Class QueryEngine<TData>

A QueryEngine defines how to build a query from an input string. It can be customized to support custom filters and operators.

Inheritance

Object

QueryEngine<TData>

QueryEngine

Namespace: Unity.QuickSearch

Syntax

public class QueryEngine<TData>

Type Parameters

Name	Description
TData	The filtered data type.

Constructors

QueryEngine()

Construct a new QueryEngine.

Declaration

public QueryEngine()

QueryEngine(Boolean)

Construct a new QueryEngine.

Declaration

public QueryEngine(bool validateFilters)

Parameters

Type	Name	Description
Boolean	validateFilters	Indicates if the engine must validate filters when parsing the query.

QueryEngine(QueryValidationOptions)

Construct a new QueryEngine with the specified validation options.

Declaration

public QueryEngine(QueryValidationOptions validationOptions)

Parameters

Type	Name	Description
QueryValidationOptions	validationOptions	The validation options to use in this engine.

Properties

globalStringComparison

Global string comparison options for word matching and filter handling (if not overridden).

Declaration

public StringComparison globalStringComparison { get; }

Property Value

Type	Description
StringComparison

searchDataCallback

The callback used to get the data to match to the search words.

Declaration

public Func<TData, IEnumerable<string>> searchDataCallback { get; }

Property Value

Type	Description
Func<TData, IEnumerable<String>>

searchDataOverridesStringComparison

Indicates if word/phrase matching uses searchDataStringComparison or not.

Declaration

public bool searchDataOverridesStringComparison { get; }

Property Value

Type	Description
Boolean

searchDataStringComparison

String comparison options for word/phrase matching.

Declaration

public StringComparison searchDataStringComparison { get; }

Property Value

Type	Description
StringComparison

skipUnknownFilters

Boolean indicating if unknown filters should be skipped. If validateFilters is true and skipUnknownFilters is false, unknown filters will generate errors if no default handler is provided.

Declaration

public bool skipUnknownFilters { get; set; }

Property Value

Type	Description
Boolean

validateFilters

Get of set if the engine must validate filters when parsing the query. Defaults to true.

Declaration

public bool validateFilters { get; set; }

Property Value

Type	Description
Boolean

Methods

AddFilter<TFilter>(String, Func<TData, TFilter>, String[])

Add a new custom filter.

Declaration

public void AddFilter<TFilter>(string token, Func<TData, TFilter> getDataFunc, string[] supportedOperatorType = null)

Parameters

Type	Name	Description
String	token	The identifier of the filter. Typically what precedes the operator in a filter (i.e. "id" in "id>=2").
Func<TData, TFilter>	getDataFunc	Callback used to get the object that is used in the filter. Takes an object of type TData and returns an object of type TFilter.
String[]	supportedOperatorType	List of supported operator tokens. Null for all operators.

Type Parameters

Name	Description
TFilter	The type of the data that is compared by the filter.

AddFilter<TFilter>(String, Func<TData, TFilter>, StringComparison, String[])

Add a new custom filter.

Declaration

public void AddFilter<TFilter>(string token, Func<TData, TFilter> getDataFunc, StringComparison stringComparison, string[] supportedOperatorType = null)

Parameters

Type	Name	Description
String	token	The identifier of the filter. Typically what precedes the operator in a filter (i.e. "id" in "id>=2").
Func<TData, TFilter>	getDataFunc	Callback used to get the object that is used in the filter. Takes an object of type TData and returns an object of type TFilter.
StringComparison	stringComparison	String comparison options.
String[]	supportedOperatorType	List of supported operator tokens. Null for all operators.

Type Parameters

Name	Description
TFilter	The type of the data that is compared by the filter.

AddFilter<TFilter>(String, Func<TData, String, TFilter, Boolean>, String[])

Add a new custom filter with a custom resolver. Useful when you wish to handle all operators yourself.

Declaration

public void AddFilter<TFilter>(string token, Func<TData, string, TFilter, bool> filterResolver, string[] supportedOperatorType = null)

Parameters

Type	Name	Description
String	token	The identifier of the filter. Typically what precedes the operator in a filter (i.e. "id" in "id>=2").
Func<TData, String, TFilter, Boolean>	filterResolver	Callback used to handle any operators for this filter. Takes an object of type TData, the operator token and the filter value, and returns a boolean indicating if the filter passed or not.
String[]	supportedOperatorType	List of supported operator tokens. Null for all operators.

Type Parameters

Name	Description
TFilter	The type of the data that is compared by the filter.

AddFilter<TParam, TFilter>(String, Func<TData, TParam, TFilter>, Func<String, TParam>, String[])

Add a new custom filter function.

Declaration

public void AddFilter<TParam, TFilter>(string token, Func<TData, TParam, TFilter> getDataFunc, Func<string, TParam> parameterTransformer, string[] supportedOperatorType = null)

Parameters

Type	Name	Description
String	token	The identifier of the filter. Typically what precedes the operator in a filter (i.e. "id" in "id>=2").
Func<TData, TParam, TFilter>	getDataFunc	Callback used to get the object that is used in the filter. Takes an object of type TData and TParam, and returns an object of type TFilter.
Func<String, TParam>	parameterTransformer	Callback used to convert a string to the type TParam. Used when parsing the query to convert what is passed to the function into the correct format.
String[]	supportedOperatorType	List of supported operator tokens. Null for all operators.

Type Parameters

Name	Description
TParam	The type of the constant parameter passed to the function.
TFilter	The type of the data that is compared by the filter.

AddFilter<TParam, TFilter>(String, Func<TData, TParam, TFilter>, Func<String, TParam>, StringComparison, String[])

Add a new custom filter function.

Declaration

public void AddFilter<TParam, TFilter>(string token, Func<TData, TParam, TFilter> getDataFunc, Func<string, TParam> parameterTransformer, StringComparison stringComparison, string[] supportedOperatorType = null)

Parameters

Type	Name	Description
String	token	The identifier of the filter. Typically what precedes the operator in a filter (i.e. "id" in "id>=2").
Func<TData, TParam, TFilter>	getDataFunc	Callback used to get the object that is used in the filter. Takes an object of type TData and TParam, and returns an object of type TFilter.
Func<String, TParam>	parameterTransformer	Callback used to convert a string to the type TParam. Used when parsing the query to convert what is passed to the function into the correct format.
StringComparison	stringComparison	String comparison options.
String[]	supportedOperatorType	List of supported operator tokens. Null for all operators.

Type Parameters

Name	Description
TParam	The type of the constant parameter passed to the function.
TFilter	The type of the data that is compared by the filter.

AddFilter<TParam, TFilter>(String, Func<TData, TParam, TFilter>, String[])

Add a new custom filter function.

Declaration

public void AddFilter<TParam, TFilter>(string token, Func<TData, TParam, TFilter> getDataFunc, string[] supportedOperatorType = null)

Parameters

Type	Name	Description
String	token	The identifier of the filter. Typically what precedes the operator in a filter (i.e. "id" in "id>=2").
Func<TData, TParam, TFilter>	getDataFunc	Callback used to get the object that is used in the filter. Takes an object of type TData and TParam, and returns an object of type TFilter.
String[]	supportedOperatorType	List of supported operator tokens. Null for all operators.

Type Parameters

Name	Description
TParam	The type of the constant parameter passed to the function.
TFilter	The type of the data that is compared by the filter.

AddFilter<TParam, TFilter>(String, Func<TData, TParam, TFilter>, StringComparison, String[])

Add a new custom filter function.

Declaration

public void AddFilter<TParam, TFilter>(string token, Func<TData, TParam, TFilter> getDataFunc, StringComparison stringComparison, string[] supportedOperatorType = null)

Parameters

Type	Name	Description
String	token	The identifier of the filter. Typically what precedes the operator in a filter (i.e. "id" in "id>=2").
Func<TData, TParam, TFilter>	getDataFunc	Callback used to get the object that is used in the filter. Takes an object of type TData and TParam, and returns an object of type TFilter.
StringComparison	stringComparison	String comparison options.
String[]	supportedOperatorType	List of supported operator tokens. Null for all operators.

Type Parameters

Name	Description
TParam	The type of the constant parameter passed to the function.
TFilter	The type of the data that is compared by the filter.

AddFilter<TParam, TFilter>(String, Func<TData, TParam, String, TFilter, Boolean>, Func<String, TParam>, String[])

Add a new custom filter function with a custom resolver. Useful when you wish to handle all operators yourself.

Declaration

public void AddFilter<TParam, TFilter>(string token, Func<TData, TParam, string, TFilter, bool> filterResolver, Func<string, TParam> parameterTransformer, string[] supportedOperatorType = null)

Parameters

Type	Name	Description
String	token	The identifier of the filter. Typically what precedes the operator in a filter (i.e. "id" in "id>=2").
Func<TData, TParam, String, TFilter, Boolean>	filterResolver	Callback used to handle any operators for this filter. Takes an object of type TData, an object of type TParam, the operator token and the filter value, and returns a boolean indicating if the filter passed or not.
Func<String, TParam>	parameterTransformer	Callback used to convert a string to the type TParam. Used when parsing the query to convert what is passed to the function into the correct format.
String[]	supportedOperatorType	List of supported operator tokens. Null for all operators.

Type Parameters

Name	Description
TParam	The type of the constant parameter passed to the function.
TFilter	The type of the data that is compared by the filter.

AddFilter<TParam, TFilter>(String, Func<TData, TParam, String, TFilter, Boolean>, String[])

Add a new custom filter function with a custom resolver. Useful when you wish to handle all operators yourself.

Declaration

public void AddFilter<TParam, TFilter>(string token, Func<TData, TParam, string, TFilter, bool> filterResolver, string[] supportedOperatorType = null)

Parameters

Type	Name	Description
String	token	The identifier of the filter. Typically what precedes the operator in a filter (i.e. "id" in "id>=2").
Func<TData, TParam, String, TFilter, Boolean>	filterResolver	Callback used to handle any operators for this filter. Takes an object of type TData, an object of type TParam, the operator token and the filter value, and returns a boolean indicating if the filter passed or not.
String[]	supportedOperatorType	List of supported operator tokens. Null for all operators.

Type Parameters

Name	Description
TParam	The type of the constant parameter passed to the function.
TFilter	The type of the data that is compared by the filter.

AddFiltersFromAttribute<TFilterAttribute, TTransformerAttribute>()

Add all custom filters that are identified with the method attribute TAttribute.

Declaration

public void AddFiltersFromAttribute<TFilterAttribute, TTransformerAttribute>()
    where TFilterAttribute : QueryEngineFilterAttribute where TTransformerAttribute : QueryEngineParameterTransformerAttribute

Type Parameters

Name	Description
TFilterAttribute	The type of the attribute of filters to fetch.
TTransformerAttribute	The attribute type for the parameter transformers associated with the filter attribute.

AddNestedQueryAggregator<TNestedQueryData>(String, Func<IEnumerable<TNestedQueryData>, IEnumerable<TNestedQueryData>>)

Add a new nested query aggregator. An aggregator is an operation that can be applied on a nested query to aggregate the results of the nested query according to a certain criteria.

Declaration

public void AddNestedQueryAggregator<TNestedQueryData>(string token, Func<IEnumerable<TNestedQueryData>, IEnumerable<TNestedQueryData>> aggregator)

Parameters

Type	Name	Description
String	token	Name of the aggregator used when typing the query. This name will be lowercased when parsing the query to speedup the process.
Func<IEnumerable<TNestedQueryData>, IEnumerable<TNestedQueryData>>	aggregator	Aggregator function. Takes the results of the nested query, and returns an aggregate that contains any number of items.

Type Parameters

Name	Description
TNestedQueryData	The type of data returned by the nested query.

AddOperator(String)

Add a custom filter operator.

Declaration

public void AddOperator(string op)

Parameters

Type	Name	Description
String	op	The operator identifier.

AddOperatorHandler<TFilterVariable, TFilterConstant>(String, Func<TFilterVariable, TFilterConstant, Boolean>)

Add a custom filter operator handler.

Declaration

public void AddOperatorHandler<TFilterVariable, TFilterConstant>(string op, Func<TFilterVariable, TFilterConstant, bool> handler)

Parameters

Type	Name	Description
String	op	The filter operator.
Func<TFilterVariable, TFilterConstant, Boolean>	handler	Callback to handle the operation. Takes a TFilterVariable (value returned by the filter handler, will vary for each element) and a TFilterConstant (right hand side value of the operator, which is constant), and returns a boolean indicating if the filter passes or not.

Type Parameters

Name	Description
TFilterVariable	The operator's left hand side type. This is the type returned by a filter handler.
TFilterConstant	The operator's right hand side type.

AddOperatorHandler<TFilterVariable, TFilterConstant>(String, Func<TFilterVariable, TFilterConstant, StringComparison, Boolean>)

Add a custom filter operator handler.

Declaration

public void AddOperatorHandler<TFilterVariable, TFilterConstant>(string op, Func<TFilterVariable, TFilterConstant, StringComparison, bool> handler)

Parameters

Type	Name	Description
String	op	The filter operator.
Func<TFilterVariable, TFilterConstant, StringComparison, Boolean>	handler	Callback to handle the operation. Takes a TFilterVariable (value returned by the filter handler, will vary for each element), a TFilterConstant (right hand side value of the operator, which is constant), a StringComparison option and returns a boolean indicating if the filter passes or not.

Type Parameters

Name	Description
TFilterVariable	The operator's left hand side type. This is the type returned by a filter handler.
TFilterConstant	The operator's right hand side type.

AddTypeParser<TFilterConstant>(Func<String, ParseResult<TFilterConstant>>)

Add a type parser that parse a string and returns a custom type. Used by custom operator handlers.

Declaration

public void AddTypeParser<TFilterConstant>(Func<string, ParseResult<TFilterConstant>> parser)

Parameters

Type	Name	Description
Func<String, ParseResult<TFilterConstant>>	parser	Callback used to determine if a string can be converted into TFilterConstant. Takes a string and returns a ParseResult object. This contains the success flag, and the actual converted value if it succeeded.

Type Parameters

Name	Description
TFilterConstant	The type of the parsed operand that is on the right hand side of the operator.

Parse(String)

Parse a query string into a Query operation. This Query operation can then be used to filter any data set of type TData.

Declaration

public Query<TData> Parse(string text)

Parameters

Type	Name	Description
String	text	The query input string.

Returns

Type	Description
Query<TData>	Query operation of type TData.

RemoveFilter(String)

Remove a custom filter.

Declaration

public void RemoveFilter(string token)

Parameters

Type	Name	Description
String	token	The identifier of the filter. Typically what precedes the operator in a filter (i.e. "id" in "id>=2").

Remarks

You will get a warning if you try to remove a non existing filter.

SetDefaultFilter(Func<TData, String, String, String, Boolean>)

Set the default filter handler for filters that were not registered.

Declaration

public void SetDefaultFilter(Func<TData, string, string, string, bool> handler)

Parameters

Type	Name	Description
Func<TData, String, String, String, Boolean>	handler	Callback used to handle the filter. Takes an object of type TData, the filter identifier, the operator and the filter value, and returns a boolean indicating if the filter passed or not.

SetDefaultParamFilter(Func<TData, String, String, String, String, Boolean>)

Set the default filter handler for function filters that were not registered.

Declaration

public void SetDefaultParamFilter(Func<TData, string, string, string, string, bool> handler)

Parameters

Type	Name	Description
Func<TData, String, String, String, String, Boolean>	handler	Callback used to handle the function filter. Takes an object of type TData, the filter identifier, the parameter, the operator and the filter value, and returns a boolean indicating if the filter passed or not.

SetFilterNestedQueryTransformer<TNestedQueryData, TRhs>(String, Func<TNestedQueryData, TRhs>)

Set a filter's nested query transformer function. This function takes the result of a nested query and extract the necessary data to compare with the filter.

Declaration

public void SetFilterNestedQueryTransformer<TNestedQueryData, TRhs>(string filterToken, Func<TNestedQueryData, TRhs> transformer)

Parameters

Type	Name	Description
String	filterToken	The identifier of the filter. Typically what precedes the operator in a filter (i.e. "id" in "id>=2").
Func<TNestedQueryData, TRhs>	transformer	The transformer function.

Type Parameters

Name	Description
TNestedQueryData	The type of data returned by the nested query.
TRhs	The type expected on the right hand side of the filter.

SetGlobalStringComparisonOptions(StringComparison)

Set global string comparison options. Used for word matching and filter handling (unless overridden by filter).

Declaration

public void SetGlobalStringComparisonOptions(StringComparison stringComparison)

Parameters

Type	Name	Description
StringComparison	stringComparison	String comparison options.

SetNestedQueryHandler<TNestedQueryData>(Func<String, String, IEnumerable<TNestedQueryData>>)

Set the function that will handle nested queries. Only one handler can be set.

Declaration

public void SetNestedQueryHandler<TNestedQueryData>(Func<string, string, IEnumerable<TNestedQueryData>> handler)

Parameters

Type	Name	Description
Func<String, String, IEnumerable<TNestedQueryData>>	handler	The function that handles nested queries. It receives the nested query and the filter token on which the query is applied, and returns an IEnumerable.

Type Parameters

Name	Description
TNestedQueryData	The type of data returned by the nested query.

SetSearchDataCallback(Func<TData, IEnumerable<String>>)

Set the callback to be used to fetch the data that will be matched against the search words.

Declaration

public void SetSearchDataCallback(Func<TData, IEnumerable<string>> getSearchDataCallback)

Parameters

Type	Name	Description
Func<TData, IEnumerable<String>>	getSearchDataCallback	Callback used to get the data to be matched against the search words. Takes an object of type TData and return an IEnumerable of strings.

SetSearchDataCallback(Func<TData, IEnumerable<String>>, Func<String, String>, StringComparison)

Set the callback to be used to fetch the data that will be matched against the search words, plus a transformer on those words.

Declaration

public void SetSearchDataCallback(Func<TData, IEnumerable<string>> getSearchDataCallback, Func<string, string> searchWordTransformerCallback, StringComparison stringComparison)

Parameters

Type	Name	Description
Func<TData, IEnumerable<String>>	getSearchDataCallback	Callback used to get the data to be matched against the search words. Takes an object of type TData and return an IEnumerable of strings.
Func<String, String>	searchWordTransformerCallback	Callback used to transform a search word during the query parsing. Useful when doing lowercase or uppercase comparison. Can return null or an empty string to remove the word from the query.
StringComparison	stringComparison	String comparison options.

SetSearchDataCallback(Func<TData, IEnumerable<String>>, StringComparison)

Set the callback to be used to fetch the data that will be matched against the search words.

Declaration

public void SetSearchDataCallback(Func<TData, IEnumerable<string>> getSearchDataCallback, StringComparison stringComparison)

Parameters

Type	Name	Description
Func<TData, IEnumerable<String>>	getSearchDataCallback	Callback used to get the data to be matched against the search words. Takes an object of type TData and return an IEnumerable of strings.
StringComparison	stringComparison	String comparison options.