ResponseMX Blog

I’ve just knocked up a little application that brings together the Google Latitude service with the Ordnance Survey OpenSpace API.

A number of guys in the team have signed up for Latitude and enabled sharing their location. Latitude provides the ability to request a users last know location as either a JSON or KML document; in this case I’m requesting the location of the guys as a JSON feed which is then simply displayed in the user list and on the OpenSpace map.

Clicking on a user in the user list simply centres the map and displays some information about their location including a reverse geocode and accuracy.

Give it a try: http://www.dottedeyes.com/latitude/

MyNeighbourhood Accessibility Upgrades

We’ve recently overhauled the West Midlands Police crime mapping website, MyNeighbourhood.info, with a number of enhancements aimed at improving usability and accessability. The site had received feedback to the effect of ‘great information, not very easy to understand’. So in combination with West Midlands Police and ourselves we set about redesigning the user interface to better communicate the information that was already in there, whilst taking the opportunity to improve the site’s accessibility for disabled users.

Usability

Existing feedback was combined with some informal interviewing to figure what was broken with the current site design. It became apparent after a few interviews that there were three major aspects of the design that were causing trouble: The site was too map-focused; The language was inconsistent and non-standard; The interface was cluttered and not very web-page like.

A new site design was invented, and our guinea pigs were taken through the new site to confirm we improved on our previous design. The site’s navigation was re-organised dramatically, a separate page being set aside for each set of figures we wanted to present for a neighbourhood. We moved summary information to the front and a big ‘table of crime’ next, as it turned out this is what users wanted to see most. All of the sites language was debated, picked over, changed ten times and then finally agreed upon. Overall, it made the site feel a lot more like a web-site and less like a computer game.

Accessibility

While we overhauled the design for the masses, we also tried to improve the user experience for disabled users and users without the latest software. We made the site using semantic markup, so that it is still usable in a text-based browser and can be interpreted by screen readers, we made the statistics available in the maps and charts available in a tabular view and we made sure the site degrades nicely when there is no java script or flash installed. Any functionality that was implemented using AJAX-type techniques was first developed with a traditional page reload, then enhanced with AJAX if available.

Summing Up

Since the site has gone live, we’ve had a lot of positive feedback from West Midlands Police and their users, as well as being a great learning experience for all of us.

In the past, if you used mapserver as the mapping engine, you could only use one ResponseMX server application inside Tomcat. This was due to the fact that mapserver uses native libraries, which can only be loaded once by any given process, rather than pure java libraries.

We have found a way to remove this restriction, which opens up a number of possibilities. For example, it allows different applications to be created for different user groups. We are already using this to allow us to host several different ResponseMX applications in our test environment.

The change requires a small code modification to the ResponseMX server. If you would like to run multiple ResponseMX servers on the same tomcat, please contact Dotted Eyes so we can supply you with a new version of ResponseMX server.

There is no configuration required, but you have to make the following changes to your software installation once you have the new server software.

Set up

Assuming you have two ResponseMX applications called rmxa and rmxb, you’ll need to do the following:

Copy the mapscript.jar file from the WEB-INF/lib folder of one of the ResponseMX applications to $TOMCAT_HOME/shared/lib

For example

cd /opt/app/apache-tomcat-5.5.17/webapps/rmxa/WEB-INF/lib
cp mapscript.jar /opt/app/apache-tomcat-5.5.17/shared/lib

Then for each ResponseMX application installation inside your tomcat, rename the mapscript.jar file so that it is not automatically loaded when ResponseMX starts.

For example

cd /opt/app/apache-tomcat-5.5.17/webapps/rmxa/WEB-INF/lib
mv mapscript.jar mapscript.jar-DO-NOT-LOAD
cd /opt/app/apache-tomcat-5.5.17/webapps/rmxb/WEB-INF/lib
mv mapscript.jar mapscript.jar-DO-NOT-LOAD

Restart tomcat and have fun with maps.

Troubleshooting

It is important that none of the applications try to load mapscript.jar from the WEB-INF/lib folder any more, so if the server won’t start or won’t produce maps, check each installed webapp for mapscript.jar first.

I’ve been busy this week enhancing ResponseMX’s database search functionality.

At the moment if you have spatial data in Oracle, SQLServer, MySQL or access databases you can configure ResponseMX to search your database records and locate points on your maps.

In ResponseMX 3 you’ll have more flexibility when configuring searches. You’ll be able to specify how records are matched. Currently if you enter ‘Abbey’ into the search form, you’ll only find records that start with the word ‘Abbey’. However, if you add <matchmethod>contains</matchmethod> inside the <search/> tag, the word Abbey could appear anywhere in field that is being searched, so if you were searching a list of addresses you’d find ‘Mary’s Abbey Road’ as well as any Abbey Roads, Abbey Streets or Abbey Avenues you might have in your database.

Also, you’ll be able to conditionally filter out certain records. This can be useful when generating pre-populated searches. Say for example you have the locations of pharmacists in your database but wanted to have two pre-populated searches, one showing those offering evening and weekend services and another showing those with daytime opening hours. In ResponseMX 3 you’ll be able to add something like the following to your search xml:

<filter>
<field>Out_Of_Hours</field>
<string>Y</string>
</filter>

This will change the search so that unless the Out_Of_Hours field contains a Y, the record will not be displayed in the search results.

By the way, both these changes will work the same if you are using database layers or are searching layers drawn from .TAB files and will work the same if you are using MapXtreme Java or MapServer.

Jon

We’re looking to recruit a Front End Web Developer into the ResponseMX team.

We’re looking for someone who is familiar with Object Orientated JavaScript and ActionScript; can create good looking, usable and accessible content and is motivated and willing to learn all about this spatial stuff.

See the careers section for more details.