So if you have been following my blog lately you would have noticed I am doing some adventures in HTML lately… No I am not leaving my XAML love behind I just feel that I should look at other stuff and get ideas from different technology stacks.
In todays article I want to show how layout specifically one nicknamed as the “Traditional Box Model” comes in handy to know for those that like me come form a XAML background, a background which has a rich layout system, a background where panels are the kings of the realm. We’ll see how in HTML, yes this is a bit harder, but very achievable. We will also see how HTML5 and CSS3 introduces some really cool concepts and how layout becomes comparable to XAML layout and panels.
I remember back in the days when I used to do web (around 6 years ago) many would layout the page by using a <table />. Yes a table believe it or not! You might ask yourself “but a table is really for displaying lists of data no??”. Well layout is not really the most intuitive thing to figure out in HTML and devs love shortcuts thus yes; tables were (and in some cases still are) a tool to do layout. But is it the best way to do layout?? No, its not really… A more flexible way to do layout is by using divs. Enter the “Box Model”.
Lets say we wanted to do something like this
One way of picturing this layout is that every box is a div (some might argue it doesn’t really need to be a div but really any element that has display: block, but for simplicity, let’s say divs for now). A div by default will occupy all the width available, so if we had the following HTML the output would not really resemble the layout we have in the image here.
This would actually render into something like this
Blue div == ‘mainSection’; Red div == ‘sideSection’;
In order to get these 2 divs side by side, we need to specify a CSS property called float. You can specify left, right, none or inherit. In our case we will want to set the mainSection to float: left and the sideSection to float: left. The piece that many forget to add, which then results in chaos is to set to the next element (in our case the footer) the css property clear: both. This will restore the flow of the document and basically in our case it will prevent the footer from going up on the side of the sideSection div.
So here is the CSS styling we have done so far
And here is the result we got
Nothing really changed did it?? Nope it did not. And the reason for that is that as I was saying before a div will occupy the full width available by default. What we can do here to make the mainSection and sideSection layout side by side is to set a width for the divs. And we finally get a result that looks like this
What is annoying here is that we had to specify a width to both divs… In all fairness the sideSection can stay without a width and this would make it occupy the reminder width inside the page. That’s cool BUT we want our mainSection to take the dynamic width and not really the sideSection, right? Yes you can do it with the Traditional Box Model BUT instead lets have a look at how we can do this and much more using the new hot stuff from HTML5 and CSS3.
Enter “Flexible Box Model”
The flexible box model is still something that browsers are experimenting with in fact you’ll find that you will need to annotate the properties for this with –webkit and –moz- and –ms . don’t you love experimental things Anyways, the idea with this is to be able to be more dynamic, to have a proper way how to specify layout. With this model you’ll be able to specify if you want the flow to be horizontal or vertical (just like orientation in StackPanel for those XAML guys reading) you’ll be able to specify how much “percentage” of the space available vertically/horizontal should a box take up (just like ColumnDefenitions and RowDefinitions in Grid for those XAML guys reading). You will also be able to specify the alignment and yes also the index you want each box to be in…
Does this feel more like panels in the XAML world. WUHUU now we are talking …. so let’s pimp up our screen with some hot and spicy HTML 5 / CSS3.
Let’s start fresh… here is some new HTML … Basically a parent div with 4 divs and lets start rocking!
As I was saying the new flexible box model supports orientation, you do this by specifying box-orient. As expected this takes horizontal and vertical . P.S do not forget to add the –webkit- and all the rest.
And this gives us
This might look like its nothing but hey we just started… Ok seems like these boxes are only using the width that the inside text measures, lets make them use all space available evenly (just like we would do with a XAML Grid)
To do so we use another cool CSS3 feature. The magic property is called box-flex.
And this gives us
Already very exciting isn’t it?! What was that 1 we set to box-flex. The 1 is basically being used in the following formula >> widthOfParent * 1/numberOfElements = widthForElement (ex: 600 * 1/4 = 150). For example if I set 3 for one of the boxes, I get this result which is Box3 is as big as the other 3 boxes all together. (doesn’t it sound like a * measure for ColumnDefinitions in XAML )
Yes resizing the browser window will nicely resize these boxes just like one would expect. AWESOMENESS on a stick!!!!!
What if I want that all boxes are 100px BUT (since I am a crazy evil designer that likes to bully developers) I want them to be all centred in the middle of the screen. Well to give each box a size we know what we have to do, set the width css property. To specify how to layout them there is a new CSS3 property called box-pack. This property will tell the Browser how to distribute the free space. You can set this to start, end, center and justify. Lets go for center (-webkit-box-pack:center;) and we get something like this
if I specify –webkit-box-pack: justify I get this
What if we want to change the rendering order of the boxes? CSS3 to the rescue box-direction a new CSS property will do the trick by setting it to reverse. –webkit-box-direction:reverse
And yes you can even change the order of the boxes (just like a XAML Panel) by specifying the box-ordinal-group
Last but not least is box-align which can be center, left, right and also stretch.
Check out more details on this over here. I hope that this article really shows you that HTML5 and CSS3 are really making some very cool and exciting things for us devs. If like me you come from a background where layout is something really rich (which in any XAML technology, layout is super easy to work with) HTML5 and CSS3 are building mechanisms to be leveraged and easily build awesome web applications.
I am very excited about this, layout sometimes is taken for granted but what is a good UI platform without a good and flexible layout system. Thankfully HTML5 and CSS3 are here to rescue us from the evil designer requests
Introduction >> The clash of the Titans is on
Developers right this second are at some bar / restaurant / lounge / god knows where else being “social” i.e. having geeky discussions about technology, what language/platform is best to use or even better “what’s coolest right now”
I am one of those developers and I must say, when it comes to such discussions I am always biased towards XAML technologies. Yet recently I started diving in what I used to call the “darker side” i.e. HTML5, JS and CSS3 (the “dark side” is reserved for things like Java ). It’s been years (6 to be exact) since I was doing some HTML and Co and I must say; I am really impressed. HTML5 just takes everything to a whole new level BUT what impresses me most is JS and CSS3.
CSS3 because WOW its frekin cool!! The new box modelling with the Flexible box model, the gardients, the transforms, the transitions and I can go on and on…
So yea I must admit, web development (presentation layer) of today is becoming loads of fun! Backend for Web with MVC its also frekin cool! so I guess the questions that readers of my blog / people who know me would ask “Is Marlon turning his back on XAML?” The answer is simple and its NO, my car number plate still says WPF so I guess I cannot change everything now Joking aside, I see both technologies as super awesome and both of them have a different realms (to a certain extend). “to a certain extend” for the reason that WinRT will also support HTML5 JS and CSS3 as a first class citizen just like it will for XAML and C# / C++.
Does this mean we should say bye bye to XAML and just focus on HTML5 and Co?? If it can do web + desktop why bother looking at XAML??
Ok so lets be a bit metaphoric about this and let’s compare technologies with cars. There are many different brands, there is Audi, there is Honda and you can go on and on… They all take you from place A – B. How they take you is a bit different, some are super confortable, some are fast. Some are perfect for one thing some are perfect for another! You buy a car that fits your needs and the same can be said to technology you decide to use. There are those scenarios, for example when you are moving house, where you do not have the luxury to use your “preferred car” because hey; if its a sports car, it will be no good when you are moving, so in such a case you are coerced to use a specific type. Such an example for developers is the web / mobile phones … Yet again just like in real life there are many different trucks for moving there is HTML5, and then there are the plugins (Flash, Silverlight) …
Which one should you go for? HTML5 or Plugins?
Looking at web tech today I would say go for HTML5. It will work on devices such as phones, if done properly it will be super fast. On the other hand I would strongly suggest you consider SL / Flash if your users cannot install/already have a browser that supports HTML5. In that case then yea I would not go for the HTML < 5 because you’re in for nightmares! Maybe mix and match! Some things are better done with plugins some other with HTML. Do not be afraid to try both worlds, it will not hurt.
What about WPF??
WPF will still have a place but I guess we will slowly see it being used lesser and lesser, reason being with WinRT you are not using WPF you are using WinRT, yes its XAML but NO it is not WPF. There are cases such as VS and similar heavy weight products that would require something like WPF. Trading applications and internal banking applications is another example for WPF apps. But yea if you are building a simple app, going forward one would be better off with something Metro style i.e. WinRT based. So should WPF developers say “cr*p I wasted a lot of time learning something I will not use anymore”?? Whoever says that is really talking bull***t! WPF thought us a lot, WPF gave us so many concepts and ideas… WPF will always continue living in other technologies… Its concepts that really are hard to learn not how to use a framework, example DataTemplates, ControlTemplates, Binding and many other concepts … For me WPF showed me what an awesome API should look like! Besides that you learnt XAML that is something that is not a waste of time since XAML is here to stay !
Final verdict – Who will be the last technology standing?
None probably technology evolves … sorry my fellow geeks, I like you used to treat a technology stack (and must admit still do sometimes) as my one and true love and I could not use another technology without feeling that I am being MARLONCHANGE… well its not the case, when it comes to technology you can mix and match as much as you want and no you will not be called a “Cheater”
Take it from me, if you did not have a look at HTML5 and co, maybe its time for you to do so. Maybe you will not use it but I am sure you’ll get something out of it. I am learning so much, getting so many new ideas (that yea I can even apply for WPF) from doing some HTML5 and Co.
Hope I did not bore you to death with this post but I felt I needed to share this with you guys! I’ll be posting more on HTML5 and Co this year but yea of course I will also do the same for XAML and Co.
Long live XAML
Long live HTML5 (and co)
Today I stumbled upon a timeout issue while building a web application and felt like I need to share this for those that like me wasted/are wasting hours trying to figure out why you are getting a timeout.
Here is a diagram that show the structure of the request response stack I have.
The reason why I went for an AsyncController is that the long running operation is not CPU-bound processing thus the thread that would be waiting for the response would be wasting its time waiting. More info on why and how to use Async Controllers in MVC3 can be found here.
All is fine and good until my I hit a request that took more than 1 minute, and then the nightmare of timeouts begun… So first thing I did is make sure I make the timeout for the WCF service longer. You can do this by setting the sendTimeout and the receiveTimeout of the binding in the binding configuration.
Don’t forget to do the same thing on the client side otherwise you’ll get in trouble (the config is the same as the server, and if you are using VS to generate the config then this will be done for you when you refresh the ServiceReference).
At this stage I said, wuhooo, it’s all done… but nope… it was still timing out … I was confused and puzzled… WHY WHY WHY!!!!!
Well AsyncController also have a timeout (or 90seconds as per MSDN doc), you also need to set the timeout to the async controller action in order for this to work. You do this by setting the AsyncTimeout attribute on the action that you want to extend its timeout.
With this in place all started working… but yea the errors don’t really help !
Hope this helps…
Today I stumbled upon a bizarre problem, I wanted to parse an HTML for a site to find out if the site contains any RSS feeds. After some research I found out that finding the RSS feed for a site is not that hard, you have to look for an element that looks like this
“Easy task”, I said, me Mr.Optimistic; “I will just load it up in XElement and using Linq to XML to get the data I want”. BUT guess what the web is filled with crazy HTML that a standard .NET parser such as XElement just gives up on and blows up in flames.
After some heavy head banging to walls and ceilings, I found the solution, HtmlAgilityPack. This open source project lets you load HTML even if it is not in a good shape. With some options HTMLAgilityPack will fix these errors and then you can query the HTML to get elements and their attributes as you please.
Here is the code I used to load the HTML and find the data I need
Kudos to the guys from HTMLAgilityPack!!!
The WordPress.com stats helper monkeys prepared a 2011 annual report for this blog.
Here’s an excerpt:
London Olympic Stadium holds 80,000 people. This blog was viewed about 350,000 times in 2011. If it were competing at London Olympic Stadium, it would take about 4 sold-out events for that many people to see it.