Can QGIS generate a has-attribute map that composed of several .shp maps?
I'm using QGIS-2.4.0 API to develop application.
I need a map that composed of several vector layers. If only this, it can be done by merge in QGIS, but I need more for that: the map(or project?) I want is composed of several layers, each layer has its own attributes, such as style: color/labels, the visibility of scale dependent. For example, the map MYMAP I made is composed of city.shp layer, river.shp layer, road.shp layer. When scale is changed, it displays different from city to river,road. I don't think this can be done by merge only.
It can be done by the software QGIS, but in API development, it is difficult to do such things. So I think there got be a better way, for now I think it can be done by:
1.A composed map. A map that composed by several .shp maps, and their attributes, make it in QGIS software and use the map in apps. In apps, it can load the map and the rest things are same as a single map. 2.A project. A project that composed by these things, this also be done in QGIS software. In apps, it can load project, but at the same time, the .shp maps used in project will be needed too.
I don't know if I make my point clear, and I don't know how to do it for my point, or if there is a better way to do it, any advice appreciated!