Mentaer: Created page with '== The Problem == I imported a shapefile and put its contents in a jump FeatureCollection. With these Features I’m doing some calculations and now I want to add the result as …'

2009-10-18T21:47:27Z

Created page with '== The Problem == I imported a shapefile and put its contents in a jump FeatureCollection. With these Features I’m doing some calculations and now I want to add the result as …'

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== The Problem ==

I imported a shapefile and put its contents in a jump FeatureCollection. With these Features I’m doing some calculations and now I want to add the result as a new attribute to the features, so I can export it as a new shapefile.

So basically I want to add a new field to attribute table and fill it with values.

But I just can’t figure it out! I played with with the addAttribute Method of the FeatureSchema, but that didn’t really work.

== The Solution ==

you need to do the following:
* create a new FeatureSchema based on the old one
* create a new FeatureDataset with that FeatureSchema
* copy every feature from old to new FeatureSchema (use the function FeatureCollectionTools.copyFeatureAndSetFeatureSchema for this)
* add the features to the new FeatureSchema
* display

a code example can be found below

Another option, with respect to updating, may be to look on how the "View / Edit Schema"-Function from the mouse menu works (class: com.vividsolutions.jump.workbench.ui.plugin.ViewSchemaPlugIn)

'''Example'''
* the input is pFeatures
* I assume that this code is in the "run" or "execute" method of a plugin.

<pre>
FeatureSchema fsNew=(FeatureSchema)pFeatures.getFeatureSchema().clone();
fsNew.addAttribute("huhuattribut",AttributeType.STRING);
resultFC = new FeatureDataset(fsNew);
//-- set the attribute for every feature in the collection
for (Iterator iterator = pFeatures.iterator(); iterator.hasNext();) {
Feature ftemp = (Feature) iterator.next();
//-- copies the original feature to the new feature schema
Feature fcore = FeatureCollectionTools.copyFeatureAndSetFeatureSchema(ftemp, fsNew);
//-- in case the geometry changed:
fcore.setGeometry(core);
//-- set the new attribute
fcore.setAttribute("huhuattribut", "helloworld");
resultFC.add(fcore);
}
//-- display
context.addLayer(StandardCategoryNames.RESULT, "newLayer", resultFC);
</pre>

Extending a FeatureCollection by Adding new Attributes - Revision history

Mentaer: Created page with '== The Problem == I imported a shapefile and put its contents in a jump FeatureCollection. With these Features I’m doing some calculations and now I want to add the result as …'