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Showing posts from 2011

Stubbing out AJAX methods

I have always had trouble with the standard way of testing out AJAX calls with QUnit. There are a number of problems with it. 1) You have to stop and start the tests while waiting for an AJAX response 2) If you don't give a large enough gap, then your test may fail while waiting for an AJAX response. 3) If you have too large a gap, it slows down your tests However, today I found this cool method of dealing with it. Essentially, you stub out jQuery's $.ajax() method with your own for your tests (as for unit testing, you really just want to test your code around the ajax method, not test jQuery's ajax method). In my own case, I was using $.ajax and not $.getJSON. It took me a little while to work out I had to create a trigger for the success() function rather then callback() as mentioned in the article. var stubbedAjax = function(settings){ settings.beforeSend(); // s


Just a couple of links today (more details to follow). I found a great reference for JavaScript and jQuery Design Patterns here: Also, I learned about the Presenter pattern today. We were having a discussion at work about what to do with presentation logic in Rails. On the one hand you don't want it in the controller because you want to keep your controllers thin, on the other hand you don't want it in the models either because it's presentational. You can't put it in the erb because they shouldn't contain logic. Enter the Presenter Pattern: Enjoy your homework!

What is !important?

In CSS, you can override a style on a class simply by declaring a new style further down the page i.e. p { padding-top:5px; } p.custom { padding:10px; } Basically the above code sets the padding-top on all paragraphs to 5px, but sets the padding to 10px on paragraphs with the "custom" class. So we are overriding padding on our custom class. However, you can actually prevent an attribute's style from being overridden if for some reason you really really don't want the padding to change in your design. Perhaps you are working with multiple people and you really don't want someone to accidentally override your design. Perhaps you just want to ensure your padding-top is always 5px even if padding is reset somewhere else. In order to do this we use !important. p { padding-top:5px !important; } p.custom { padding:10px; } In this case, the padding-top on a paragraph will always stay at 5px regardless of whether or not it has a "custom" class. It

The REAL reason you need Flash in a mobile device...

People keep going on about how you don't need Flash on a mobile device because most video sites like YouTube provide HTML 5 flash free versions. Therefore the limitation of no Flash on an iPhone isn't really a limitation (if you have been drinking Steve Jobs' Apple juice/kool aid). Anyways, last Saturday I found out the REAL reason you need Flash on a mobile device and it has nothing to do with video. It has to do with restaurant sites. For some reason at least 80% of restaurants out there have Flash only websites. If you need to make a reservation and you can't find the phone number in Yelp or UrbanSpoon then you have a problem. In any case, I was trying to find the number for a restaurant and Google gave me a link to their website. Unfortunately, their website is in Flash. Fortunately for me though, my phone is an Android phone and I was able to look up their phone number and address in spite of the limitation. In general though, having Flash on a restaurant website i

CSS Back to basics: Here comes TRBL

So I guess CSS is not obvious to everyone. One of my coworkers asked today why you sometimes had 1 value after a "padding" attribute and sometimes you had 2 or 4 values. Basically, padding: 5px; Puts a 5 pixel padding on an element. padding: 5px 3px; Means you have 5 pixels of padding on the top and bottom and 3 pixels on the sides padding: 3px 4px 5px 10px; Means you have 3 pixels of padding on top, 4 on the right, 5 on the bottom and 10 on the left. A good way to remember this is the acronym TRBL (like "trouble"). The same applies to "margin". As well as this, you also have extra attributes which can specify the top, bottom, right and left paddings on their own i.e. padding-left: 10px; Sometimes, if only one side is unique, it's better to refer to it in the following way (for readability). padding:5px; padding-left: 10px; The "padding-left" of 10px will override the "padding" of 5px, but only on the left side of the element. paddi

Rails file uploads: Limiting a user's uploads by space available

Let's say that you want to allow people to upload files to your server. Let's also say that we want to make sure any particular user does not hog up all the space available. Let's also say you want to give each user a variable limit as to how much they can upload (i.e. for tiered services). How would you go about doing that? Well, from a pseudo code perspective you would do the following. 1) Create a folder for each user based on the user id 2) Make sure all the user's uploads go to that folder 3) Before you do an upload, check against the user's settings to see how much space s/he is allowed 4) Check their folder to see how much space has been used 5) If they have no space left, message the user So let's see how we do this in practice... I guess we really want to see how much space is used, so let's start there on the User. In this example the user has a UUID as well as a space_allowed attribute which is set to a default value (and which an admin can change

Reading AJAX XHR File Uploads in Sinatra

So in my last post I talked about Drag and Drop file uploading with qq.FileUploader ( ). Anyways, I discovered that qq.FileUploader uses AJAX/XHR to post the file uploads. What I also discovered is that these file uploads need to be handled in a separate manner from a regular file upload form post. A normal form post (when File upload XHR requests are not available on the client like in Internet Explorer) passes in the following parameters params: {"qqfile"=>{:type=>"image/png", :head=>"Content-Disposition: form-data; name=\"qqfile\"; filename=\"bb2.png\"\r\nContent-Type: image/png\r\n", :tempfile=># , :name=>"qqfile", :filename=>"bb2.png"}, "upload_type"=>"rec", "id"=>"24db8cab-285a-abcb-cb47-4daceee977ca"} Sinatra then reads the :tempfile and :filename parameters to write the file to the server name = params[:qqfile][:fil

Ajax File Uploading

You know that cool Drag and Drop file uploading they have in Gmail? You know, the one where you can drag a file from a folder onto a webpage and upload it? Have you looked at the code? Looks complicated huh? Well, thankfully, for any cool bit of JavaScript functionality out there, someone has created a plug in (most likely in jQuery, but not always...). is (as far as I can tell) a library agnostic JavaScript plug in which factors out all the hard work. All you have to do is put in a "dummy" element on to which to hook (never end a sentence in a preposition) and then put in a small snippet of code to turn it into a file upload element <div id="file-uploader"> <noscript> <p>Please enable JavaScript to use file uploader.</p> </noscript> </div> var uploader = new qq.FileUploader({ // pass the dom node (ex. $(selector)[0] for jQuery users) element: document.


I had a quick look at Node.js . Looks very interesting (kind of like a JavaScript version of Sinatra ). Now all I need to do is find out if they have any frameworks...

Show Off IO

Just found a great new service called Show Off IO This is a godsend for Ruby contractors. Basically you port forward the web server on your laptop to showoff and they give you a URL which you can send to a client which allows him to see your website (for a limited time for the free version). Previous to this, you would have to wait until you had staged the site to show it to your clients. Good job guys!

RhoMobile - Ruby Development for Mobile

RhoMobile ( ) offers an open source framework which allows Ruby developers to write mobile apps using web technologies. I have been using it for about a year now. You can find out the details of it on the website linked above, but I just wanted to go over some of the issues I have found and cover some of the pluses in minuses from a personal perspective to help you decide whether or not this is a technology you will want to exploit on your next project. So what is it? At a basic level, a Rhodes ( ) app comprises of a small Ruby web server/framework and an embedded browser. Server is a little bit of a misnomer because it lives on the client, but essentially it's like a small Rails server which is only used by one client (though in theory you can connect to it from another client if you so choose). Because the display is done in an embedded browser, you can mark it up in HTML and CSS and even (in some cases) use JavaScript t

Responsive Web Design

I wanted to go over Responsive Web Design using CSS. In the old days of web development, we had to code to common screen sizes (i.e. 800 X 600, 1024 X 768) and we patiently waited for people to upgrade their computers to have a decent amount of screen real estate so we could design things the way we really wanted. We also took on semi stretchy web layouts etc to expand and contract appropriately. Then about 2 or 3 years ago, Apple released this little device called an iPhone with a 320 X 480 resolution which took the world by storm and suddenly a lot of people were viewing your website on a tiny screen again... Anyways, as it can be difficult to design a site which looks good on 320 X 480 AND 1680 X 1050, we need to come up with some kind of solution. One way is to sniff the client and then use an appropriate stylesheet, but then you are mixing CSS with either JavaScript or server side programming and also potentially maintaining a list of appropriate clients and stylesheets. Also, you