RKPathMatcher Class Reference
| Inherits from | NSObject |
| Conforms to | NSCopying |
| Declared in | RKPathMatcher.h |
Overview
The RKPathMatcher class performs pattern matching and parameter parsing of strings, typically representing the path portion of an NSURL object. 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 the RKManagedObjectCaching protocol and generate NSFetchRequest objects 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.
Tasks
Matching Paths to Patterns
-
+ pathMatcherWithPath:Creates a path match object starting from a path string. This method should be followed by
matchesPattern:tokenizeQueryStrings:parsedArguments: -
– matchesPattern:tokenizeQueryStrings:parsedArguments: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
pathMatcherWithPath:Pattern strings should include encoded parameter keys, delimited by a single colon at the beginning of the key name.
Matching Patterns to Paths
-
+ pathMatcherWithPattern:Creates a path matcher object 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. -
– matchesPath:tokenizeQueryStrings:parsedArguments: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
pathMatcherWithPattern:.
Creating Paths from Objects
-
– pathFromObject:addingEscapes:Generates a path by interpolating the properties of the ‘object’ argument, assuming the existence of a previously specified pattern established via
pathMatcherWithPattern:. Otherwise, this method is identical in function toRKPathFromPatternWithObject(in fact it is a shortcut for this method).
Class Methods
pathMatcherWithPath:
Creates a path match object starting from a path string. This method should be followed by matchesPattern:tokenizeQueryStrings:parsedArguments:
+ (RKPathMatcher *)pathMatcherWithPath:(NSString *)pathStringParameters
- pathString
The string to evaluate and parse, such as
/districts/tx/upper/?apikey=GC5512354
Return Value
An instantiated RKPathMatcher without an established pattern.
Declared In
RKPathMatcher.hpathMatcherWithPattern:
Creates a path matcher object 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.
+ (RKPathMatcher *)pathMatcherWithPattern:(NSString *)patternStringParameters
- patternString
The pattern to use for evaluating, such as
/:entityName/:stateID/:chamber/
Return Value
An instantiated RKPathMatcher with an established pattern.
Discussion
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
Declared In
RKPathMatcher.hInstance Methods
matchesPath:tokenizeQueryStrings:parsedArguments:
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 pathMatcherWithPattern:.
- (BOOL)matchesPath:(NSString *)pathString tokenizeQueryStrings:(BOOL)shouldTokenize parsedArguments:(NSDictionary **)argumentsParameters
- pathString
The string to evaluate and parse, such as
/districts/tx/upper/?apikey=GC5512354
- shouldTokenize
If YES, any query parameters will be tokenized and inserted into the parsed argument dictionary.
- arguments
A pointer to a dictionary that contains the key/values from the pattern (and parameter) matching.
Return Value
A boolean value indicating if the path string successfully matched the pattern.
Declared In
RKPathMatcher.hmatchesPattern:tokenizeQueryStrings:parsedArguments:
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 pathMatcherWithPath: Pattern strings should include encoded parameter keys, delimited by a single colon at the beginning of the key name.
- (BOOL)matchesPattern:(NSString *)patternString tokenizeQueryStrings:(BOOL)shouldTokenize parsedArguments:(NSDictionary **)argumentsParameters
- patternString
The pattern to use for evaluating, such as
/:entityName/:stateID/:chamber/
- shouldTokenize
If YES, any query parameters will be tokenized and inserted into the parsed argument dictionary.
- arguments
A pointer to a dictionary that contains the key/values from the pattern (and parameter) matching.
Return Value
A boolean value indicating if the path string successfully matched the pattern.
Discussion
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
Declared In
RKPathMatcher.hpathFromObject:addingEscapes:
Generates a path by interpolating the properties of the ‘object’ argument, assuming the existence of a previously specified pattern established via pathMatcherWithPattern:. Otherwise, this method is identical in function to RKPathFromPatternWithObject (in fact it is a shortcut for this method).
- (NSString *)pathFromObject:(id)object addingEscapes:(BOOL)addEscapesParameters
- object
The object containing the properties to interpolate.
- addEscapes
Conditionally add percent escapes to the interpolated property values
Return Value
A string with the object’s interpolated property values inserted into the receiver’s established pattern.
Discussion
For example, given an ‘article’ object with an ‘articleID’ property value of 12345 and a code of “This/That”…
RKPathMatcher *matcher = [RKPathMatcher pathMatcherWithPattern:@"/articles/:articleID/:code"];
NSString *path = [matcher pathFromObject:article addingEscapes:YES];
… will produce a ‘path’ containing the string @"/articles/12345/This%2FThat"
Declared In
RKPathMatcher.h