Offline App using Open Street Map and HTML5

Question

We want to create an offline map application and here's my thoughts on how I will implement it:

• Download map data from OSM (XML)
• Store OSM map data on the client browser
• Render map using an API

My problems:

• Downloading data from OSM, they only allow a small portion of the map to be exported, and I don't want to download 30GB database. Is there an application that can download map data of a whole country for me?
• Rendering the map, what is the best JavaScript API for OSM? It should allow working offline and preferably, those with capability of rendering routes.

Answer 1

As already mentioned by SlavenRezic there are country and area extracts available. The only reason why exporting large areas via the main API isn't allowed are performance reasons because that would involve running a rather heavy query on the main database. Alternatively you could download the whole planet and split it into geographical regions yourself or try using the Overpass API which is significantly faster than the main API.

For rendering a map there are various libraries available. Choose the one that fits your needs. I'm not sure if anyone is able to display a route because their main purpose is rendering. But maybe you can use LeafLet or OpenLayers to create an overlay on top of your rendered map.