclusion. The most common being widget.
What does it actually do:
take an id of some sort as parameter
use the id to fetch some specific data (most likely from a database)
generate some js and html based on the id/data
usually this involves iframes of some sort.
To use a script rather than an html iframe has multiple advantages
you can change what is actually delivered to the users browsers without changing the include
you can resize the iframe to fit certain predefined sizes
you can inject the necessary things into the page the widget is included (of course you need to make sure this is sanctioned)
We use this all the time and we never regreted it.
If you don't want to build the widget infrastructure yourself you can always use one of the widget providers like widgetbox:
http://www.widgetbox.com/widgets/make/
With those you are up and running in no time.
This is typically called a script include.
Google have lots of these types of items, and even they call them by many names,
widgets, custom javascript, snippets, custom code, etc. It really depending on who you are writing for... I would go with "cross platform embeddable javascript code" meaning that it would need to load all its dependancies. Also specify which browsers need to be supported and what should happen is the user has javascript turned off.
EDIT :
Actually since we are talking unique IDs, you will need 2 parts probably, the user/site unique "cross platform embeddable javascript code" and whatever serverside code to support it. Basically this is an API that is accessed using your own javascript widget. Feel free you point to examples in your requirements document, programmers love examples.

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