Recently I embarked on porting the TagLib# library to a Portable Class Library (PCL).  In my efforts I noted some frustration I had of the “convert and compile” flow to find issues.  Well, turns out I didn’t have to do that much pain as pointed out by Daniel in the comments!  The .NET team has released a tool to help out us developers called the API Portability Analyzer (currently in Alpha).  This tool basically looks at any existing .NET assembly and gives you a report to help you see where the APIs used are supported in the various .NET profiles available.

The tool is a single command-line exe and is as simple as launching:

ApiPort.exe path-to-your-assembly-file.dll

I recommend putting this in your path somewhere so you don’t have to remember the full path to launch.  The output from the console tells you very little and only really about what you it is doing:

Microsoft (R) API Portability Analyzer version 1.0 (alpha)
Copyright (C) Microsoft Corporation. All rights reserved.

To learn more about how this tool works, including the data we are collecting, go here - http://go.microsoft.com/fwlink/?LinkId=397652

Identifying assemblies to scan. Done in 0.01s.
Detecting assembly references. Processed 1/1 files.Done in 0.23s.
Sending data to service. Done in 2.88s.
Computing report. Processed 508 items.Done in 0.02s.
Writing report. Done in 0.17s.

Replaced output file "c:\ApiPortAnalysis.xlsx"

You may notice that the tool says ‘sending’ and yes, it is communicating with a public service.  The team notes this in the download:

NOTE: During the process of identifying the .NET APIs used by a binary Microsoft collects the list of .NET APIs used by the user submitted binaries. Microsoft also collects the names of various user created APIs. The tool does not collect the binary code, only names of APIs are collected. Microsoft will also collect assembly information such as assembly references for the binary & the Target Framework Moniker (TFM).

The real value is in the output data conveniently formatted into a pre-filterable Excel document.  The process was fairly fast for me, but I suspect might take longer for larger libraries (duh).  An example of the output is like the one here directly showing the TagLib# data that I used above.

If you read my previous post you will see that the areas I had frustrations about are clearly identified in the Unsupported columns for my target platform.  The tool attempts to recommend some alternatives when it can.  I can imagine this gets better over time as the recommendations for TagLib# were only two, whereas it should have provided recommendations for XmlDocument/XmlElement/etc. to the XLINQ equivalent areas.

In the end though, this is a helpful tool for those looking to convert.  I wish I had known about it in advance, but now that I know it is in my toolbox and my PATH!

Hope this helps!

A long while back I had written a quick sample when Silverlight introduced drag-and-drop into the framework.  Then I decided to show dragging MP3 files into a Silverlight app and reading the metadata and album art.  In order to accomplish this I had to read into the ID3 data from a Silverlight library.  I found a few libraries but settled on TagLib# to do the job.  I had to modify it a bit to get it working in Silverlight as the .NET profile wasn’t the same.  Recently a surge of people have been emailing me for the code.  I spent time searching and apparently I didn’t think the TagLib# modifications were that important because I never saved them anywhere!  A conversation started on Twitter and I decided to devote some “20% time” to making these modifications and take it a step further and make it into a Portable Class Library (PCL).  Here’s my journey…

Deciding to Fork

My first task was finding the source of truth for TagLib#.  The main link on the Novell developer site was broken and stale.  I found it on GitHub and started looking around.  It really hadn’t been updated in a long while (after all, it really didn’t need to be fore core .NET framework) and the project is very stale.  There is no open issues list on GitHub as you have to use Bugzilla, but that didn’t even look like it was getting much attention.  I emailed the maintainer listed in the authors file in the repository and he indicated he’s not really the maintainer.  This felt like a project kind of fizzling down (if not fizzled already).

In looking at the tests, the project structure, and taking into account that I may want to do some things different, I made the decision to fork rather than clone.  I’m not totally married to the decision but I don’t think anyone is keeping the lights on to take a pull request either though.  I forked the code and started with new projects and using Visual Studio 2013 as my tool of choice.

Using Shared Projects

At first I thought that I would be doing perhaps a few different flavors, portable and full .NET framework.  Because I thought I would I decided to use the new Shared Project system in Visual Studio 2013 and the new Shared Project Reference Manager VS extension that allows me to add references from any project to shared code easily.  This gives me the flexibility for the future and sets my project system up in advance.  You’ll see in the end I haven’t actually needed to take that step and perhaps won’t even need the Shared Project anymore, but for now I’m keeping it as it does me no harm.

First Compile

Once I moved the code over and set my target profile for PCL, I hit build.  Whoa.  About 140 compile errors.  Immediately I thought that I didn’t want to spend the time.  I took a look at the issues and quickly realized that the base code had, in fact, changed a bit from when I messed with it in Silverlight.  I started making a list of the things that weren’t compiling as I was targeting .NET 4.5, Silverlight 5, Windows 8+, Windows Phone 8+, and iOS/Android (Xamarin).  The biggest errors came from the fact that the library was still using XmlDocument and hadn’t moved to XLinq.  Beyond that there were things like Serializable, ICloneable, ComVisible and File IO that weren’t going to work.  I got really frustrated quickly and about gave up.

Working at Microsoft I am fortunate to have access to try more things and indeed I reached out to some folks for help.  I was able to get some things working continued with XmlDocument, but it didn’t feel right and starting to think about releasing this updated library I just realized this wasn’t going to work.  I remained frustrated.

Helpful Friends

Sometimes when you are frustrated you just want to vent to the world.  We call that Twitter these days.  I was pulling some hair out and posted a comment, which was quickly replied by a member of the .NET team with a bit of a touché comment. 

@timheuer Funny, because I spent the day trying to write Windows XAML from the millions of WPF examples in the wild. :)

— David Kean (@davkean) May 23, 2014

I chuckled but I also knew that David and others were going to be the key to helping me find the fastest path here.  I started emails with the PCL team, including David and Daniel, who are incredibly knowledgeable and responsive.  I finally got most working and then my colleague and I started chatting about my frustrations.  He worked on XLinq for a bit and basically told me to suck it up and do the conversions and that it wasn’t that bad.  We walked through a few of the scenarios and indeed it really ended up all being isolated into one area that I could quickly scan through.  I could now remove my dependency on XmlDocument and have no other dependencies for this portable library.

Hooray for helpful people!  Even when you vent, the good peeps will still help out!

Changes to TagLib# for portability

After the full conversion, a few things remain.  Right now I have #ifdef’d out come of the interfaces and attributes that weren’t working.  Once I get to a point of porting all the tests over, I’ll decide if they are even needed.  Perhaps the biggest change though for users of this lib will be the removal of the default string path of file access.  In discussing with some folks, I could have tried to make a portable storage layer work, but it started to make less sense quickly to do that in the library and leave that simple task to the app developer.  This provides flexibility for the app to do what they want without the library trying to work around how different platforms do their file IO routines.  What that means is that the default way of reading a file’s tags changes from:

var tagFile = File.Create("ironlionzion.mp3");
var tags = tagFile.GetTag(TagTypes.Id3v2);
string album = tags.Album;

to

' file is a StorageFile
var fileStream = await file.OpenStreamForReadAsync();
var tagFile = File.Create(new StreamFileAbstraction(file.Name, fileStream, fileStream));
var tags = tagFile.GetTag(TagTypes.Id3v2);
string album = tags.Album;

in a simple case.  Yes, you as the app author have to write a bit more code, but it puts you in control of ensuring the file location you are reading.  You can see here that I did add my StreamFileAbstraction class to my fork by default, which was the key in the Silverlight port and is actually the key for WinRT as well.  Any app developer can create their own IFileAbstraction implementation and substitute it in the ctor of the create functions and be ready to read.  I actually did this in the test project to re-implement a LocalFileAbstraction for test purposes and used the System.IO.File classes to achieve that, which are available when running VS unit tests.

Summary

What started out as a frustrating exercise turned out to be helpful for me to better understand PCLs and hopefully add value to those who have been asking for this.  As mentioned, this isn’t fully tested and still a ways to go, so if you use it please log bugs (and help fix them) to complete the implementation.  I won’t be working on this full time of course, but do hope to get the test suite ported over as well.  Here are some relevant links:

• TagLib.Portable – source code repository for my fork
• TagLib.Portable NuGet Package

Hope this helps!

I’m just coming back from Build 2014 and it was a great pleasure to talk to customers/developers.  It is one of the best parts of my job right now in seeing how customers use the technology our team represents.  If you are a XAML developer and didn’t have a chance to go to Build or haven’t watched all the sessions, here’s a quick short list of recommendations I’d have:

• Common XAML UI Platform overview (Tim Heuer)
• XAML UI Controls (Shawn Oster)
• Developing across multiple form factors (Peter Torr)
• What’s new with Windows Phone Silverlight apps (Sam Jarawan and Harini Kannan)
• Using VS to build universal Windows apps (Navit Saxena)

There are many more (app model, localization, accessibility, tiles, notifications, etc.) so please do look at the event site and download/watch your favorites.  I think the list above gives you a good intro to the UI area changes and introduction to the concepts of Universal Windows apps.  If you haven’t heard of that concept yet, you can jump to the Keynote from Day 1 for the quick demo.

Add Reference

The last session above is one that I want to write about today in this post.  In current form, a Universal Windows app in Visual Studio Update 2 allows you to maximize your sharing of code/assets across your Windows Store and Windows Phone app.  If you are like most developers, you rely on a great ecosystem of libraries and SDKs to augment your app and add functionality, UI or make things easier to develop.  In our keynote sample, the app we migrated (SportsLeague app) used JSON.NET and we showed that we are able to re-use the same library (which in this case happened to be a Portable Class Library, aka PCL) across the different endpoints.

One thing that is important is that you will need to add these references to each of your project ‘heads’ (the term we use to describe each endpoint in a shared project solution).  For some that are using direct binary DLL references to PCL libraries should be okay.  For others that are using Extension SDKs and/or NuGet packages, you may find yourself into some scenarios where either the SDK is different or the NuGet package isn’t updated yet to understand the Windows Phone 8.1 project type.  There are a number of these that are already updated like JSON.NET, Caliburn.Micro, etc.  If you find yourself using a library that isn’t updated yet, you may want/need to prod the author to update.  Better yet, if it is Open Source, submit a pull request with the update yourself!

SQLite or other native Extension SDKs

The other category are things that might be platform-specific and/or native.  These things are generally more complex than something that might work in a PCL and have dependencies on various native compiler/linker options or have been compiled in such a way that are different for the Phone device versus a tablet device.  One such example is SQLite.

SQLite is an in-process library that implements a self-contained, serverless, zero-configuration, transactional SQL database engine. The code for SQLite is in the public domain and is thus free for use for any purpose, commercial or private. SQLite is currently found in more applications than we can count, including several high-profile projects.

SQLite links against the C++ Runtime and as such needs to make sure the right linking happens for the phone and tablet CRT profiles.  Right now, the SQLite for Windows Phone Runtime 8.1 is in some testing, but since a lot of people have been asking me about it, I’ll share my private build from source of the SDK.  This comes with a “works on my machine” guarantee :-).  This is a build of SQLite from their source, which is Open Source, and modified to compile/link against the Windows Phone 8.1 SDK.  When the official version comes out you should update to that version from their site.  For now, you can download my build of  UPDATE (12-MAY-2014): SQLite team put out their official build for Windows Phone 8.1: SQLite for Windows Phone 8.1 here.

Updating your Extension SDKs and NuGet packages

If you are an author of one of these SDKs that people use, please consider doing an update to make your customers happy.  If you are an Extension SDK provider you will want to produces an Extension SDK for Windows Phone 8.1.  If you already have a WinRT SDK, then you may just be able to copy the manifest, etc. and just produce changes to your manifest so it installs to the right location.  Here is an example:

<Installation AllUsers="true" Scope="Global">
  <InstallationTarget Id="Microsoft.ExtensionSDK" 
    TargetPlatformIdentifier="WindowsPhoneApp" 
    TargetPlatformVersion="v8.1" 
    SdkName="SQLite.WinRTPhone81" SdkVersion="3.8.4.1" />
</Installation>

As you can see in lines 3,4 above the TPI/V values are different than your existing SDK which tell the SDK where to install.

If you are an author of a NuGet package, you also will want to make your package Windows Phone 8.1 aware.  Again, if you have an existing package that works with Windows 8.1, then you may just be able to duplicate the content/lib/tools to a folder labeled ‘wpa81’ and test that out.  Example NuSpec:

<?xml version="1.0" encoding="utf-8"?>
<package xmlns="http://schemas.microsoft.com/packaging/2010/07/nuspec.xsd">
    <metadata>
        <id>Callisto</id>
        <version>1.5.0</version>
        <title>Callisto</title>
        <authors>Tim Heuer</authors>
        <owners>Tim Heuer</owners>
    </metadata>
    <files>
        <file src="lib\portable-win81+wpa81" target="lib\portable-win81+wpa81" />
    </files>
</package>

If you see at line 11 the ‘portable-win81+wpa81’ it allows me to combine the two targets telling NuGet this applies to either.  Of course if I had any nuanced differences I could also just use ‘wpa81’ and put the phone-specific lib (or assets) there.

In both cases if you have any UI aspects, most likely you may want to do some work here to make sure that any UI assets are tailored to the device targets for a great experience.

I hope this helps clarify some of the reference questions that I’ve received and I hope that if you are an SDK author you will work quickly to help your customers realize their goals of a universal Windows app!

Hope this helps!

Recently I’ve been writing a few XAML Behaviors for Callisto and looking to take some contributions on this front as well.  One thing that I realized is that this will bring in a new dependency for my toolkit.  I’m still trying to figure out if I want to do that or not, but that’s not what this post is about.  My #1 consumers of Callisto are using the NuGet package.  I also distribute Callisto through the Visual Studio gallery as an Extension SDK. 

What’s the difference you ask?

Extension SDK vs. NuGet package

While not an official answer, this is my basic definition I always describe to people.  It is not complete comparing all features but defines what I see as the core difference between the two.

An Extension SDK is installed per-machine and allows you to install it once and use for multiple projects.  It is deployed through the Visual Studio extensions mechanism (VSIX) which has a feature that allows for you to be notified if a version is updated in the IDE.  This is a proactive update that even if you just have VS open you get a little toast if any of your extensions are updated…very handy.  Extension SDKs also have some cool features about enabling you to supply design-time assets that don’t ship with your application and also provide some nice per-architecture deployment capabilities rather easily.  Extensions SDKs have great support for native projects as well.

NOTE: People sometimes confuse VSIX == Extension SDK.  VSIX is a packaging and installer mechanism, not an SDK only.  You can have a VSIX that deploys a tool, templates or an SDK. 

A NuGet package is installed per-project when added as a reference to your project in Visual Studio.  You can add them similarly through the “Add Reference” type dialogs (although in VS it is called Manage NuGet References) and once you select your package it is installed (per the package’s manifest instructions) into your project.  If you want to use the package for multiple projects, you must repeat this step for each project.  One benefit of the NuGet route is that it does become a part of your project, you can check it in to source control, etc.  One disadvantage currently is it doesn’t do the design-time aspects and the per-architecture deployment aspects well.

You might look at these differences and wonder why you would want to take a dependency on a per-machine item in a per-project package.  And you’d be right to ask that question.  Again, I’m still wondering myself.  However one thing to note is some Microsoft-delivered SDKs are delivered shipped with Visual Studio as Extension SDKs, as is the case with the Behaviors SDK.  So you can’t have VS installed without it, but NuGet also can be used in non-VS scenarios as well.  This can be complex depending on your package/needs.  For mine, this might be acceptable.

Telling your NuGet package to include an Extension SDK

I admit that this title is a bit misleading, but allow me to explain first.  NuGet allows for you to extend the package install a bit by including a PowerShell script to run during install (and uninstall) of the package.  This script can give you context of 4 things in your project/tools environment: install path (where the package is being installed), tools path (the folder where the script will actually reside), package (the NuGet package object) and project (a reference to the IDE Project instance).  It is this last piece that helps you manipulate the project structure.

In Visual Studio 2012 a new interface was added to the VS project extensibility to accommodate automating adding Extension SDKs.  This new interface, References2, includes a new method AddSDK.  This is the hook where you can add Extension SDKs.

NOTE: The other methods of Add() are still supported and would allow you to add references to files, GAC assemblies, etc.

The AddSDK has 2 parameters but only one is required, the identifier of the Extension SDK (it is weird to me that the first param is optional but oh well).  The ID of the Extension SDK is the name of the SDK (as defined by the deployed folder or the ProductFamilyName in the SDKManifest.xml) combined with the version number.  A final string to pass in the second parameter of AddSDK is then something like:

BehaviorsXamlSDKManaged, version=12.0

Now that we know this format we can add this to our NuGet install PowerShell script.  Here’s an example of what one might look like:

param($installPath, $toolsPath, $package, $project)
$moniker = $project.Properties.Item("TargetFrameworkMoniker").Value
$frameworkName = New-Object System.Runtime.Versioning.FrameworkName($moniker)
Write-Host "TargetFrameworkMoniker: " $moniker
if ($frameworkName.Version.Build -ge 1)
{
    Write-Host "Adding Behaviors SDK (XAML)"
    $project.Object.References.AddSDK("Behaviors SDK (XAML)", "BehaviorsXamlSDKManaged, version=12.0")
}

Notice the first line with the param() function.  Per the NuGet documentation this is required to get the environment objects like $project.  Now in line 8 we have a reference to the VSProject, then can get at its object model, get to the references and add one to an Extension SDK, in this case the Behaviors SDK installed with Visual Studio 2013.

The tricky thing with this approach is that when someone were to remove a package you may be tempted to remove the SDK reference as well.  Since there is not really good tracking whether someone may be using the reference, it is advised against that approach.  Your app developer may be using that Extension SDK now outside of your package and you have no reliable way of knowing that.  What you can do is alert the developer during uninstall:

param($installPath, $toolsPath, $package, $project)
Write-Host "Callisto was removed, however Blend SDK (XAML) was not
 as it may be a dependent reference on other things in your project.
  If you do not need it, manually remove it."

Not awesome, but helpful at least to output some data to the developer.

Summary

Again, while this may be unconventional and some NuGet purists will scoff at the mere suggestion of doing something like this, it is good to know this is easily available.  My goal is to help developers (including myself) and if there are ways to merge these two worlds of Extension SDKs and NuGet packages until (if?) they unify then by all means I love helping make my productivity better.

Hope this helps anyone!

I’m an avid user of Twitter (join me on Twitter @timheuer) for things social, family and technical.  I use it to keep in touch with friends, learn things from technical sources, get news and otherwise interact with names I’ve never met in person.  My use of Twitter has changed much over the years and I’ve found myself just using the web site more and more while on the desktop where a full browser is available.  On my mobile I use native clients but presently not one of the ‘official’ Twitter mobile apps (I find them less full-featured than the 3rd party ones which also offer a better performing experience for me).  In my use of the web site I’ve noticed more and more links that say “view summary” in my feed. 

Sample Twitter Summary Card from dev.twitter.com

When expanding this, the twitter post (which is limited to 140 characters itself) basically provides more information about the post.  The most frequent I’ve seen is what Twitter calls a Summary Card, which reads metadata from the URL posted in the Tweet, effectively extending the 140 character limitation a bit (however summary descriptions are limited to 200 characters).  I post to Twitter most of my blog posts and thought it would be a great little enhancement to provide this summary data in the feed view (it isn’t expanded by default so users must explicitly click ‘view summary’ and thus there is no real risk of making your Twitter feed more noisy without you choosing to read more).

Learning about Twitter Cards

I recently learned more about these after a quick exchange with @JeffSand (former director at Channel 9, now at Twitter) about another implementation (more on that later) and thought I’d get into doing the Summary Card for my own personal use.  Twitter has some pretty decent documentation on this topic on their Dev center.  There are a few types of Cards available for content authors to leverage and the great thing is that you, the content author, really just have to add metadata to your content and that’s it.  Twitter feeds/apps do the rest by interpreting and displaying that data in a Card view in the feed.

Summary Cards seem to be the most popular to me but that could be just my own personal use.  The others that I could see add value are the App info/install and deep-linking ones.  These do presently, however, seem to add most value in the mobile space and not the desktop space.

• App Cards – provide a link to mobile apps and product page information.  This is currently limited to iOS and Google Play store listings it seems.  There is also some documentation on App Install/Deep-linking techniques.
• Photo Cards – provide a good representation of an image in-line.  You see this for images from Twitter, Flicker, SkyDrive, etc.  Sadly, Instagram chose not to pull this support for their usage last year (yay customers…grrr).
• Player Card – seems great for podcast publishers!  You see YouTube usage of this most of the time as well.
• Product Cards – I’ve not seen usage of this in my interactions but I would imagine we’ll see more of this in sponsored posts/ads as they become more prevalent

After reading about these, I set out to add this metadata to my own content on my site.

Modifying my blog engine

At present I use Subtext as my blogging engine of choice.  This is due to some choices made long ago using .Text and then migrating to Subtext when that transitioned the work.  Subtext has served me very well over the years but is showing its age more recently as I’ve been desiring to modernize some things and leverage the vast ecosystem of WordPress type themes and plugins.  Still, it is Open Source, written in ASP.NET and so I could modify things as I need.

I first went to the source of Subtext and thought I’d just upgrade.  The version I run is the latest stable/release build of Subtext and hasn’t really evolved since that version release a few years back.  The version on GitHub now is moving toward ASP.NET 4, which is good and I thought I’d just move to that.  I had an immensely painful time trying to do this upgrade and ultimately decided against it (blog post on my ASP.NET migration woes perhaps to come) as there wasn’t much return on my time investment at present to do that.

The first thing you have to do is set up your Twitter Card.  Twitter’s docs have a cool Cards validator tool (only works on Webkit browsers for some reason) to give you a display of your card so you can tweak settings.  Once you do this and have your metadata set up, you need to submit your URI to Twitter for validation.  This step is critical or they won’t show up.  This step is also not entirely clear in the process and you may think that just setting the META tags are sufficient…they are not.  Use the validator tool to see the second tab to “Validate & Apply” for your card view.  I did a basic Summary Card for my entire site to get through this process so I could test/validate my own logic for the per-post metadata later.

I wanted the data from each of my posts to be a unique Summary Card as I felt that has been the most valuable I’ve used in my feed.  Card data is implemented as META tags so your mileage may vary on how you need to implement this. 

If you are a WordPress user, there is an amazing ecosystem of plugin developers who have already done this for you and you just install a plugin.  It doesn’t seem that Twitter provides a directory of recommended plugins for popular CMS systems, so I can’t speak to which ones are reliable or not.  Twitter Cards for WordPress seems to have a lot of downloads so I’d check that one out first if you are a WordPress user.

Unfortunately the way Subtext is architected doesn’t easily let me jam new META tags into my site that are dynamic (there is a tool that allows me to easily add static ones without altering the page itself).  A few properties for my cards would indeed be static (creator, site, domain) so I just used the Subtext admin area to add those.  The title and description I wanted to be content-specific.  I didn’t modify the Subtext source, but rather created my own ASP.NET 3.5 control that did this.  I put the code on my GitHub repository for you to view…you’ll see it is a quick few lines of code.  My control basically gets the context of the request, pulls the title/body out and sets these META tags.  Now whenever I post a URL to Twitter, my Summary Card option will be there and provide some helpful information to the reader (hopefully).

Viewing the results on different platforms

Looking at the results, I’m happy with my quick hack.  Outside of the web site, the cards only show on Twitter official apps it seems.  Here are some examples based on my site content.  The red box is only there to illustrate what content is actually the card:

View on twitter.com when expanding ‘view summary’

View on Twitter for iOS when viewing full Tweet detail

View on Twitter for Windows

Simple metadata additions providing some more content beyond the 140 characters Twitter allows in the post itself.  I chose to use my face in the image because my blog doesn’t associate a “poster” image per-post.  If yours does, you should use that if available and change the twitter:image value as needed.

Summary

This didn’t take me long to implement and adds some additional value on to the content I post on Twitter (I hope).  Again, this is optional for the user, they have to click “view summary” or view the Tweet in details view to see this, so there is no general feed noise here.  I have found that it appears to cache the results per URL so there may be an issue if you change title/description on a post.  I’ve found that my initial tests wouldn’t update the previous Cards I had which were just the blog summary data…that’s unfortunate, but now I know.

When I talked with @JeffSand he mentioned this would be nice to have the App cards for Windows Phone/Windows Store apps (ugh, we really have to do something about that name).  I think this is a great idea!  Unfortunately it looks like Twitter needs to do something to understand Windows apps as it only understands iOS/Google Play app stores.  I’ve started a conversation with Jeff’s team as of the date of this writing and hopefully we can understand what might be required and deliver some goodness here.

If you are a content publisher (hint: if you are a blogger you are) this is a subtle and helpful addition to your content in my opinion.  If you are podcaster, consider using the Player Card as well.  It was really easy to understand and implement and I like the results.

Hope this helps!