Smart TV 101: Wrap up

Year of 101s, Part 2 – Smart TV February

Summary – What was it all about?

February was my 101 on developing for the Samsung Smart TV; a bit of a random subject n the first place and I also managed to get quite off track by the end after a hiatus in the middle.

Part #1 – Intro

I started with an intro to what Smart TVs are.

Part #2 – App Development

Second was an overview of what apps are, how they’re developed and then got into developing a basic app.

Part #3 – Deploying Apps

Next I did a post about deploying the apps to your tv for testing

I had intended to give a detailed article on developing these apps since I had spent a lot of time in January researching these posts and couldn’t find a decent article anywhere containing this info.

However, during the writing of my second or third post I found a well hidden but utterly perfect article covering everything I had planned to write about; my post would have ended up being a reproduction of that article which is a waste of everyone’s time and not very nice for the author of the original article!

The more useful resources are:

As such I had to think of something still related to Smart TV apps, but also interesting and different enough to be worth writing.

This is where the plan to do without the IDE came in and I tried to dissect the process and implement it manually.

Part #4 – Creating Packages without the SDK

I finally attempted to do without, Apache (done), generate the package (uh.. not quite), and scrap Eclipse (no dice).

What I gained from this was more headaches related to node’s async fun, and also opened up a few other avenues for future development; essentially I’ll be able to link Jan’s 101, Feb’s 101, and also March’s 101 all together!

Summary

Once I realised that Smart TV apps were just webpages, the creation of apps become kinda boring for a blog series. Deploying apps was still quite interesting, so I liked that one. The detail of creating an app was covered wonderfully in the other articles I found, so no point repeating that stuff.

A few things I discovered that weren’t really related; if you start your node server on port 80 and get a failure related to “ENV” and “process” that looks like it couldn’t access the port and you’re not sure what process is stealing that port, try [code]netstat -anbo | findstr :80[/code]

Next Up

Hopefully March will be a more fruitful month – I’ll be getting stuck into a tasty slice of raspberryPi!

Smart TV 101 : Part #4 – Creating packages without the SDK

I’m committing to doing 12 months of “101″s; posts and projects themed at beginning something new (or reasonably new) to me. January was all about node development awesomeness. February is all about Smart TV apps.

To IDE or not to IDE

I’ve mentioned how I’m not the greatest fan of Eclipse, so working on a development method that doesn’t rely on it intrigued me.

Given that all the Smart TV apps consist of are pretty standard web pages, then surely it’s possible to do this without the integrated IDE and webserver?

Starting at the end and working backwards:

Web server

The SDK bundles Apache for serving the apps. I don’t really have any problem with Apache; it’s currently the most commonly used web server  on the interwebs, free, and stable. I just don’t see why I’d need it to serve up an XML page and some zip files!

Looking into the contents of the widgetlist.xml from previous posts we can see that it’s just listing the contents of a Widget subdirectory. That should be easy enough to manage ourselves. I’ve decided to dive back into nodejs for a lightweight alternative.

The code I’ve used is the same as that from most of January. The one that I’ve changed is requestHandlers.js to serve the listing xml and the zip files:

requestHandlers.js[js]var fs = require(‘fs’);

// build the full xml file
function widgetlist(response, notused, request) {
console.log("Request handler ‘widgetlist’ was called");
var packageDir = "packages";

BuildPackageXml(__dirname, packageDir, request, function(packageXml){
var content = ‘<?xml version="1.0" encoding="UTF-8" standalone="no"?>\r\n<rsp stat=\’ok\’>\r\n<list>\r\n’ + packageXml + ‘\r\n</list>\r\n</rsp>’;
var headers = {
"Content-Type": "application/xml",
"Content-Length": content.length
};
response.writeHead(200, headers);
response.end(content);
});
}

// build the xml for each package, getting the stats for each zip
function BuildPackageXml(directory, packageDir, request, callback){
var filesData =”;
var host = request.headers.host;

fs.readdir(‘packages’, function(err, files){
files.forEach(function(file){
console.log(‘found: ‘+ file);
var stats = fs.statSync(directory + ‘\\’ + packageDir + ‘\\’ + file)
filesData += ‘<widget id="’ + file + ‘">\r\n’ +
‘<title>’ + file + ‘</title>\r\n’ +
‘<compression size="’ + stats.size + ‘" type="zip" />\r\n’ +
‘<description>’ + file + ‘</description>\r\n’ +
‘<download>http://’ + host + ‘/Widget/’ + file + ‘</download>\r\n’+
‘</widget>’;
});
callback(filesData);
});
}

// serve the zip file
function widget(response, path) {
console.log("Request handler ‘widget’ was called for " + path);

var packageDir = "packages";
var packagepath = __dirname + ‘\\’ + packageDir + ‘\\’ + path.split(‘/’)[2];
var widget = fs.readFile(packagepath, ‘binary’, function(err, data){

var headers = {
"Content-Type": "application/zip",
"Content-Length": data.length // to avoid the "chunked data" response
};

response.writeHead(200, headers);
response.end(data,’binary’);
});
}

exports.widgetlist = widgetlist;
exports.widget = widget;[/js]

This will give us the same XML and also serve the Zip files; they don’t even need to be in the Widgets subdirectory since we’ve implemented basic routing here.

widgetlist_xml

 

Problems encountered

  • my general inability to comprehend node’s inherently async implementation caused me much confusion throughout this development
  • xml generation node modules over-complicates what is a very basic file; hence why I went for inline
  • getting the content-length header is important if you want to avoid the "content chunked" response in your http request for the zip file; the smart tv isn’t so smart in this scenario.

 

Generating the packages

Moving backwards another stage we get to the generation of the zip files themselves. This should be easy, but again I over-complicated things by trying to implement js-zip using node-zip to recursively traverse the directory containing my work files. Async recursive archive creation was a bad idea for a Sunday evening so I should have instead opted for firing a command line call to the OS’s built-in archive-er.

Luckily my code had at least abstracted this functionality out so I could easily replace it with another implementation. The code in my git repo uses this implementation, which appears to create the archive, but that file is apparently corrupt/invalid; patches/forks/pull requests welcome!

pack.js
[js]var fs = require(‘fs’);

// main function – loop through the root package dir and create one archive per sub directory
// (assumption is that each sub dir contains one entire project)
function createPackages(rootDirectory)
{
fs.readdir(rootDirectory, function(err, files)
{
files.forEach(function(item){
if (item.indexOf(‘.’) != 0)
{
var file = rootDirectory + ‘\\’ + item;
fs.stat(file, function(err,stats){
if (stats.isDirectory()){
console.log(‘** PACKAGE **\n’ + item);
createPackage(item, file, rootDirectory);
}
});
}
});
});
}

// create each zipped archive
function createPackage(packageName, path, rootPath)
{
console.log(‘* PACKING ‘ + packageName);
var zip = new require(‘node-zip’)();

var archive = zipMe(path, zip);
console.log(‘** ARCHIVING’)
var content = archive.generate({base64:false,compression:’DEFLATE’});

fs.writeFileSync(rootPath + ‘\\’ + packageName + ‘.zip’, content);
console.log(‘saved as ‘ + rootPath + ‘\\’ + packageName + ‘.zip’);
}

// recursive function to either add a file to the current archive or recurse into the sub directory
function zipMe(currentDirectory, zip)
{
console.log(‘looking at: ‘ + currentDirectory);
var dir = zip.folder(currentDirectory);

var files = fs.readdirSync(currentDirectory)

files.forEach(function(item){
if (item.indexOf(‘.’) != 0)
{
var file = currentDirectory + ‘\\’ + item;
var stats = fs.statSync(file);
if (stats.isDirectory())
{
console.log(‘directory; recursing..’)
return zipMe(file, dir);
}
else
{
console.log(‘file; adding..’)
dir.file(file, fs.readFileSync(file,’utf8′));
}
}
});

return dir
}

exports.createPackages = createPackages;[/js]

 

Using a different IDE

This is slightly more difficult; the SDK creates a bunch of files automatically (.widgetinfo, .metadata, that sort of thing). This does add an extra manual step, but isn’t impossible.

One thing I couldn’t actually get around is the debugging and testing locally; the commands being passed to the emulator aren’t easy to manipulate. When you choose to run the emulator from within Eclipse the only parameter passed is something which tells it you’re running it from Eclipse; nothing handy like a path or filename, dammit!

 

Summary

I realise I went off on a tangent in this post and I’ll explain more in the next one. However, we’re now at a point where we can save our project files *somewhere* (locally, on the LAN, on the interwebs – so long as you have the IP on their location) and spin up a nodejs script to serve them upon request to our TV.

The code from this post is over on github here https://github.com/rposbo/basic-smart-tv-app-server

 

Next up

Conclusion of February – why I had that huge gap in the middle, and why it went off on a massive tangent!

Smart TV 101 : Part #3 – Deploying to TV

I’m committing to doing 12 months of “101”s; posts and projects themed at beginning something new (or reasonably new) to me. January was all about node development awesomeness. February is all about Smart TV apps.

Deploying to a TV

Now that we’ve got a basic Smart TV app this post will investigate how to get that app on to the TV itself.

Packaging using the IDE

During the initial installation of the IDE you will have been asked to installed Apache; this is what it’s all been leading up to! You actually just need a web server on your home network somewhere; doesn’t have to be apache, doesn’t have to be on your developer pc.

Prerequisites

Make sure you’ve configured your Server settings within the IDE preferences:
samsung-packaging-server-prefs
samsung-packaging-server-prefs-root

The packaging process will drop a zip file into a Widget/ subdirectory of this directory.

Initiating package creation

As for actually creating the package, if you’re using the Eclipse IDE then you’re spoiled for choice: highlight the project in your project explorer and then either

  1. Click the Samsung App Packaging button
    samsung-app-packaging-1
  2. Click the Samsung Smart TV SDK menu, then click App Packaging
    samsung-smart-sdk-packaging-menu
  3. Right click the project in project explorer, Samsung Smart TV SDK, Packaging
    samsung-sdk-packaging-context-menu

Whichever you do you’ll end up with the same results:
samsung-packaging-dialog
samsung-packaging-confirmation

Results

Assuming you’ve set up the server settings in your preferences then you’ll end up with:

  1. a zip file placed within the SDK installation’s Package/ directory
    samsung-package-sdk-dir
  2. the same zip file placed in a Widget/ subdirectory on your configured server
    samsung-package-widget-dir
  3. a new (or updated) widgetlist.xml file in the root of your configured server’s directory

    samsung-widgetlist-xml

Make sure that you can browse to this file and that Apache is running by opening a browser and putting in http://<your development pc’s IP>/widgetlist.xml

Anatomy of a package and a widgetlist

So what is a package made of? Looking at the image above for the the zip file that’s created you’ll see that it looks almost identical to the contents of your application within the workspace:
samsung-app-workspace

So essentially the packaging step is zipping up your project directory, putting it into a specified web server subdirectory, and updating an XML file. Obviously, you shouldn’t need an IDE or SDK to do this sort of thing and I’ll be getting on to this development & deployment process without using Eclipse or installing Apache in a later post.

Deploying!!

Now that we have a package it’s time to load it on to your Smart TV. For this post I’ll be talking about deploying from the development pc via your home network, and in a later post will be talking about loading in packages externally.

TV setup

Make sure your TV is connected to your network and that your development pc’s Windows Firewall is off (or at least configured to allow local network traffic).

  • Turn on the TV
  • Go to your app hub/Smart Hub
  • Press the Login button
  • Create an account using the username “develop” and set a password

developer account

After you’ve successfully created the develop user you need to

  • Open the Settings menu
  • Open the new Development sub menu
  • Choose Setting server IP and enter the IP of your development PC
  • Choose User application synchronisation to check the apps that are listed in widgetlist.xml and install (or update) them all

download dev app

You should now find your application on the App Hub screen with a little red “user” banner over it; select it to run it, just like any other app.

asos-app-running-on-smart-tv-1

Smart TV 101 : Part #2 – App Development

I’m committing to doing 12 months of “101”s; posts and projects themed at beginning something new (or reasonably new) to me. January was all about node development awesomeness. February is all about Smart TV apps.

SDK

There is a wonderfully detailed SDK document for the current latest version (v4.0) which provides the environment to develop and test apps for the 2011, 2012, and 2013 series of TVs.

This consists of an IDE (a version of Eclipse), a selection of emulators for the three series of TVs it supports, automated test tools, app packaging facilities, and a few other tools.

There are examples and tutorials for projects ranging from gesture recognition, voice recognition, adaptive video streaming, through to advertisment embedding.

Developing gesture recognition apps for the 2013 Smart TV series

IDE – Ecplise

I’ve never been a fan of Eclipse as an IDE, but I’m stuck with it at the moment since it’s part of the Samsung SDK! To be fair, it does integrate into app development process quite well.

Once you’ve downloaded it from the SamsungDForum website and installed it you can create one of three types of application:

  1. Basic – for the less codey-types, using as visual editor. A bit like Visual Studio in design mode.
  2. Javascript – for writing the css, html, and js code yourself; this is the one I’ll be using
  3. Flash – strangely enough, for embedding flash into your app

ecplise-1

Within this flavour of Eclipse is the facility to launch the current application under development directly in an emulator, and also the ability to create a package for deployment (to be covered in the next post).

Emulator

As with any project in which you’re developing an application which will be running on a system that is different to the one on which you’re developing – such as iPhone or Android apps – you’re going to need a solid emulator.

The Samsung ones are actually reasonably good. There are some reasonably advanced debugging and testing facilities built into the SDK but even just having any javascript alert display within a debug window is extremely useful.

Smart TV Emulator

Developing a basic app

Right, let’s get down to business.

  1. Install the SDK
  2. Open up Eclipse
  3. Create a new Javascript app
  4. Make sure you’ve selected the project in the file explorer tab (i.e., not one of the js or html files)
  5. Click the Samsung Smart TV menu and select Open current project in Emulator

aaaaannnnd

samsung-emulator-1

WOW! Nothing!

Ok, let’s make it do something.

Add in a new div, give it an id, and whack in some text. This still won’t actually appear so edit the css and give it a height, width, and garish background colour.

There’s still one thing that you may need to check; I believe that this is now part of the standard base project, but in previous versions of the SDK you had to edit the Main.onLoad event and wire up a call to let the application manager know it was now ok to start showing things:
[js]widgetAPI.sendReadyEvent[/js]

My resulting HTML looks a bit like:
[html highlight=”8,9″]<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>AlrightMate</title>

<!– TODO : Common API –>
<script type="text/javascript" language="javascript" src="$MANAGER_WIDGET/Common/API/Widget.js"></script>
<script type="text/javascript" language="javascript" src="$MANAGER_WIDGET/Common/API/TVKeyValue.js"></script>

<!– TODO : Javascript code –>
<script language="javascript" type="text/javascript" src="app/javascript/Main.js"></script>

<!– TODO : Style sheets code –>
<link rel="stylesheet" href="app/stylesheets/Main.css" type="text/css">

<!– TODO: Plugins –>

</head>

<body onload="Main.onLoad();" onunload="Main.onUnload();">
<div id="content">Alright mate?</div>

<!– Dummy anchor as focus for key events –>
<a href="javascript:void(0);" id="anchor" onkeydown="Main.keyDown();"></a>

<!– TODO: your code here –>
</body>
</html>[/html]

and the autogenerated Main.js script has this onLoad method:
[js]Main.onLoad = function()
{
// Enable key event processing
this.enableKeys();
widgetAPI.sendReadyEvent();
}[/js]

Notice the $MANAGER_WIDGET files referenced in the head; these files allow access to common object modules and are on the TV itself and installed as part of the SDK.

Try running the emulator again –

samsung-emulator-2

Stonking.

Developing a slightly less basic app

Using the API created in my January posts on nodejs I’m going to create a tv app which will display the results of a product search on the Asos catalogue.

The main.js file now has an updated onload method, which makes a call to the API and then passes the returned data to a new method:
[js]Main.onLoad = function()
{
var URL = "http://rposbo-basic-node-api.apphb.com/products/socks?key=" + api_key;

if (this.XHRObj != null){
this.XHRObj.destroy();
}
this.XHRObj = new XMLHttpRequest();

if (this.XHRObj) {
alert("got XHR");
this.XHRObj.onreadystatechange = function () {
alert("State changed to " + Main.XHRObj.readyState);
if (Main.XHRObj.readyState == 4) {
alert("got data");
Main.recieveData();
}
};
this.XHRObj.open("GET", URL, true);
this.XHRObj.send(null);
}

// Enable key event processing
this.enableKeys();
widgetAPI.sendReadyEvent();
};[/js]

The new recieveData method which loops through the returned product data and creates some basic html elements to display the image and title in a list item:
[js]Main.recieveData = function () {

alert("alerting data…");
var data = JSON.parse(this.XHRObj.responseText);
for(var i=0; i<data.products.length; i++)
{
var product = data.products[i];
alert("adding " + product.title);

// image
var productImg = document.createElement("img");
productImg.setAttribute("src", product.image);

// text
var title = document.createTextNode(product.title);

// link containing both
var link = document.createElement("a");
link.appendChild(productImg);
link.appendChild(title);

// list item containing link
var listItem = document.createElement("li");
listItem.appendChild(link);

document.getElementById(‘listing’).appendChild(listItem);
}
};[/js]

No jQuery here, since I don’t want to have to load it up locally on to the tv and waste precious memory.

The single html file now looks like
index.html
[html highlight=”12″]<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>rposboBasicTvApp</title>

<!– TODO : Common API –>
<script type="text/javascript" language="javascript" src="$MANAGER_WIDGET/Common/API/Widget.js"></script>
<script type="text/javascript" language="javascript" src="$MANAGER_WIDGET/Common/API/TVKeyValue.js"></script>

<!– TODO : Javascript code –>
<script language="javascript" type="text/javascript" src="app/javascript/key.js"></script>
<script language="javascript" type="text/javascript" src="app/javascript/Main.js"></script>

<!– TODO : Style sheets code –>
<link rel="stylesheet" href="app/stylesheets/Main.css" type="text/css">

<!– TODO: Plugins –>

</head>

<body onload="Main.onLoad();" onunload="Main.onUnload();">

<div id="listing"></div>

<!– Dummy anchor as focus for key events –>
<a href="javascript:void(0);" id="anchor" onkeydown="Main.keyDown();"></a>

<!– TODO: your code here –>
</body>
</html>[/html]
The highlighted line is just where I define my API key and refer to it in Main.js.

This subtly changed code now looks something like:
asos-tv-emulator

Next up – deploying to a TV

We’ve got a basic app, now it’s time to get it on to the TV!

The code from this post is available on github