Files
RestKit/OTRestModelMapper.m
2010-01-15 13:04:28 -05:00

413 lines
16 KiB
Objective-C

//
// OTModelMapper.m
// OTRestFramework
//
// Created by Blake Watters on 8/14/09.
// Copyright 2009 Objective 3. All rights reserved.
//
// #import <objc/objc-runtime.h>
#import <objc/message.h>
#import "OTRestModelMapper.h"
#import "OTRestModelMapper_Private.h"
#import "ElementParser.h"
#import "JSON.h"
// Used for detecting property types at runtime
#import <objc/runtime.h>
@implementation OTRestModelMapper
@synthesize format = _format;
- (id)init {
if (self = [super init]) {
_elementToClassMappings = [[NSMutableDictionary alloc] init];
_format = OTRestMappingFormatXML;
}
return self;
}
- (void)dealloc {
[_elementToClassMappings release];
[super dealloc];
}
- (BOOL)mappingFromJSON {
return _format == OTRestMappingFormatJSON;
}
- (BOOL)mappingFromXML {
return _format == OTRestMappingFormatXML;
}
- (void)registerModel:(Class)aClass forElementNamed:(NSString*)elementName {
[_elementToClassMappings setObject:aClass forKey:elementName];
}
- (id)buildModelFromString:(NSString*)string {
id object = nil;
if ([self mappingFromJSON]) {
object = [self buildModelFromJSON:string];
} else if ([self mappingFromXML]) {
Element* e = [[[[[ElementParser alloc] init] autorelease] parseXML:string] firstChild];
object = [self buildModelFromXML:e];
} else {
[NSException raise:@"No Parsing Style Set" format:@"you must specify a valid mapping format"];
}
return object;
}
- (NSArray*)buildModelsFromString:(NSString*)string {
NSMutableArray* objects = [NSMutableArray array];
if ([self mappingFromJSON]) {
NSArray* collectionDicts = [[[[SBJSON alloc] init] autorelease] objectWithString:string];
for (NSDictionary* dict in collectionDicts) {
id object = [self buildModelFromJSONDict:dict];
[objects addObject:object];
}
} else if ([self mappingFromXML]) {
Element* collectionElement = [[[[[ElementParser alloc] init] autorelease] parseXML:string] firstChild];
for (Element* e in [collectionElement childElements]) {
id object = [self buildModelFromXML:e];
[objects addObject:object];
}
} else {
[NSException raise:@"No Parsing Style Set" format:@"you must specify a valid mapping format"];
}
return (NSArray*)objects;
}
#pragma mark -
#pragma mark shared parsing behavior
- (void)updateObject:(id)model ifNewPropertyPropertyValue:(id)propertyValue forPropertyNamed:(NSString*)propertyName {
id currentValue = [model valueForKey:propertyName];
if (nil == currentValue && nil == propertyValue) {
// Don't set the property, both are nil
} else if (nil == propertyValue || [propertyValue isKindOfClass:[NSNull class]]) {
// Clear out the value to reset it
[model setNilValueForKey:propertyName];
} else if (currentValue == nil || [currentValue isKindOfClass:[NSNull class]]) {
// Existing value was nil, just set the property and be happy
[model setValue:propertyValue forKey:propertyName];
} else {
SEL comparisonSelector;
if ([propertyValue isKindOfClass:[NSString class]]) {
comparisonSelector = @selector(isEqualToString:);
} else if ([propertyValue isKindOfClass:[NSNumber class]]) {
comparisonSelector = @selector(isEqualToNumber:);
} else if ([propertyValue isKindOfClass:[NSDate class]]) {
comparisonSelector = @selector(isEqualToDate:);
} else {
[NSException raise:@"NoComparisonSelectorFound" format:@"You need a comparison selector for %@ (%@)", propertyName, [propertyValue class]];
}
// Comparison magic using function pointers. See this page for details: http://www.red-sweater.com/blog/320/abusing-objective-c-with-class
// Original code courtesy of Greg Parker
// This is necessary because isEqualToNumber will return negative integer values that aren't coercable directly to BOOL's without help [sbw]
BOOL (*ComparisonSender)(id, SEL, id) = (BOOL (*)(id, SEL, id)) objc_msgSend;
BOOL areEqual = ComparisonSender(currentValue, comparisonSelector, propertyValue);
if (NO == areEqual) {
NSLog(@"Setting property %@ to new value %@", propertyName, propertyValue);
[model setValue:propertyValue forKey:propertyName];
}
}
}
#pragma mark -
#pragma mark JSON Parsing
- (id)buildModelFromJSON:(NSString*)JSON {
SBJsonParser* parser = [[[SBJsonParser alloc] init] autorelease];
NSDictionary* jsonDict = [parser objectWithString:JSON];
if (jsonDict == nil) {
return nil;
}
return [self buildModelFromJSONDict:jsonDict];
}
- (id)buildModelFromJSONDict:(NSDictionary*)dict {
assert([[dict allKeys] count] == 1);
NSString* keyName = [[dict allKeys] objectAtIndex:0];
Class class = [_elementToClassMappings objectForKey:keyName];
return [self createOrUpdateInstanceOf:class fromJSONDict:[dict objectForKey:keyName]];
}
- (id)createOrUpdateInstanceOf:(Class)class fromJSONDict:(NSDictionary*)dict {
id object = nil;
if ([class respondsToSelector:@selector(findByPrimaryKey:)]) {
// TODO: factor to class method? incase it is not a number
NSNumber* pk = [dict objectForKey:[class primaryKey]];
object = [class findByPrimaryKey:pk];
}
// instantiate if object is nil
if (object == nil) {
if ([class respondsToSelector:@selector(newObject)]) {
object = [class newObject];
} else {
object = [[[class alloc] init] autorelease];
}
}
// check to see if we should hand the object the JSON to set it's own properties
// (custom implementation)
if ([object respondsToSelector:@selector(digestJSONDict:)]) {
[object digestJSONDict:dict];
} else {
// update attributes
[self setAttributes:object fromJSONDict:dict];
}
return object;
}
- (void)setAttributes:(id)object fromJSONDict:(NSDictionary*)dict {
[self setPropertiesOfModel:object fromJSONDict:dict];
[self setRelationshipsOfModel:object fromJSONDict:dict];
}
- (void)setPropertiesOfModel:(id)model fromJSONDict:(NSDictionary*)dict {
for (NSString* selector in [[model class] elementToPropertyMappings]) {
NSString* propertyName = [[[model class] elementToPropertyMappings] objectForKey:selector];
NSString* propertyType = [self typeNameForProperty:propertyName ofClass:[model class] typeHint:nil];
id propertyValue = [dict objectForKey:selector];
// Types of objects SBJSON does not handle:
if ([propertyType isEqualToString:@"NSDate"]) {
NSDateFormatter* formatter = [[NSDateFormatter alloc] init];
// Times coming back are in utc. we should convert them to the local timezone
// TODO: Make sure this is working correctly
[formatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
[formatter setDateFormat:kRailsToXMLDateFormatterString];
propertyValue = [formatter dateFromString:propertyValue];
[formatter release];
}
[self updateObject:model ifNewPropertyPropertyValue:propertyValue forPropertyNamed:propertyName];
}
}
- (void)setRelationshipsOfModel:(id)model fromJSONDict:(NSDictionary*)dict {
for (NSString* selector in [[model class] elementToRelationshipMappings]) {
NSString* propertyName = [[[model class] elementToRelationshipMappings] objectForKey:selector];
if ([self isParentSelector:selector]) {
NSMutableSet* children = [NSMutableSet set];
// If the collection key doesn't appear, we will not set the collection to nil.
NSString* collectionKey = [self containingElementNameForSelector:selector];
// Used to figure out what class to map to, since we don't have element names for the dictionaries in the array
NSString* objectKey = [self childElementNameForSelelctor:selector];
NSArray* objects = [dict objectForKey:collectionKey];
if (objects != nil) {
for (NSDictionary* childDict in objects) {
Class class = [_elementToClassMappings objectForKey:objectKey];
[children addObject:[self createOrUpdateInstanceOf:class fromJSONDict:childDict]];
}
[model setValue:(NSSet*)children forKey:propertyName];
}
} else {
NSDictionary* objectDict = [dict objectForKey:selector];
Class class = [_elementToClassMappings objectForKey:selector];
id child = [self createOrUpdateInstanceOf:class fromJSONDict:objectDict];
[model setValue:child forKey:propertyName];
}
}
}
#pragma mark -
#pragma mark XML Parsing
- (id)buildModelFromXML:(Element*)XML {
if (XML == nil) {
return nil;
}
NSString* elementName = [XML key];
Class class = [_elementToClassMappings objectForKey:elementName];
if (class == nil) {
NSLog(@"Encountered an unmapped class while processing XML Element: %@", XML);
[NSException raise:@"NoClassMappingForModel" format:@"No Class Mapping for Element name '%@'", elementName];
}
id object = [self createOrUpdateInstanceOf:class fromXML:XML];
return object;
}
- (id)createOrUpdateInstanceOf:(Class)class fromXML:(Element*)XML {
id object = nil;
// Find by PK, if it responds to it
if ([class respondsToSelector:@selector(findByPrimaryKey:)]) {
// TODO: factor to class method? incase it is not a number
NSNumber* pk = [XML contentsNumberOfChildElement:[class primaryKeyElement]];
NSLog(@"Attempting to find object by primary key %@ via primaryKeyElement %@", pk, [class primaryKeyElement]);
object = [class findByPrimaryKey:pk];
}
// instantiate if object is nil
if (object == nil) {
if ([class respondsToSelector:@selector(newObject)]) {
object = [class newObject];
} else {
object = [[[class alloc] init] autorelease];
}
}
// check to see if we should hand the object the xml to set it's own properties
// (custom implementation)
if ([object respondsToSelector:@selector(digestXML:)]) {
[object digestXML:XML];
} else {
// update attributes
[self setAttributes:object fromXML:XML];
}
return object;
}
- (void)setAttributes:(id)object fromXML:(Element*)XML {
[self setPropertiesOfModel:object fromXML:XML];
[self setRelationshipsOfModel:object fromXML:XML];
}
- (id)propertyValueForElement:(Element*)propertyElement type:(NSString*)type{
//NSString* typeHint = [propertyElement attribute:@"type"];
id propertyValue = nil;
if ([type isEqualToString:@"NSString"]) {
propertyValue = [propertyElement contentsText];
} else if ([type isEqualToString:@"NSNumber"]) {
propertyValue = [propertyElement contentsNumber];
} else if ([type isEqualToString:@"NSDate"]) {
NSString* dateString = [propertyElement contentsText];
if (nil != dateString) {
NSDateFormatter* formatter = [[NSDateFormatter alloc] init];
// Times coming back are in utc. we should convert them to the local timezone
// TODO: Need a way to handle date/time formats. Maybe part of the mapper?
[formatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
[formatter setDateFormat:kRailsToXMLDateTimeFormatterString];
propertyValue = [formatter dateFromString:dateString];
if (nil == propertyValue) {
[formatter setDateFormat:kRailsToXMLDateFormatterString];
propertyValue = [formatter dateFromString:dateString];
}
[formatter release];
}
} else if ([type isEqualToString:@"nil"]) {
[NSException raise:@"PropertyTypeError" format:@"Don't know how to handle property type '%@'", type];
}
return propertyValue;
}
- (void)setPropertiesOfModel:(id)model fromXML:(Element*)XML {
for (NSString* selector in [[model class] elementToPropertyMappings]) {
NSString* propertyName = [[[model class] elementToPropertyMappings] objectForKey:selector];
Element* propertyElement = [XML selectElement:selector];
NSString* typeHint = [propertyElement attribute:@"type"];
NSString* propertyType = [self typeNameForProperty:propertyName ofClass:[model class] typeHint:typeHint];
NSLog(@"The propertyType is %@", propertyType);
id propertyValue = [self propertyValueForElement:propertyElement type:propertyType]; // valueForElement instead???
if (typeHint) {
NSLog(@"TypeHint is %@", typeHint);
if ([typeHint isEqualToString:@"boolean"]) {
// Booleans must be cast to NSNumber...
NSLog(@"Boolean value before cast: %@", propertyValue);
propertyValue = [NSNumber numberWithBool:[propertyValue boolValue]];
NSLog(@"Boolean value after cast: %@", propertyValue);
}
}
NSLog(@"Trying potential update to %@ with value %@", propertyName, propertyValue);
[self updateObject:model ifNewPropertyPropertyValue:propertyValue forPropertyNamed:propertyName];
}
}
- (void)setRelationshipsOfModel:(id)model fromXML:(Element*)XML {
for (NSString* selector in [[[model class] elementToRelationshipMappings] allKeys]) {
NSString* propertyName = [[[model class] elementToRelationshipMappings] objectForKey:selector];
if ([self isParentSelector:selector]) {
NSMutableSet* children = [NSMutableSet set];
// If the parent element doesn't appear, we will not set the collection to nil.
NSString* containingElementName = [self containingElementNameForSelector:selector];
if ([XML selectElement:containingElementName] != nil) {
NSArray* childrenElements = [XML selectElements:selector];
for (Element* childElement in childrenElements) {
[children addObject:[self buildModelFromXML:childElement]];
}
[model setValue:(NSSet*)children forKey:propertyName];
}
} else {
Element* childElement = [XML selectElement:selector];
id child = [self buildModelFromXML:childElement];
[model setValue:child forKey:propertyName];
}
}
}
#pragma mark -
#pragma mark selector methods
- (BOOL)isParentSelector:(NSString*)key {
return !NSEqualRanges([key rangeOfString:@" > "], NSMakeRange(NSNotFound, 0));
}
- (NSString*)containingElementNameForSelector:(NSString*)selector {
return [[selector componentsSeparatedByString:@" > "] objectAtIndex:0];
}
- (NSString*)childElementNameForSelelctor:(NSString*)selector {
return [[selector componentsSeparatedByString:@" > "] objectAtIndex:1];
}
#pragma mark -
#pragma mark Property Type Methods
- (NSString*)propertyTypeFromAttributeString:(NSString*)attributeString {
NSString *type = [NSString string];
NSScanner *typeScanner = [NSScanner scannerWithString:attributeString];
[typeScanner scanUpToCharactersFromSet:[NSCharacterSet characterSetWithCharactersInString:@"@"] intoString:NULL];
// we are not dealing with an object
if([typeScanner isAtEnd]) {
return @"NULL";
}
[typeScanner scanCharactersFromSet:[NSCharacterSet characterSetWithCharactersInString:@"\"@"] intoString:NULL];
// this gets the actual object type
[typeScanner scanUpToCharactersFromSet:[NSCharacterSet characterSetWithCharactersInString:@"\""] intoString:&type];
return type;
}
- (NSDictionary *)propertyNamesAndTypesForClass:(Class)class {
NSMutableDictionary *propertyNames = [NSMutableDictionary dictionary];
//include superclass properties
Class currentClass = class;
while (currentClass != nil) {
// Get the raw list of properties
unsigned int outCount;
objc_property_t *propList = class_copyPropertyList(currentClass, &outCount);
// Collect the property names
int i;
NSString *propName;
for (i = 0; i < outCount; i++) {
// TODO: Add support for custom getter and setter methods
// property_getAttributes() returns everything we need to implement this...
// See: http://developer.apple.com/mac/library/DOCUMENTATION/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtPropertyIntrospection.html#//apple_ref/doc/uid/TP40008048-CH101-SW5
objc_property_t * prop = propList + i;
NSString *type = [NSString stringWithCString:property_getAttributes(*prop) encoding:NSUTF8StringEncoding];
propName = [NSString stringWithCString:property_getName(*prop) encoding:NSUTF8StringEncoding];
if (![propName isEqualToString:@"_mapkit_hasPanoramaID"]) {
[propertyNames setObject:[self propertyTypeFromAttributeString:type] forKey:propName];
}
}
free(propList);
currentClass = [currentClass superclass];
}
return propertyNames;
}
- (NSString*)typeNameForProperty:(NSString*)property ofClass:(Class)class typeHint:(NSString*)typeHint {
if ([typeHint isEqualToString:@"boolean"]) {
return @"NSString";
} else {
return [[self propertyNamesAndTypesForClass:class] objectForKey:property];
}
}
@end