From 03296ef59e9900684193dfda243b96b291272fb5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20P=C3=A9ters?= <fpeters@entrouvert.com>
Date: Sat, 26 May 2018 21:29:21 +0200
Subject: [PATCH] general: add support for using templates to prefill fields
 (#24094)

---
 tests/test_admin_pages.py | 43 +++++++++++++++++++++++++++++++++++++++
 tests/test_form_pages.py  | 15 ++++++++++++++
 wcs/fields.py             | 16 ++++++++++++++-
 3 files changed, 73 insertions(+), 1 deletion(-)

diff --git a/tests/test_admin_pages.py b/tests/test_admin_pages.py
index ab2658f5..606b620e 100644
--- a/tests/test_admin_pages.py
+++ b/tests/test_admin_pages.py
@@ -1129,6 +1129,49 @@ def test_form_edit_field_advanced(pub):
     assert resp.body.index('<legend>Additional parameters</legend>') > \
             resp.body.index('<label for="form_data_source">Data Source</label>')
 
+def test_form_prefill_field(pub):
+    create_superuser(pub)
+    create_role()
+
+    FormDef.wipe()
+    formdef = FormDef()
+    formdef.name = 'form title'
+    formdef.fields = [fields.StringField(id='1', label='1st field', type='string')]
+    formdef.store()
+
+    app = login(get_app(pub))
+
+    resp = app.get('/backoffice/forms/1/fields/1/')
+    resp.form['prefill$type'] = 'String'
+    resp.form['prefill$value_string'] = 'test'
+    resp = resp.form.submit('submit').follow()
+    assert FormDef.get(formdef.id).fields[0].prefill == {'type': 'string', 'value': 'test'}
+
+    resp = app.get('/backoffice/forms/1/fields/1/')
+    resp.form['prefill$type'] = 'Formula (Python)'
+    resp.form['prefill$value_formula'] = 'True'
+    resp = resp.form.submit('submit').follow()
+    assert FormDef.get(formdef.id).fields[0].prefill == {'type': 'formula', 'value': 'True'}
+
+    resp = app.get('/backoffice/forms/1/fields/1/')
+    resp.form['prefill$type'] = 'String'
+    resp.form['prefill$value_string'] = '{{form_var_toto}}'
+    resp = resp.form.submit('submit').follow()
+    assert FormDef.get(formdef.id).fields[0].prefill == {'type': 'string', 'value': '{{form_var_toto}}'}
+
+    # check error handling
+    resp = app.get('/backoffice/forms/1/fields/1/')
+    resp.form['prefill$type'] = 'Formula (Python)'
+    resp.form['prefill$value_formula'] = ':'
+    resp = resp.form.submit('submit')
+    assert 'invalid expression: unexpected EOF while parsing' in resp.body
+
+    resp = app.get('/backoffice/forms/1/fields/1/')
+    resp.form['prefill$type'] = 'String'
+    resp.form['prefill$value_string'] = '{% if %}'
+    resp = resp.form.submit('submit')
+    assert 'syntax error in Django template: Unexpected end of expression' in resp.body
+
 def test_form_edit_item_field(pub):
     create_superuser(pub)
     create_role()
diff --git a/tests/test_form_pages.py b/tests/test_form_pages.py
index b567cf22..0b8376d0 100644
--- a/tests/test_form_pages.py
+++ b/tests/test_form_pages.py
@@ -88,6 +88,7 @@ def create_user(pub):
     PasswordAccount.wipe()
 
     user = pub.user_class()
+    user.name = 'User Name'
     user.email = 'foo@localhost'
     user.store()
     account = PasswordAccount(id='foo')
@@ -1887,6 +1888,20 @@ def test_form_page_formula_prefill(pub):
     assert resp.forms[0]['f0'].value == 'HELLO WORLD'
     assert 'widget-prefilled' in resp.body
 
+def test_form_page_template_prefill(pub):
+    user = create_user(pub)
+    formdef = create_formdef()
+    formdef.data_class().wipe()
+    formdef.fields = [
+        fields.StringField(id='0', label='string',
+            prefill={'type': 'string', 'value': '{{session_user_display_name}}'})]
+    formdef.store()
+
+    app = login(get_app(pub), username='foo', password='foo')
+    resp = app.get('/test/')
+    assert resp.form['f0'].value == 'User Name'
+    assert 'widget-prefilled' in resp.body
+
 def test_form_page_query_string_prefill(pub):
     user = create_user(pub)
     formdef = create_formdef()
diff --git a/wcs/fields.py b/wcs/fields.py
index e38eefe5..e4f7c4a0 100644
--- a/wcs/fields.py
+++ b/wcs/fields.py
@@ -34,6 +34,7 @@ from qommon import _
 from qommon import evalutils
 from qommon.form import *
 from qommon.misc import localstrftime, strftime, date_format, ellipsize
+from qommon.template import Template, TemplateError
 from qommon import get_cfg, get_logger
 
 import data_sources
@@ -133,6 +134,11 @@ class PrefillSelectionWidget(CompositeWidget):
                 compile(values.get('value', ''), '<string>', 'eval')
             except (SyntaxError, TypeError), e:
                 self.set_error(_('invalid expression: %s') % e)
+        if values and values['type'] == 'string' and Template.is_template_string(values.get('value')):
+            try:
+                Template(values.get('value'), raises=True)
+            except TemplateError as e:
+                self.set_error(str(e))
 
     def render_content(self):
         r = TemplateIO(html=True)
@@ -294,7 +300,15 @@ class Field(object):
         #     (that will therefore be marked as readonly etc.)
         t = self.prefill.get('type')
         if t == 'string':
-            return (self.prefill.get('value'), False)
+            value = self.prefill.get('value')
+            if not Template.is_template_string(value):
+                return (value, False)
+
+            context = get_publisher().substitutions.get_context_variables()
+            try:
+                return (Template(value, autoescape=False).render(context), False)
+            except TemplateError:
+                return (None, False)
 
         elif t == 'user' and user:
             x = self.prefill.get('value')
-- 
2.17.1