/// <summary>
/// Attempts to extract a match from a <c>candidate</c> character sequence.
/// </summary>
///
/// <param name="candidate">the candidate text that might contain a phone number</param>
/// <param name="offset">the offset of <c>candidate</c> within <see cref="text" /></param>
/// <returns>the match found, null if none can be found</returns>
private PhoneNumberMatch ExtractMatch(string candidate, int offset)
{
// Skip a match that is more likely a publication page reference or a date.
if (PubPages.IsMatch(candidate) || SlashSeparatedDates.IsMatch(candidate))
{
return(null);
}
// Skip potential time-stamps.
if (TimeStamps.IsMatch(candidate))
{
var followingText = text.Substring(offset + candidate.Length);
if (TimeStampsSuffix.IsMatchBeginning(followingText))
{
return(null);
}
}
// Try to come up with a valid match given the entire candidate.
var rawString = candidate;
var match = ParseAndVerify(rawString, offset);
return(match ?? ExtractInnerMatch(rawString, offset));
// If that failed, try to find an "inner match" - there might be a phone number within this
// candidate.
}
/// <summary>
/// Parses a phone number from the {@code candidate} using {@link PhoneNumberUtil#parse} and
/// verifies it matches the requested {@link #leniency}. If parsing and verification succeed, a
/// corresponding <see cref="PhoneNumberMatch" /> is returned, otherwise this method returns null.
/// </summary>
///
/// <param name="candidate">the candidate match</param>
/// <param name="offset">the offset of <c>candidate</c> within <see cref="text" /></param>
/// <returns>the parsed and validated phone number match, or null</returns>
private PhoneNumberMatch ParseAndVerify(string candidate, int offset)
{
try
{
// Check the candidate doesn't contain any formatting which would indicate that it really
// isn't a phone number.
if (!MatchingBrackets.IsMatchAll(candidate))
{
return(null);
}
// If leniency is set to VALID or stricter, we also want to skip numbers that are surrounded
// by Latin alphabetic characters, to skip cases like abc8005001234 or 8005001234def.
if (leniency >= PhoneNumberUtil.Leniency.VALID)
{
// If the candidate is not at the start of the text, and does not start with phone-number
// punctuation, check the previous character.
if (offset > 0 && !LeadClass.IsMatchBeginning(candidate))
{
var previousChar = text[offset - 1];
// We return null if it is a latin letter or an invalid punctuation symbol.
if (IsInvalidPunctuationSymbol(previousChar) || IsLatinLetter(previousChar))
{
return(null);
}
}
var lastCharIndex = offset + candidate.Length;
if (lastCharIndex < text.Length)
{
var nextChar = text[lastCharIndex];
if (IsInvalidPunctuationSymbol(nextChar) || IsLatinLetter(nextChar))
{
return(null);
}
}
}
var number = phoneUtil.ParseAndKeepRawInput(candidate, preferredRegion);
if (leniency.Verify(number, candidate, phoneUtil, this))
{
// We used parseAndKeepRawInput to create this number, but for now we don't return the extra
// values parsed. TODO: stop clearing all values here and switch all users over
// to using rawInput() rather than the rawString() of PhoneNumberMatch.
var bnumber = number.ToBuilder();
bnumber.ClearCountryCodeSource();
bnumber.ClearRawInput();
bnumber.ClearPreferredDomesticCarrierCode();
return(new PhoneNumberMatch(offset, candidate, bnumber.Build()));
}
}
catch (NumberParseException)
{
// ignore and continue
}
return(null);
}