source: MILK/trunk/milk_server/milk_server/models/DiscoveryState.py @ 4469

from paste.request import parse_querystring
import cgi,urllib
class constraints:
    ''' A container object for constraints on a search '''
    def __init__(self, **kw):
        self.values={}
        keys=['dateRange','bbox','scope','textTarget','searchString','geoSearchType']
        for key in keys:self.values[key]=None
        print kw
        for k in kw: self[k]=kw[k]
            
    def __setitem__(self,key,value):
        if key in self.values:
            self.values[key]=value
        else:
            raise ValueError('Unknown key [%s] in constraints')
    
    def __getitem__(self,key):
        if key in self.values: 
            return self.values[key]
        else:
            raise ValueError('Unknown key [%s] in constraints'%key)
    
    def __str__(self):
        c=''
        if self.values['dateRange'] is not None:
            dr=self.values['dateRange'] 
            c+='Including %s to %s; '%('%s,%s,%s'%dr[0],'%s,%s,%s'%dr[1])
        bbox=self.values['bbox']
        if bbox is None or bbox==['90.0','-180.0','180.0','-90.0']:
            c+='Global; '
        else:
            overlaps=self.values['geoSearchType'] or 'overlaps'
            c+='which %s latitude %s to %sN and longitude %s to %sE; '%(
                overlaps,bbox[3],bbox[0],bbox[1],bbox[2])
            #c+='Bounding Box: %sN,%sW,%sE,%sS; '%tuple(bbox)
        if self.values['scope'] is not None or self.values['textTarget'] is not None:
            c+='Restricted to '
        if self.values['scope'] is not None: c+='%s; '%self.values['scope']
        if self.values['textTarget'] is not None: c+='%s; '%self.values['textTarget']
        return c[:-2]

class DiscoveryState:
    ''' This class holds the state associated with a search (including presenting multiple slices
    of a large result set) '''
    def __init__(self,sessionID,searchString,environ,hits,constraints,offset=1,stride=10):
        ''' On instantiation, provide
                the backend sessionID
                the application URL that produced this query
                the stride through the result set '''
        self.environ=environ # the wsgi environment
        self.constraintsInstance=constraints
        self.constraints=str(constraints) # some text to show constraints on search
        self.constrainedurl=self.geturl(constrained=1)+'&constrained'
        self.sessID=sessionID
        self.hits=hits
        self.offset=offset
        self.stride=stride
        self.searchString=searchString
        self.alternatives=None
    def geturl(self,**kw):
        ''' Get a url from the wsgi environment, modified by the keyword arguments offset and stride 
        which are to be part of the querystring '''
        args=dict(parse_querystring(self.environ))
        offset,stride=kw.get('offset'),kw.get('stride')
        if offset is not None:args['start']=offset
        if stride is not None:args['howmany']=stride
        constrained=kw.get('constrained')
        if constrained is not None:
            if 'start' in args: del args['start']
            if 'howmany' in args: del args['howmany']
        q='?'
        for i in args: q+='%s=%s&'%(i,args[i])
        q=q[0:-1]
        url=urllib.quote(self.environ.get('SCRIPT_NAME','')) + \
            urllib.quote(self.environ.get('PATH_INFO','')) + q
        #url=cgi.escape(url)
        return url
    def getNext(self):
        ''' Get the next slice '''
        result=[]
        defStride=10
        if self.offset+self.stride<self.hits:
            #there are more to look at
            r=[self.offset+self.stride,self.stride]
            if r[0]+r[1]-1>self.hits: r[1]=self.hits+1-r[0]
            result.append(r)
        else:result.append([])
        if self.offset>1:
            #there are previous records
            b=max(self.stride,defStride)
            r=[self.offset-b,b]
            if r[0]<1: r[0]=1
            if r[1]>self.hits: r[1]=self.hits
            result.append(r)
        else: result.append([])
        return result
        
    def __str__(self):
        return ''' 
___ Discovery State ___
searchString: %s
constraints: %s
sessionID: %s
hits: %s
offset,stride: %s,%s
environment: %s
========================
'''%(self.searchString,self.constraints,self.sessID,self.hits,self.offset,self.stride,self.environ)