Monthly Archives: February 2012

Sublime Text: Fashion and Form Text Editing

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I have an odd love of text editors,though considering I love to code perhaps it’s not that odd at all. I’ve gone through quite a few over the years, I was a huge TextPad fan for a long time and I still pull it up now and then but then I saw a bunch of screen shots of TextMate on Mac and realized the bar had been reset. From there I was on a search for an editor that was both smart AND sexy and I went through a bunch of editors looking for “the right one”, from E Text Editor (nice but made me install cygwin for full power) to Intype (beautiful and had a great start but languished for a year though I hear they’re working again in earnest) and finally to Sublime Text 2 which is what this post is all about.

I’ve been using Sublime for about a year, since roughly Build 2020 of Subliime Text 2 and the project just keeps getting better and better. I highly recommend you grab the development builds and install the latest as they come down the pipe. Sublime is even nice enough to let you know when there are new builds available.

Sublime Text Main

Why Use Anything Besides Visual Studio?

Why indeed since I sling a lot of C# during my day? First is the speed, VS does a lot for you and sometimes you pay that cost and when I just want to work with text I reach for Sublime.

Snippet support. It’s super fast to create new snippets as well as build in some intelligence via regex. It’s probably just me but creating new snippets in VS always seems like a heavy process but it’s so easy with Sublime I find myself creating them for any block code more than two lines long. I have one cool snippet for creating new properties with a backing private variable and it takes care of creating both the public and private variables and correctly casing each one, something I don’t believe you can do in VS.

Multiple Selection. This is a must have for any modern editor and it’s best if you see it in action but roughly if you Ctrl select multiple words and then start typing all of the selected items will start updating. Great for quickly changing types such swapping from a Grid to StackPanel in XAML.

Auto-Complete. You won’t lose any of your fancy auto-complete either, Sublime uses the current syntax bundle to parse your files and determine what should be considered key words.

Jump To. Ctrl+P to jump to any file in your project. Ctrl+, to jump to any symbol. Ctrl+Shift+P to look at all available commands and snippets. Awesome and super fast.

Project Management. Drag & drop a folder into Sublime and now all your jump to features become much more powerful as you can move between files in your project.

And so much more. Seriously. Support for TextMate bundles, great color themes, code-folding, macro support, margin guides, a ton of extensibility, active forums, weekly updates, etc.

Pro-Tips & Downloads

  1. Keep your Sublime configuration in sync between computers with DropBox (see Using Dropbox to sync Sublime Text settings across Windows computers).
  2. If you use VS don’t forget to setup Sublime as an External Tool. I’m constantly moving between VS & Sublime and since both programs are great about picking up changes this is a great combo.
  3. Install Sublime Package Control. Think of it as gems or NuGet for Sublime. After you install it browse some of the cool packages available. My current favs are:
    • Sublime TFS – check out, commit & via history for files under TFS control.
    • sublime-github – A great list of commands for managing your Gists from Github.
    • SublimeAStyleFormatter – A pretty code formatter for C#.
    • Theme – Soda - A nice dark theme for the entire editor itself.
  4. Check out what others are saying (Rob Conery)
  5. Check out this great list of pro-tips (Sublime Text 2 Tips and Tricks (Updated))
  6. If you edit in XAML here is a XAML bundle I ported (it’s basically a copy of the XML bundle and a porting of some of the TextMate snippets from the Microsoft Gestalt project).

Using RestSharp with AgFx in your Windows Phone app

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I’m using the excellent REST library RestSharp for all my REST and OAuth calls.  I’m also using the amazing data caching framework AgFx written by Shawn Burke which handles caching your web requests, something that goes from a nice to have to critical when writing high performance Windows Phone apps.

Out of the box AgFx handles all your requests so it can do it’s caching thing, getting in the front of each request to determine if it should give you a cached version instead of hitting the web, if it should invalidate the cache, if it should give you a cached version and then make a live request, etc.  This is how you want it but sometimes you want more control over how those live requests are made.  In my case I’m using OAuth and requesting protected resources that require OAuth access tokens and RestSharp has some very nice methods for both authenticating and making those pesky protected calls.  The question is how to slip RestSharp into the middle of the AgFx mechanism?

AgFx Out of the Box

Your basic AgFx call looks like this:

ZipCodeVm viewModel = DataManager.Current.Load<ZipCodeVm>(txtZipCode.Text);

Which eventually executes code like this (which you the developer has written):

public LoadRequest GetLoadRequest(ZipCodeLoadContext loadContext, Type objectType)
{
    // build the URI, return a WebLoadRequest.
    string uri = String.Format(ZipCodeUriFormat, loadContext.ZipCode);
    return new WebLoadRequest(loadContext, new Uri(uri));
}

AgFx will call GetLoadRequest() to get a LoadRequest which it’ll use when it needs to fetch live data.  This example is using the default WebLoadRequest which uses HttpWebRequest under the covers to fetch the data but as long as you return an object that descends from LoadRequest you can use whatever requesting mechanism you like.

RestSharpLoadRequest

That’s where RestSharp comes in.  Instead of hand-crafting HTTP requests including hand-crafting headers and building POST payloads I’m going to let RestSharp do the heavy lifting by creating a custom RestSharpLoadRequest.  It’s based heavily on the WebLoadRequest in AgFX, right down to the comments and took all of 15 minutes to code up.  It’s not that exciting of a class but you can download it and view it on github as a gist:

An AgFx LoadRequest that uses RestSharp to make the actual request, supports passing in OAuth tokens

Download it and drop it into your application as is (well, I’d probably change the namespace to something more appropriate).  Sorry about it being a tar.gz file, maybe I’ll ping Phil Haack now that he works there to offer up .zips for gists as well.

WOW, sorry folks, I didn’t realize I’d created the Gist as private, if you tried to view it before you should have better luck now.

RestSharpLoadRequest in Action

I’m going straight to a meaty example where I create a few parameters to throw on the URL and pass in all my OAuth token goodness:

public LoadRequest GetLoadRequest(ShelfLoadContext loadContext, Type objectType)
{
    var resource = BuildResource(
        "review/list.xml",
        new Dictionary()
        {
            {"v", "2"},
            {"id", loadContext.UserId},
            {"page", loadContext.Page.ToString()},
            {"shelf", loadContext.Shelf}
        });
    return new RestSharpLoadRequest(
        loadContext,
        resource,
        Client.Current.ConsumerKey,
        Client.Current.ConsumerSecret,
        Client.Current.AccessToken,
        Client.Current.AccessTokenSecret);
}

Don’t worry about the BuildResource call, that’s simply building up your REST API end-point (aka “resource”).  The only difference from the standard usage of AgFx is instead of a WebLoadRequest I’m using RestSharpLoadRequest.

And there you have it, now you can lean on RestSharp inside of the AgFx framework.  Also If you’re using Hammock as your REST library as choice it should take all of 15 minutes to whip up a HammockLoadRequest following the same basic principles.

UPDATE (02.14.2010): The way I was handing parameters above was just plain weird, the RestRequest object that I’m using inside of RestSharpLoadRequest already has robust AddParameter() logic so I exposed it.  The above code now looks like this:

public override LoadRequest GetLoadRequest(ShelfLoadContext loadContext, Type objectType)
{
    var request = new RestSharpLoadRequest(
        loadContext,
        GoodReadsClient.Current.BuildResource("review/list.xml"),
        GoodReadsClient.Current.ConsumerKey,
        GoodReadsClient.Current.ConsumerSecret,
        GoodReadsClient.Current.AccessToken,
        GoodReadsClient.Current.AccessTokenSecret);
    request.AddParameter("key", GoodReadsClient.Current.ConsumerKey);
    request.AddParameter("shelf", loadContext.Shelf);
    request.AddParameter("v", "2");
    request.AddParameter("id", loadContext.UserId);
    request.AddParameter("page", loadContext.Page.ToString());
    return request;
}

Not only does it leverage existing code it follows the pattern most RestSharp/Hammock users are used to, namely you create the request and then you add on parameters.

Selecting into an ObservableCollection in LINQ: a ToObservable() extension method for Enumerable

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I love me to some LINQ, especially some LINQ to XML (otherwise known as XLinq) for parsing meaty XML files into objects.  Anywhere there is XML parsing going on in my app you’ll see code similar to this:

var list = (from review in reviews.Descendants("review")
            select new BookReview
            {
                StartedAt = (string)review.Element("started_at"),
                Book = (from b in review.Elements("book")
                        select new Book((string)b.Element("id"))
                        {
                            Title = (string)b.Element("title"),
                            CoverUrl = new Uri((string)b.Element("image_url")),
                            NumberOfPages = (string)b.Element("num_pages"),
                            AverageRating = (string)b.Element("average_rating"),
                            Description = (string)b.Element("description").Value,
                            Authors = (from a in b.Descendants("author")
                                        select new Author
                                        {
                                            Name = (string)a.Element("name")
                                        }).ToObservable<Author>()
                        }).SingleOrDefault()
            }).ToList();

This is a medium complexity example, I’m selecting a list of BookReview objects which contains a Book which in turn has a collection of Author objects. 

One thing to pay attention to is that the default return type for a collection of items returned via Linq is a Enumerable and if you’re using a different collection type you’ll need to use one of the built-in extension methods to convert it to the appropriate collection type.  You can see where I’m doing this on the last line above with the call to ToList().

There are built-in extension methods to convert to List, Dictionary, Array and a bevy of others but not ObservableCollection, which you’re probably using in some form if you’re data binding your collection to your UI.  You could select into an Enumerable and then manually add each item into your ObservableCollection but that’s no fun and it’s much simpler to just write your own Enumerable extension method to take care of it:

public static class Enumerable
{
    public static ObservableCollection<TSource> ToObservable<TSource>(this IEnumerable<TSource> source)
    {
        return new ObservableCollection<TSource>(source);
    }
}

I’m using it in the first sample to convert the Authors collection.  Hope you find this useful, I know I use it all the time in my Windows Phone apps!

By the way it’s also a “gist”, a version controlled snippet, over on github.com:  LinqExtensions.cs.

A few of my favorite tips for writing Windows Phone applications end-to-end

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I’m currently working on a GoodReads client for Windows Phone and while I’ve written a ton of phone code for various demos, API smoke testing, targeted “how do I” questions, etc. it’s an entirely different beast to write an application end-to-end.  The technical questions are often the easiest and if you’ve been coding for more than a few years (or months, you rockstar you) the problems and questions that keep you up at night shift from technical (“how do I save an image to the phone?”) to architectural (“what’s the best pattern for integrating a REST client into my caching framework?”).

As a knowledge and data capturing exercise I’m collecting the various articles, resources and code snippets that I found extremely helpful as I fleshed out my application, grouped by the order I came across the issues and roughly the order I architected my application.

This is a “live” document that will to continue to grow as I finish my application. Also if you’ve found articles that made a key difference in your application development let me know so I can check them out!

User Experience/UI Design

Kudu UI Sketch

Close down Visual Studio, stop building up your class library and do something that you’ve been told is anathema to good development.  Start with your UI and build out from there.  It is key you understand the layout of your application, roughly what each page will look, what functions it’ll perform, what states it can be in. Seriously. I crafted this lovely rich client that modeled my entire backend in a clean, crisp way and then I threw it all away.  Why? Because when I started mapping the client to my UI I was making 3 or 4 calls to the backend when if I’d just understand HOW I’d be displaying it I would have crafted my middle-layer differently.  It’s one of the dirty secrets of creating lean and mean apps, you do end up building you middle-tier to optimize for the end result, not as some model that has been delivered from high on top.

  • When you need a little more structure than just a piece of blank paper try the Windows Phone Sketch Pad from UI Stencils.  I love this sketch pad and it helped me a ton in crafting my UI and work flow.
  • Make sure you’re familiar with the User Experience Design Guidelines for Windows Phone over on MSDN as you start thinking about your application.
  • The Windows 7 Snipping Tool.  It’s already on your machine (you are running Win7 right?) and I use it about a dozen times a day to screen grab my current page and drop it into Paint.NET to take pixel measurements to make sure my UI is as close Metro design guidelines as possible.

Architecture

  • You’ll need to think about caching if you deal with any significant amount of data and on a mobile device that pretty much means any data at all.  I’m using Shawn Burke’s excellent web request data caching framework AgFx.
  • I am using a form of MVVM but I haven’t jumped on board with either Prism or MVVM Light, mostly because I’m a nerd and I don’t trust anyone else’s code until I’ve written my own framework, formed my own opinion of how things should be done and then adopt the one that I best align with.

Login/Authentication

A great number of applications are skins over some backend that requires a login and these days there is a good chance it’s via OAuth.  It’s actually not that hard but it can be a huge in the arse to debug and get just right as each back-end does things just slightly differently.  Here are the articles that helped me along:

  • From my colleague Sam Jarawan I cribbed a bunch of code from his article, “Building a ‘real’ Windows Phone 7 Twitter App Part 2 – oAuth”
  • I used both excellent .NET REST helper libs Hammock & RestSharp.  I ran into some issues with params with square brackets using Hammock so had to switch to RestSharp but I honestly couldn’t find any major different between the two to recommend one over the other.  RestSharp seems to have a slightly more active community and docs.
  • A lot of apps simply won’t work if you don’t log in so you want to conditionally show a login page based on some state.  For that turn to Peter Torr’s blog post, “Redirecting an initial navigation”.

Certification

Tools

My supporting cast of tools.

  • Git - Whether you’re a lone wolf, a pack of one, coding the next great thing or a corporate developer you need to version control. If you’re in a company you probably already have a solution but if you’re a coffee shop coder you may not be using anything and that my friend is a mistake. You’ll get on a caffeine buzz and decide to refactor your entire application only to get distracted and find your app in pieces wishing you could just get back to how everything was pre-latté. There are a ton of great source control systems but lately I’ve been using git like all the cool kids. To do local versioning is a snap, without the need for a server or service running. I also still love Subversion and the server I put in place at my last job is still rocking along being a source control hero.
  • Dropbox – I code on three different machines and Dropbox makes it possible for me not to worry if I have the latest source for my project. Best of all it works well with my source control so I get portability as well as versioning.