RestKit/Code/Support/RKPathMatcher.h

//
//  RKPathMatcher.h
//  RestKit
//
//  Created by Greg Combs on 9/2/11.
//  Copyright (c) 2009-2012 RestKit. All rights reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.
//

#import <Foundation/Foundation.h>
@class SOCPattern;

/**
 This class performs pattern matching and parameter parsing of strings, typically paths.
 It provides much of the necessary tools to map a given path to local objects (the inverse
 of RKRouter's function).  This makes it easier to implement RKManagedObjectCache, and generate fetched
 requests from a given path.  There are two means of instantiating and using a matcher object
 in order to provide more flexibility in implementations, and to improve efficiency by eliminating
 repetitive and costly pattern initializations.

 @see RKManagedObjectCache
 @see RKMakePathWithObject
 @see RKRouter
 */
@interface RKPathMatcher : NSObject <NSCopying>

@property (copy, readonly) NSDictionary *queryParameters;

/**
 Creates an RKPathMatcher starting from a path string.  This method should be followed by
 matchesPattern:tokenizeQueryStrings:parsedArguments:

 @param pathString The string to evaluate and parse, such as /districts/tx/upper/?apikey=GC5512354
 @return An instantiated RKPathMatcher without an established pattern.
 */
+ (RKPathMatcher *)matcherWithPath:(NSString *)pathString;

/**
 Determines if the path string matches the provided pattern, and yields a dictionary with the resulting
 matched key/value pairs.  Use of this method should be preceded by matcherWithPath:
 Pattern strings should include encoded parameter keys, delimited by a single colon at the
 beginning of the key name.

 *NOTE 1 *- Numerous colon-encoded parameter keys can be joined in a long pattern, but each key must be
 separated by at least one unmapped character.  For instance, /:key1:key2:key3/ is invalid, whereas
 /:key1/:key2/:key3/ is acceptable.

 *NOTE 2 *- The pattern matcher supports KVM, so :key1.otherKey normally resolves as it would in any other KVM
 situation, ... otherKey is a sub-key on a the object represented by key1.  This presents problems in circumstances where
 you might want to build a pattern like /:filename.json, where the dot isn't intended as a sub-key on the filename, but rather
 part of the json static string.  In these instances, you need to escape the dot with two backslashes, like so:
 /:filename\\.json

 @param patternString The pattern to use for evaluating, such as /:entityName/:stateID/:chamber/
 @param shouldTokenize If YES, any query parameters will be tokenized and inserted into the parsed argument dictionary.
 @param arguments A pointer to a dictionary that contains the key/values from the pattern (and parameter) matching.
 @return A boolean indicating if the path string successfully matched the pattern.
 */
- (BOOL)matchesPattern:(NSString *)patternString tokenizeQueryStrings:(BOOL)shouldTokenize parsedArguments:(NSDictionary **)arguments;

/**
 Creates an RKPathMatcher starting from a pattern string.  This method should be followed by
 matchesPath:tokenizeQueryStrings:parsedArguments:  Patterns should include encoded parameter keys,
 delimited by a single colon at the beginning of the key name.

 *NOTE 1 *- Numerous colon-encoded parameter keys can be joined in a long pattern, but each key must be
 separated by at least one unmapped character.  For instance, /:key1:key2:key3/ is invalid, whereas
 /:key1/:key2/:key3/ is acceptable.

 *NOTE 2 *- The pattern matcher supports KVM, so :key1.otherKey normally resolves as it would in any other KVM
 situation, ... otherKey is a sub-key on a the object represented by key1.  This presents problems in circumstances where
 you might want to build a pattern like /:filename.json, where the dot isn't intended as a sub-key on the filename, but rather
 part of the json static string.  In these instances, you need to escape the dot with two backslashes, like so:
 /:filename\\.json

 @param patternString The pattern to use for evaluating, such as /:entityName/:stateID/:chamber/
 @return An instantiated RKPathMatcher with an established pattern.
 */
+ (RKPathMatcher *)matcherWithPattern:(NSString *)patternString;

/**
 Determines if the given path string matches a pattern, and yields a dictionary with the resulting
 matched key/value pairs.  Use of this method should be preceded by matcherWithPattern:

 @param pathString The string to evaluate and parse, such as /districts/tx/upper/?apikey=GC5512354
 @param shouldTokenize If YES, any query parameters will be tokenized and inserted into the parsed argument dictionary.
 @param arguments A pointer to a dictionary that contains the key/values from the pattern (and parameter) matching.
 @return A boolean indicating if the path string successfully matched the pattern.
 */
- (BOOL)matchesPath:(NSString *)pathString tokenizeQueryStrings:(BOOL)shouldTokenize parsedArguments:(NSDictionary **)arguments;

/**
 Generates a new path by interpolating the properties of the 'object' argument, assuming the existence
 of a previously specified pattern established via matcherWithPattern:.  Otherwise, this method is identical in
 function to RKMakePathWithObject (in fact it is a shortcut for this method).

 For example, given an 'article' object with an 'articleID' property value of 12345 ...

   RKPathMatcher *matcher = [RKPathMatcher matcherWithPattern:@"/articles/:articleID"];
   NSString *path = [matcher pathFromObject:article];

 ... will produce a 'path' containing the string "/articles/12345"

 @param object The object containing the properties to interpolate.
 @return A string with the object's interpolated property values inserted into the receiver's established pattern.
 @see RKMakePathWithObject
 @see RKRouter
 */
- (NSString *)pathFromObject:(id)object;

/**
 Generates a path by interpolating the properties of the 'object' argument, assuming the existence
 of a previously specified pattern established via matcherWithPattern:.  Otherwise, this method is identical in
 function to RKMakePathWithObject (in fact it is a shortcut for this method).

 For example, given an 'article' object with an 'articleID' property value of 12345 and a code of "This/That"...

 RKPathMatcher *matcher = [RKPathMatcher matcherWithPattern:@"/articles/:articleID/:code"];
 NSString *path = [matcher pathFromObject:article addingEscapes:YES];

 ... will produce a 'path' containing the string "/articles/12345/This%2FThat"

 @param object The object containing the properties to interpolate.
 @param addEscapes Conditionally add percent escapes to the interpolated property values
 @return A string with the object's interpolated property values inserted into the receiver's established pattern.
 @see RKMakePathWithObjectAddingEscapes
 @see RKRouter
 */
- (NSString *)pathFromObject:(id)object addingEscapes:(BOOL)addEscapes;

@end