Adds Finds support to is_element_present() (#17)

Finds returns a list of WebElements, not a single WebElement, and thus
is_displayed() fails when called upon said list. This commit adds
handling to check if there are any elements in the list, and if so,
determines if they are all visible.

docs/is_element_present.rst

@@ -7,6 +7,13 @@ It returns if an element with corresponding name is shown on the page.
 
 .. literalinclude:: ../examples/12_is_element_present.py
 
+*Note*: Containers with elements located via ``Finds`` also support
+``is_element_present``, albeit with special behaviour. Since the attribute will
+be a list of elements, rather than a single element, ``True`` will be returned
+only if all elements in the list are present. In the event that no elements are
+found (i.e. an empty list), or one or more elements do not qualify as present,
+``False`` will be returned.
+
 just_in_dom
 -----------
 
@@ -17,4 +24,4 @@ timeout
 -------
 ``timeout`` in seconds allows you to wait for ``True`` value.
 
-*Note:* if an element is not shown this option will delay ``False`` value from being returned.
+*Note:* if an element is not shown this option will delay ``False`` value from being returned.

tests/simple_page/test_is_element_present.py

@@ -8,5 +8,11 @@ def test_is_element_present(self):
         ok_(self.page.is_element_present('icon_link'))
         assert_false(self.page.is_element_present('unexistent_element'))
 
+    def test_is_element_present_via_finds(self):
+        ok_(self.page.is_element_present('anchor_list'))
+
+    def test_is_element_present_via_finds_empty_list(self):
+        assert_false(self.page.is_element_present('empty_element_list'))
+
     def test_no_attribute(self):
         assert_raises(WebiumException, self.page.is_element_present, 'no_such_attribute')

webium/base_page.py

@@ -21,9 +21,15 @@ def _get_driver():
     _get_driver().implicitly_wait(timeout)
     try:
         def is_displayed():
-            element = getattr(self, element_name, None)
-            if not element:
+            try:
+                element = getattr(self, element_name)
+            except AttributeError:
                 raise WebiumException('No element "{0}" within container {1}'.format(element_name, self))
+            if isinstance(element, list):
+                if element:
+                    return all(ele.is_displayed() for ele in element)
+                else:
+                    return False
             return element.is_displayed()
 
         is_displayed() if just_in_dom else wait(lambda: is_displayed(), timeout_seconds=timeout)