def find_valid(node, file, target_alt):
name = getattr(node.value, "name", None)
is_img = (isinstance(node.value, ast.Element) and name
and name.lower() == "img")
if is_img:
attributes = []
if getattr(node.value, "opening_tag", None):
attributes = {}
for n in node.value.opening_tag.attributes.nodes:
if not isinstance(n, JinjaElement):
attributes[str(n.name)] = str(n.value).strip("\"'")
if len(attributes) == 0 or "alt" not in attributes:
return [
Issue.from_node(
file,
node,
"The `<img>` tag must have a `alt` attribute, either with meaningful text, or an empty string for decorative images",
"image_alt",
)
]
if not node.children:
return []
return sum(
(find_valid(child, file, target_alt) for child in node.children), [])
def find_valid(node, file, target_alt):
name = getattr(node.value, "name", None)
is_input = (isinstance(node.value, ast.Element) and name
and name.lower() == "input")
if is_input:
attributes = []
if getattr(node.value, "opening_tag", None):
attributes = {}
for n in node.value.opening_tag.attributes.nodes:
attributes[str(n.name)] = str(n.value).strip("\"'")
if "autofocus" in attributes:
return [
Issue.from_node(
file,
node,
"Do not use the `autofocus` attribute, which causes issues for screen reader users",
"no_autofocus",
)
]
if not node.children:
return []
return sum(
(find_valid(child, file, target_alt) for child in node.children), [])
def find_role_errors(node, file, target_roles):
attributes = []
if getattr(node.value, "opening_tag", None):
attributes = {}
for n in node.value.opening_tag.attributes.nodes:
attributes[str(n.name)] = str(n.value).strip("\"'")
target = VALID_ROLES if target_roles is True else target_roles
if "role" in attributes:
return (
[]
if attributes["role"] in target
else [
Issue.from_node(
file,
node,
"The `role` attribute needs to have a valid value",
"aria_role",
)
]
)
if not node.children:
return []
return sum(
(
find_role_errors(child, file, target_roles)
for child in node.children
),
[],
)
def check_tab_only_indent(file):
issues = []
for i, line in enumerate(file.lines):
indent = WHITESPACE_INDENT_RE.match(line).group(0)
if not contains_exclusively(indent, "\t"):
loc = IssueLocation(file_path=file.path, line=i, column=0)
issue = Issue(loc, "Should be indented with tabs", INDENT)
issues.append(issue)
return issues
def find_valid(node, file):
name = getattr(node.value, "name", None)
is_meta = (
isinstance(node.value, ast.Element) and name and name.lower() == "meta"
)
if is_meta:
attributes = []
if getattr(node.value, "opening_tag", None):
attributes = {}
for n in node.value.opening_tag.attributes.nodes:
attributes[str(n.name)] = str(n.value).strip("\"'")
if "name" in attributes and attributes["name"] == "viewport":
if "user-scalable=no" in attributes["content"]:
return [
Issue.from_node(
file,
node,
"Remove `user-scalable=no` from the viewport meta so users can zoom",
"meta_viewport",
)
]
if (
"maximum-scale=1" in attributes["content"]
or "maximum-scale=0" in attributes["content"]
):
return [
Issue.from_node(
file,
node,
"`maximum-scale` should not be less than 2",
"meta_viewport",
)
]
if not node.children:
return []
return sum((find_valid(child, file) for child in node.children), [])
def find_valid(node, file, target_lang):
name = getattr(node.value, "name", None)
is_html = (isinstance(node.value, ast.Element) and name
and name.lower() == "html")
if is_html:
attributes = []
if getattr(node.value, "opening_tag", None):
attributes = {}
for n in node.value.opening_tag.attributes.nodes:
attributes[str(getattr(n, "name",
""))] = str(getattr(n, "value",
"")).strip("\"'")
if len(attributes) == 0 or "lang" not in attributes:
return [
Issue.from_node(
file,
node,
"The `<html>` tag should have a `lang` attribute with a valid value, describing the main language of the page",
"html_has_lang",
)
]
if target_lang[0] is True or attributes["lang"] in target_lang:
return []
else:
return [
Issue.from_node(
file,
node,
f"The `<html>` tag should have a `lang` attribute with a valid value, describing the main language of the page. Allowed values: {', '.join(target_lang)}",
"html_has_lang",
)
]
if not node.children:
return []
return sum(
(find_valid(child, file, target_lang) for child in node.children), [])
def find_valid(node, file, disallowed_variants):
if isinstance(node.value, ast.JinjaVariable):
matches = [v for v in disallowed_variants if v in node.value.content]
if matches:
return [
Issue.from_node(
file,
node,
f"Avoid using `{matches[0]}` to render Django forms",
DJANGO_FORMS_RENDERING,
)
]
if not node.children:
return []
return sum(
(
find_valid(child, file, disallowed_variants)
for child in node.children
),
[],
)
def find_valid(node, file):
is_elt = isinstance(node.value, ast.Element)
if is_elt:
attributes = []
if getattr(node.value, "opening_tag", None):
attributes = {}
for n in node.value.opening_tag.attributes.nodes:
attributes[str(n.name)] = str(n.value).strip("\"'")
if "tabindex" in attributes and int(attributes["tabindex"]) > 0:
return [
Issue.from_node(
file,
node,
"Avoid positive `tabindex` values, change the order of elements on the page instead",
"tabindex_no_positive",
)
]
if not node.children:
return []
return sum((find_valid(child, file) for child in node.children), [])
def add_issue(location, msg):
issues.append(
Issue.from_ast(file, location.line, location.column, msg, INDENT))