Python script to create an example of data that can be displyaed in DARIAH geo-browser <http://dev2.dariah.eu/e4d/>, a tool to visualize data in time and space. Data are drawn from the Gazetteer and the Opac (library catalogue) of the German Archaeological Institute (DAI). This dataset contains data about publications related to the Limes groupe…

gistfile1.py

import json
import urllib
import urllib2
import sys
import codecs

"""
Author: Matteo Romanello, <mro@dainst.de>
"""

def to_KML(place_name, coord, date, desc):
  """
	This function exports data to KML format
	"""
	
	template = """<Placemark>
      <name>%s</name>
      <Point>
        <coordinates>%s,%s</coordinates>
      </Point>
      <TimeSpan>
        <begin>%s</begin>
        <end>%s</end>
      </TimeSpan>
	  <description><![CDATA[
	%s
	]]></description>
    </Placemark>"""%(place_name,coord[0],coord[1],date,date,desc)
	return template

def get_related_publications(zenon_url = "http://highgrass.uni-koeln.de/elwms-zenon/search", key = None):
	"""
	This function fetches publication from Zenon, DAI's opac, using `key` as search key and by querying its RESTful API.
	In this context we used as search key the subject entry in the thesaurus corresponding to a given place in the Limes.
	"""
	result = []
	if(key is not None):
		zenon_params = {'q':'f999_1:%s'%key,'limit': 1000}
		zenon_full_url = "%s?%s"%(zenon_url,urllib.urlencode(zenon_params))
		zenon_data = urllib2.urlopen(zenon_full_url)
		js_publications = json.load(zenon_data)
		if(js_publications.has_key('data')):
			for pub in js_publications['data']:
				temp = {}
				temp['id'] = pub["id"]
				temp['title'] = pub["title"]
				temp['author'] = pub["author"]
				temp['date'] = pub['imprint'].replace('.','') # here we need to have some more sophisticated normalization
				temp['zenon_id'] = pub['id']
				temp['link'] = "http://testopac.dainst.org/&#35;book/%s"%temp['zenon_id']
				result.append(temp)
	return result

def get_places(url = "http://gazetteer.dainst.org/search.json"):
	"""
	This function retrieves geo-data for Limes locations from DAI's gazetteer using its RESTful API. 
	"""
	result = []
	# here is about querying the gazetters and getting the places related to the Limes
	params = {'limit': 1000, 'q': 'tags:limes'} # limit param is very important here to get the full results
	url_values = urllib.urlencode(params)
	full_url = "%s?%s"%(url,url_values)
	data = urllib2.urlopen(full_url)
	js_places = json.load(data)
	for pl in js_places['result']:
		if(pl.has_key('prefLocation')):
			temp = {}
			temp['coord'] = pl['prefLocation']['coordinates']
			temp['name'] = pl['prefName']['title'] # there could be multiple names here in diff languages
			temp['id'] = pl['@id']
			temp['subject_headings'] = [id['value'] for id in pl['identifiers'] if id['context']==u'zenon-thesaurus']
			temp['gazlink'] =  temp["id"].replace("#","&#35;")
			result.append(temp)
		else:
			print >> sys.stderr, "Skipped %s as it has no coordinates"%temp['id']
	return result

def main(ofname="output.kml"):
	pubs = []
	places = get_places()
	file = codecs.open(ofname,'w','utf-8')
	
	metadata = """
	<ExtendedData xmlns:dc="http://purl.org/dc/elements/1.1/">
                 <dc:description>
				This dataset contains data about publications related to the Limes grouped by the place in the Limes they relate to.
				The main purpose is the display within the DARIAH Geo-browser, a tool to visualize data in time and space.
                 </dc:description>
                 <dc:subject>Archaeology, geo-date, Limes</dc:subject>
                 <dc:identifier>http://de.digitalclassicist.org/berlin/files/output.kml</dc:identifier>   
                 <dc:language>de</dc:language>
                 <dc:date>2013-03-15</dc:date>
                 <dc:rights>Copyright 2000, O'Reilly Network</dc:rights>
                 <dc:publisher>German Archaeological Institute</dc:publisher>
                </ns:metadata>
            </ExtendedData>
	"""
	
	intro = """<?xml version="1.0" encoding="utf-8"?>
	<kml xmlns="http://www.opengis.net/kml/2.2">
	  <Document>%s
	"""%metadata
	outro = """
	  </Document>
	</kml>"""
	
	file.write(intro)
	for place in places:
		for key in place["subject_headings"]:
			temp = get_related_publications(key = key.encode('utf-8'))
			if(len(temp)>0):
				pubs += temp
				print >> sys.stderr,"Found %i related publications in Zenon related to %s"%(len(temp),place['name'])
				for pub in temp:
					if(len(pub['date'])<=4):
						desc = "<p>%s <em>%s</em> (%s) [<a target=\"_blank\" href='%s'>View in Zenon</a> ; <a href='%s' target=\"_blank\">View in Gazetteer</a> ] </p>"%(pub['author'],pub['title'],pub['date'],pub['link'],place['gazlink'])
						file.write(to_KML(place['name'],place['coord'],pub['date'],desc))
	#print >> sys.stderr, len(pubs)
	file.write(outro)
	file.close()
	
	
if __name__ == "__main__":
	main()
	# if you want the output printed to another destination
	#main(ofname="thefilenameidecide.kml")