source: TI07-MOLES/tags/wsgi-beta/ndgBrowse.py @ 2364

from Utilities import myConfig
from paste.request import parse_querystring
from ndgObject import ndgObject

def browseFactory(global_config,**local_conf):
    
    ''' This factory is intended to be used by paste-deploy to return
    the ndgBrowse wsgi application, configured to use the configDir
    to find local configuration information '''
    
    if 'configDir' in local_conf.keys():
        configDir=local_conf[configDir]
    else:
        try:
            configDir=global_config['configDir']
        except:
            configDir=None
            
    def filter(app):
        return ndgBrowse(app,configDir)
    
    return filter        

         
class ndgBrowse:
    
    ''' This is the ndgBrowse GUI application, all it does is clean up a URL to ensure
    it passes the right things to ndgRetrieve in the case of a browse request. In the
    fullness of time it may do something smart with a registyr '''
    
    def __init__(self,app,configDir):
        
        ''' Instantiate a wsgi ndgBrowse GUI application '''
        self.configDir=configDir
        self.config=myConfig(configDir+'ndgDiscovery.config')
        self.app=app
    
    def __call__(self,environ,start_response):
        
        ''' This is the function which implements the ndgBrowse '''
        
        inputs=dict(parse_querystring(environ))
        try:
            if 'uri' not in inputs: raise ValueError('No URI requested')
            if 'repository' not in inputs:
                # check the config file to find an appropriate repository ... 
                n=ndgObject(inputs['uri'])
                repository=self.config.get('NDG_B_SERVICE',n.repository,'NOREP')
                if repository=='NOREP':
                    server=self.config.get('DEFAULT','server',None)
                    if server is None: raise ValueError('Corrupt browse/discovery config file')
                    raise ValueError('Unable to retrieve [%s] via server [%s]'%(n.uri,server))
                # now modify the query string to get the repository into it
                environ['QUERY_STRING']+='&repository=%s'%repository
            html=self.app(environ,start_response)
        except ValueError,e:
            start_response('200 OK', [('Content-Type','text/html')])
            html=['<p> (Browse) Unable to retrieve document, error [%s]</p>'%e]
        return html