Technology Primer

Before starting to build a site with Indicia, it’s worth taking a few moments for a quick primer of the technologies which Indicia utilises.

Installing Indicia is not like installing an application to run locally on your computer because it is

  • designed to run from a web browser over the internet.
  • a toolkit designed to help you build something, rather than a finished product in itself.

When you view a web page over the internet, your web browser has sent a request for information to another computer called a web server. This is a specially configured computer with a permanent connection to the internet. The web server includes a special program (a web server process) that is set up to respond to your requests by sending back web page content as appropriate. Although Indicia, being a web based solution, is typically set up this way, it is perfectly possible to use the same technologies to install Indicia on a local web server process running on your computer and access it from the web browser on the same computer. In fact this is what we typically do as developers of products like Indicia. Installing Indicia from scratch is a bit more complicated than installing a typical desktop application though, mainly because there are more components required to set up the web server.

There are quite a few different web servers which you can install on most machines. The two most commonly used contenders are IIS (Internet Information Services, Windows only) and Apache (Windows, Mac, Linux). Because the latter is the most widely used web server on the internet today Apache is a good choice if you don’t have any other factors in your selection of web server. Another point to be aware of is that when you purchase some web space from a host, the typical low cost options are shared web servers, that is, the server is shared between your website and a number of other websites. That is how the host can make money by only charging a few pounds a month.

All web servers have one thing in common – they are designed to receive requests from web browsers and other web enabled applications, and to respond to those requests by sending back web content and other data. When you build a website, ultimately you are building a set of web pages which can be viewed on a browser. The content you write for your website is returned to the browser as text with special tags inserted into it to denote formatting, links to images and so forth. For example to output emphasized (italic) text the text can be marked up as follows:

<em>This text is emphasized</em>. This text is normal.

This would appear in the browser as:

This text is emphasized. This text is normal.

The language used to format text for use on the web is called HTML (HyperText Markup Language). It is beyond the scope of this documentation to teach HTML and the associated technologies but there are many books and websites on the topic which are readily available if you are interested. However, it is fairly obvious that writing a large website by hand using HTML is quite a laborious task. There are tools such as Adobe Dreamweaver which facilitate this task. But what happens if you want to change the layout of the pages across the site, e.g. to insert a new menu at the top? And what happens if you want functionality on your site rather than just content, for example a weather widget on the home page which shows the latest weather? We can get around the problem of supporting functionality such as this by using a program on the server to perform tasks which result in the output of HTML. For example, the weather widget could be explained by the following workflow:

Todo

Weather widget, image from existing docs

The actual technologies available on the servers will vary from server to server. For example, a web server will support one or more programming languages to allow you to write the programs required to implement this sort of functionality. A web server will often also have access to one or more database management systems allowing it to store and retrieve the information typically required to build a web page. For example, on a news based website, when you visit a web page, code on the web server might retrieve news items from a database and use them to construct the page you finally see.

Indicia uses a language on the server called PHP, chosen because it is very widely available on web servers, probably more so than any other language. Likewise Indicia websites built using Drupal, including Instant Indicia websites, require a database management system called MySQL which is also found on more web servers than any other database technology. This means that the software required to run your biological recording website can be installed on many low cost shared web accounts. PhpMyAdmin is a piece of web software which you can install on web servers (it is often provided on shared web servers). It is a web application that lets you perform management tasks on MySQL databases on a web server such as creating databases and tables or backing up the data.

However, all these technologies put together help, but it is still an enormous task to write the code required to build a large site. Developing sites this way doesn’t solve the problem of making site-wide changes such as the addition of a new menu either, though we could probably work out how to do that using some code. But worst of all, the task of editing a web page requires someone with programming skills which is clearly not cost effective in a real world scenario. The solution to all these problems is to use something called a content management system. A content management system (CMS) is a piece of software running on a web server that provides the functionality required to allow site editors to create, modify, delete and publish content. Rather than writing code for each web page, the site editor can access an administration interface which lets them type content straight into an editor, rather like when typing a document in a Word processor. A content management system typically also provides the following useful functionality:

  • Ability to install plugin modules to extend the functionality. For example rather than writing a weather widget or code for a site search, just install the module and it is done.
  • Ability to let users register, login and to control the functionality that is available to them. For example, only site editors are allowed to add or edit pages.

Clearly then, once a website grows beyond a simple site with a handful of static pages, using a content management system to manage the creation of content on the site is vastly preferable to writing the site’s pages directly in HTML.

There are a huge number of content management systems available which are based on a variety of different technologies and costing anything from nothing to hundreds of thousands of pounds. Fortunately there are excellent free ones which are capable of running very extensive and powerful websites. The benefits of integrating Indicia into a content management system are clear – the CMS can provide content editing and other miscellaneous functionality, whereas Indicia can provide online recording, reporting and other specialist facilities. For Indicia, we have elected to focus our efforts on a single CMS called Drupal for the following reasons:

  • Drupal is one of the most used free and open source content management systems.
  • Drupal is built using PHP and JavaScript so closely matches the toolset used for Indicia development.
  • Although Drupal has a higher learning curve than some CMS, it is also one of the most powerful.
  • There is a huge library of free modules available which extend the core functionality of Drupal for all sorts of purposes.
  • Drupal is widely used in the biodiversity “industry”, e.g. see the Biodiversity Informatics in Drupal group.
  • We felt that it would be better to focus available resources on a single, high quality CMS integration than to spread the available effort across several different CMS.

It is possible to use Indicia alongside many of the other available content management systems though of course it will require a bit more effort, since the Indicia project has already included development of extensive integration with Drupal in order to make setting up online recording sites as simple as possible.