Back to Philip's IMMA page.

Interactive IMMA editor

When making IMMA files from newly digitised observations I wanted to be able to plot the observation positions on a map, and examine and edit the records that looked doubtful. Google maps offers a technology ideally suited to this, so I made an IMMA viewer/editor that can be used in any modern web browser.

The editor requires four components:

  1. A JavaScript class for handling IMMA records.
  2. A Javascript program that displays a set of records as text and on a map.
  3. A web page to run the program and display the data.
  4. A Javascript program to support interactive editing of a single record.
  5. A web page to run the single record editing program.

Use is fairly self-explanatory: load data by selecting the links in the sidebar, when the data has loaded, select observations by clicking on either the markers on the map or the data lines in the bottom pane; clicking again on a selected record will open an editor window for that record. The map scrolls and zooms like any other Google map.

Note that not there will not usually be a marker visible on the map for every record: a subset only are shown, for speed and clarity. Zooming in on an area will reveal more markers. (Records without a valid lat and long are never shown on the map.)

Limitations

I've tested it in Firefox (Linux and Mac), Safari (Mac) and Opera (Mac). In theory it should work in IE, but I haven't been able to test it, and experience suggests that it won't work. Loading data is slow in all browsers; scrolling the map and selecting records is slow in Firefox 2 (much better in Firefox 3, Safari and Opera). Even with a fast computer and a broadband internet link, 10,000 records will bring the computer to its knees, and smaller files are strongly recommended. (There are no hard limits on size - if you have enough patience files of any size should work). If you are using Firefox, set the parameter "dom.max_script_run_time" (from about:config) to a large number (>100) or you will get lots of pop-up windows warning you that a script is slow to respond.

Customisation

To change the appearance of the page, or make it work with a different set of IMMA files, copy the main HTML file to another server and edit it according to the instructions in the HTML source.