Extension methods and classes I often find useful for C# development.
The extension methods are written to make the source code read more like a natural language, sometimes just wrapping an existing "negative" function into a more natural "not postive" name, eliminating the need for a "!", which doesn't read as naturally.
The package is annotated for nullable reference types, so the compiler can tell you which arguments accept a null and which returns can be one.
Attribute classes to validate properties in models, and to declare how a property should be displayed.
AlphaOnlyAttribute: Check that a string only contains letters. A letter is anythingchar.IsLetteraccepts, so letters outside the ASCII range pass and a space does not. Strings only: it throwsInvalidCastExceptionon a member of any other type.ConditionalRequiredAttribute: Check that a property has a value when another property on the same object holds a particular value. SetDependentPropertyandRequiredWhenValue.IsInListAttribute: Check that a property holds one of a fixed list of allowed values. SetIgnoreCaseto compare strings without regard to case.MaskAttribute: Declare how a property's value should be masked when displayed or logged. SetMaskChar,VisiblePrefixLengthandVisibleSuffixLength. Not a validation attribute: apply it withToMaskedStringinMaskExtensionMethods.NumericOnlyAttribute: Check that a string holds a number and nothing else. With no option set, every character has to be an ASCII digit, which brings in no culture and puts no limit on how many there are. SetAllowDecimal,AllowThousandsSeparator,AllowCurrencySymbolorAllowNegativeand the text is read as a number under the current culture instead, so which separators it may use is that culture's answer, andUseInvariantCulturereads it the same way everywhere. Reading it as a number bringsdecimal's ceiling with it, so a run of more than 29 digits passes with no option set and fails with one set. Strings only: it throwsInvalidCastExceptionon a member of any other type.UniqueItemsAttribute: Check that a collection property does not contain duplicate items.
This class creates a cache object with a generic key and generic value.
Clear: Remove all items from the cache.Get: Retrieves a value from the cache, or default, if not in the cache.Set: Adds or updates a value in the cache.Remove: Remove an entry fom the cache.RemoveExpiredItems: Removes all expired items from the cache.Dispose: Stops the background cleanup, for a cache that was given a cleanup interval. A cache without one has nothing to stop.
Expired entries are dropped as they are read, so a cache that is read regularly needs nothing else. For entries nobody reads again, either call RemoveExpiredItems or hand the constructor a cleanup interval:
using var cache = new GenericCache<int, string>(
defaultExpiration: TimeSpan.FromMinutes(15),
cleanupInterval: TimeSpan.FromMinutes(5));That drops expired entries on a thread pool timer every five minutes. A tick arriving while the previous pass is still running is dropped rather than queued. A cache given a cleanup interval has to be disposed: the timer holds a reference to the cache, so until then the cache cannot be collected and the pass keeps running. The constructor that takes no interval starts no timer, which is what it has always done.
This class provides extension methods for reading a column out of an IDataReader by name instead of by ordinal, which is the forward-only path used for anything too large to pull into a DataSet.
Every method returns default when the column holds DBNull, and a nullable type is converted to its underlying type, so a null column read as int? returns null. A column name that is not in the result set throws IndexOutOfRangeException naming the column and listing the ones that are there. A value that will not convert throws InvalidCastException naming the column, which is the whole point of reading by name.
GetValue<T>: Gets a typed value from a column, by name.GetBoolean,GetDateTime,GetDecimal,GetDouble,GetFloat,GetGuid,GetInt32,GetString: Typed wrappers aroundGetValue<T>.GetByteArray: Gets a column as abyte[]. Named for the type becauseIDataReaderalready declares aGetBytesthat copies into a caller's buffer.
These share their names with the ordinal-based methods IDataReader declares itself. Overload resolution separates them by argument type, so reader.GetString("Name") reaches this class and reader.GetString(0) reaches the reader's own.
This class provides extension methods for DataTables and DataSets
Get<T>: Gets a typed value from a column in a DataRow.HasColumn: Checks if a DataSet has a column with the specified name.HasRows: Checks if a DataSet has any rows.
This class provides extension methods for DateTime in C#.
EndOfDay: Returns the end of the day 23:59:59 for the provided date.EndOfMonth: Returns the date for the end of the month, at 23:59:59, for the provided date.IsWeekday: Checks if the given date is a weekday.IsWeekend: Checks if the given date is a weekend.NextDay: Gets the next day from the given date.PreviousDay: Gets the previous day from the given date.StartOfDay: Returns the start of the day 00:00:00 for the provided date.StartOfMonth: Returns the date for the start of the month, at 00:00:00, for the provided date.ToIso8601String: Converts the provided date to an ISO 8601 round-trip ("O") string. AUtcvalue ends in "Z", aLocalvalue carries its real offset, and anUnspecifiedvalue carries neither.
This class applies the DisplayFormatAttribute from System.ComponentModel.DataAnnotations, which is otherwise only honored by UI frameworks. A bare specifier ("yyyy-MM-dd") and the conventional wrapped form ("{0:yyyy-MM-dd}") are both accepted.
ToDisplayString: Returns the named property's value, formatted with itsDisplayFormatAttribute.ToDisplayStrings: Returns every property carrying aDisplayFormatAttribute, formatted, keyed by property name.
This class provides extension methods for Enums in C#.
GetEnumDescription: Gets the description of an enum value, from its[Description]attribute.GetEnumDescriptions: Gets all descriptions of a specific enum type.GetEnumDisplayName: Gets the display name of an enum value, from theNameon its[Display]attribute. Falls back to the value's string representation when there is no attribute, or the attribute sets noName.GetEnumDisplayNames: Gets all display names of a specific enum type.GetEnumValues: Gets all values of a specific enum type, as a read-only collection. The same instance is returned to every caller.ParseEnum: Parses a string to an enum value.
This class provides extension methods for JSON manipulation in C#.
AsDeserializedJson: Deserializes the JSON string to an object of the specified type.AsSerializedJson: Serializes the specified object to a JSON string.GetValueFromJsonPath: Retrieves a value from a JSON string using a JSON path.GetValueFromJsonPath<T>: Retrieves a typed value from a JSON string using a JSON path.PrettyPrintJson(string): Formats the JSON string with indented formatting.PrettyPrintJson(object): Serializes the specified object to a JSON string with indented formatting.
This class provides LINQ-related extension methods in C#.
ForEach(IEnumerable): Applies an action to each element in the collection.ForEach(List): Applies an action to each element in the list.HasDuplicatePropertyValue<T, TProperty>: Checks if any objects have the same value in the specified property.HasDuplicatePropertyValue<T>: Checks if any objects have the same value in the specified string property.None: Checks if none of the elements in the collection satisfy the provided condition. If no condition is provided, it checks if the collection is empty.RandomElement: Returns a random element from the list.
This class applies the MaskAttribute declared on a property, for hiding a value when it is displayed or logged.
ToMaskedString: Returns the named property's value with itsMaskAttributeapplied.ToMaskedStrings: Returns every property carrying aMaskAttribute, masked, keyed by property name.
This class provides extension methods for numerical operations in C#.
ApproximatelyEquals: Checks if two floating point numbers are approximately equal, within a specified tolerance.IsEven: Checks if the given integer is even.IsEvenlyDivisibleBy: Checks if the given integer is evenly divisible by another integer.IsNegative: Checks if the given integer is negative.IsOdd: Checks if the given integer is odd.IsPositive: Checks if the given integer is positive.PopulationStandardDeviation: Calculates the standard deviation of a collection, dividing by n. Use when the values are the complete set. Overloads fordouble,intanddecimal.StandardDeviation: Calculates the sample standard deviation of a collection, dividing by n-1. Use when the values are a sample of a larger population. Overloads fordouble,intanddecimal.
This class provides extension methods for objects in C#.
DeepClone: Creates a deep clone of the source object.HasCustomAttributeOfType: Checks if the property info has a custom attribute of a specific type.IsFloatingPointType: Checks if the object is of a floating point type.IsIntegerType: Checks if the object is of an integer type.IsNotNull: Checks if the object is not null.IsNotOfType(with Type parameter): Checks if the object is not exactly of a specific type.IsNotOfType(for Type with baseType parameter): Checks if the type is not exactly a specific type.IsNotOfType<T>: Checks if the object is not exactly of a specific type.IsNotOfType<T>(for Type): Checks if the type is not exactly a specific type.IsNotOfTypeOrSubclass(with Type parameter): Checks if the object is not of a specific type, a subclass of it, or an implementation of it.IsNotOfTypeOrSubclass(for Type with baseType parameter): Checks if the type is not a specific type, a subclass of it, or an implementation of it.IsNotOfTypeOrSubclass<T>: Checks if the object is not of a specific type, a subclass of it, or an implementation of it.IsNotOfTypeOrSubclass<T>(for Type): Checks if the type is not a specific type, a subclass of it, or an implementation of it.IsNull: Checks if the object is null.IsNumericType: Checks if the object is of a numeric type.IsOfType(with Type parameter): Checks if the object is exactly of a specific type.IsOfType(for Type with baseType parameter): Checks if the type is exactly a specific type.IsOfType<T>: Checks if the object is exactly of a specific type.IsOfType<T>(for Type): Checks if the type is exactly a specific type.IsOfTypeOrSubclass(with Type parameter): Checks if the object is of a specific type, a subclass of it, or an implementation of it.IsOfTypeOrSubclass(for Type with baseType parameter): Checks if the type is a specific type, a subclass of it, or an implementation of it.IsOfTypeOrSubclass<T>: Checks if the object is of a specific type, a subclass of it, or an implementation of it.IsOfTypeOrSubclass<T>(for Type): Checks if the type is a specific type, a subclass of it, or an implementation of it.
The IsOfType family is an exact type match. The IsOfTypeOrSubclass family also accepts subclasses and, when the type is an interface, implementations of it.
The same reflection helpers as the SmartReflection service class, called on an object instead of on a Type, so myObject.GetPropertyValue<string>("Name") reads the way the rest of this package does. They share SmartReflection's property cache.
Lookups use the object's runtime type, so an object held in a base-class or object variable still finds its own properties.
GetPropertiesWithAttribute<TAttribute>: Retrieves all properties on the object that have a specific attribute.GetPropertyNames: Gets the names of all public instance properties on the object.GetPropertyType: Gets the type of a specified property on the object.GetPropertyValue<TProperty>: Gets the value of a property from the object, with type safety.HasAttribute<TAttribute>: Checks if the object's type has a specific attribute.HasProperty: Checks if the object has a specific property.HasPropertyAttribute<TAttribute>: Checks if a property on the object has a specific attribute.InvokeMethod<TResult>: Invokes a method on the object by name, with type-safe return value.SetPropertyValue<TProperty>: Sets the value of a property on the object, with type safety.
This class provides extension methods for string manipulations in C#.
CollapseWhitespace: Trims the text and reduces every run of whitespace inside it to a single space, tabs and line breaks included. A null returns null, and text that needs nothing changed is returned as the same instance.ConvertFromString<T>: Converts a string to the specified type, if possible.DoesNotHaveText: Returns 'true' if the string is null, empty, or only contains whitespace.DoesNotMatch: Check if strings are not equal, using InvariantCultureIgnoreCase.HasText: Returns 'true' if the string is not null, empty, or only contains whitespace.IncludesTheWords: Checks if a string contains all the words in the specified array. Compares withCurrentCultureIgnoreCase, or pass aStringComparisonas the first argument.OrdinalandOrdinalIgnoreCaseare an order of magnitude faster.IsDigitsOnly: Returns 'true' if the string only contains digits. A null returns 'false'. An empty string returns 'true', because it holds no character that is not a digit.Mask: Replaces the middle of a string with a mask character, leaving a number of characters visible at each end. Separators stay visible by default, so"1234-5678-9012-5678".Mask('*', 4, 4)returns"1234-****-****-5678".Matches: Check if strings are equal, using InvariantCultureIgnoreCase.NullIfEmpty: Returns a null if the string is null, empty, or only contains whitespace.RemoveText: Removes all instances of the specified text from the string.Repeat: Returns a string with the text repeated the specified number of times.SplitPath: Convert a file path into an array of the individual directories, splitting on both forward and back slashes. Entries are trimmed, and no empty entries are returned.ToDigitsOnly: Returns a string with all non-digits removed.ToMaxLengthOf: Trims string to a maximum length, if it exceeds that lengthToStringWithLineFeeds: Converts an IEnumerable of strings to a single string with line feeds between each string.
This class provides extension methods for StringBuilder objects in C#.
All functions accept an optional StringBuilderOptions object, which can be used to specify the behavior of the function.
When it is omitted, the text is appended unchanged.
Append: Appends a string to the StringBuilder object.AppendFormatted: Appends a formatted string to the StringBuilder object. The options are an overload rather than an optional parameter, sosb.AppendFormatted("{0} of {1}", current, total)needs nothing standing in front of the arguments.AppendIf: Appends text to the StringBuilder object, if a function evaluates to 'true'.AppendJoined: Appends a joined string to the StringBuilder object, using the specified separator.AppendLine: Appends a string and line feed to the StringBuilder object.AppendLineFormatted: Appends a formatted string and line feed to the StringBuilder object. Same two overloads asAppendFormatted.AppendLineIf: Appends text and line feed to the StringBuilder object, if a function evaluates to 'true'.AppendLineIfNotEmpty: If the passed in line is not empty, it will be appended to the StringBuilder object.AppendLineJoined: Appends a joined string and line feed to the StringBuilder object, using the specified separator.
Properties on the options object, all optional. A new StringBuilderOptions with nothing set leaves the text alone.
EscapeHtml: HTML-encodes the text.Format: A composite format string the text is passed through, such as"[{0}]".IndentDepth: How many tabs or spaces make up one indent level. Defaults to 4.IndentLevel: How many levels to indent the text.IndentType:IndentType.Spaces(the default) orIndentType.Tabs.MaxLength: Caps the length of the value, not the length of the finished string. It is applied afterToUpper,ToLowerandEscapeHtmlhave rewritten the value, and beforeFormat,PrefixText,SuffixTextand the indent wrap it, so none of those four is ever cut in half. AMaxLengthof 3 with aSuffixTextof]returns four characters.PrefixText: Text placed before the value.SuffixText: Text placed after the value.ToLower/ToUpper: Changes the case of the text. Setting both leaves the case alone.
This class reads version numbers out of strings, keeping the alpha text rather than stripping it. 1.2.3-beta.1, 2.0.0-rc1 and 3.1.0+build7 all read. The result is a SemanticVersion, described under Models below, so the prerelease label survives alongside the numbers.
ToSemanticVersion: Reads a version string. ThrowsFormatExceptionon text it cannot read.TryParseSemanticVersion: The same, without throwing. Returns false and sets null for text it cannot read.NumericPartOfVersion: Returns the numbers only, so"1.2.3-beta.1"gives"1.2.3". Null when the text is not a version.PrereleaseLabelOf: Returns the label without its leading-, so"1.2.3-beta.1"gives"beta.1". Null when there is no label.
ToSemanticVersion and TryParseSemanticVersion divide the work the way Version.Parse and Version.TryParse do, so the caller picks whether unreadable input is exceptional rather than having that decided for them. Nothing here returns a zero version for input it could not read.
This class provides extension methods for XElement, the LINQ to XML API, mirroring the XmlNode set below member for member. A missing attribute or element returns null from the string methods and the type's default from the others, and a value that will not parse returns the type's default rather than throwing, which is what the XmlNode set does. An unprefixed name matches only attributes and elements that are in no namespace.
Both sets parse the same way, under the invariant culture, so a document reads the same on every machine. A boolean accepts true, false, 1 and 0 in any casing, covering both what bool.ToString() writes and what schema-generated XML writes. A date keeps what the text said about its time zone, so a value ending in Z comes back with Kind of Utc, and a slash-separated date is always MM/dd/yyyy.
AttributeAsBool: Returns the value of the specified attribute as a boolean.AttributeAsDateTime: Returns the value of the specified attribute as a DateTime.AttributeAsInt: Returns the value of the specified attribute as an integer.AttributeAsString: Returns the value of the specified attribute as a string.ElementAsInt: Returns the text of the specified child element as an integer.ElementAsString: Returns the text of the specified child element as a string.GetValue: Returns the value of an attribute or a child element of the given name, whichever carries it, for XML that writes the same value either way. The attribute wins when both carry it, and a miss returns null. This is the one member with noXmlNodecounterpart.
These throw ArgumentNullException for a null element, where the XmlNode set throws NullReferenceException.
This class provides extension methods for XML handling in C#, using XmlNode, the pre-LINQ API. See XElementExtensionMethods above for the same set over XElement.
AttributeAsBool: Returns the value of the specified attribute as a boolean.AttributeAsDateTime: Returns the value of the specified attribute as a DateTime.AttributeAsInt: Returns the value of the specified attribute as an integer.AttributeAsString: Returns the value of the specified attribute as a string.ElementAsInt: Returns the inner text of the specified child element as an integer.ElementAsString: Returns the inner text of the specified child element as a string.
These classes can be used as base classes for models and handle property changed notification and logging of changed property values.
An immutable record holding a version's numeric parts alongside its prerelease label and build metadata, so 1.2.3-beta.1 stays one value. System.Version has no room for a label, which is why this exists: through a Version, 1.2.3-beta.1 and 1.2.3 compare as equal, and a caller deciding whether to upgrade gets the wrong answer with nothing to tell them so. Build it with ToSemanticVersion or TryParseSemanticVersion, above.
Major,Minor,Patch,Revision: The numeric parts. A part the text did not carry is zero.Revisionis there because .NET version strings often have a fourth part; Semantic Versioning does not.PrereleaseLabel: The label without its leading-, or null.BuildMetadata: The metadata without its leading+, or null.IsPrerelease: Whether there is a label.NumericPart: The numbers on their own, as a string.ToVersion: Converts to aSystem.Version. Lossy on purpose: the label and metadata are dropped.
Ordering follows the Semantic Versioning precedence rules, through IComparable<SemanticVersion> and the <, >, <= and >= operators, so 1.0.0-alpha < 1.0.0-beta.2 < 1.0.0-beta.11 < 1.0.0-rc.1 < 1.0.0. Build metadata takes no part in precedence, while equality covers every part including it. Those disagree in one case: 1.2.3+a and 1.2.3+b are not equal, but neither is greater.
Base class that handles property changed notification.
-SetProperty<T>: Used to set a property's backing field and raise property changed event.
Base class that inherits from ObservableModel (to handle property change notification) and also logs the values of the changed properties. Implements IChangeTracking.
-AcceptChanges: Clears the PropertyChangeLog.
-IsChanged: True when the PropertyChangeLog holds at least one entry. Raises property changed when that changes.
-PropertyChangeLog: ObservableCollection of properties values that were changed.
One entry in a PropertyChangeTrackingModel's log. Inherit from it to record more about a change, such as the user who made it.
-ChangeDateTime: When the property was changed, in UTC. Kind is DateTimeKind.Utc, so call ToLocalTime() to display it.
-NewValue: The value the property was changed to.
-PropertyName: The name of the property that changed.
Classes to handle common tasks.
The shared base behind JsonRedactionService and XmlRedactionService. It holds the supplied patterns as a CompositeRegexMatcher, which its subclasses reach through the protected _matcher field.
Both services expose the same four members, Redact and RedactToString over the document type and over text, and every one of them throws ArgumentNullException for a null argument.
Accepts a list of regex patterns and checks if a string matches any of them. This is what BaseRedactionService uses to decide which paths get redacted.
-MatchesAny (string): Checks if the string matches any of the regex patterns.
-MatchesAny (ReadOnlySpan<char>): The same check, for text a caller has built and does not need as a string.
-HasPatterns: Whether any pattern was supplied. False means nothing can ever match, so a caller can skip work it would only do to find that out.
Removes sensitive values from JSON, for paths matching any of a list of regex patterns.
Paths are property names from the root, separated by ., with array entries indexed: the ssn property in {"user": {"ssn": "..."}} has the path user.ssn, and the first entry of an items array has the path items[0]. Patterns are matched anywhere in a path rather than against the whole of it, so a pattern matching an object also matches everything below it.
A redacted string becomes empty, a number becomes zero, a boolean becomes false, and an object or array becomes null. Pass ignoreCase: true to the constructor to match paths case-insensitively.
Redact(JsonObject): Redacts the JsonObject in place and returns it.Redact(string): Parses the JSON string, redacts it, and returns the result as a JsonObject.RedactToString(JsonObject): Redacts the JsonObject in place and returns the result as a JSON string.RedactToString(string): Parses the JSON string, redacts it, and returns the result as a JSON string.
This class is designed to create cryptographically random numbers in C#.
GetNumberBetween: Generates a cryptographically random number between the specified minimum and maximum values.
This class provides efficient, type-safe reflection utilities with property caching for improved performance in .NET applications.
HasAttribute<TAttribute>: Checks if a type has a specific attribute.HasPropertyAttribute<TAttribute>: Checks if a property on a type has a specific attribute.GetPropertiesWithAttribute<TAttribute>: Retrieves all properties on a type that have a specific attribute.GetPropertyValue<TProperty>: Gets the value of a property from an object, with type safety.SetPropertyValue<TProperty>: Sets the value of a property on an object, with type safety.GetPropertyNames: Gets the names of all public instance properties on a type.HasProperty: Checks if a type has a specific property.GetPropertyType: Gets the type of a specified property on a type.InvokeMethod<TResult>: Invokes a method on an object by name, with type-safe return value.
Removes sensitive values from XML, for paths matching any of a list of regex patterns.
Paths are element names from the root, separated by ., so the ssn element in <person><ssn/></person> has the path person.ssn. An attribute is its element's path plus .@ and the attribute name, so person.@id. Repeated sibling elements are not indexed, so one pattern redacts every element sharing a path. Patterns are matched anywhere in a path rather than against the whole of it, so a pattern matching an element also matches everything below it, including its attributes.
A redacted element keeps its tag and loses all of its content, including child elements. A redacted attribute keeps its name and gets an empty value. Pass ignoreCase: true to the constructor to match paths case-insensitively.
Redact(XmlDocument): Redacts the XmlDocument in place and returns it.Redact(string): Loads the XML string, redacts it, and returns the result as an XmlDocument.RedactToString(XmlDocument): Redacts the XmlDocument in place and returns the result as an XML string.RedactToString(string): Loads the XML string, redacts it, and returns the result as an XML string.