[ Ø ] Harsh Prakash

Quiet Musings on Cloud, Machine Learning, Big Data, Health, Disaster, et al.

Archive for the ‘howto’ tag

Webinar Series: GIS TECH 101 – Mapping Mashups

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Half-life of a Webpage

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The primary objective of this blog is to mull over industry trends and abstract ideas relevant to the profession, not to regurgitate “operational details”. However, this post may bend that rule.

For those not in the know, a webpage does a lot of behind-the-scene work before it spits-out text on the screen. Here’s a summary of what this webpage does:

• The very first thing it does is send out a header depending on the client-browser. This is recommended when, say, different protocols are used to access the webpage. Note that this step gets initiated only after the Apache Webserver has finished running through its configuration directives. The webpage then marks the start-time for script download and execution. Measuring script download and execution time helps in diagnostics. The webpage also goes down a list of red-flags checking for browser compatibility and permission-settings. Later, it establishes connections with MySQL databases and fetches or defines client and script variables.

• Only then does the layout begin to emerge with some CSS, XHTML and plenty of include files. Care is taken to separate presentation which has been kept to a minimum given the volunteer nature of the website, from content and function, and make it easier to reuse data. To display news feeds, as is the case here, the webpage fetches the feed URL and slices its content into nodes. Sometimes feed URLs do not provide information as desired. For example, this feed URL does not provide a direct hyperlink to its article. Sometimes a feed URL includes an image-path in its description that needs to be dropped. For such cases, scripting languages like PHP offer a wide-array of string-manipulation functions. It is advisable to ensure that the webpage continues to get parsed in a timely manner even if the fetching fails.

• The webpage then wraps-up logging of relevant variables and closes open database connections. If script execution has generated any errors, a summary gets emailed to the administrator. The webpage then spits-out the footer. Its decay into dead text is finally complete […well, unless you use AJAX to monitor client-behavior, as is the case here].

• A quick note on the website maintenance: Given its volunteer nature, it is maintained in small nudges i.e. “minor increments made frequently”, with the emphasis being on function over form.

• World Wide Web Consortium
• Web Style Guide
• Interesting Website
  º http://www.nyas.org/
  º http://news.google.com/
  º http://www.cancer.gov/
  º http://www.nobodyhere.com/
• Website Theme: A lot of experiences came together to start and shape the evolving theme of this website- During the 2002 Colorado/Arizona wildfire disaster, I received an email from the FGDC list serve requesting volunteers for assistance; Then at the 2003 ESRI Annual Conference, I learnt how volunteering is not easy- how the volunteer is not always in control; The omnipresence of mature opensource software not getting enough attention from the general public was a cause for concern; Also, a need was felt to enhance the functionality of my cellphone by connecting it with custom online applications; Additionally, there was a personal need to digest vast amounts of professional information from anywhere.


Written by Harsh

May 8th, 2005 at 10:55 pm

Posted in Programming,Web

Tagged with ,