With the popularity of jQuery, AJAX, and client-side programming operations in general, there’s more use made of JSON as a format for getting data backwards and forwards.

For example, the Twitter API offers data as JSON – and more manageably than accessing their RSS XML feeds for user timelines etc.

http://twitter.com/status/user_timeline/USERNAME.json?count=10 

The issue is how to make use of JSON-encoded information in the WordPress environment – much of what is available is only recently available, so some care has to be taken about how it’s used.

1. Native PHP functions

json_encode() and json_decode() make life very simple – but these functions are only available in PHP >= 5.2.0 and WordPress is still designed to run on significantly older versions of PHP than this. Alternatives would have to be supplied if you were thinking about releasing a plugin. There are custom-written functions to reproduce these in PHP4, see for example user contributions to json_encode. These are often not 100% perfect, but one may well do all that you require…

2. JSON2

If you’re happy to do the work in jQuery/javaScript, WordPress 2.9 comes with JSON2 bundled, registered and ready to go…

add_action('wp_print_scripts','load_json_parser');

function load_json_parser(){

	if (is_admin()) return; // probably don't want this on admin pages

	wp_enqueue_script('json2');

}

No need any more to play around with eval in the javaScript, but again, this is a WordPress >= 2.9 thing….

3. Borrowing the Text Editor

Lastly, there is one more, slightly unofficial, dodge that can be used. WordPress makes use of TinyMCE as its rich text editor and this comes with the its own JSON parser. Results may not be completely predictable.

require_once(ABSPATH."/wp-includes/js/tinymce/plugins/spellchecker/classes/utils/JSON.php");

$jsObj = new Moxiecode_JSON();

// encodes the supplied array to JSON format
$json = $jsObj->encode(array("key1"=>"value1","key2"=>"value2"));

//decodes supplied JSON to a PHP array
$json_array = $jsObj->decode($json);

Some thoughts on Twitter and how it affects the average WordPress blogger presently :- how to get value out of it, what to avoid and how to maintain a decent etiquette – it does seem to have grown slightly in the last year or so.

Success requires 2-way communication. “Broadcasters” – you know the ones… Their profile says 3 following 12,455 followers – they’re not being a success via Twitter, they’re trading off an established reputation.

It would be nice not to have to do the work, but if you’re starting at the bottom… you’ll have to do the work, no one else will. Follow those who follow you.

Twitter is networking, linking, creating connections, so there’s logic in not just tweeting your own content.
If someone tweets your content tweet about theirs and/or retweet them. People do respond well to being talked up – shameless, I know, but we are creatures of vanity. Giving someone a positive mention can pay a dividend. You can give them a recommendation at MrTweet and elsewhere, and there’s always #followfriday.

Note that there are 2 competing factors with retweeting someone else’s content.

1. You want to keep retweets vaguely accurate to your niche, obviously
2. But you’ll want to introduce your followers to someone/something new – they’ll think of you as authoritative, god forbid…

Try to keep a handle on what you retweet, it’s all too easy to get carried away by the urge to fill up the timeline and look busy. So careful who you recommend and retweet because it all reflects on you. Avoid the gimmicks of you follow me, I’ll follow you etc etc. looks tacky….

And do watch out for shortened urls – don’t display or retweet anything you haven’t first checked, and that definitely includes anything that arrives in a comment.

The nature of Twitter now is that nobody can read all their tweets – so a little bit of duplicate tweeting for your own content has its value. Too much and the risk is obvious, so maybe if you’re tweeting up a new blog post, mention it a couple of times on the day and then again a couple of days later, no great harm in that. Schedule – a little bit. Socialoomph, CoTweet and others have the means to schedule your priceless content.

But definitely – we’re not always as good at this as we’d like to be – make some reply to your @mentions, if they’re not completely auto-generated.

On the other hand again, it’s more difficult, and probably not efficient, to keep up with all your direct messages – far too many of these are auto-generated marketing drivel. So there’s probably no good reason to DM somebody if you want to make sensible contact – you might try tweeting an @mention as well to indicate you sent a DM…

Don’t bother to get annoyed if someone makes no response – they may be far too busy with other things, they may be grateful but not inclined to fill up their timeline with mutual congratulations, they may be a bit of a tosser. Who knows… Don’t take it personally, get on with what’s next…

And lastly – waste no time on the pointless building of followers. There are good and bad followers, but the vast majority are meaningless followers. Yes, I know there are a few things around the web that reward huge metrics, but you’re sending out a tweet that even if noticed is never going to be in the sphere of interest of the noticer – what’s the point?

My guess, and that of others, is that Twitter is starting to fight a battle with its signal-to-noise ratio, other options such as FriendFeed seem to have their advantages (for how long…?) so it is up to you to keep it relevant…

You’re producing a WordPress theme, or plugin, that is related to Twitter and for obvious reasons you want to include url-shortening functionality… How’s it, generally, done?

Just the briefest snippet of PHP, this example for is.gd:-

	function shorten_url($url)	{
		$request = 'http://is.gd/api.php?longurl=' . $url;
		return @file_get_contents($request);
	}

You might want to do a bit of error-catching on that. We’ve used file_get_contents() on the basis that we write themes and plugins that work on PHP5 – the ‘official’ WordPress way is probably still to use the bundled version of Snoopy. Or there’s always cURL – unless there isn’t on your server…

Any decent url-shortening service will have its own RESTful API location to do this – hunt in their Developer Tools

http://tinyurl.com/api-create.php?url={long_url}

et al… though some require login/password parameters to be passed, and some definitely require urlencoded parameters

But…. your own name

Don’t forget, in the particular case, if you’re customising your own WordPress installation, the possibility of using $_GET urls -these may well be short enough (if your domain name is short enough… obviously….) . Using your own domain name has 2 advantages, 1 significant

1. If third parties quote the link directly on their web pages it’s your site getting the link value.
2. Still works if the url-shortening site happens to die before your blog does…

And even if you have permalinks active, urls will redirect….

http://themocracy.com/?p=188 will redirect you to the pretty permalink version – job done.

Publicity, relationship-building, just plain keeping in touch – Twitter offers it all and the art is to integrate your tweeting into your blogging, if that doesn’t sound too salacious. Here’s a few scattered suggestions on the subject.

First up, to begin at the beginning, reply to @’s – I know it’s absolutely bleedin’ obvious, but if you’re going to use Twitter at all, then it does make sense to keep an eye on people taking the trouble to contact you – if the @message isn’t total spam, of course. And probably a good idea nowadays never to let a tweet out on the world without one #hashtag.

Display your twitterstream on the blog – there’s WordPress plugins for this – a lot of plugins, in all shapes, sizes and functionalities, such that the jury is still out on who’s the market leader. At the moment, the advice has to be download two or three, try them out and find the one that suits you…

Twitter Tools has a fair few features. Personally, I haven’t had much luck with this one – it seems to give up after a while and only start again when re-installed, and I haven’t got round to digging around the code to see if it’s a localised problem or intrinsic to the plugin. There’s also the issue of deleting manually, ie directly at the database level, any deleted tweets.

Twitter itself supplies javascript snippets to produce a badge of tweet lists – just paste it on your page somewhere, somehow – in practice, not recommended simply because the request takes a while to come back from Twitter’s overburdened servers and your page will likely hang at times. Tho’ fair enough, things seem to be improving a lot in that direction recently – and I wouldn’t like the job myself of keeping Twitter up and running at that rate of growth.

Wider than just Twitter, there’s also the Lifestream WordPress plugin. Lots of features included, which do take a little bit of figuring out but you can merge twitter feeds, extra RSS and then any of the other social entities, Digg, FriendFeed etc etc.

One thing – if you’re going through a twitter-lazy period and all that appears in the sidebar is a set of auto-generated new blog posts 181 days ago, 193 days ago – that doesn’t look so good. A successful blog does actually require some work.

Among other Twitter-related WordPress plugins: -

TwitterLink Comments is a WordPress plugin which adds an input field to a post’s comment form for commenters to include their Twitter username – a follow me link is shown against that commenter’s profile – caution, a definite invitation for spam…

The slightly bilious TweetMeme retweet button does what it says – a link allowing visitors to your blog to quickly retweet the post. For the competitive, there’s also a display of number of retweets of that url across Twitter.

Do consider having a custom Twitter landing page on your blog. A relatively old dodge, but useful…

Instead of using your blog front page as your profile url without even thinking about it – take the trouble to produce a specialised landing page – a digest of who you are, what’s going on, all in a couple of hundred words. The logic behind this is that people using Twitter may well have different priorities and interests than your average blog-reader who’s arrived via search engine.

This profile url appears on your Twitter web page (and with the growth in non-browser-based twitter tools that gets viewed less and less) but also in various other places, directories etc. so it’s worth considering.

If you can give them what they want, grab their attention better, that’s one more connection made. Attention spans (of the young) are not very long nowadays…

And do watch out for shortened urls – don’t display or retweet anything you haven’t checked, and that definitely includes anything that arrives in a comment.

So you want to get a RSS feed and echo it to a WordPress page or sidebar – you’ve already got the RSS sidebar widget feature, but what if you want a little more control over what’s coming out?

New in WordPress 2.8 is the fetch_feed() function – as the name suggests, a means of retrieving an external RSS feed, parsing it (extracting the relevant info, for output purposes) and also caching the raw data to ease the strain on both servers.

fetch_feed() uses the Simplepie class to fetch and manipulate the RSS – in constrast to the functions it replaces, wp_rss(), get_rss() etc., which stuck with good old Magpie and Snoopy to get the job done.

And the use of the function itself is simplicity:

if(function_exists('fetch_feed')){
$uri = 'http://themocracy.com/feed/';
$feed = fetch_feed($uri);
}

Notice the function_exists check, to ensure compatibility…

The simplepie object returned is complex (some might say a touch clumsy, but probably necessarily so in order to handle the wide variety of XML lumped together under the heading RSS). Don’t try to work with it directly…

Instead, what Simplepie has is methods to get at the data:
This code retrieves the overall feed title and then loops through the RSS items, grabbing and outputting the relevant item data.

printf( $feed->get_title());

foreach ($feed->get_items() as $item){

printf('<p><a href="%s">%s</a></p>',$item->get_permalink(), $item->get_title());
printf('<p>%s</p>',$item->get_description());
printf('<p><small>%s</small></p>',$item->get_date('j F Y | g:i a'));
}

That’s the basic idea – see the Simplepie docs for more…

You might want to try it as a quick way of getting a Twitter feed onto a page – or any other ideas for using RSS feeds directly…?