NetNewsWire/Parser/Sources/ObjC/RSOPMLParser.m

311 lines
7.2 KiB
Objective-C
Executable File

//
// RSOPMLParser.m
// RSParser
//
// Created by Brent Simmons on 7/12/15.
// Copyright © 2015 Ranchero Software, LLC. All rights reserved.
//
#import "RSOPMLParser.h"
#import "RSSAXParser.h"
#import "RSOPMLItem.h"
#import "RSOPMLDocument.h"
#import "RSOPMLAttributes.h"
#import "RSOPMLError.h"
#import "RSOPMLParser.h"
#import "ParserData.h"
#import <libxml/xmlstring.h>
@interface RSOPMLParser () <RSSAXParserDelegate>
@property (nonatomic, readwrite) RSOPMLDocument *OPMLDocument;
@property (nonatomic, readwrite) NSError *error;
@property (nonatomic) NSMutableArray *itemStack;
@end
void RSParseOPML(ParserData *parserData, OPMLParserCallback callback) {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
@autoreleasepool {
NSError *error = nil;
RSOPMLDocument *opmlDocument = [RSOPMLParser parseOPMLWithParserData:parserData error:&error];
dispatch_async(dispatch_get_main_queue(), ^{
callback(opmlDocument, error);
});
}
});
}
@implementation RSOPMLParser
#pragma mark - Class Methods
+ (RSOPMLDocument *)parseOPMLWithParserData:(ParserData *)parserData error:(NSError **)error {
RSOPMLParser *parser = [[RSOPMLParser alloc] initWithParserData:parserData];
RSOPMLDocument *document = parser.OPMLDocument;
document.url = parserData.url;
if (parser.error && error) {
*error = parser.error;
return nil;
}
return document;
}
#pragma mark - Init
- (instancetype)initWithParserData:(ParserData *)parserData {
self = [super init];
if (!self) {
return nil;
}
[self parse:parserData];
return self;
}
#pragma mark - Private
- (void)parse:(ParserData *)parserData {
@autoreleasepool {
if (![self canParseData:parserData.data]) {
NSString *filename = nil;
NSURL *url = [NSURL URLWithString:parserData.url];
if (url && url.isFileURL) {
filename = url.path.lastPathComponent;
}
if ([parserData.url hasPrefix:@"http"]) {
filename = parserData.url;
}
if (!filename) {
filename = parserData.url;
}
self.error = RSOPMLWrongFormatError(filename);
return;
}
RSSAXParser *parser = [[RSSAXParser alloc] initWithDelegate:self];
self.itemStack = [NSMutableArray new];
self.OPMLDocument = [RSOPMLDocument new];
[self pushItem:self.OPMLDocument];
[parser parseData:parserData.data];
[parser finishParsing];
}
}
- (BOOL)canParseData:(NSData *)d {
// Check for <opml and <outline near the top.
@autoreleasepool {
NSString *s = [[NSString alloc] initWithBytesNoCopy:(void *)d.bytes length:d.length encoding:NSUTF8StringEncoding freeWhenDone:NO];
if (!s) {
NSDictionary *options = @{NSStringEncodingDetectionSuggestedEncodingsKey : @[@(NSUTF8StringEncoding)]};
(void)[NSString stringEncodingForData:d encodingOptions:options convertedString:&s usedLossyConversion:nil];
}
if (!s) {
return NO;
}
static const NSInteger numberOfCharactersToSearch = 4096;
NSRange rangeToSearch = NSMakeRange(0, numberOfCharactersToSearch);
if (s.length < numberOfCharactersToSearch) {
rangeToSearch.length = s.length;
}
NSRange opmlRange = [s rangeOfString:@"<opml" options:NSCaseInsensitiveSearch range:rangeToSearch];
if (opmlRange.length < 1) {
return NO;
}
}
return YES;
}
- (void)pushItem:(RSOPMLItem *)item {
[self.itemStack addObject:item];
}
- (void)popItem {
NSAssert(self.itemStack.count > 0, nil);
/*If itemStack is empty, bad things are happening.
But we still shouldn't crash in production.*/
if (self.itemStack.count > 0) {
[self.itemStack removeLastObject];
}
}
- (RSOPMLItem *)currentItem {
return self.itemStack.lastObject;
}
#pragma mark - RSSAXParserDelegate
static const char *kOutline = "outline";
static const char kOutlineLength = 8;
- (void)saxParser:(RSSAXParser *)SAXParser XMLStartElement:(const xmlChar *)localName prefix:(const xmlChar *)prefix uri:(const xmlChar *)uri numberOfNamespaces:(NSInteger)numberOfNamespaces namespaces:(const xmlChar **)namespaces numberOfAttributes:(NSInteger)numberOfAttributes numberDefaulted:(int)numberDefaulted attributes:(const xmlChar **)attributes {
if (RSSAXEqualTags(localName, kTitle, kTitleLength)) {
[SAXParser beginStoringCharacters];
return;
}
if (!RSSAXEqualTags(localName, kOutline, kOutlineLength)) {
return;
}
RSOPMLItem *item = [RSOPMLItem new];
item.attributes = [SAXParser attributesDictionary:attributes numberOfAttributes:numberOfAttributes];
[[self currentItem] addChild:item];
[self pushItem:item];
}
- (void)saxParser:(RSSAXParser *)SAXParser XMLEndElement:(const xmlChar *)localName prefix:(const xmlChar *)prefix uri:(const xmlChar *)uri {
if (RSSAXEqualTags(localName, kTitle, kTitleLength)) {
RSOPMLItem* item = [self currentItem];
if ([item isKindOfClass:[RSOPMLDocument class]]) {
((RSOPMLDocument *)item).title = SAXParser.currentStringWithTrimmedWhitespace;
}
return;
}
if (RSSAXEqualTags(localName, kOutline, kOutlineLength)) {
[self popItem];
}
}
static const char *kText = "text";
static const NSInteger kTextLength = 5;
static const char *kTitle = "title";
static const NSInteger kTitleLength = 6;
static const char *kDescription = "description";
static const NSInteger kDescriptionLength = 12;
static const char *kType = "type";
static const NSInteger kTypeLength = 5;
static const char *kVersion = "version";
static const NSInteger kVersionLength = 8;
static const char *kHTMLURL = "htmlUrl";
static const NSInteger kHTMLURLLength = 8;
static const char *kXMLURL = "xmlUrl";
static const NSInteger kXMLURLLength = 7;
- (NSString *)saxParser:(RSSAXParser *)SAXParser internedStringForName:(const xmlChar *)name prefix:(const xmlChar *)prefix {
if (prefix) {
return nil;
}
size_t nameLength = strlen((const char *)name);
if (nameLength == kTextLength - 1) {
if (RSSAXEqualTags(name, kText, kTextLength)) {
return OPMLTextKey;
}
if (RSSAXEqualTags(name, kType, kTypeLength)) {
return OPMLTypeKey;
}
}
else if (nameLength == kTitleLength - 1) {
if (RSSAXEqualTags(name, kTitle, kTitleLength)) {
return OPMLTitleKey;
}
}
else if (nameLength == kXMLURLLength - 1) {
if (RSSAXEqualTags(name, kXMLURL, kXMLURLLength)) {
return OPMLXMLURLKey;
}
}
else if (nameLength == kVersionLength - 1) {
if (RSSAXEqualTags(name, kVersion, kVersionLength)) {
return OPMLVersionKey;
}
if (RSSAXEqualTags(name, kHTMLURL, kHTMLURLLength)) {
return OPMLHMTLURLKey;
}
}
else if (nameLength == kDescriptionLength - 1) {
if (RSSAXEqualTags(name, kDescription, kDescriptionLength)) {
return OPMLDescriptionKey;
}
}
return nil;
}
static const char *kRSSUppercase = "RSS";
static const char *kRSSLowercase = "rss";
static const NSUInteger kRSSLength = 3;
static NSString *RSSUppercaseValue = @"RSS";
static NSString *RSSLowercaseValue = @"rss";
static NSString *emptyString = @"";
static BOOL equalBytes(const void *bytes1, const void *bytes2, NSUInteger length) {
return memcmp(bytes1, bytes2, length) == 0;
}
- (NSString *)saxParser:(RSSAXParser *)SAXParser internedStringForValue:(const void *)bytes length:(NSUInteger)length {
if (length < 1) {
return emptyString;
}
if (length == kRSSLength) {
if (equalBytes(bytes, kRSSUppercase, kRSSLength)) {
return RSSUppercaseValue;
}
else if (equalBytes(bytes, kRSSLowercase, kRSSLength)) {
return RSSLowercaseValue;
}
}
return nil;
}
@end