summaryrefslogtreecommitdiffstats
path: root/dom/html/nsDOMStringMap.cpp
blob: 0f2171ed79fbe1fd20f38dad762b955955e54f16 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsDOMStringMap.h"

#include "jsapi.h"
#include "nsError.h"
#include "nsGenericHTMLElement.h"
#include "nsContentUtils.h"
#include "mozilla/dom/DOMStringMapBinding.h"
#include "mozilla/dom/MutationEventBinding.h"

using namespace mozilla;
using namespace mozilla::dom;

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(nsDOMStringMap)

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsDOMStringMap)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mElement)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsDOMStringMap)
  NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
  // Check that mElement exists in case the unlink code is run more than once.
  if (tmp->mElement) {
    // Call back to element to null out weak reference to this object.
    tmp->mElement->ClearDataset();
    tmp->mElement->RemoveMutationObserver(tmp);
    tmp->mElement = nullptr;
  }
  tmp->mExpandoAndGeneration.OwnerUnlinked();
NS_IMPL_CYCLE_COLLECTION_UNLINK_END

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsDOMStringMap)
  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  NS_INTERFACE_MAP_ENTRY(nsIMutationObserver)
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

NS_IMPL_CYCLE_COLLECTING_ADDREF(nsDOMStringMap)
NS_IMPL_CYCLE_COLLECTING_RELEASE(nsDOMStringMap)

nsDOMStringMap::nsDOMStringMap(Element* aElement)
    : mElement(aElement), mRemovingProp(false) {
  mElement->AddMutationObserver(this);
}

nsDOMStringMap::~nsDOMStringMap() {
  // Check if element still exists, may have been unlinked by cycle collector.
  if (mElement) {
    // Call back to element to null out weak reference to this object.
    mElement->ClearDataset();
    mElement->RemoveMutationObserver(this);
  }
}

DocGroup* nsDOMStringMap::GetDocGroup() const {
  return mElement ? mElement->GetDocGroup() : nullptr;
}

/* virtual */
JSObject* nsDOMStringMap::WrapObject(JSContext* cx,
                                     JS::Handle<JSObject*> aGivenProto) {
  return DOMStringMap_Binding::Wrap(cx, this, aGivenProto);
}

void nsDOMStringMap::NamedGetter(const nsAString& aProp, bool& found,
                                 DOMString& aResult) const {
  nsAutoString attr;

  if (!DataPropToAttr(aProp, attr)) {
    found = false;
    return;
  }

  found = mElement->GetAttr(attr, aResult);
}

void nsDOMStringMap::NamedSetter(const nsAString& aProp,
                                 const nsAString& aValue, ErrorResult& rv) {
  nsAutoString attr;
  if (!DataPropToAttr(aProp, attr)) {
    rv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
    return;
  }

  nsresult res = nsContentUtils::CheckQName(attr, false);
  if (NS_FAILED(res)) {
    rv.Throw(res);
    return;
  }

  RefPtr<nsAtom> attrAtom = NS_Atomize(attr);
  MOZ_ASSERT(attrAtom, "Should be infallible");

  res = mElement->SetAttr(kNameSpaceID_None, attrAtom, aValue, true);
  if (NS_FAILED(res)) {
    rv.Throw(res);
  }
}

void nsDOMStringMap::NamedDeleter(const nsAString& aProp, bool& found) {
  // Currently removing property, attribute is already removed.
  if (mRemovingProp) {
    found = false;
    return;
  }

  nsAutoString attr;
  if (!DataPropToAttr(aProp, attr)) {
    found = false;
    return;
  }

  RefPtr<nsAtom> attrAtom = NS_Atomize(attr);
  MOZ_ASSERT(attrAtom, "Should be infallible");

  found = mElement->HasAttr(kNameSpaceID_None, attrAtom);

  if (found) {
    mRemovingProp = true;
    mElement->UnsetAttr(kNameSpaceID_None, attrAtom, true);
    mRemovingProp = false;
  }
}

void nsDOMStringMap::GetSupportedNames(nsTArray<nsString>& aNames) {
  uint32_t attrCount = mElement->GetAttrCount();

  // Iterate through all the attributes and add property
  // names corresponding to data attributes to return array.
  for (uint32_t i = 0; i < attrCount; ++i) {
    const nsAttrName* attrName = mElement->GetAttrNameAt(i);
    // Skip the ones that are not in the null namespace
    if (attrName->NamespaceID() != kNameSpaceID_None) {
      continue;
    }

    nsAutoString prop;
    if (!AttrToDataProp(nsDependentAtomString(attrName->LocalName()), prop)) {
      continue;
    }

    aNames.AppendElement(prop);
  }
}

/**
 * Converts a dataset property name to the corresponding data attribute name.
 * (ex. aBigFish to data-a-big-fish).
 */
bool nsDOMStringMap::DataPropToAttr(const nsAString& aProp,
                                    nsAutoString& aResult) {
  // aResult is an autostring, so don't worry about setting its capacity:
  // SetCapacity is slow even when it's a no-op and we already have enough
  // storage there for most cases, probably.
  aResult.AppendLiteral("data-");

  // Iterate property by character to form attribute name.
  // Return syntax error if there is a sequence of "-" followed by a character
  // in the range "a" to "z".
  // Replace capital characters with "-" followed by lower case character.
  // Otherwise, simply append character to attribute name.
  const char16_t* start = aProp.BeginReading();
  const char16_t* end = aProp.EndReading();
  const char16_t* cur = start;
  for (; cur < end; ++cur) {
    const char16_t* next = cur + 1;
    if (char16_t('-') == *cur && next < end && char16_t('a') <= *next &&
        *next <= char16_t('z')) {
      // Syntax error if character following "-" is in range "a" to "z".
      return false;
    }

    if (char16_t('A') <= *cur && *cur <= char16_t('Z')) {
      // Append the characters in the range [start, cur)
      aResult.Append(start, cur - start);
      // Uncamel-case characters in the range of "A" to "Z".
      aResult.Append(char16_t('-'));
      aResult.Append(*cur - 'A' + 'a');
      start = next;  // We've already appended the thing at *cur
    }
  }

  aResult.Append(start, cur - start);

  return true;
}

/**
 * Converts a data attribute name to the corresponding dataset property name.
 * (ex. data-a-big-fish to aBigFish).
 */
bool nsDOMStringMap::AttrToDataProp(const nsAString& aAttr,
                                    nsAutoString& aResult) {
  // If the attribute name does not begin with "data-" then it can not be
  // a data attribute.
  if (!StringBeginsWith(aAttr, u"data-"_ns)) {
    return false;
  }

  // Start reading attribute from first character after "data-".
  const char16_t* cur = aAttr.BeginReading() + 5;
  const char16_t* end = aAttr.EndReading();

  // Don't try to mess with aResult's capacity: the probably-no-op SetCapacity()
  // call is not that fast.

  // Iterate through attrName by character to form property name.
  // If there is a sequence of "-" followed by a character in the range "a" to
  // "z" then replace with upper case letter.
  // Otherwise append character to property name.
  for (; cur < end; ++cur) {
    const char16_t* next = cur + 1;
    if (char16_t('-') == *cur && next < end && char16_t('a') <= *next &&
        *next <= char16_t('z')) {
      // Upper case the lower case letters that follow a "-".
      aResult.Append(*next - 'a' + 'A');
      // Consume character to account for "-" character.
      ++cur;
    } else {
      // Simply append character if camel case is not necessary.
      aResult.Append(*cur);
    }
  }

  return true;
}

void nsDOMStringMap::AttributeChanged(Element* aElement, int32_t aNameSpaceID,
                                      nsAtom* aAttribute, int32_t aModType,
                                      const nsAttrValue* aOldValue) {
  if ((aModType == MutationEvent_Binding::ADDITION ||
       aModType == MutationEvent_Binding::REMOVAL) &&
      aNameSpaceID == kNameSpaceID_None &&
      StringBeginsWith(nsDependentAtomString(aAttribute), u"data-"_ns)) {
    ++mExpandoAndGeneration.generation;
  }
}