Archive for the ' Apache' Tag

Hosting more than one WordPress blog on your website

Wednesday, March 12th 2008   
Topics: Web Development, Web Technologies, Web Tools    Tags: , , , , , , , ,
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An idea recently popped into my head for my hillwalking website: collecting a listing of bus services of use and interest to hillwalkers. Being rural, these services may not get the publicity that they deserve. In addition, they are generally subsidised so any increase in their patronage can only help maintain their survival.

Currently, the list lives on a page in the blog but another thought has come to mind: using WordPress to host the list as a series of log entries, a sort of blog if you like. Effectively, that would involve having two blogs on the same website it can be done. One way is to set up up two instances of WordPress and they could work from the same database; the facility for this is allowed by the ability to use different table prefixes for the different blogs so that there are no collisions. There’s nothing to stop you having two databases but your hosting provider may charge extra for this. This set up will work but there is a  caveat: you now have two blogs to maintain and, with regular WordPress releases, that means an extra overhead. Apart from that, it’s a workable approach.

Another option is to use WordPress MU. That would cut down on the maintenance but there are costs here too. It’s need of virtual hosts is a big one. If my experience is any guide, you probably need a dedicated server to go down this route and they aren’t that cheap. I needed to do a spot of Apache configuration and some editing of my hosts file to get my own installation off the ground; I don’t reckon that would be an option with shared hosting. Once I sorted out the hosts with a something.something.else address, set up was very much quick and easy.

Apart from a tab named Site Admin, the administration dashboard isn’t at all that different from a standard WordPress 2.3.x arrangement. In the extra tab, you can create blogs and users, control blogs and themes as well upgrade everything in a single step. Themes and plugins largely work as usual from an administration point of view. With plugins, you have just to try them and see what happens; one adding FCKEditor threw an error while the editor window was loading but it otherwise worked OK. I had no trouble at all with themes so all looks very well on that front.

Importing and editing posts worked as usual but for two perhaps irritating behaviours: tags are, not unreasonably, removed from titles and inline styled and class declarations are removed from tags in the body of a blog entry. Both could be resolved by post processing in the blog’s theme but the Sniplets plugin allows a better way out for the latter and I have been putting it to good use.

In summary, WordPress MU worked well and looks a very good option for multi-blog sites. However, the need for a dedicated server and the quirks that I have seen when it comes to handling post contents keep me away from using it for production blogs for now. Even so, I’ll be retaining it as a test system anyway. As regards the country bus log, I think that I’ll be sticking with the blog page for the moment.

Setting up a test web server on Ubuntu

Thursday, November 1st 2007   
Topics: Databases, Linux, Operating Systems, Programming, Scripting, Software, Web Development, Web Technologies    Tags: , , , , , , , ,
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Installing all of the bits and pieces is painless enough so long as you know what’s what; Synaptic does make it thus. Interestingly, Ubuntu’s default installation is a lightweight affair with the addition of any additional components involving downloading the packages from the web. The whole process is all very well integrated and doesn’t make you sweat every time you to install additional software. In fact, it resolves any dependencies for you so that those packages can be put in place too; it lists them, you select them and Synaptic does the rest.

Returning to the job in hand, my shopping list included Apache, Perl, PHP and MySQL, the usual suspects in other words. Perl was already there as it is on many UNIX systems so installing the appropriate Apache module was all that was needed. PHP needed the base installation as well as the additional Apache module. MySQL needed the full treatment too, though its being split up into different pieces confounded things a little for my tired mind. Then, there were the MySQL modules for PHP to be set in place too.

The addition of Apache preceded all of these but I have left it until now to describe its configuration, something that took longer than for the others; the installation itself was as easy as it was for the others. However, what surprised me were the differences in its configuration set up when compared with Windows. Same software, different operating system and they have set up the configuration files differently. I have no idea why they did this and it makes no sense at all to me; we are only talking about text files after all. The first difference is that the main configuration file is called apache2.conf in Ubuntu rather than httpd.conf as in Windows. Like its Windows counterpart, Ubuntu’s Apache does uses subsidiary configuration files. However, there is an additional layer of configurability added courtesy of a standard feature of UNIX operating systems: symbolic links. Rather than having a single folder with the all configuration files stored therein, there are two pairs of folders, one pair for module configuration and another for site settings: mods-available/mods-enabled and sites-available/sites-enabled, respectively. In each pair, there is a folder with all of the files and another containing symbolic links. It is the presence of a symbolic link for a given configuration file in the latter that activates it. I learned all this when trying to get mod_rewrite going and changing the web server folder from the default to somewhere less susceptible to wrecking during a re-installation or, heaven forbid, a destructive system crash. It’s unusual but it does work, even if it takes that little bit longer to get things sorted out when you first meet up with it.

Apart from the Apache set up and finding the right things to install, getting a test web server up and running was a fairly uneventful process. All’s working well now and I’ll be taking things forward from here; making website Perl scripts compatible with their new world will be one of the next things that need to be done.

An unexpected side effect

Friday, June 29th 2007   
Topics: Web Development    Tags: , , ,
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I recently posted about using mod_rewrite to block access to your images from all but the websites to which you want access to be available. Following so doing, I discovered that my FAVICON had disappeared from Firefox’s address. As it turned out, it was easy to fix and that is covered in another recent post.

More on mod_rewrite

Monday, June 25th 2007   
Topics: Web Development    Tags: ,
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Today, I caught sight of an article on anti-plagiarism tools at The Blog Herald and among the tricks was to use mod-rewrite to stop people "borrowing" both your images and your bandwidth. The gist is that you set up one or more conditions that exclude websites from the application of a rule forbidding access to images; the logic is that if the website referencing an image is not one of the websites listed in the conditions, then it doesn’t get to display any of your images.

RewriteCond %{HTTP_REFERER} !^http://(www\.)?awebsite.com(/)?.*$ [NC]

RewriteRule .*\.(gif|jpe?g|png|bmp)$ [F,NC]

The wonders of mod_rewrite

Sunday, June 24th 2007   
Topics: Web Development    Tags: ,
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When I wrote about tidying dynamic URL’s a little while back, I had no inkling that that would be a second part to the tale. My discovery of mod_rewrite, an Apache module that facilitates URL translation. The effect is that one URL is presented to the user in the browser address bar, and the exact same URL is also seen by search engines, while another is passed to the server for processing. It might sound like subterfuge but it works very well once you manage to get it set up properly. The web host for my hillwalking blog/photo gallery has everything configured such it is ready to go but the same did not apply to the offline Apache 2.2.x server that I have going on my own Windows XP box. There were two parts to getting it working there:

  1. Activating mod-rewrite on the server: this is as easy as uncommenting a line in the httpd.conf file for the site (the line in question is: LoadModule rewrite_module modules/mod_rewrite.so).
  2. Ensuring that the .htaccess file in the root of the web server directory is active. You need to set the values of the AllowOverride directives for the server root and CGI directories to All so that .htaccess is active. Not doing it for the latter will result in the an error beginning with the following: Options FollowSymLinks or SymLinksIfOwnerMatch is off which implies that RewriteRule directive is forbidden. Having Allow from All set for the required directories is another option to consider when you see errors like that.

Once you have got the above sorted, adding this line to .htaccess: RewriteEngine On. Preceding it with an Options directive to ensure that FollowSymLinks and SymLinksIfOwnerMatch are switched on does no harm at all and may even be needed to get things running. That done, you can set about putting mod_write to work with lines like this:

RewriteRule ^pages/(.*)/?$ pages.php?query=$1

The effect of this is to take http://www.website.com/pages/input and convert it into a form for action by the server; in this case, that is http://www.website.com/pages.php?query=input. Anything contained by a bracket is assigned to the value of a system-named variable. If you have several bracketed sections, they are assigned to sequentially numbered variables as follows: $1 for the first, $2 for the second and so on. It’s all good stuff when you get it going and not only does it make things look much neater but it also possesses an advantage when it comes to future-proofing too. Web addresses can be kept constant over time, even if things change behind the scenes. It means that returning visitors will find what they saw the last time that they visited and surely must ensure good karma in eyes of those all important search engines.

A web development toolbox

Friday, March 23rd 2007   
Topics: Web 2.0, Web Development, Web Tools    Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,
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Having been on a web building journey from Geocities to having a website with my own domain hosted by Fasthosts, I should come as no surprise that I have encountered a number of tools and technologies over this time and that my choices and knowledge have evolved too. I’ll muse over the technologies first before going on to the tools that I use.

Technologies

XHTML

When I started building websites, HTML 4 was not long in existence and I devoured most if not all of Elizabeth Castro’s Peachpit Visual Quickstart guide to the language in a weekend. Having previously used fairly primitive WYSIWYG tools like Netscape Composer and Claris Home Page, it was an empowering experience and the first edition (it’s now on its third) of Jennifer Niederst Robbins’ Web Design in a Nutshell took things much further, becoming something of a bible for a number of years.

When it first appeared, XHTML 1.0 wasn’t a major change from HTML 4 but its stricter more XML compliant syntax was meant to point the way to the future and semantic mark up was at its heart at least as much as it was for HTML 4. XHTML 2.0 is on the horizon and after the modular approach of XHTML 1.1 (which I have never used), it will be interesting to see how it develops. Nevertheless, there is a surprising development in that some people are musing over the idea of having an HTML 5. Let’s hope that the (X)HTML apple cart doesn’t get completely overturned after some years of relative stability. I still bear scars from the browser wars raging in the 1990’s and don’t want to see standards wars supplanting the relative peace that we have now. That said, I don’t mind peaceful progression.

CSS

Only seems to be coming into its own in the last few years and is truly an amazing technology in spite of the hobbles that MSIE places on our ambitions. CSS Zen Garden has been a major source of ideas; I wouldn’t have been able to customise this blog as much as I have without them. I was an early adopter of the technology and got burnt by inconsistent browser support; Netscape 4 was the proverbial bête noir back then, fulfilling the role that MSIE plays today. In those days, it was idea of controlling text display and element backgrounds from a single place that appealed. Since then, I have progressed to using CSS to replace table-based layouts and to control element positioning. It can do more…

JavaScript

Having had a JavaScript-powered photo gallery before my current Perl-driven one, I can say that I have definitely sampled this ever pervasive scripting language. Being a client side language rather than a server side one, it does place you rather at the mercy of the browser purveyors and it never ceases to amaze me that there is a buzz around AJAX because of this. In fact, the abundance of AJAX cross-browser function libraries is testimony to need for browser-specific code. Despite my preferences for server-side scripting, I still find a use for JavaScript and its main use for me these days is to dynamically control CSS elements to do such things as control the height of a page element or whether it is shown or not. Apparently, CSS may get some dynamic capabilities in the future and reduce my dependence on JavaScript. In the meantime, Jeremy Keith’s DOM Scripting (Friends of Ed) will prove as much of an asset as it has done.

XML

These days, a lot of the raw data underlying my personal website is stored in XML. I did try to dynamically transform the display of the XML into something meaningful with CSS and XSLT when I first scaled its dizzy heights but I soon resorted to other techniques. Browser support and the complexity of what I required were the major contributors to this. The new strategy involved two different approaches. The first was to create PHP/XHTML pages from the precursor XML off-line and this is how I generate the website’s directory pages. The other one is to process the XML as text to dynamically supply an XHTML page as the user visits it; this is the way that the photo gallery works.

Perl

This still powers all of my photo gallery. While thoughts of changing it all to PHP linger, there is a certain something about the Perl language that keeps it there. I suppose it is that PHP is entangled in the HTML while Perl encases the whole business and I am reasonably familiar with its syntax these days which is why it still does a lot of the data processing grunt work that I need.

PHP

PHP is everywhere these days, though it doesn’t attract quite the level of hype that used to be the case. It still appears with its sidekick MySQL in many website applications. Blogging software such as WordPress and content management systems like Drupal, Mambo and Joomla! wouldn’t exist without the pair. It appears on my website as the glue that holds my visitor directories together and is the processing engine of my Wordpress blog. And if I ever get to a Drupal element to the site, by no means a foregone conclusion though I am spending a lot of time with it at the moment, PHP will continue its presence in my web site scripting as it powers that too.

Applications

Macromedia HomeSite

I have a liking for hand coding so this does most of what I need. When Macromedia (itself since taken over by Adobe, of course) took over Allaire, HomeSite sadly lost its WYSIWYG capability but the application still soldiers on even though Dreamweaver offers a lot to code cutters these days. Nevertheless, it does have certain advantages over Dreamweaver: it is a fleeter beast to start up and colour codes Perl syntax.

Macromedia Dreamweaver

There was a time when Dreamweaver was solely a tool for visual web page development but the advent of Dreamweaver UltraDev added server side development capabilities to the Dreamweaver family. These days, there is only one Dreamweaver version but UltraDev’s capabilities still live on in the latest version and I would not be surprised if they were taken further in these database-driven times.

Nowadays, Dreamweaver isn’t an application where I spend a great deal of time. In former times, when my site was made up of static HTML pages, I used Dreamweaver a lot even if its rendering capabilities were a step behind the then current browser versions. I suppose that it didn’t fit the way in which I worked but its template driven work flow would have been a boon back then.

However, my move from a static site to a dynamic one, starting with my photo gallery, has meant that I haven’t used it as much since then. However, with my use of PHP/MySQL components on my site. its server side abilities could get a the level of investigation that its PHP/MySQL capabilities allow.

Altova XMLSpy Professional

Adding MySQL databases to my web hosting costs money, not a lot but it could be spent on other (more important?) things. Hence, I use XML as the data store for my photo gallery and XML files are pre-processed into XHTML/PHP pages for my visitor directories prior to uploading onto the server.

I use XMLSpy to edit and manage the XML files that I use: its ability to view XML in grid format is killer feature as far as I am concerned and XML validation also proves very useful; particularly with regarding to ensuring that DTD’s and XML files are in step and for the correct coding of XSLT files. There are other features that I need to explore and that would also take my knowledge of the XML further to boot, not at all a bad thing.

Saxon

For processing XML into another file format such as XHTML, you need a parser and I use the free version of Saxon to do the needful, Saxonica offer commercial versions of it. There is, I believe, a parser in XMLSpy but I don’t use it because Saxon’s command line interface fits better into my work flow. This is a Perl-driven process where XML files are read in and XSLT files, one per XML file, built before both are fed to Saxon for transforming into XHTML/PHP files. It all works smoothly and updating the XML inputs is all that is required.

AceFTP

If I were looking for an FTP client now, it would be FileZilla but AceFTP has served me well over the last few years and it looks as if that will continue. It does have some extra features over FileZilla: transfers between remote sites, and scheduling, for example. I have yet to use either but they look valuable.

Hutmil

In bygone days when I had loads of static HTML files, making changes was a bit of a chore if they affected every single file. An example is changing the year on the copyright message on the page footers. Hutmil, which I found on a magazine cover-mounted disc, was a great time saver in those days. Today, I achieve this by putting this information into a single file and get Perl of PHP to import that when building the page. The same “define once, use anywhere” approach underlies CSS as well and scripting very usefully allows you to take that into the XHTML domain.

Apache

Apache is ubiquitous these days and both the online and offline versions of my site are powered by it. It does require some configuration but it is a very powerful piece of kit. The introduction of 2.2.x meant a big change in the way that configuration files were modularised and while most things were contained in a single file for 2.0.x, the setting are broken up into different files in 2.2.x and it can take a while to find things again. Without having it on my home PC, I would not be able to use Perl, PHP or MySQL. Apart from this, I especially like its virtual site capability; very useful for offline development.

WordPress

My hosting supplier offers blogs on Blogware but that didn’t offer the level of configuration that I would have liked. It is true that this is probably true of any host of blogs. I can’t speak for Blogger but Wordpress.com does have its restrictions too. In order to make my hillwalking blog fit in with the appearance of my photo gallery, I went popped over to WordPress.org to download Wordpress so that I could host a blog myself and have maximum control over its appearance. WordPress supports themes so I created my own and got my blog pages looking as if they are part of my website, rather than looking like something that was bolted on. Now that I think of it, what about WordPress supporting user created themes? I support that there is the worry of insecure PHP code but what about it?

MySQL

I am between minds on whether this is a technology or a tool. The SQL language certainly would be a technology but I am not so clear on what MySQL would be. In any case, I have classed it as a tool and a very useful one at that. It is the linchpin for my WordPress blogs and, if I go for a content management system like Drupal, its role would surely grow. While I do have a lot of experience with using SAS SQL and these helps me to deal with other varieties, there is still a learning curve with MySQL that gets me heading for a good book and Kofler’s The Definitive Guide to MySQL5 (Apress) seems to perform more than adequately in this endeavour.

Paint Shop Pro

As someone who hosts an online photo gallery, it won’t come as a surprise that I have had exposure to image editors. Despite various other flirtations, Paint Shop Pro has been my tool of choice over the years but it is now set to be usurped by a member of Adobe’s Photoshop family. Paint Shop Pro does have books devoted to it but it seems that Photoshop gets better coverage and I feel that my image processing needs to be taken up a gear, hence the potential move to Photoshop