A Styled Layer Descriptor (SLD) is an XML schema specified by the Open
Geospatial Consortium (OGC) for describing the appearance of map layers. It is
capable of describing the rendering of vector and raster data. Using SLD
provides a lot of convenience when working with GIS as it allows to save the layer
style separately from the map (layer) and to use it in other projects or other softwares.
In this regard, recently in OpenWebGIS the new feature
has been added which allows to change the legend (style) vector layers of the
map using SLD files. OpenWebGIS users can apply their SLD files, that were
created by other software, and they can also export the layer style, that was
created with the help of OpenWebGIS, in the SLD file and use it in other Geographic Information System
(GIS)
programs such as the QGIS. To import your legend (style) in a single SLD file you
need to select the menu item "Edit-> Import / Export SLD legend".
Then select layer name (in this case, "Cities") from the list
"Select the Layer:" which style you want to export to a SLD file and
click "Export legend to SLD" (see Figure 1).
After clicking this button the window opens with the file contents, which you can save on your hard drive by pressing the "Save Data" (see Figure 2).
Figure 2. |
Then you can use this file, for example, for
changing the "Cities" layer style previously added to QGIS. To do this, in the QGIS
interface right click on the layer name to open the context menu and select the
menu item "Properties" (see Figure 3).
Figure 3. |
In the window that appears, click "Style" button, then "Load
Style" and set the path to the saved SLD file (see Figure 4), then click “Apply”
button and you will see the result shown
in Figure 5.
Figure 4. |
Figure 5. |
The above describes a simple example, when the
style is a "Single symbol". It works similarly, if in OpenWebGIS the sophisticated
style was created - for example, when the size and color of the points,
representing cities, vary depending on the size of the population living in
them. This you can see in this video:
Figure 6. |
Then open
OpenWebGIS in your browser, select the menu item "Edit-> Import /
Export SLD legend". In the window that appears, enter the name of the
layer which style you want to change and using the button "Browse"
select SLD file that you created and saved using QGIS. And finally, click "Load
(import) SLD". You will see the result shown in Figures 7 and 8.
Figure 7. |
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