blob: fe18e05680c674abe0ae6e9c80c07e6befb51850 [file] [log] [blame]
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
import 'package:csslib/visitor.dart';
import 'package:source_span/source_span.dart';
/// Can be thrown on any Css runtime problem includes source location.
class CssSelectorException extends SourceSpanException {
CssSelectorException(String message, [SourceSpan span])
: super(message, span);
}
List<String> classes = [];
List<String> ids = [];
class Validate {
static int _classNameCheck(SimpleSelectorSequence selector, int matches) {
if (selector.isCombinatorDescendant ||
(selector.isCombinatorNone && matches == 0)) {
if (matches < 0) {
var tooMany = selector.simpleSelector.toString();
throw CssSelectorException(
'Can not mix Id selector with class selector(s). Id '
'selector must be singleton too many starting at $tooMany');
}
return matches + 1;
} else {
var error = selector.toString();
throw CssSelectorException(
'Selectors can not have combinators (>, +, or ~) before $error');
}
}
static int _elementIdCheck(SimpleSelectorSequence selector, int matches) {
if (selector.isCombinatorNone && matches == 0) {
// Perfect just one element id returns matches of -1.
return -1;
} else if (selector.isCombinatorDescendant) {
var tooMany = selector.simpleSelector.toString();
throw CssSelectorException(
'Use of Id selector must be singleton starting at $tooMany');
} else {
var error = selector.simpleSelector.toString();
throw CssSelectorException(
'Selectors can not have combinators (>, +, or ~) before $error');
}
}
// Validate the @{css expression} only .class and #elementId are valid inside
// of @{...}.
static template(List<Selector> selectors) {
var found = false; // signal if a selector is matched.
var matches = 0; // < 0 IdSelectors, > 0 ClassSelector
// At most one selector group (any number of simple selector sequences).
assert(selectors.length <= 1);
for (final sels in selectors) {
for (final selector in sels.simpleSelectorSequences) {
found = false;
var simpleSelector = selector.simpleSelector;
if (simpleSelector is ClassSelector) {
// Any class name starting with an underscore is a private class name
// that doesn't have to match the world of known classes.
if (!simpleSelector.name.startsWith('_')) {
// TODO(terry): For now iterate through all classes look for faster
// mechanism hash map, etc.
for (final className in classes) {
if (selector.simpleSelector.name == className) {
matches = _classNameCheck(selector, matches);
found = true; // .class found.
break;
}
for (final className2 in classes) {
print(className2);
}
}
} else {
// Don't check any class name that is prefixed with an underscore.
// However, signal as found and bump up matches; it's a valid class
// name.
matches = _classNameCheck(selector, matches);
found = true; // ._class are always okay.
}
} else if (simpleSelector is IdSelector) {
// Any element id starting with an underscore is a private element id
// that doesn't have to match the world of known elemtn ids.
if (!simpleSelector.name.startsWith('_')) {
for (final id in ids) {
if (simpleSelector.name == id) {
matches = _elementIdCheck(selector, matches);
found = true; // #id found.
break;
}
}
} else {
// Don't check any element ID that is prefixed with an underscore.
// Signal as found and bump up matches; it's a valid element ID.
matches = _elementIdCheck(selector, matches);
found = true; // #_id are always okay
}
} else {
var badSelector = simpleSelector.toString();
throw CssSelectorException('Invalid template selector $badSelector');
}
if (!found) {
var unknownName = simpleSelector.toString();
throw CssSelectorException('Unknown selector name $unknownName');
}
}
}
// Every selector must match.
var selector = selectors[0];
assert((matches >= 0 ? matches : -matches) ==
selector.simpleSelectorSequences.length);
}
}