templatetags: manage string concatenation on add filter (#42062)

tests/test_formdata.py

@@ -1620,6 +1620,103 @@ def test_lazy_formdata_mathematics_filters(pub):
         assert tmpl.render(context) == '0.75'
 
 
+def test_lazy_formdata_add_filters(pub):
+    formdef = FormDef()
+    formdef.name = 'foobar'
+    formdef.url_name = 'foobar'
+    formdef.fields = [
+        fields.StringField(id='0', label='term0', varname='term0'),
+        fields.StringField(id='1', label='term1', varname='term1'),
+        fields.StringField(id='2', label='term2', varname='term2'),
+        fields.StringField(id='3', label='term3', varname='term3'),
+        fields.StringField(id='4', label='term4', varname='term4'),
+    ]
+    formdef.store()
+    formdata = formdef.data_class()()
+    formdata.data = {'0': 'foo', '1': '3,14', '2': '', '3': None}
+    formdata.store()
+    pub.substitutions.feed(formdata)
+    for mode in (None, 'lazy'):
+        context = pub.substitutions.get_context_variables(mode=mode)
+
+        # add
+        tmpl = Template('{{ form_var_term1|add:form_var_term1 }}')
+        assert tmpl.render(context) == '6.28'
+
+        tmpl = Template('{{ form_var_term1|add:form_var_term2 }}')
+        assert tmpl.render(context) == '3.14'
+
+        tmpl = Template('{{ form_var_term1|add:form_var_term3 }}')
+        assert tmpl.render(context) == '3.14'
+
+        tmpl = Template('{{ form_var_term1|add:form_var_term4 }}')
+        assert tmpl.render(context) == '3.14'
+
+        tmpl = Template('{{ form_var_term2|add:form_var_term1 }}')
+        assert tmpl.render(context) == '3.14'
+
+        tmpl = Template('{{ form_var_term3|add:form_var_term1 }}')
+        assert tmpl.render(context) == '3.14'
+
+        tmpl = Template('{{ form_var_term4|add:form_var_term1 }}')
+        assert tmpl.render(context) == '3.14'
+
+        # fallback to Django native add filter
+        tmpl = Template('{{ form_var_term0|add:form_var_term0 }}')
+        assert tmpl.render(context) == 'foofoo'
+
+        tmpl = Template('{{ form_var_term0|add:form_var_term1 }}')
+        assert tmpl.render(context) == 'foo3,14'
+
+        tmpl = Template('{{ form_var_term0|add:form_var_term2 }}')
+        assert tmpl.render(context) == 'foo'
+
+        tmpl = Template('{{ form_var_term0|add:form_var_term3 }}')
+        assert tmpl.render(context) == 'foo'
+
+        tmpl = Template('{{ form_var_term0|add:form_var_term4 }}')
+        assert tmpl.render(context) == 'foo'
+
+        tmpl = Template('{{ form_var_term1|add:form_var_term0 }}')
+        assert tmpl.render(context) == '3,14foo'
+
+        tmpl = Template('{{ form_var_term2|add:form_var_term0 }}')
+        assert tmpl.render(context) == 'foo'
+
+        tmpl = Template('{{ form_var_term2|add:form_var_term2 }}')
+        assert tmpl.render(context) == ''
+
+        tmpl = Template('{{ form_var_term2|add:form_var_term3 }}')
+        assert tmpl.render(context) == ''
+
+        tmpl = Template('{{ form_var_term2|add:form_var_term4 }}')
+        assert tmpl.render(context) == ''
+
+        tmpl = Template('{{ form_var_term3|add:form_var_term0 }}')
+        assert tmpl.render(context) == 'foo'
+
+        tmpl = Template('{{ form_var_term3|add:form_var_term2 }}')
+        assert tmpl.render(context) == ''
+
+        tmpl = Template('{{ form_var_term3|add:form_var_term3 }}')
+        assert tmpl.render(context) == ''
+
+        tmpl = Template('{{ form_var_term3|add:form_var_term4 }}')
+        assert tmpl.render(context) == ''
+
+        tmpl = Template('{{ form_var_term4|add:form_var_term0 }}')
+        assert tmpl.render(context) == 'foo'
+
+        tmpl = Template('{{ form_var_term4|add:form_var_term2 }}')
+        assert tmpl.render(context) == ''
+
+        tmpl = Template('{{ form_var_term4|add:form_var_term3 }}')
+        assert tmpl.render(context) == ''
+
+        tmpl = Template('{{ form_var_term4|add:form_var_term4 }}')
+        assert tmpl.render(context) == ''
+
+
 def test_mathematic_conditions_django(pub, variable_test_data):
     for true_condition_value in (
             # reminder

tests/test_templates.py

@@ -364,11 +364,11 @@ def test_decimal_templatetag():
 def test_mathematics_templatetag():
     tmpl = Template('{{ term1|add:term2 }}')
 
-    # using string: convert to number or 0
+    # using strings
     assert tmpl.render({'term1': '1.1', 'term2': 0}) == '1.1'
-    assert tmpl.render({'term1': 'not a number', 'term2': 1.2}) == '1.2'
+    assert tmpl.render({'term1': 'not a number', 'term2': 1.2}) == ''
     assert tmpl.render({'term1': 0.3, 'term2': "1"}) == '1.3'
-    assert tmpl.render({'term1': 1.4, 'term2': "not a number"}) == '1.4'
+    assert tmpl.render({'term1': 1.4, 'term2': "not a number"}) == ''
 
     # add
     assert tmpl.render({'term1': 4, 'term2': -0.9}) == '3.1'
@@ -376,12 +376,37 @@ def test_mathematics_templatetag():
     assert tmpl.render({'term1': 4, 'term2': '-0.7'}) == '3.3'
     assert tmpl.render({'term1': '4', 'term2': '-0.6'}) == '3.4'
     assert tmpl.render({'term1': '', 'term2': 3.5}) == '3.5'
+    assert tmpl.render({'term1': None, 'term2': 3.5}) == '3.5'
     assert tmpl.render({'term1': 3.6, 'term2': ''}) == '3.6'
-    assert tmpl.render({'term1': '', 'term2': ''}) == '0'
+    assert tmpl.render({'term1': '', 'term2': ''}) == ''
+    assert tmpl.render({'term1': 3.6, 'term2': None}) == '3.6'
     assert tmpl.render({'term1': 0, 'term2': ''}) == '0'
     assert tmpl.render({'term1': '', 'term2': 0}) == '0'
     assert tmpl.render({'term1': 0, 'term2': 0}) == '0'
 
+    # add using ',' instead of '.' decimal separator
+    assert tmpl.render({'term1': '1,1', 'term2': '2,2'}) == '3.3'
+    assert tmpl.render({'term1': '1,1', 'term2': '2.2'}) == '3.3'
+    assert tmpl.render({'term1': '1,1', 'term2': 2.2}) == '3.3'
+    assert tmpl.render({'term1': '1,1', 'term2': 0}) == '1.1'
+    assert tmpl.render({'term1': '1,1', 'term2': ''}) == '1.1'
+    assert tmpl.render({'term1': '1,1', 'term2': None}) == '1.1'
+    assert tmpl.render({'term1': '1.1', 'term2': '2,2'}) == '3.3'
+    assert tmpl.render({'term1': 1.1, 'term2': '2,2'}) == '3.3'
+    assert tmpl.render({'term1': 0, 'term2': '2,2'}) == '2.2'
+    assert tmpl.render({'term1': '', 'term2': '2,2'}) == '2.2'
+    assert tmpl.render({'term1': None, 'term2': '2,2'}) == '2.2'
+
+    # fallback to Django native add filter
+    assert tmpl.render({'term1': 'foo', 'term2': 'bar'}) == 'foobar'
+    assert tmpl.render({'term1': 'foo', 'term2': ''}) == 'foo'
+    assert tmpl.render({'term1': 'foo', 'term2': None}) == 'foo'
+    assert tmpl.render({'term1': '', 'term2': 'bar'}) == 'bar'
+    assert tmpl.render({'term1': '', 'term2': None}) == ''
+    assert tmpl.render({'term1': None, 'term2': 'bar'}) == 'bar'
+    assert tmpl.render({'term1': None, 'term2': ''}) == ''
+    assert tmpl.render({'term1': None, 'term2': None}) == ''
+
     # subtract
     tmpl = Template('{{ term1|subtract:term2 }}')
     assert tmpl.render({'term1': 5.1, 'term2': 1}) == '4.1'

wcs/qommon/templatetags/qommon.py

@@ -147,7 +147,7 @@ def time(value, arg=None):
     return defaultfilters.date(value, arg=arg)
 
 
-def parse_decimal(value):
+def parse_decimal(value, do_raise=False):
     if hasattr(value, 'get_value'):
         value = value.get_value()  # unlazy
     if isinstance(value, six.string_types):
@@ -156,6 +156,8 @@ def parse_decimal(value):
     try:
         return Decimal(value).quantize(Decimal('1.0000')).normalize()
     except (ArithmeticError, TypeError):
+        if do_raise:
+            raise
         return Decimal(0)
 
 
@@ -277,7 +279,37 @@ def action_button(context, action_id, label, delay=3):
 @register.filter
 def add(term1, term2):
     '''replace the "add" native django filter'''
-    return parse_decimal(term1) + parse_decimal(term2)
+
+    # consider None content as the empty string
+    if term1 is None:
+        term1 = ''
+    if term2 is None:
+        term2 = ''
+
+    # return available number if the other term is the empty string
+    if term1 == '':
+        try:
+            return parse_decimal(term2, do_raise=True)
+        except (ArithmeticError, TypeError):
+            pass
+    if term2 == '':
+        try:
+            return parse_decimal(term1, do_raise=True)
+        except (ArithmeticError, TypeError):
+            pass
+
+    # compute addition if both terms are numbers
+    try:
+        return parse_decimal(term1, do_raise=True) + parse_decimal(term2, do_raise=True)
+    except (ArithmeticError, TypeError):
+        pass
+
+    # fallback to django add filter
+    if hasattr(term1, 'get_value'):
+        term1 = term1.get_value()  # unlazy
+    if hasattr(term2, 'get_value'):
+        term2 = term2.get_value()  # unlazy
+    return defaultfilters.add(term1, term2)
 
 
 @register.filter