From 093431df3f440c93bfc99308e5ee0e67b6022c6f Mon Sep 17 00:00:00 2001
From: Benjamin Dauvergne <bdauvergne@entrouvert.com>
Date: Wed, 27 Nov 2019 23:56:28 +0100
Subject: [PATCH 5/7] formdata: make LinkedFormdataSubstitutionProxy work in
 pickle-lazy mode

To fixup with previous commit.
---
 wcs/formdata.py           |  3 +++
 wcs/wf/create_formdata.py | 44 ++++++++++++++++++++++++++++-----------
 2 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/wcs/formdata.py b/wcs/formdata.py
index 976cb7ca..4189f7f6 100644
--- a/wcs/formdata.py
+++ b/wcs/formdata.py
@@ -819,6 +819,7 @@ class FormData(StorableObject):
         lazy = self.get_substitution_variables()
         del lazy['form']
         del lazy['attachments']
+        del lazy['linked']
         d.update(lazy)
 
         d = copy.deepcopy(d)
@@ -830,9 +831,11 @@ class FormData(StorableObject):
         from .qommon.substitution import CompatibilityNamesDict
         from wcs.variables import LazyFormData
         from wcs.workflows import AttachmentsSubstitutionProxy
+        from wcs.wf.create_formdata import LinkedFormdataSubstitutionProxy
         variables = CompatibilityNamesDict({
             'form': LazyFormData(self),
             'attachments': AttachmentsSubstitutionProxy(self),
+            'linked': LinkedFormdataSubstitutionProxy(self),
         })
         if self.formdef.category:
             variables.update(self.formdef.category.get_substitution_variables(minimal=minimal))
diff --git a/wcs/wf/create_formdata.py b/wcs/wf/create_formdata.py
index f5e653b4..d2a68080 100644
--- a/wcs/wf/create_formdata.py
+++ b/wcs/wf/create_formdata.py
@@ -110,10 +110,15 @@ class MappingsWidget(WidgetListAsTable):
 
 
 class LazyLinkedFormData(object):
+    __part = None
+
     def __init__(self, part):
         self.__part = part
 
     def __getattr__(self, name):
+        if name.startswith('__'):
+            raise AttributeError(name)
+
         formdata = self.__part.formdata
         if formdata is not None:
             return getattr(LazyFormData(self.__part.formdata), name)
@@ -131,15 +136,28 @@ class LazyLinkedFormData(object):
 
 
 class LinkedFormdataSubstitutionProxy(object):
-    def __init__(self, parts):
-        self.__parts = parts
-        self.__formdatas = [(part.varname, part, LazyLinkedFormData(part)) for part in parts]
-        self.__formdatas.reverse()
-        self.__varnames = set(varname for varname, _1, _2 in self.__formdatas)
-        self.__varname = None
+    __varname = None
+
+    def __init__(self, formdata):
+        self.formdata = formdata
+
+    @property
+    def __parts(self):
+        return [part for part in self.formdata.iter_evolution_parts()
+                if isinstance(part, LinkedFormdataEvolutionPart)]
+
+    @property
+    def __formdatas(self):
+        formdatas = [(part.varname, part, LazyLinkedFormData(part)) for part in self.__parts]
+        formdatas.reverse()
+        return formdatas
+
+    @property
+    def __varnames(self):
+        return set(varname for varname, _1, _2 in self.__formdatas)
 
     def __iter__(self):
-        for varname, part, formdata in self.__formdatas:
+        for varname, part, formdata in self.__formdatas or []:
             if self.__varname is None or self.__varname == varname:
                 yield formdata
 
@@ -147,13 +165,16 @@ class LinkedFormdataSubstitutionProxy(object):
         return list(self)[idx]
 
     def __getattr__(self, name):
-        if self.__varname or name not in self.__varnames:
+        if name.startswith('__'):
+            raise AttributeError(name)
+
+        if self.__varname or name not in (self.__varnames or []):
             try:
                 first = self[0]
-            except KeyError:
+            except IndexError:
                 raise AttributeError(name)
             return getattr(first, name)
-        elif name in self.__varnames:
+        elif name in (self.__varnames or []):
             new_sub = copy.copy(self)
             new_sub.varname = name
             return new_sub
@@ -193,8 +214,7 @@ class LinkedFormdataEvolutionPart(object):
     @classmethod
     def get_substitution_variables(cls, formdata):
         return {
-            'linked': LinkedFormdataSubstitutionProxy(
-                [part for part in formdata.iter_evolution_parts() if isinstance(part, LinkedFormdataEvolutionPart)]),
+            'linked': LinkedFormdataSubstitutionProxy(formdata),
         }
 
     @property
-- 
2.24.0