Or, you could use RSS for what’s intended for – content syndication. With Simple XML, it’s a piece of cake to use an RSS feed to add a list of links to relevant articles on your page.

What Are RSS Feeds and XML Files?

Hopefully you know what an XML file and an RSS feed is. If not, here’s the quick and dirty explanation.

An XML file is a special way to store information. All of the information is wrapped in tags – kind of like HTML. However, instead of using this to format the output, this is used to tell the reader what the information means.

So, for example, a <link> tag would probably describe a link.

XML was created to allow information to be easily ported between platforms and systems. An RSS feed is a special type of XML file to help reach that goal. Most websites (including almost all blogs), publish an RSS feed that is simply an XML file containing the latest few entries on the website.

An RSS feed also has a standard structure – which is why we can easily build a script that can parse any valid RSS feed and add the links to your site.

Getting Started with Simple XML

Before SimpleXML, you had to build your own XML parser to work with PHP and XML files. This was possible, but it meant a lot of overhead – so it wasn’t a good idea for small projects.

With SimpleXML, you can load any XML file into PHP as a specially structured object. The object’s structure mirrors the XML file. So, if there’s a <item> tag, it creates an object with name “item.” It then creates children objects of every tag inside that item tag.

To load an XML file into a SimpleXML object, you simply use this function call. Run this entire script to see what the SimpleXML object looks like after it’s loaded.

$filename = "http://www.dzone.com/links/feed/frontpage/rss.xml";
//  That's the DZone RSS Feed
 
$feed = simplexml_load_file($filename);
var_dump($feed);

What’s In an RSS Feed, and How Do We Use It?

If you ran that script, you should see the guts of an RSS feed. I’d suggest you view the source code of the output page, since it’ll be formatted nicely for you.

Like I mentioned before, RSS feeds have a standard structure so that apps can predictably interact with them. This is the basic structure you should see inside the DZone RSS feed.

//  Some random stuff up top
<channel>  // This parent tag holds all the page information
  <item>  //  There's one item per page listed in the feed
    <title> ... </title>
    <link> ... </link>
    <description> ... </description>
    <pubDate> ... </pubDate>
  </item>
  //  You could have a lot more <item> tags here
</channel>

All of this information is nicely placed in our SimpleXML object for us to manipulate.

The entire channel (all of the children tags inside the channel tag) is stored in the ‘channel’ object, which is a child of the larger ‘feed’ object that we created earlier ($feed).

You can access the channel like this.

var_dump ($feed->channel);

If there were multiple channels, then ‘channel’ wouldn’t be a single object – it would be an array of objects. This is the case with the ‘item’ tags. There are a lot of items, so they are stored in an array – which is a child object of the ‘channel.’

You can access the items like this.

var_dump ($feed->channel->item[n]);

Finally, the individual item holds most of the information we want. It has children named ‘pubDate,’ ‘title,’ and ‘link’ (along with a few other optional parameters).

echo $feed->channel->item[0]->title;
echo $feed->channel->item[0]->link;
echo $feed->channel->item[0]->pubDate;

So How Is This Useful to Us?

As you may have noticed, each item consists of the information you need to make a link back to it. The item consists of a title, a URL, a pubDate, and a description. You could use any combination of these that you feel is useful – but here’s an example of how to create a link to an article.

echo '<a href="' . $feed->channel->item[0]->link . '">' .
  $feed->channel->item[0]->title . '</a>';

And that’s all there is to it. You could spruce it up by adding a date underneath the link. Or you could add a short excerpt of the description.

What If I Want to Include All of the Links?

I suppose adding one link is kind of silly. With a loop, we can easily iterate through the item[] array and output a link for every item in the RSS feed.

For good measure, we’ll also format it nicely in an unordered list. From there, you can add some styling and it’ll fit right into the sidebar of your page.

//  Load the XML file into a Simple XML object
$filename = "http://www.dzone.com/links/feed/frontpage/rss.xml";
$feed = simplexml_load_file($filename);
 
//  Iterate through the list and create the ul
echo "<ul>";
foreach ($feed->channel->item as $item) {
  echo "<li><a href='" . $item->link . "'>" .
    $item->title . "</a></li>";
}
echo "</ul>";

There ya have it. A semantically structured list, built from a remote RSS feed. All in a couple lines of code.

You could of course separate this out into a function, and then pass a filename (and perhaps a limiting # of items to print) to your function. The function would return a string with the html list, or output it directly (depending on your preference).

Word of Caution: Remember that you don’t own content just because it is published in an RSS feed. The author still does.

I would assume that it’s fair game and free of copyright issues to print links to the original author’s site. However, some authors publish their entire articles in their RSS feeds. Do not re-publish the entire article. That is copyright infringement, it is illegal, and you can get in a lot of trouble. Not to mention it’s highly unethical.

With that in mind, happy syndicating!

There are plenty of places to look for free backlinks – some of better quality than others. One trick you can use to build up a decent collection of backlinks is to regularly post on forums in your niche.

Not All Backlinks Are Created Equally

Before you go about posting on every forum you can find, understand that not all backlinks are of equal value.

Some forums (as well as blog comment areas) use the rel="nofollow" attribute in links. This means that Google (and possibly other search engines) ignores the link when crawling and calculating search engine placement.

Some other search engines – like Yahoo – may still count these. There’s no certain way to know how valuable they are, so I wouldn’t just ignore them. However, if you have a choice you should steer your time and effort to forums where the links you create do not contain the rel="nofollow" attribute.

Where Do I Put the Links?

On most forums, it’s considered bad form to just run around posting links to your site. Be sure to read the rules for the forum. Some forums may allow you to link to your site if the article directly relates to a question someone else asked.

However, there are two places you’ll generally be able to put backlinks.

In your profile, you should be able to set a “Homepage” value. Always do this. On some forums – like Programming Talk – each post contains a link to your homepage by your name.

You can also create a signature. This appears at the end of every post you make, and it is typically considered ok to place self-promoting links here. Some forums will have special rules about this – so be sure to read them.

Once you place links in your signature, make them count. This is a great place to start doing SEO. If you already have a link to your homepage underneath your name, I would use the signature to link to some deeper pages – like content categories. Give the links targeted text (like “PHP Tutorials” or “Web Design Tips”).

A Few Forums to Start With

Since you’re a webmaster, you’ll always find something interesting to talk about on webmaster forums. Here are a few well-trafficked forums that I frequent.

• DaniWeb – I think signature links here are rel=nofollow, but it’s a good forum
• Digital Point – Lots of traffic, and links are followed
• Programming Talk – Decent traffic, and links are followed
• Site Point – Lots of traffic, and links are followed

Start Posting!

What are you waiting for? Get out there and start posting!

If your website isn’t about websites, then you should probably search out some other forums based on your niche as well.

Forum backlinks aren’t going to make your website a success by themselves, but they are a good stepping stone to better SEO. You can use them to quickly build up backlinks for a new site until you start getting better backlinks from other sites.

Another site I’ve found useful is Gimp Tutorials. They’re a great place to list any graphics tutorials that you write for the GIMP graphic design program.

In case you don’t know what GIMP is, head to the Gimp homepage. It’s a free, open source graphic editing suite – similar in many ways to the expensive, proprietary Adobe Photoshop.

Gimp Tutorials is another niche directory where you can submit appropriate tutorials for listing. In this case, appropriate means just about anything related to creating or editing an image in Gimp.

I wrote a very basic tutorial to show users how to create a gradient background image in GIMP. Since I submitted the tutorial to Gimp Tutorials, slightly less than week ago, they’ve sent me 200 visits.

There was a brief spike on the first day, and I’ve been getting a steady stream of 20-30 visitors each day after that.

There doesn’t appear to be a lot of turnover on the site, so my tutorial is still listed third on the front page. That’s after five days. That’s a pretty lengthy period of exposure – considering that others sites (like Good Tutorials) turnover in about a day.

So if you write any tutorials for GIMP, don’t hesitate to submit them here. It’s a good way to drive a few extra users to your latest article.

Some blogs automatically resize the pictures for you into a thumbnail – like the image to the right. What if you want the image a different size, though? You could allow the browser to resize it for you, or – better yet – write your own php script to resize the image dynamically.

Why You Shouldn’t Let the Browser Resize Images

Look at the original picture – the small thumbnail created by WordPress. Notice how large it is – 13.9kb. When WordPress resizes the image, it also reduces the file size. If I were to include the fullsize image and resize it using css height and width attributes, the file size would not be cut down.

Want proof? Look at the second image to the right – that’s simply resized by the browser. It’s a whopping 284.21kb.

If we write our own php script to resize the image dynamically, we can control both the image size and the file size. Check out the third image to the right – which was resized with a php script. You’ll notice that it looks nicer too – the browser isn’t designed to resize images.

Using the PHP GD Library to Resize the Image

So how do we do this? We’re going to make use of the PHP GD library to manipulate the image, and a $_GET parameter to tell it which image to re-size.

Let’s walk through using the GD library to re-size an image. Then we’ll see how to include that in your HTML to actually do the resizing for you.

First, we need to open up the original file and get it’s size and type characteristics.

$src_img = imagecreatefrompng('image.png');
$srcsize = getimagesize('image.png');

imagecreatfrompng() creates an image object and stores it in $src_image. If the file was a different type we could replace “png” with “jpeg” or “gif.” getimagesize() stores an array in $srcsize that contains the width of the image ($srcsize[0]), the height of the image ($srcsize[1]), and the filetype of the image ($srcsize[2]).

Now we need to create new dimensions for the new image and actually create an image. We’ll resize it to 200 pixels wide – and then adjust the height to maintain the ratio.

$dest_x = 200;
$dest_y = (200 / $srcsize[0]) * $srcsize[1];
$dst_img = imagecreatetruecolor($dest_x, $dest_y);

The calculations should be self explanatory. imagecreatetruecolor() creates a new image object for us with the given dimensions – which we will soon fill in with our resized image.

The next step is to place the resized image into $dst_img and output the image as Image content.

imagecopyresampled($dst_img, $src_img, 0, 0, 0, 0, 
    $dest_x, $dest_y, $srcsize[0], $srcsize[1]);
 
header("content-type: image/png");
imagepng($dst_img);

imagecopyresampled() copies an image ($dst_img) into a new image ($src_img) with a set of given attributes (including our sizes). The “Header” line tells the browser that this is an image – so that it’s not displayed as a bunch of gibberish. Finally, the imagepng() function actually displays the image.

Now, we need to clean up and destroy the image objects. Otherwise, we could end up sapping a lot of memory from the server.

imagedestroy($src_img);
imagedestroy($dst_img);

Displaying the Script in HTML

If you load the script directly, you should simply see the image. It creates an image resource and displays it in the browser – as if “resize-image.php” was really “image.png.”

Therefore all we need to do to include this new image in an HTML page is use the php script as the src attribute of our <img> tag. Like so…

<img src='resize-image.php' />

The script will execute, create an image, and use that as the src.

The last thing we need to do is modify our script so that we can pass it some information.

It wouldn’t do much good if we had to write a new php script for every image we wanted to resize. Instead, we can use the $_GET array to send a variable (the image filename) to our image resizing script.

Here’s the entire image resizing script, with the $_GET variable used for the filename.

//  Create source image and dimensions
$src_img = imagecreatefrompng($_GET['image']);
$srcsize = getimagesize($_GET['image']);
$dest_x = 200;
$dest_y = (200 / $srcsize[0]) * $srcsize[1];
$dst_img = imagecreatetruecolor($dest_x, $dest_y);
 
//  Resize image
imagecopyresampled($dst_img, $src_img, 0, 0, 0, 0, $dest_x, $dest_y, $srcsize[0], $srcsize[1]);
 
//  Output image
header("content-type: image/png");
imagepng($dst_img);
 
//  Destroy images
imagedestroy($src_img);
imagedestroy($dst_img);

To use this, you need to slightly modify your HTML and add an “image” parameter to the URL of your script. Like so…

<img src='resize-image.php?image=image.png' />

There ya go! Now you can resize images on the fly.

Next Steps to Take…

This is of course a basic introduction to the topic. You can add a lot of functionality to resize-image.php.

For example, you could take extra parameters – like a width and/or height. You might also want to include a bunch of error checking – make sure the file exists, make sure the new dimensions are appropriate, etc.

You could also use a switch() statement to open different types of images – based on the contents of $srcsize[2]. Remember, you can use the GD library to do more than work with .png files. By replacing ‘png’ with ‘jpeg’ or ‘gif’ you can use the same functions to work with these file types. For example, imagecreatefromjpeg is equivalent to imagecreatefrompng.

In the near future, I plan on extending this example into a full-fledged script for immediate download and use. So stay tuned – and leave any comments with suggestions for what the script should be able to do.

If you operate a website (like this blog), Google Adsense is probably one of your main streams of revenue. Although you may eventually outgrow Adsense, chances are you’ll have used it at some point.

While looking through my Adsense stats, I noticed an odd trend. This trend suggested a few things about monetizing a site through Adsense – questions that I don’t have an answer for yet, but that I will be looking for.

On this and my other site (Babel), I use a few main types of ads – a horizontal image banner, a skyscraper with text and images, and square boxes with text and images.

It’s natural to wonder, “Which ad is the most efficient and most effective?”

Both of these sites are relatively new, so I don’t have a lot of data to work with. From the data that I do have, though, I’ve noticed a few key trends.

• The tall vertical skyscraper and the square blocks seem to have the best click-through rate
• The horizontal image banner (like the one in the header) seems to have a low click-through rate
• The tall vertical skyscraper and the square blocks seem to have lower pay-per-click values
• The horizontal image banner seems to have a much higher payout than the other two options

Like I said, I don’t have a whole lot of data to support these trends at the moment. Over the next month or two, I plan on watching these trends and testing them out (using random tests of text verse image ads).

It’s something to keep in mind, though. The horizontal image banner seems to be the most effective – the high payout makes up for the low click-through rate. Although I wouldn’t get rid of the other ads, it’s a good justification for making sure you have at least one horizontal image banner on your site.

Notice any trends in your own Adsense reports? I’d be interested to hear what other people have come up.

So how do you keep on writing? Where do all the new ideas come from?

Everybody’s got their own tricks, but here’s one that I love to use when I’m short on ideas. Go through your search engine logs and see what people are searching for – and not finding.

Here’s an example. Last week I wrote an article on How to Create Style-able CSS Tooltips.

As usual, I was browsing through the Google Analytics data a day or two later. While looking through the Search Engine results (the queries that people used to come to my site), I noticed that someone used the query “gradient background image gimp.”

The odd thing about this was that the article wasn’t about creating background images in Gimp – I just happened to mention at the end that you could use Gimp to create a gradient background image and add it to your tooltip.

This tells me two things.

First, someone is looking for this information. If I write it… they will come.

Second, someone else is not serving this information up. If a user stumbles on one of my articles that just barely mentions the topic, there can’t be a lot of targeted articles out there.

I decided to take the topic and run with it. A few days later, I wrote a simple tutorial about how to create a gradient background image in Gimp. I targeted the article at those major keywords – gradient, background, image, Gimp – and now it’s getting some nice search engine traffic.

So if you’re ever short on ideas, this is a great way to respark that creativity. Look through your search engine logs for queries that bring people in – but don’t bring people to what they’re looking for. Then… give them what they want.

But even if you’re not interested in being published on someone else’s site, AC can be a great tool for you as a webmaster. You can use it to get optimized backlinks and targeted traffic.

If you’re not familiar with AC, here’s a quick rundown of how it works. You write an article which you can either submit for up front payment (in which you get paid ~3-8 bucks if they like it) or you can bypass the review process and get published immediately (without upfront payment).

Either way, once your article is published you earn a revenue share (Performance Payment, $1.50 per 1000 page views). The good thing about skipping the up front payment is you can post articles that advertise your site – without it getting reviewed and picked over.

Although most of my AC articles are strictly for content, I have created a few as an experiment for gaining backlinks and traffic. Here’s what I typically do.

I identify a topic on one of my sites that I’ve written a few articles on (3-4). Then I write a brief “Guide” article that gives the reader an overview of the topic. I dedicate one to two paragraphs to the sub-topics that each of my pages targets, and I include a link to my content page so that the reader can get more information.

You can see an example with this article on graphic organizers. It targets three content pages that I wrote on my other website (Babel). It also gives the user some useful information.

I originally tried this strictly as a method to gain backlinks. On that grounds, it definitely worked. I included four links to my site – one to the front page and three to individual content pages. They were indexed quickly and picked up by the search engines.

The unintended consequence of this is that it directed a bit of traffic to my site, too. It’s by no means a vast amount of traffic, but every little bit counts. In the past week, that article sent 21 visits to my site – a couple of visits per day (see the Google Analytics screenshot).

Doesn’t sound like a lot, but consider this. If you write ten guide articles that get an average of ten click throughs per week – that’s another 400 visits per month. On top of that, you’ll get 30-40 backlinks with keywords that you chose to best benefit your site.

This seems like a great tool for promoting your site – especially a relatively new site. You can get optimized backlinks, you can drive some traffic, and you even get income from Associated Content if people do read your article.

Get paid for advertising your own site? I don’t think it gets any better than that. Go sign up for Associated Content and write a few stump articles yourself.

You can test how your site displays in a few browsers – for example, I often check mine out in Windows IE, Ubuntu Firefox, and Ubuntu Opera. But how am I going to check it on Mac browsers like Safari?

Enter Browsershots.

The premise is very simple. You check off a list of browsers and platforms, enter your website’s url, and click submit. Then the servers open your site, take a screenshot, and upload the display to Browsershots.

You can then view the screenshots and see how your website appeared in those browsers. You can check out some sample displays for an education related website that I created.

Your options are pretty extensive. At the moment you can choose from 36 Linux browsers, 12 Windows browsers, and 4 Mac OS browsers.

After you submit your request, you need to wait until your website comes up in the queue. Each server (factory, as they call it at Browsershots) has its own queue. A lot of the servers will be done in a couple of minutes, but some queues can be one to two hours long.

One of the downsides to the site is that your request will expire in 30 minutes. The completed screenshots will stay up there, but if you have any requests left in the queue they will be canceled.

You can refresh your request by clicking a button, but if you get stuck in a 90 minute queue you’ll have to remember to refresh your request several times.

All in all, very useful tool. I plan to use it to test out any future design projects. So the next time you want to see how a foreign browser would display your site, head over to Browsershots.

I’m sure we’ve all faced this problem at one point or another – how do we get sample HTML to display properly, without being rendered, so that users can view it? Moreover, what’s the best method of doing this?

I first struggled with this when I was writing for another site (Associated Content). Because they filtered out a lot of html tags, it was pretty tough to find a way to get it to display properly. The only method I could get to work reliably was to pad the tags with spaces, like < html >.

Not the best method, but thankfully there are better ways to do it on your own site.

The basic trick is to convert all of your < characters into < and > characters into >. Want to go do all that by hand?

I didn’t think so. I tend to do it by hand if I’m just typing one or two tags, but for a full-fledged example it’s much easier to have a script do the work for you. So I built a tool to do just that.

Head over to the HTML Encoding Form, copy and paste your sample code into one textarea, and press submit. The HTML will be escaped for you, at which point you can copy and paste it back into your tutorial.

The other day I came across something truly disturbing in the way of online writing. I stumbled on the website Senserely.

It was kind of like a train wreck – it was horrifying, but I had to keep looking around just to see if it could get any worse.

The website, like other online websites, works on a basic premise: you write an article, they host the article, you split the ad revenues. The topic of the site is supposed to be AdSense and similar items.

On the surface, this doesn’t sound like a horrible idea. Helium, Associated Content, and other sites have been working fine. But none have looked quite as disgusting as Senserely.

The layout of the site is horrible. It’s completely bogged down with ads – with three large square blocks and three rows of text ads before any content appears. The color scheme doesn’t mesh well, and the content is near un-findable under the mountain of ads.

The site is also incredibly slow to load. The site is built on top of a table based layout, with markup that doesn’t come close to passing validation. Between the poor design and the load of javascript advertisements, it takes quite some time for the page to load and for me to be able to scroll around.

Go check it out for a minute. You’ll get a good laugh out of it. I couldn’t even bring myself to sign up and get a referral id – I’d feel a little bit dirty about actually referring someone to this site and recommending that you sign up.

Bottom line – check it out for a laugh, and then run far far away. You can get similar functionality – with a better layout and better search engine placement – through Associated Content and Xomba.