leafletpyqgisqgisstyle
I have a polygon layer in QGIS that I have applied a random color style to each polygon. Under Layer Properties -> Style I selected a Categorized style and then generated a random color ramp. I added a color column to the layer table. Is there a way to automatically copy the color assigned in the style to the color column for each polygon in the form "#ff0000".
Ultimately, I want to export it as a GeoJSON layer and import it into a leaflet map. The color column will set the color in leaflet.
The issue is that the renderer class is QgsCategorizedSymbolRendererV2 instead of QgsGraduatedSymbolRendererV2. So, I categorized next shapefile by FID field:
and identical code (Germán Carrillo' script ) was run at the Python Console of QGIS:
prefix = "'"
layer = iface.activeLayer()
attr = layer.rendererV2().classAttribute()
attrColor = 'color' # Name of the field to store colors
fieldIndex = layer.dataProvider().fieldNameIndex(attrColor)
attrFeatMap = {}
for cat in layer.rendererV2().categories():
expr = "\""+attr+"\"="+prefix+unicode(cat.value())+prefix
for f in layer.getFeatures(QgsFeatureRequest(QgsExpression(expr))):
attrMap = { fieldIndex : cat.symbol().color().name()}
attrFeatMap[ f.id() ] = attrMap
layer.dataProvider().changeAttributeValues( attrFeatMap )
As you can see at the next image, result was completely satisfactory (I am not getting any error):
Editing Note:
This is the code for Graduated Symbol Renderer:
layer = iface.activeLayer()
provider = layer.dataProvider()
renderer = layer.rendererV2()
feats = [ feat for feat in layer.getFeatures() ]
values = [ feat.attribute('FID') for feat in feats ] #change for 'NDVI' in case of NDVI field
n = len(feats)
color_feats = [ renderer.symbolForValue(value).color().name() for value in values ]
idx = layer.fieldNameIndex('color')
for i, feat in enumerate(feats):
new_values = {idx : color_feats[i]}
provider.changeAttributeValues({i:new_values})
After running it at the Python Console of QGIS, values at 'color' field were placed as expected.
By using 'NDVI' field it also works perfectly:
This seems to be a highly ranked result on search engines so I thought I would stop in and update + add to it.
The Leaflet documentation seems to have been updated since the original answer was provided (v1.03 vs v1.40 at the time of this posting), but even then the documentation on polylines hasn't ever identified any style options outside of the 3 used in the example (that the OP mentions). That makes finding the rest of the options somewhat time consuming. Those options are actually inherited from Path and that's where you'll find the documentation on them. I've attached an image of the options available and tested as many of them as I could to see if they work (2nd column), but only in so far as my current project can make use of them.
NOTE the last item, 'className'. This will allow you to set a CSS class name and use CSS (or SASS) to style your Polyline instead of hard coding it. It should also be noted that CSS rules seem to override the Leaflet style options you configure in your code. Unfortunately, that still doesn't get you borders, ie. border: 1px solid red; doesn't work. This is due to the fact that these aren't HTML elements, but rather SVG.
SVG doesn't recognize the concept of a "border" aka a line around an object. A Polyline is already a "line". SVG does recognize the concept of fill and stroke, however, which can be used to achieve a border-like effect. If you draw a polygon around the polyline and set the stroke to your desired border style and the fill color to your desired line color you'll get a "border". You can read more on that approach here: https://stackoverflow.com/questions/36132689/how-to-convert-polyline-with-weight-to-polygon-in-leaflet
And in text those Path options are:
Best Answer
You could use PyQGIS for that (not sure is the best solution for it, though).
Assuming your layer has a
colorfield (type: string), select (or activate) the layer in the QGIS ToC, open the QGIS Python console, and copy this code snippet:After running it, you'll obtain this:
Let me know if you face any problem.