Move some complex logic into its own class

so it will easier to write some unit tests and refactor some of the code.

1 files changed, 225 insertions, 0 deletions

diff --git a/Source/SPTableFilterParser.m b/Source/SPTableFilterParser.m
new file mode 100644
index 00000000..96ba8368
--- /dev/null
+++ b/Source/SPTableFilterParser.m
@@ -0,0 +1,225 @@
+//
+//  SPTableFilterParser.m
+//  sequel-pro
+//
+//  Created by Max Lohrmann on 22.04.15.
+//  Relocated from existing files. Previous copyright applies.
+//
+//  Permission is hereby granted, free of charge, to any person
+//  obtaining a copy of this software and associated documentation
+//  files (the "Software"), to deal in the Software without
+//  restriction, including without limitation the rights to use,
+//  copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the
+//  Software is furnished to do so, subject to the following
+//  conditions:
+//
+//  The above copyright notice and this permission notice shall be
+//  included in all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+//  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+//  OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+//  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+//  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+//  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+//  OTHER DEALINGS IN THE SOFTWARE.
+//
+//  More info at <https://github.com/sequelpro/sequelpro>
+
+#import "SPTableFilterParser.h"
+#import "RegexKitLite.h"
+
+@interface SPTableFilterParser (Private)
++ (NSString *)escapeFilterArgument:(NSString *)argument againstClause:(NSString *)clause;
+@end
+
+@implementation SPTableFilterParser
+
+@synthesize suppressLeadingTablePlaceholder = suppressLeadingTablePlaceholder;
+@synthesize caseSensitive                   = caseSensitive;
+@synthesize currentField                    = _currentField;
+@synthesize argument                        = _argument;
+@synthesize firstBetweenArgument            = _firstBetweenArgument;
+@synthesize secondBetweenArgument           = _secondBetweenArgument;
+@synthesize numberOfArguments               = numberOfArguments;
+@synthesize clause                          = _clause;
+
+- (id)initWithFilterClause:(NSString *)filter numberOfArguments:(NSUInteger)numArgs
+{
+	self = [super init];
+	if (self) {
+		numberOfArguments = numArgs;
+		_clause           = [filter copy];
+	}
+	return self;
+}
+
+- (void)dealloc
+{
+	SPClear(_clause);
+	
+	[self setCurrentField:nil];
+	[self setArgument:nil];
+	[self setFirstBetweenArgument:nil];
+	[self setSecondBetweenArgument:nil];
+	
+	[super dealloc];
+}
+
+- (NSString *)filterString
+{
+	NSString *filterString;
+	
+	// argument if Filter requires only one argument
+	NSMutableString *argument = [[NSMutableString alloc] initWithString:_argument];
+
+	// If the filter field is empty and the selected filter does not require
+	// only one argument, then no filtering is required - return nil.
+	if (![argument length] && numberOfArguments == 1) {
+		[argument release];
+		return nil;
+	}
+	
+	// arguments if Filter requires two arguments
+	NSMutableString *firstBetweenArgument  = [[NSMutableString alloc] initWithString:_firstBetweenArgument];
+	NSMutableString *secondBetweenArgument = [[NSMutableString alloc] initWithString:_secondBetweenArgument];
+	
+	// If filter requires two arguments and either of the argument fields are empty
+	// return nil.
+	if (numberOfArguments == 2) {
+		if (([firstBetweenArgument length] == 0) || ([secondBetweenArgument length] == 0)) {
+			[argument release];
+			[firstBetweenArgument release];
+			[secondBetweenArgument release];
+			return nil;
+		}
+	}
+	
+	// Retrieve actual WHERE clause
+	NSMutableString *clause = [[NSMutableString alloc] init];
+	[clause setString:_clause];
+	
+	[clause replaceOccurrencesOfRegex:@"(?<!\\\\)\\$BINARY " withString:(caseSensitive) ? @"BINARY " : @""];
+	[clause flushCachedRegexData];
+	[clause replaceOccurrencesOfRegex:@"(?<!\\\\)\\$CURRENT_FIELD" withString:(_currentField) ? [_currentField backtickQuotedString] : @""];
+	[clause flushCachedRegexData];
+	
+	// Escape % sign for format insertion ie if number of arguments is greater than 0
+	if(numberOfArguments > 0)
+		[clause replaceOccurrencesOfRegex:@"%" withString:@"%%"];
+	[clause flushCachedRegexData];
+	
+	// Replace placeholder ${} by %@
+	NSRange matchedRange;
+	NSString *re = @"(?<!\\\\)\\$\\{.*?\\}";
+	if([clause isMatchedByRegex:re]) {
+		while([clause isMatchedByRegex:re]) {
+			matchedRange = [clause rangeOfRegex:re];
+			[clause replaceCharactersInRange:matchedRange withString:@"%@"];
+			[clause flushCachedRegexData];
+		}
+	}
+	
+	// Check number of placeholders and given 'NumberOfArguments'
+	if([clause replaceOccurrencesOfString:@"%@" withString:@"%@" options:NSLiteralSearch range:NSMakeRange(0, [clause length])] != numberOfArguments) {
+		SPLog(@"Error while setting filter string. “NumberOfArguments” differs from the number of arguments specified in “Clause”.");
+		NSBeep();
+		[argument release];
+		[firstBetweenArgument release];
+		[secondBetweenArgument release];
+		[clause release];
+		return nil;
+	}
+	
+	// Construct the filter string according the required number of arguments
+	
+	if(suppressLeadingTablePlaceholder) {
+		if (numberOfArguments == 2) {
+			filterString = [NSString stringWithFormat:clause,
+							[[self class] escapeFilterArgument:firstBetweenArgument againstClause:clause],
+							[[self class] escapeFilterArgument:secondBetweenArgument againstClause:clause]];
+		} else if (numberOfArguments == 1) {
+			filterString = [NSString stringWithFormat:clause, [[self class] escapeFilterArgument:argument againstClause:clause]];
+		} else {
+			filterString = [NSString stringWithString:clause];
+			if(numberOfArguments > 2) {
+				SPLog(@"Filter with more than 2 arguments is not yet supported.");
+				NSBeep();
+			}
+		}
+	} else {
+		if (numberOfArguments == 2) {
+			filterString = [NSString stringWithFormat:@"%@ %@",
+							[_currentField backtickQuotedString],
+							[NSString stringWithFormat:clause,
+							 [[self class] escapeFilterArgument:firstBetweenArgument againstClause:clause],
+							 [[self class] escapeFilterArgument:secondBetweenArgument againstClause:clause]]];
+		} else if (numberOfArguments == 1) {
+			filterString = [NSString stringWithFormat:@"%@ %@",
+							[_currentField backtickQuotedString],
+							[NSString stringWithFormat:clause, [[self class] escapeFilterArgument:argument againstClause:clause]]];
+		} else {
+			filterString = [NSString stringWithFormat:@"%@ %@",
+							[_currentField backtickQuotedString], clause];
+			if(numberOfArguments > 2) {
+				SPLog(@"Filter with more than 2 arguments is not yet supported.");
+				NSBeep();
+			}
+		}
+	}
+	
+	[argument release];
+	[firstBetweenArgument release];
+	[secondBetweenArgument release];
+	[clause release];
+	
+	// Return the filter string
+	return filterString;
+}
+
+/**
+ * Escape argument by looking for used quoting strings in a clause.  Attempt to
+ * be smart - use a single escape for most clauses, doubling up for LIKE clauses.
+ * Also attempt to not escape what look like common escape sequences - \n, \r, \t.
+ *
+ * @param argument The to be used filter argument which should be be escaped
+ *
+ * @param clause The entire WHERE filter clause
+ *
+ */
++ (NSString *)escapeFilterArgument:(NSString *)argument againstClause:(NSString *)clause
+{
+	BOOL clauseIsLike = [clause isMatchedByRegex:@"(?i)\\blike\\b.*?%(?!@)"];
+	NSString *recognizedEscapeSequences, *escapeSequence, *regexTerm;
+	NSMutableString *arg = [argument mutableCopy];
+	
+	// Determine the character set not to escape slashes before, and the escape depth
+	if (clauseIsLike) {
+		recognizedEscapeSequences = @"nrt_%";
+		escapeSequence = @"\\\\\\\\\\\\\\\\";
+	} else {
+		recognizedEscapeSequences = @"nrt";
+		escapeSequence = @"\\\\\\\\";
+	}
+	regexTerm = [NSString stringWithFormat:@"(\\\\)(?![%@])", recognizedEscapeSequences];
+	
+	// Escape slashes appropriately
+	[arg replaceOccurrencesOfRegex:regexTerm withString:escapeSequence];
+	[arg flushCachedRegexData];
+	
+	// Get quote sign for escaping - this should work for 99% of all cases
+	NSString *quoteSign = [clause stringByMatching:@"([\"'])[^\\1]*?%@[^\\1]*?\\1" capture:1L];
+	
+	// Escape argument
+	if(quoteSign != nil && [quoteSign length] == 1) {
+		[arg replaceOccurrencesOfRegex:[NSString stringWithFormat:@"(%@)", quoteSign] withString:@"\\\\$1"];
+		[arg flushCachedRegexData];
+	}
+	
+	return [arg autorelease];
+}
+
+
+@end