浏览器如何存储自动完成的数据以及在哪里？

我最近遇到了有关浏览器自动完成功能的问题.有人可能会在网页上的表单中找到它.

问题在于数据,根据对一个字段的自动完成选择,数据被放入其他字段.更详细地说,它与AngularJS的使用有关.

我确实找到了有关角度变通方法的主题,但我感兴趣的是,浏览器存储数据的位置以及收集数据的逻辑是什么.

是否有一些已定义的字段列表,由浏览器监视？

数据主机(位置)是否特定于字段？

何时由浏览器存储？在正常表格提交活动或其他一些事件？

先感谢您.

自动填充功能的实现取决于浏览器供应商.如果他们实现Web超文本应用技术工作组的"活HTML标准",则适用第4.10.19.8.1段(自动填充表单控件:自动完成属性).在那里,定义了以下自动填充字段名称:

"名称"

"尊敬的前缀"

"给定的名称"

"额外的名称"

"姓"

"敬语后缀"

"昵称"

"用户名"

"新密码"

"当前密码"

"组织标题"

"组织"

"街道地址"

"地址第一行"

"地址第2行"

"地址3号线"

"地址 - 级别4"

"地址-3级"

"地址(第二级)"

"地址(第一级)"

"国家"

"国家的名字"

"邮政编码"

"CC-名"

"CC-给出名"

"CC-附加名称"

"CC-家族名"

"CC-数"

"CC-EXP"

"CC-EXP-月"

"CC-EXP-年"

"CC-CSC"

"CC型"

"交易货币"

"交易量"

"语言"

"BDAY"

"BDAY天"

"BDAY月"

"BDAY年"

"性别"

"URL"

"照片"

让我们考虑一下使用这个标准的流行开源浏览器Chromium.

在src/components/autofill/core/browser/form_structure.cc中,上述自动填充字段名称的子集用于在内部映射这些:

// Returns the Chrome Autofill-supported field type corresponding to the given
// |autocomplete_attribute_value|, if there is one, in the context of the given
// |field|.  Chrome Autofill supports a subset of the field types listed at
// http://is.gd/whatwg_autocomplete
HtmlFieldType FieldTypeFromAutocompleteAttributeValue(
    const std::string& autocomplete_attribute_value,
    const AutofillField& field) {
  if (autocomplete_attribute_value == "name")
    return HTML_TYPE_NAME;

  if (autocomplete_attribute_value == "given-name")
    return HTML_TYPE_GIVEN_NAME;

  if (autocomplete_attribute_value == "additional-name") {
    if (field.max_length == 1)
      return HTML_TYPE_ADDITIONAL_NAME_INITIAL;
    else
      return HTML_TYPE_ADDITIONAL_NAME;
  }

  if (autocomplete_attribute_value == "family-name")
    return HTML_TYPE_FAMILY_NAME;

  if (autocomplete_attribute_value == "organization")
    return HTML_TYPE_ORGANIZATION;

  if (autocomplete_attribute_value == "street-address")
    return HTML_TYPE_STREET_ADDRESS;

  if (autocomplete_attribute_value == "address-line1")
    return HTML_TYPE_ADDRESS_LINE1;

  if (autocomplete_attribute_value == "address-line2")
    return HTML_TYPE_ADDRESS_LINE2;

  if (autocomplete_attribute_value == "address-line3")
    return HTML_TYPE_ADDRESS_LINE3;

  // TODO(estade): remove support for "locality" and "region".
  if (autocomplete_attribute_value == "locality")
    return HTML_TYPE_ADDRESS_LEVEL2;

  if (autocomplete_attribute_value == "region")
    return HTML_TYPE_ADDRESS_LEVEL1;

  if (autocomplete_attribute_value == "address-level1")
    return HTML_TYPE_ADDRESS_LEVEL1;

  if (autocomplete_attribute_value == "address-level2")
    return HTML_TYPE_ADDRESS_LEVEL2;

  if (autocomplete_attribute_value == "address-level3")
    return HTML_TYPE_ADDRESS_LEVEL3;

  if (autocomplete_attribute_value == "country")
    return HTML_TYPE_COUNTRY_CODE;

  if (autocomplete_attribute_value == "country-name")
    return HTML_TYPE_COUNTRY_NAME;

  if (autocomplete_attribute_value == "postal-code")
    return HTML_TYPE_POSTAL_CODE;

  // content_switches.h isn't accessible from here, hence we have
  // to copy the string literal. This should be removed soon anyway.
  if (autocomplete_attribute_value == "address" &&
      base::CommandLine::ForCurrentProcess()->HasSwitch(
          "enable-experimental-web-platform-features")) {
    return HTML_TYPE_FULL_ADDRESS;
  }

  if (autocomplete_attribute_value == "cc-name")
    return HTML_TYPE_CREDIT_CARD_NAME;

  if (autocomplete_attribute_value == "cc-number")
    return HTML_TYPE_CREDIT_CARD_NUMBER;

  if (autocomplete_attribute_value == "cc-exp") {
    if (field.max_length == 5)
      return HTML_TYPE_CREDIT_CARD_EXP_DATE_2_DIGIT_YEAR;
    else if (field.max_length == 7)
      return HTML_TYPE_CREDIT_CARD_EXP_DATE_4_DIGIT_YEAR;
    else
      return HTML_TYPE_CREDIT_CARD_EXP;
  }

  if (autocomplete_attribute_value == "cc-exp-month")
    return HTML_TYPE_CREDIT_CARD_EXP_MONTH;

  if (autocomplete_attribute_value == "cc-exp-year") {
    if (field.max_length == 2)
      return HTML_TYPE_CREDIT_CARD_EXP_2_DIGIT_YEAR;
    else if (field.max_length == 4)
      return HTML_TYPE_CREDIT_CARD_EXP_4_DIGIT_YEAR;
    else
      return HTML_TYPE_CREDIT_CARD_EXP_YEAR;
  }

  if (autocomplete_attribute_value == "cc-csc")
    return HTML_TYPE_CREDIT_CARD_VERIFICATION_CODE;

  if (autocomplete_attribute_value == "cc-type")
    return HTML_TYPE_CREDIT_CARD_TYPE;

  if (autocomplete_attribute_value == "transaction-amount")
    return HTML_TYPE_TRANSACTION_AMOUNT;

  if (autocomplete_attribute_value == "transaction-currency")
    return HTML_TYPE_TRANSACTION_CURRENCY;

  if (autocomplete_attribute_value == "tel")
    return HTML_TYPE_TEL;

  if (autocomplete_attribute_value == "tel-country-code")
    return HTML_TYPE_TEL_COUNTRY_CODE;

  if (autocomplete_attribute_value == "tel-national")
    return HTML_TYPE_TEL_NATIONAL;

  if (autocomplete_attribute_value == "tel-area-code")
    return HTML_TYPE_TEL_AREA_CODE;

  if (autocomplete_attribute_value == "tel-local")
    return HTML_TYPE_TEL_LOCAL;

  if (autocomplete_attribute_value == "tel-local-prefix")
    return HTML_TYPE_TEL_LOCAL_PREFIX;

  if (autocomplete_attribute_value == "tel-local-suffix")
    return HTML_TYPE_TEL_LOCAL_SUFFIX;

  if (autocomplete_attribute_value == "email")
    return HTML_TYPE_EMAIL;

  return HTML_TYPE_UNKNOWN;
}

然后在解析表单字段时使用此方法:

void FormStructure::ParseFieldTypesFromAutocompleteAttributes() {
  const std::string kDefaultSection = "-default";

  has_author_specified_types_ = false;
  has_author_specified_sections_ = false;
  for (AutofillField* field : fields_) {
    // To prevent potential section name collisions, add a default suffix for
    // other fields.  Without this, 'autocomplete' attribute values
    // "section--shipping street-address" and "shipping street-address" would be
    // parsed identically, given the section handling code below.  We do this
    // before any validation so that fields with invalid attributes still end up
    // in the default section.  These default section names will be overridden
    // by subsequent heuristic parsing steps if there are no author-specified
    // section names.
    field->set_section(kDefaultSection);

    // Canonicalize the attribute value by trimming whitespace, collapsing
    // non-space characters (e.g. tab) to spaces, and converting to lowercase.
    std::string autocomplete_attribute =
        base::CollapseWhitespaceASCII(field->autocomplete_attribute, false);
    autocomplete_attribute = base::ToLowerASCII(autocomplete_attribute);

    // The autocomplete attribute is overloaded: it can specify either a field
    // type hint or whether autocomplete should be enabled at all.  Ignore the
    // latter type of attribute value.
    if (autocomplete_attribute.empty() ||
        autocomplete_attribute == "on" ||
        autocomplete_attribute == "off") {
      continue;
    }

    // Any other value, even it is invalid, is considered to be a type hint.
    // This allows a website's author to specify an attribute like
    // autocomplete="other" on a field to disable all Autofill heuristics for
    // the form.
    has_author_specified_types_ = true;

    // Tokenize the attribute value.  Per the spec, the tokens are parsed in
    // reverse order.
    std::vector tokens = base::SplitString(
        autocomplete_attribute, " ", base::KEEP_WHITESPACE,
        base::SPLIT_WANT_NONEMPTY);

    // The final token must be the field type.
    // If it is not one of the known types, abort.
    DCHECK(!tokens.empty());
    std::string field_type_token = tokens.back();
    tokens.pop_back();
    HtmlFieldType field_type =
        FieldTypeFromAutocompleteAttributeValue(field_type_token, *field);
    if (field_type == HTML_TYPE_UNKNOWN)
      continue;

    // The preceding token, if any, may be a type hint.
    if (!tokens.empty() && IsContactTypeHint(tokens.back())) {
      // If it is, it must match the field type; otherwise, abort.
      // Note that an invalid token invalidates the entire attribute value, even
      // if the other tokens are valid.
      if (!ContactTypeHintMatchesFieldType(tokens.back(), field_type))
        continue;

      // Chrome Autofill ignores these type hints.
      tokens.pop_back();
    }

    // The preceding token, if any, may be a fixed string that is either
    // "shipping" or "billing".  Chrome Autofill treats these as implicit
    // section name suffixes.
    DCHECK_EQ(kDefaultSection, field->section());
    std::string section = field->section();
    HtmlFieldMode mode = HTML_MODE_NONE;
    if (!tokens.empty()) {
      if (tokens.back() == kShippingMode)
        mode = HTML_MODE_SHIPPING;
      else if (tokens.back() == kBillingMode)
        mode = HTML_MODE_BILLING;
    }

    if (mode != HTML_MODE_NONE) {
      section = "-" + tokens.back();
      tokens.pop_back();
    }

    // The preceding token, if any, may be a named section.
    const std::string kSectionPrefix = "section-";
    if (!tokens.empty() &&
        base::StartsWith(tokens.back(), kSectionPrefix,
                         base::CompareCase::SENSITIVE)) {
      // Prepend this section name to the suffix set in the preceding block.
      section = tokens.back().substr(kSectionPrefix.size()) + section;
      tokens.pop_back();
    }

    // No other tokens are allowed.  If there are any remaining, abort.
    if (!tokens.empty())
      continue;

    if (section != kDefaultSection) {
      has_author_specified_sections_ = true;
      field->set_section(section);
    }

    // No errors encountered while parsing!
    // Update the |field|'s type based on what was parsed from the attribute.
    field->SetHtmlType(field_type, mode);
  }

  was_parsed_for_autocomplete_attributes_ = true;
}