Conference Paper

During last year, situation on JavaScript mapping frameworks market has changed dramatically. There are several new projects at hand, which can be used for visualization of geodata in the web browser environment. Also technologies of common web browsers used for data rendering have dramatically changed. WebGL is common thing, as well as Canvas. Vector data can be rendered faster than ever, we are able to display n×10000 of vector features in web browser, while two years ago, only hundreds of features were still usable. Also touch devices, such as tablets, are very common now, which was not the case only a few years ago. 3D visualization is possible in both real 3D as well as 2.5D mode.

Some people said about the popular OpenLayers 2.x library, that they considered it being unnecessarily big and complicated. Truth is, that OpenLayers was (and still is) the only JavaScript GIS library around. For those, who did not need its advanced GIS features, it might be looking complicated.

Several other projects have started to think about the vector data rendering in different way, like Leaflet or D3.js to name some of them. Also OpenLayers 3 started to be written from scratch. OpenLayers 3 seems to be the most promising and advanced GIS mapping framework around. Though still beta (this abstract is submitted in April 2014), the library has also enough functionality, so it can be used for serious web mapping projects.

Since it is written with Google Closure library, it can be complied with only necessary amount of code, which is later compressed effectively.

Geosense mapping portal is used for creation of rich mapping applications using OpenLayers 3 and Closure library. During testing phase, we tried to render 20 to 80 thousand vector features in various libraries (OL2, Leaflet, OL3) using various rendering techniques. OpenLayers 3 was always the fastest library, regarding feature rendering. It is possible to use it for visualisation of n×10000 vector features, which are dynamically styled on the client. Also basic client-side analysis is possible (feature selection, filtering).

The mapping portal introduces several GUI elements, such as data viewer, carousel switcher for various mapping topics. Also some tools, like (classical) area and distance measuring as well as feature filtering or editing on the client side.

With help of OpenLayers 3, web developers are able to customize final application for the purpose, it has been designed for. No unnecessary JavaScript code is transferred to the client. Touch devices are also supported very well. We are looking forward to see OpenLayers 3 growing.