wheresrhys

Well, this has to be the quickest I’ve ever gone from idea to publishable (albeit limited functionality) website.

Deletious is my new site for simultaneously viewing a page bookmarked in Delicious and deciding whether to keep or delete the bookmark. I’ve had quite a lot of fun using it the last few days, rediscovering all sorts of articles, games, tools and other long forgotten sites. As well as wasting a lot of time reacquainting myself with all these I’ve also managed to de-clutter my Delicious account; all the CSS articles from 2-3 years ago giving an introduction to topics I now know inside out are gone from my bookmarks, as are all those gimmicky websites I can’t believe i found funny at one time.

Disappointingly, I’m having problems uploading the logo to the website’s folder, but it’ll be sorted sometime soon I hope.

So please do give it a go and let me know what you think.

EDIT – There’s a bug that pops up every now and then (something to do with caching) which leads Deletious to show zero bookmarks for your account. I’ll fix the bug when I get time, but waiting a few hours seems to clear the cache (at least, it works for my account) and then you can access your bookmarks again.

For a long time I’ve wanted to work with the Delicious API. Initially it was because the Delicious website not only had the difficult to remember del.icio.us url, but was also very badly designed. If you compared its progress – addition of new features, cleaning up of design, making use of new techniques suchas AJAX – with its web2.0 compatriots (Flickr, Digg, boris-johnson.com) it lagged way behind.

So I initially planned to build a new front-end for it, making it easier to work with your bookmarks, but before I could progress far enough in my coding abilities they completely redesigned the site; a vast improvement.

Though still not perfect. For a while I’ve found it frustrating that there is no easy way to simultaneously see the content of a bookmarked page and delete the bookmark if you deem it no longer useful, so my delicious account gradually got more and more cluttered. Well, this afternoon I decided to do something about it (and not just because I’m avoiding doing more important stuff).

But I was foiled for a long time by the laziness of the Delicious developers. My initial plan was to use javascript to get a JSON of all my bookmarks (or alternatively request one at a time) and go through them one by one, displaying the webpage in an iframe, and offering the option to discard or keep the bookmark. However, delicious only publish this data as XML which means, due to cross-domain restrictions on AJAX, you can’t just use javascript. I may be a bit hasty in pinning this on developer laziness, but I imagine creating alternate templates (because that’s all the difference between JSON and XML really) wouldn’t be too time consuming, and would greatly enhance the versatility of the API.

Anyway, I realised I would have to use a bit of PHP to get the XML and create pages from which my javascript would be able to access the data. Luckily, before I dived straight in I came across phpdelicious (which, appropriately, I have now bookmarked in Delicious) , a very easy to use php class for wrapping the Delicious API, which is very handy indeed. Less than an hour later I had built exactly what I wanted.

I reckon a few more hours development and I can make it a publicly available service.  All I need to do is include a form for other users to be able to login, and (ideally) preload websites in the iframe to speed things up (though this is problematic as some sites force the whole web page to be redirect if you try and put them in an iframe).

I haven’t blogged much about programming recently due to being too busy… too busy to blog, not too busy to program.

This is just a swift post to highlight an important distinction that I haven’t seen mentioned anywhere else, and which recently I realised the siginificance of.

In javascript, what’s the difference between

delete my_array[i];

and

my_array.splice(i, 1);

Superficially they’re the same – they each remove the ith element from an array. But the crucial difference is that delete leaves a gap in the array, so there will no longer be an ith element – the array jumps straight from the (i-1)th to the (i+1)th element. But splice moves the (i+1)th element into the ith place in the array, and so on, shortening the array by one but moving everything along to fill the gap.

Why is this important?

If your code relies often on iterating through an array thus:

for(i=0;i<my_array.length;i++)
{
    //some code
}

then any future iterations over the array will throw errors if you used delete to remove the ith element. But the iterations should still work if you used the splice method.

One note of caution, if you carry out

my_array.splice(i, 1);

within a loop over i, you should add the line

i--;

immediately after, to make sure you don’t miss out the next array element (which is now, of course, not in the (i+1)th place, but in the ith place).