Implementing Forwarders #69

clam/clamservice.py

@@ -968,6 +968,7 @@ def response(user, project, parameters, errormsg = "", datafile = False, oauth_a
                 accesstoken=Project.getaccesstoken(user,project),
                 interfaceoptions=settings.INTERFACEOPTIONS,
                 customhtml=customhtml,
+                forwarders=[ forwarder(project, getrooturl()) for forwarder in  settings.FORWARDERS ],
                 allow_origin=settings.ALLOW_ORIGIN,
                 oauth_access_token=oauth_encrypt(oauth_access_token),
                 auth_type=auth_type()
@@ -2598,6 +2599,8 @@ def set_defaults():
         settings.PROFILES = []
     if 'INPUTSOURCES' not in settingkeys:
         settings.INPUTSOURCES = []
+    if 'FORWARDERS' not in settingkeys:
+        settings.FORWARDERS = []
     if 'PORT' not in settingkeys and not PORT:
         settings.PORT = 80
     if 'HOST' not in settingkeys and not HOST:

clam/common/data.py

@@ -2314,6 +2314,24 @@ def fromxml(node):
             raise Exception("No condition found in ParameterCondition!")
         return Action(*args, **kwargs)
 
+class Forwarder(object):
+    def __init__(self, id, name, url, description="", type='zip'):
+        self.id = id
+        self.name = name
+        self.url = url
+        self.description = description
+        self.type = type
+
+    def __call__(self, project, baseurl, outputfile=None):
+        """Return the forward link given a project and (optionally) an outputfile. If no outputfile was selected, a link is generator to download the entire output archive."""
+        if outputfile:
+            self.forwardlink = self.url.replace("$BACKLINK", outputfile.filename)
+        else:
+            self.forwardlink =  self.url.replace("$BACKLINK", baseurl + '/' + project + '/output/' + self.type)
+        return self
+
+
+
 def resolveinputfilename(filename, parameters, inputtemplate, nextseq = 0, project = None):
     #parameters are local
     if filename.find('$') != -1:

clam/common/viewers.py

@@ -54,6 +54,26 @@ def view(self, file, **kwargs):
         """Returns the view itself, in xhtml (it's recommended to use flask's template system!). file is a CLAMOutputFile instance. By default, if not overriden and a remote service is specified, this issues a GET to the remote service."""
         raise NotImplementedError
 
+class ForwardViewer(AbstractViewer):
+    """The ForwardViewer calls a remote service and passes a backlink where the remote service can download an output file. The remote service is in turn expected to return a HTTP Redirect (302) response. It is implemented as a :class:`Forwarder`. See :ref:`forwarders`"""
+
+    def __init__(self, id, name, forwarder, **kwargs):
+        self.id = id
+        self.name = name
+        self.forwarder = forwarder
+        super(ForwardViewer,self).__init__(**kwargs)
+
+    def view(self, file, **kwargs):
+        self.forwarder(None, file)
+        r = requests.get(self.forwarder.forwardlink, allow_redirects=True)
+        if r.status_code == 302 and 'Location' in r.headers:
+            url = r.headers['Location']
+            return flask.redirect(url)
+        else:
+            return "Unexpected response from Forward service (HTTP " + str(r.status_code) + ", target was " + url + "): " + r.text
+
+
+
 
 class SimpleTableViewer(AbstractViewer):
     id = 'tableviewer'

clam/config/template.py

@@ -249,6 +249,13 @@
     #Action(id='multiply',name='Multiply',parameters=[IntegerParameter(id='x',name='Value'),IntegerParameter(id='y',name='Multiplier'), function=lambda x,y: x*y ])
 ]
 
+# ======= FORWARDERS =============
+
+#Global forwarders call a remote service, passing a backlink for the remote service to download an archive of all the output data. The remote service is expected to return a redirect (HTTP 302) . CLAM will insert the backlink where you put $BACKLINK in the url:
+
+#FORWARDERS = [
+    #Forwarder(id='otherservice', name="Other service", description="", url="https://my.service.com/grabfrom=$BACKLINK")
+#]
 
 # ======== DISPATCHING (ADVANCED! YOU CAN SAFELY SKIP THIS!) ========
 

clam/static/interface.xsl

@@ -441,6 +441,7 @@
 <xsl:template match="/clam/output">
     <div id="output" class="box">
         <h2>Output files</h2>
+
         <p>(Download all as archive:
           <xsl:choose>
           <xsl:when test="/clam/@oauth_access_token = ''">
@@ -451,6 +452,18 @@
           </xsl:otherwise>
           </xsl:choose>
         </p>
+
+        <xsl:if match="/clam/forwarders">
+            <p>
+            Forward all output to:
+            <ul>
+                <xsl:for-each select="/clam/forwarders">
+                    <li><a href="{./url}"><xsl:value-of select="./name" /></a> - <xsl:value-of select="./description" /></li>
+                </xsl:for-each>
+            </ul>
+            </p>
+        </xsl:if>
+
         <table id="outputfiles" class="files">
             <thead>
                 <tr>

clam/templates/response.xml

@@ -132,4 +132,11 @@
     </input>
     {% endif %}
 {% endif %}
+{% if statuscode == 2 and forwarders %}
+    <forwarders>
+      {% for forwarder in forwarders %}
+        <forwarder id="{{ forwarder.id }}" name="{{ forwarder.name }}" description="{{ forwarder.description }}" type="{{ forwarder.type }}" url="{{ forwarder.forwardlink }}" />
+      {% endfor %}
+    </forwarders>
+{% endif %}
 </clam>

docs/source/serviceconfiguration.rst

@@ -675,6 +675,13 @@ The following example defines a boolean parameter with a parameter flag:
 Thus, if this parameter is set, the invoked command will have
 ``$PARAMETERS`` set to ``-l 1`` (plus any additional parameters).
 
+Parameters API
+~~~~~~~~~~~~~~~~~~~~~
+
+.. automodule:: clam.common.parameters
+    :members:
+    :undoc-members:
+
 .. _profile:
 
 Profile specification
@@ -1082,6 +1089,8 @@ will be performed by 3rd party software in most cases.
 Note that specific converters take specific parameters; consult the API
 reference for details.
 
+.. _viewers:
+
 Viewers
 ~~~~~~~
 
@@ -1106,6 +1115,51 @@ The below example illustrates the use of the viewer
        extension='.patterns.csv',
    )
 
+Another useful viewer is the :class:`ForwardViewer`. It forwards the viewing request to a remote service and passes a
+backlink where the remote service can *download* the output file (assuming it has proper authorization!). The remote
+service is expected to return a HTTP 302 Redirect response which CLAM will subsequently invoke.
+
+.. code-block:: python
+
+   OutputTemplate('freqlist',CSVFormat,"Frequency list",
+       ForwardViewer(Forwarder(id="some_remote_service",name="Some Remote Frequency List Viewer")),
+       url="https://remote.service.com/?download=$BACKLINK")),
+       SetMetaField('encoding','utf-8'),
+       extension='.patterns.csv',
+   )
+
+You can also use forwarders globally to redirect all output as an archive (zip/tar.gz/tar.bz2), see :ref:`forwarders`.
+
+
+Viewer API
++++++++++++++++
+
+.. automodule:: clam.common.viewers
+    :members:
+    :undoc-members:
+
+.. _forwarders:
+
+Forwarders
+~~~~~~~~~~~~~~
+
+To allow users to forward all output from one webservice to another, you can use Forwarders. The forwarder calls a remote service and passes a backlink where the remote service can *download* the output file (assuming it has proper authorization!). The remote
+service is expected to return a HTTP 302 Redirect response which CLAM will subsequently invoke.
+
+.. code-block:: python
+
+FORWARDERS = [
+       Forwarder(id="some_remote_service",name="Some Remote service",type="zip", description="",
+        url="https://remote.service.com/?downloadarchive=$BACKLINK"
+       )
+]
+
+.. note::
+
+    * Forwarders can also be used as viewers for individual files. See :ref:`viewers`
+    * A forwarder does *NOT* perform any upload, it just passes a download link to a service, the remote
+      service must also have the necessary authorization to use it.
+
 Working with pre-installed data
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~