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Initialize Regex lazy in BasicHtmlWebResponseObject #19361

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Merged
iSazonov merged 6 commits into from
Mar 18, 2023
Merged

Initialize Regex lazy in BasicHtmlWebResponseObject #19361

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0118018
regex
CarloToso Mar 17, 2023
4a8b9d2
fix build
CarloToso Mar 17, 2023
ba1d437
class HtmlParser
CarloToso Mar 17, 2023
f5e90a1
follow suggestions
CarloToso Mar 17, 2023
c0dbd6e
readonly
CarloToso Mar 18, 2023
d140ed5
solve codefactor issues, ABC Regex
CarloToso Mar 18, 2023
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67 changes: 22 additions & 45 deletions ...l.Commands.Utility/commands/utility/WebCmdlet/Common/BasicHtmlWebResponseObject.Common.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -16,17 +16,6 @@ namespace Microsoft.PowerShell.Commands
/// </summary>
public class BasicHtmlWebResponseObject : WebResponseObject
{
#region Private Fields

private static Regex s_attribNameValueRegex;
private static Regex s_attribsRegex;
private static Regex s_imageRegex;
private static Regex s_inputFieldRegex;
private static Regex s_linkRegex;
private static Regex s_tagRegex;

#endregion Private Fields

#region Constructors

/// <summary>
Expand All @@ -43,7 +32,6 @@ public BasicHtmlWebResponseObject(HttpResponseMessage response) : this(response,
/// <param name="contentStream"></param>
public BasicHtmlWebResponseObject(HttpResponseMessage response, Stream contentStream) : base(response, contentStream)
{
EnsureHtmlParser();
InitializeContent();
InitializeRawContent(response);
}
Expand Down Expand Up @@ -82,10 +70,8 @@ public WebCmdletElementCollection InputFields
{
if (_inputFields == null)
{
EnsureHtmlParser();

List<PSObject> parsedFields = new();
MatchCollection fieldMatch = s_inputFieldRegex.Matches(Content);
MatchCollection fieldMatch = HtmlParser.InputFieldRegex.Matches(Content);
foreach (Match field in fieldMatch)
{
parsedFields.Add(CreateHtmlObject(field.Value, "INPUT"));
Expand All @@ -109,10 +95,8 @@ public WebCmdletElementCollection Links
{
if (_links == null)
{
EnsureHtmlParser();

List<PSObject> parsedLinks = new();
MatchCollection linkMatch = s_linkRegex.Matches(Content);
MatchCollection linkMatch = HtmlParser.LinkRegex.Matches(Content);
foreach (Match link in linkMatch)
{
parsedLinks.Add(CreateHtmlObject(link.Value, "A"));
Expand All @@ -136,10 +120,8 @@ public WebCmdletElementCollection Images
{
if (_images == null)
{
EnsureHtmlParser();

List<PSObject> parsedImages = new();
MatchCollection imageMatch = s_imageRegex.Matches(Content);
MatchCollection imageMatch = HtmlParser.ImageRegex.Matches(Content);
foreach (Match image in imageMatch)
{
parsedImages.Add(CreateHtmlObject(image.Value, "IMG"));
Expand Down Expand Up @@ -188,27 +170,6 @@ private static PSObject CreateHtmlObject(string html, string tagName)
return elementObject;
}

private static void EnsureHtmlParser()
{
s_tagRegex ??= new Regex(@"<\w+((\s+[^""'>/=\s\p{Cc}]+(\s*=\s*(?:"".*?""|'.*?'|[^'"">\s]+))?)+\s*|\s*)/?>",
RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.Compiled);

s_attribsRegex ??= new Regex(@"(?<=\s+)([^""'>/=\s\p{Cc}]+(\s*=\s*(?:"".*?""|'.*?'|[^'"">\s]+))?)",
RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.Compiled);

s_attribNameValueRegex ??= new Regex(@"([^""'>/=\s\p{Cc}]+)(?:\s*=\s*(?:""(.*?)""|'(.*?)'|([^'"">\s]+)))?",
RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.Compiled);

s_inputFieldRegex ??= new Regex(@"<input\s+[^>]*(/?>|>.*?</input>)",
RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.Compiled);

s_linkRegex ??= new Regex(@"<a\s+[^>]*(/>|>.*?</a>)",
RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.Compiled);

s_imageRegex ??= new Regex(@"<img\s[^>]*?>",
RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.Compiled);
}

private void InitializeRawContent(HttpResponseMessage baseResponse)
{
StringBuilder raw = ContentHelper.GetRawContentHeader(baseResponse);
Expand All @@ -223,16 +184,16 @@ private static void ParseAttributes(string outerHtml, PSObject elementObject)
{
// Extract just the opening tag of the HTML element (omitting the closing tag and any contents,
// including contained HTML elements)
Match match = s_tagRegex.Match(outerHtml);
Match match = HtmlParser.TagRegex.Match(outerHtml);

// Extract all the attribute specifications within the HTML element opening tag
MatchCollection attribMatches = s_attribsRegex.Matches(match.Value);
MatchCollection attribMatches = HtmlParser.AttribsRegex.Matches(match.Value);

foreach (Match attribMatch in attribMatches)
{
// Extract the name and value for this attribute (allowing for variations like single/double/no
// quotes, and no value at all)
Match nvMatches = s_attribNameValueRegex.Match(attribMatch.Value);
Match nvMatches = HtmlParser.AttribNameValueRegex.Match(attribMatch.Value);
Debug.Assert(nvMatches.Groups.Count == 5);

// Name is always captured by group #1
Expand All @@ -259,5 +220,21 @@ private static void ParseAttributes(string outerHtml, PSObject elementObject)
}

#endregion Methods

// This class is needed so the static Regexes are initialized only the first time they are used
private static class HtmlParser
{
internal static readonly Regex AttribsRegex = new Regex(@"(?<=\s+)([^""'>/=\s\p{Cc}]+(\s*=\s*(?:"".*?""|'.*?'|[^'"">\s]+))?)", RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.Compiled);

internal static readonly Regex AttribNameValueRegex = new Regex(@"([^""'>/=\s\p{Cc}]+)(?:\s*=\s*(?:""(.*?)""|'(.*?)'|([^'"">\s]+)))?", RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.Compiled);

internal static readonly Regex ImageRegex = new Regex(@"<img\s[^>]*?>", RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.Compiled);

internal static readonly Regex InputFieldRegex = new Regex(@"<input\s+[^>]*(/?>|>.*?</input>)", RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.Compiled);

internal static readonly Regex LinkRegex = new Regex(@"<a\s+[^>]*(/>|>.*?</a>)", RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.Compiled);

internal static readonly Regex TagRegex = new Regex(@"<\w+((\s+[^""'>/=\s\p{Cc}]+(\s*=\s*(?:"".*?""|'.*?'|[^'"">\s]+))?)+\s*|\s*)/?>", RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.Compiled);
}
}
}