PayPal IPN – Creating Listener Code to Process IPN Messages

You have finally decided IPN is the solution to your website application. You do not want to pay someone else to do it. It can not be that hard, can it? Where can you get some practical advice from people who have been there, done that. This article will answer these questions and help you decide if you are able to write that code. If you find it too complicated there are a few commercial products out there that will handle everything for you so do not lose heart if you find yourself stuck.

PayPal IPN

Instant Payment Notification is better known as PayPal IPN and is PayPal's interface for handling real time confirmation of purchases. A typical use for IPN is where you want to use the software to download.

PayPal provide 3 different types of account. Personal, Premier and Business. You will need Premier or Business to use IPN.

Listener

PayPal IPN messages are not synchronized with actions on your website. You detect IPN messages from PayPal with a piece of code known as a listener.

You specify the URL of your listener in your PayPal account's profile but you can override this for specific transactions when you setup a button or API operation. You can also temporarily turn off the sending of IPN messages, useful if your site is down for maintenance. They are still generated and stored until you switch sending back on again.

You must perform a number of checks on the IPN message received from PayPal.

  • Check the email address to make sure it is yours
  • Check that you have not already processed the transaction identified by the transaction ID
  • Make sure that the transaction's payment status is "completed"
  • Verify that the payment amount actually matches what you intend to charge

PayPal Sandbox

When you are developing your website you really do not want to be trying to get it working by experimenting on a real money system. Any early bugs in the system could leave security holes but even if you write perfect code it is best not to do your testing using real money.

PayPal provides what they call a sandbox, almost identical to the live PayPal system. You can setup fake customers with fake money and make as many test purchases as you want. The perfect system to fully test your web application.

There is a Sandbox Forum on the developer network. It's a great place for advice.

Testing your Listener

The Sandbox has an excellent IPN Simulator (under Test Tools) which lets you choose the transaction type, fill in all the parameter values ​​and send a test IPN to a specified address.

IPN History

PayPal provides an IPN history page under the My Account tab. Click on History to see it. It includes everything you want to know about each IPN message including the following Status values.

  • Sent: indicates that PayPal sent the message to your IPN listener
  • Failed: indicates that PayPal did not receive an acknowledgment to the message
  • Queued: indicates that PayPal is ready to send the message
  • Retrying: indicates that message was resent between 1 and 15 times and PayPal continues to be resend the message
  • Disabled: indicating that the message will not be resent because the merchant's account has been disabled

Conclusion

The best place to search for information is the PayPal Integration Center which has guides, code and links for everything to do with integrating your website with PayPal.

The one place you MUST visit is the PayPal IPN Forum on the developer website. As well as a constantly changing list of discussion topics about IPN, there are some good sticky posts about troubleshooting tips, IPN variables, template code etc.

PayPal IPN is a difficult subject but the combination of an excellent testing environment in the form of the sandbox and the good quality advice provided through the forums should make it possible for you to get your website application up and running.

Displaying Photography on the Web

Getting Started:

When deciding to display your photography online, there are a number of considerations that need to be taken into account as presenting imagery on the web. What I will cover today is image scan quality, the dimensional size of the image, and the impact of image file formats.

Image Scan Quality:

Resolution is the image quality measured in terms of how many pixels make up your image. It is commonly referred to as “ppi”; (pixels per inch). One of the common dilemmas when scanning photo transparencies to digitize them for use on a person’s website is how detailed of a scan do you need to provide your webmaster to post your imagery online. I’m going to sidestep the issue of image copyright concerns for the time being as I’ll cover that in an upcoming article on its own. However, because your images are to be viewed on a screen, all web graphics should be no larger than 72 ppi and thus anything higher has no improved effect, and only creates longer download times. This will also reduce what an individual could do with the image file if they had alternate motives.

Image Dimension Size:

Pixels are the unit of measurement for the screen and most webmasters design a website to fit one of the standard display sizes. Based on statistics that can be looked up on the internet, we have found that most people today have their monitor’s set to display at least 1024 x 768, if not larger.

Why this is important, is that if your scan dimensions in Adobe Photoshop say that the image is 8.5 inches by 11 inches, saving the file at those dimension will not allow a user at 1024 pixels by 768 pixels to see the image in its full presentation without scrolling both vertically and horizontally. Adobe Photoshop provides the ability to resize the image to a size that will fit within your website design. As an added bonus, it will also reduce the download size of the image that the view of the image will experience without losing image quality. This is something that you will need to work with your webmaster to come up the proper tradeoff between file size and the presentation size of the image in your portfolio. It is important to realize that not everyone has broadband connections, so thumbnails are very much appreciated by those who use dialup connections. One thing I would recommend is to come up with standard dimension sizes for your horizontal, vertical, panoramic and thumbnails and stick to them as it will make your life, and your webmaster’s much easier.

Image File Format:

There are two types of color that can be used in Web graphics. The colors can be associated with the Web graphic file formats we just mentioned: GIF and JPG.

GIF:

GIF is short for Graphics Interchange Format and consists of the 216 common colors found on all computer monitors and within all Web browsers. These common colors reside in a Web palette and its advantages are that it is supported by practically all web browsers, can include transparent backgrounds, supports interlacing (providing a low-resolution preview of the graphic to the viewer while it downloads), and can be used as an image map (allowing the viewer to click on the graphic as they would a regular link to another site).

JPEG:

JPEG is short for Joint Photographers Experts Group and is superior in rendering color and detail found in photographs or graphics using blends, gradients, and other tonal variations. JPEG files use red, green, and blue (RGB) for graphical color. The strength of these colors is set in from zero to 255 with zero being the least intensity and 255 being the highest intensity. When red, green and blue are combined at zero intensity the result is black. At full strength, high intensity, where the values are set at 255, 255, 255, the result is pure white. As a photographer, it is important to utilize photographs as much as we can within your Web portfolio to present your work in the best possible quality so that it captures the true spirit of the subject work.

Choosing between the two image formats:

These full color images should not be saved as GIF files because of the limited number of colors. By having limited colors, the full color image will represent the true colors using the existing Web palette of 216 colors and will create a poor, dithered, and ugly image. That is why it is very important to use the right file format for each specific graphic. Sometimes it’s obvious that a graphic on someone’s web page was saved in the wrong file format. Photos may look too grainy, or flat-color images may look too fuzzy. When selecting GIF or JPEG for your graphics conversion, it is important to consider the type of image you will be working with. Use a GIF format if you’re graphic consists primarily of line art or flat colors without gradients. JPEG-converted graphics are best for photographs or images with fine tonal variations in colors, such as images with gradients or metallic images. Choosing the right file format is not only important for the quality, but for keeping your images file size to a minimum.

Summary:

With proper usage of image scan quality, the dimensional size of the image, and the correct image file format, you will be presenting your web portfolio in a manner that the rest of the world can fully enjoy your work.

Search Engine Optimization Technique of Choice

Search Engine Optimization is the technique of ranking a web page or site high in the free search engines listings.

The Search Engine Optimization effort evolves optimizing the various tags in the html such as the title tag, headers, alt tags, anchor text, keywords and more.

There are onsite and offsite Search Engine Optimization that both play a big part in your SEO endeavor.

Onsite returns to the tags describe above as well as the content, navigation, and many other factors.

Offsite returns to links from other sites pointing to yours. For some search engines this can also include how many visitors you receive, how they click on various links and more.

You can tune up your website by using keyword research, key phrase placement in your Meta tags and content, and the application of special formatting such as headers, bold and bullets.

Beside online optimization, you also want to do offline optimization. This will include regular practices such as submitting to directories, writing press releases, submitting articles, and getting other links pointing back to your site.

White Hat SEO is optimizing your web pages in an ethical way so that they rank better in the search engines.

Black Hat SEO is using tricky and unethical practices to try and get higher rankings.

The search engine understandably does not like Black Hat techniques. Be sure to only use the white hat techniques.

Some people strongly think that Pay-per-click may lead to a quicker conversion rate and earn them money more quickly. There is a place for paid advertising, but you are missing out on a potential broad audience who trusts a site more that is perceived as relevant but does not have to pay for promoting. Search Engine Optimization is vital for your website. You can save a lot of capital by not having to rely entirely on paid advertising, and you ever reach a wider audience.

If you are considering entering the world of Internet Marketing and making money online, you want to understand how Search Engine Optimization works, otherwise you will not know how to make your site seen by your target audience. Even if you end up outsourcing all or part of your SEO activities, a working knowledge of SEO will help you decide if the company or individuals you are working with is reputable.

Some people believe that SEO is difficult and being ranked well by search engines is near impossible. That's not true. Anyone can vastly improve their position in search engines. It's not very difficult. You just have to know what to do and apply it. To make a search engine positioning campaign worthwhile, however, you must have the right information The dynamic nature of the Internet means that various types of listings are displayed in search engines result pages, which mainly include pay per click advertisements, paid inclusion listings and organic search results. SEO focus on advancing the goals of a website by improving the number and position of its organic search results for a wide variety of relevant keywords.

Unique Gifts – Are They a Thing of the Past

Well are they? How did you stumble across my article? No doubt you were looking for this very thing "Unique" am I right?

Lets face it times have changed long gone are the days of knitting and crocheting. Yes I know what you are thinking; there are still a few talented people around that do these crafts. But let's admit it now with the introduction of computers & Xbox the next generation is more interested in helping scratch than ice age rather than doing embroidery. And with mass production of goods, from China and other countries unique is becoming rarer.

Well I have made it my personal quest to find "Unique".

Let's start by saying that on a trip to Africa, I most definitely found it. The African tribal people would unduly have to be some of the most talented people in the world.

There Beadwork / Wirework designs are really amazing. Yes you heard right! These talented artisans for the Ndebele tribe express themselves through this very art form.

Dating back they used the beadwork mostly for ceremonial occasions, using organic materials, but now with the introduction of glass beads through overseas visitors, there artist has turned to something with a more modern and creative twist.

Traditionally over the years, the tribal women were renamed for the ceremonial costumes and for basket basket weaving, put the two together and they started creating
the most beautiful designs.

Today Africa is experiencing a revolution. Numbers of talented artisans, are making these steel wire sculptures and then beading them with bright bold colors. Animal sculptures, jewelry, mobiles, wall art, decorative bottles, vases, and cutlery the list is endless.

This truly is unique artisanship.