SearchExtensions

SearchExtensions is a library of IQueryable and IEnumerable extension methods to perform searching. More information on these packages and it's use can be found by, visiting my blog.

This project is represents the source code for the following 3 nuget packages:

• NinjaNye.SearchExtensions - A fluent api for performing complex searches across IEnumerable and IQueryable collections.
• NinjaNye.SearchExtensions.Levenshtein - This package specialises in performing Levenshtein searches across IEnumerable collections.
• NinjaNye.SearchExtensions.Soundex - This package specialises in performing Soundex searches across IEnumerable collections.

Version 3 release notes

• Soundex support migrated to dedicated nuget package
• Levenshtein support migrated to dedicated nuget package
• Constructed expressions can now be pulled out and re-used.

As of version 3.0 Soundex and Levenshtein support has been migrated into their own respective packages (above). All functionality still remains. If you are currently using Levensthein or Soundex functionlity in version 2.2 or lower, please upgrade to you the dedicated package.

IQueryable Searching

The IQueryable extension methods build expression trees based on your command chain and then sends this request to the data provider when required. This means that your data provider is restricting the records that are brought into memory instead of having all records brought into, and filtered, in memory.

Methods

Search methods available to IQueryable data are:

• Containing - target property contains search term or terms
• IsEqual - target property equals search term or terms
• StartsWith - target property starts with search term or terms

How to: Performing Containing searches

Search for a single search term within a single property

var result = queryableData.Search(x => x.Property1)
                          .Containing("searchTerm");

Search for a single search term within multiple properties

var result = queryableData.Search(x => x.Property1,
                                  x => x.Property2,
                                  x => x.Property3)
                          .Containing("searchTerm");

Search for multiple search terms within a single property

var result = queryableData.Search(x => x.Property1)
                          .Containing("search", "term";

Search for multiple search terms within multiple properties

var result = queryableData.Search(x => x.Property1,
                                  x => x.Property2,
                                  x => x.Property3)
                          .Containing("searchTerm1",
                                      "searchTerm2",
                                      "searchTerm3");

How to: Performing Containing AND searches

Search where a single property contains a single search term
AND a another property contains a single search term

var result = queryableData.Search(x => x.Property1)
                          .Containing("searchTerm1")
                          .Search(x => x.Property1)
                          .Containing("searchTerm2");

Search where a single search term exists within in Property1 OR Property2
AND single search term exists within in Property3 OR Property4

var result = queryableData.Search(x => x.Property1, x => x.Property2)
                          .Containing("searchTerm")
                          .Search(x => x.Property3, x => x.Property4)
                          .Containing("searchTerm");

Search where a single search term exists in Property1 OR Property2
AND any of the multiple search terms exist within a single property

var result = queryableData.Search(x => x.Property1, x => x.Property2)
                          .Containing("searchTerm")
                          .Search(x => x.Property3)
                          .Containing("another", "term");

How to: Performing IsEqual searches

Search where a single property equals a single search term

var result = queryableData.Search(x => x.Property1)
                          .IsEqual("searchTerm");

Search where any one of multiple properties is equal to a single search term

var result = queryableData.Search(x => x.Property1,
                                  x => x.Property2,
                                  x => x.Property3)
                          .IsEqual("searchTerm");

Search where a single property is equal to any one of multiple search terms

var result = queryableData.Search(x => x.Property1)
                          .IsEqual("search", "term");

Search where any one of multiple properties is equal to any one of multiple search terms

var result = queryableData.Search(x => x.Property1,
                                  x => x.Property2,
                                  x => x.Property3)
                          .IsEqual("searchTerm1",
                                   "searchTerm2",
                                   "searchTerm3");

How to: Performing StartsWith searches

Search where a single property starts with a single search term

var result = queryableData.Search(x => x.Property1)
                          .StartsWith("searchTerm");

Search where any one of multiple properties starts with to a single search term

var result = queryableData.Search(x => x.Property1,
                                  x => x.Property2,
                                  x => x.Property3)
                          .StartsWith("searchTerm");

Search where a single property starts with any one of multiple search terms

var result = queryableData.Search(x => x.Property1)
                          .StartsWith("search", "term");

Search where any one of multiple properties starts with any one of multiple search terms

var result = queryableData.Search(x => x.Property1,
                                  x => x.Property2,
                                  x => x.Property3)
                          .StartsWith("searchTerm1",
                                      "searchTerm2",
                                      "searchTerm3");

How to: Combining instructions

With the latest version of SearchExtensions you can also combine search actions. For instance

Search where a single property starts with a single search term AND containing a single search term

var result = queryableData.Search(x => x.Property1)
                          .StartsWith("abc")
                          .Containing("mno");

The ability to pass multiple search terms to any of the action methods still remains:

var result = queryableData.Search(x => x.Property1, x => x.Property2)
                          // that starts with "abc" OR "ninja"
                          .StartsWith("abc", "ninja")
                          // and contains "xyz" OR "extensions"
                          .Containing("xyz", "extensions")  

IEnumerable (in memory) Searches

SearchExtensions has also been extended to support IEnumerable collections.

This means you can now perform all of the above searches on in memory collections should you need to.

Methods

Currently IEnumerable searching has more features available to it than IQueryable, namely EndsWith and SetCulture

• SetCulture - Sets the string comparison culture with which to perform searches
• Containing - target property contains search term or terms
• IsEqual - target property equals search term or terms
• StartsWith - target property starts with search term or terms
• EndsWith - target property ends with search term or terms

The important thing to remember when performing an in memory search is to set the culture to the type of string comparison you wish to perform. If SetCulture is not specified, StringComparison.CurrentCulture is used.

How to: Performing IEnumerable searches

These methods are identical to that of the IQueryable methods.

var result = enumerableData.Search(x => x.Property1)
                           .SetCulture(StringComparison.OrdinalIgnoreCase) // Set culture for comparison
                           .StartsWith("abc")
                           .EndsWith("xyz")
                           .Containing("mno");

It is also possible to switch the StringComparison culture context multiple times

var result = enumerableData.Search(x => x.Property1)
                           .SetCulture(StringComparison.OrdinalIgnoreCase)
                           .StartsWith("abc")  // Uses OrdinalIgnoreCase
                           .SetCulture(StringComparison.Ordinal)
                           .EndsWith("xyz")    // Uses Ordinal
                           .SetCulture(StringComparison.CurrentCulture)
                           .Containing("mno"); //Uses CurrentCulture

Ranked Searches

Another feature of the fluent api across both IQueryable and IEnumerable collections is the ToRanked() method.

As well as returning the matched items, a Ranked Search also returns a hit count for each item in the form of an IRanked<T> result. This enables you to order by hit count to retrieve the most relevant search results.

IRanked<T> result

An IRanked<T> result is simply defined as follows:

public interface IRanked<out T>
{
    int Hits { get; }
    T Item { get; }
}

This is returned using the ToRanked() method:

RankedSearch for a single search term within a single property

var result = queryableData.Search(x => x.Property1)
                          .Containing("searchTerm")
                          .ToRanked();

RankedSearch for a single search term within multiple properties

var result = queryableData.Search(x => x.Property1, x => x.Property2, x => x.Property3)
                          .Containing("searchTerm")
                          .ToRanked();

RankedSearch for multiple search terms within a single property

var result = queryableData.Search(x => x.Property1)
                          .Containing("searchTerm1", "searchTerm2", "searchTerm3")
                          .ToRanked();

RankedSearch for multiple search terms within multiple properties

var result = queryableData.Search(x => x.Property1, x => x.Property2)
                          .Containing("searchTerm1", "searchTerm2", "searchTerm3")
                          .ToRanked();

Retrieve most relevant search results

Using ranked search you can now easily order your search results by the most relevant. This following example assumes we have a list of User which has FirstName, LastName and MiddleName string properties. In this example we want to match on those with "John" in their name and retrieve the top 10 results.

var result = context.Users.Search(x => x.FirstName, x => x.LastName, x.MiddleName)
                          .Containing("John")
                          .ToRanked()
                          .OrderByDescending(r => r.Hits) // Order by Hits property of IRanked<User>
                          .Take(10);

Mixing it up

We can also mix it up with the other fluent API methods

var result = context.Users.Search(x => x.FirstName, x => x.LastName, x => x.MiddleName)
                          .StartsWith("john")
                          .Containing("nye")
                          .ToRanked()
                          .OrderByDescending(r => r.Hits) // Order by Hits property of IRanked<User>
                          .Take(10);

A word of note

Be aware that the ToRanked() method uses the search terms of the Containing() method combined with the properties to search to build its hit count. The fluent ToRanked() method also means the old RankedSearch method is now depreciated. It still lives in the code but will soon be removed so please update your code to use the fluent api.

Soundex support

NinjaNye.SearchExtensions.Soundex supports converting and searching for words that sound like a given word.

How to: Performing Soundex searches

Returning records that 'sound like' "test" using the Soundex algorythm:

Search where a single property sounds like a single search term

var result = data.SoundexOf(x => x.Property1).Matching("test")

Search where a any of multiple properties sounds like a single search term

var result = data.SoundexOf(x => x.Property1, x => x.PropertyTwo)
                 .Matching("test")

Search where a single property sounds like any one of multiple search terms

var result = data.SoundexOf(x => x.Property1).Matching("test", "another")

Search where a any of multiple properties sounds like any of multiple search terms

var result = data.SoundexOf(x => x.Property1, x => x.PropertyTwo)
                 .Matching("test", "another")

How to: Performing ReverseSoundex searches

All the abouve soundex axamples can be performed using the Reverse Soundex algorythm. Simply substitute in the ReverseSoundexOf() method. For example:

Search where a single property sounds like a single search term

var result = data.ReverseSoundexOf(x => x.Property1).Matching("test")

Search where a any of multiple properties sounds like a single search term

var result = data.ReverseSoundexOf(x => x.Property1, x => x.PropertyTwo)
                 .Matching("test")

The above SoundexOf and ReverseSoundexOf methods can also be applied to IQueryable data. For IQueryable we reduce the amount of records returned from the data source as much as possible but be aware that the soundex searching is performed on the in memory collection.

For more information about the Soundex search functionality, soundex search performance, and how it has been integrated with IQueryable, please visit http://jnye.co/soundex

If you have any new feature requests, questions, or comments, please get in touch, either, via my website, twitter or preferrably raise an issue in this github repository.