Squashing JavaScript Bugs, Grassroots Mapping, GeoJSON and KML

A JavaScript console is an extension that throws a red flag if the JavaScript on your page derails, and shows you where the problem is.

<ndoiron> Firefox, you can do Ctrl+Shift+K. Less than that, http://getfirebug.com/

<seanhorgan> in the world of javascript programming/debugging, firebug is an essential tool to get very familiar with it

<seanhorgan> if you click on the little bug symbol on the bottom right of your firefox window, it should split the screen with the bottom half showing the firebug console

<ndoiron> click the Script tab, then the down arrow, to set JavaScript to Enabled

<seanhorgan> Google Chrome has a developer mode (ctrl-shift-j, or ctrl-option-j on Apple) that is similar

Grassroots Mapping : Who, What, When, Where, Why?

<ndoiron> went to open source conference at State Dept... they are quite interested in mapping

<DoRight> Get more resources for us?

<ndoiron> got to meet some of the people behind GrassrootsMapping.org -- they go beyond satellite maps by flying balloons

<introvert> why?

<ndoiron> higher-resolution, more recent, and can be open-sourced

<ndoiron> they took great photos during the BP Oil Spill and now some of those are in Google Maps

<introvert> how old are the satellite images

<ndoiron> introvert: if you have Google Earth you can find exactly how old their images are... it can be a few years

<rrosso> huh, that's cool. do they use GPS hand-held devices, or rely just on their photographs?

<ndoiron> rrosso: they put thousands of photos online, and people vote on whether they're good quality... I will have to post a link to that

<ndoiron> then they use US gov or Google sat maps to line them up

<ndoiron> and "stitch" them together

<ndoiron> website to vote on photos http://mapmill.org/

<DoRight> Yeah, gorgeous fotos!

<DoRight> But if they use google data, does that keep it from being used in opensource?

<ndoiron> I agree, using Google would make it non-free. But if they're in the US they can use some USGS satellite maps which are free

Loading Maps through JSON or KML

<seanhorgan> I'm trying to host a page with a map that draws icons based on locations from a file

<seanhorgan> is it best to store the data in a json format?

<seanhorgan> i don't have a concrete example for you (yet), but I'd like to iterate through an array of points and plot them on the map

<ndoiron> it does have GeoJSON for input. Try that format or KML, which people can view in Google Earth

<seanhorgan> can OSM handle KML?

Leaflet.js can. More on this later.

Get Icon URLs

<introvert> I have one last q- how do I get the filename for icons?

<ndoiron> I don't know if this works in your browser... right click ( two-finger click on map ) and you should have 'Copy Image URL' or 'Copy Image Location'