// // MGTemplateStandardMarkers.m // // Created by Matt Gemmell on 13/05/2008. // Copyright 2008 Instinctive Code. All rights reserved. // #import "MGTemplateStandardMarkers.h" #import "MGTemplateFilter.h" //============================================================================== #define FOR_START @"for" #define FOR_END @"/for" #define FOR_TYPE_ENUMERATOR @"in" // e.g. for thing in things #define FOR_TYPE_RANGE @"to" // e.g. for 1 to 5 #define FOR_REVERSE @"reversed" #define FOR_LOOP_VARS @"currentLoop" #define FOR_LOOP_CURR_INDEX @"currentIndex" #define FOR_LOOP_START_INDEX @"startIndex" #define FOR_LOOP_END_INDEX @"endIndex" #define FOR_PARENT_LOOP @"parentLoop" #define STACK_START_MARKER_RANGE @"markerRange" #define STACK_START_REMAINING_RANGE @"remainingRange" #define FOR_STACK_ENUMERATOR @"enumerator" #define FOR_STACK_ENUM_VAR @"enumeratorVariable" #define FOR_STACK_DISABLED_OUTPUT @"disabledOutput" //============================================================================== #define SECTION_START @"section" #define SECTION_END @"/section" //============================================================================== #define IF_START @"if" #define ELSE @"else" #define IF_END @"/if" #define IF_VARS @"currentIf" #define DISABLE_OUTPUT @"shouldDisableOutput" #define IF_ARG_TRUE @"argumentTrue" #define IF_ELSE_SEEN @"elseEncountered" //============================================================================== #define NOW @"now" //============================================================================== #define COMMENT_START @"comment" #define COMMENT_END @"/comment" //============================================================================== #define LOAD @"load" //============================================================================== #define CYCLE @"cycle" #define CYCLE_INDEX @"lastIndex" #define CYCLE_VALUES @"value" //============================================================================== #define SET @"set" //============================================================================== @implementation MGTemplateStandardMarkers - (id)initWithTemplateEngine:(MGTemplateEngine *)theEngine { if (self = [super init]) { engine = theEngine; forStack = [[NSMutableArray alloc] init]; sectionStack = [[NSMutableArray alloc] init]; ifStack = [[NSMutableArray alloc] init]; commentStack = [[NSMutableArray alloc] init]; cycles = [[NSMutableDictionary alloc] init]; } return self; } - (void)dealloc { engine = nil; [forStack release]; forStack = nil; [sectionStack release]; sectionStack = nil; [ifStack release]; ifStack = nil; [commentStack release]; commentStack = nil; [cycles release]; cycles = nil; [super dealloc]; } - (NSArray *)markers { return [NSArray arrayWithObjects: FOR_START, FOR_END, SECTION_START, SECTION_END, IF_START, ELSE, IF_END, NOW, COMMENT_START, COMMENT_END, LOAD, CYCLE, SET, nil]; } - (NSArray *)endMarkersForMarker:(NSString *)marker { if ([marker isEqualToString:FOR_START]) { return [NSArray arrayWithObjects:FOR_END, nil]; } else if ([marker isEqualToString:SECTION_START]) { return [NSArray arrayWithObjects:SECTION_END, nil]; } else if ([marker isEqualToString:IF_START]) { return [NSArray arrayWithObjects:IF_END, ELSE, nil]; } else if ([marker isEqualToString:COMMENT_START]) { return [NSArray arrayWithObjects:COMMENT_END, nil]; } return nil; } - (NSObject *)markerEncountered:(NSString *)marker withArguments:(NSArray *)args inRange:(NSRange)markerRange blockStarted:(BOOL *)blockStarted blockEnded:(BOOL *)blockEnded outputEnabled:(BOOL *)outputEnabled nextRange:(NSRange *)nextRange currentBlockInfo:(NSDictionary *)blockInfo newVariables:(NSDictionary **)newVariables { if ([marker isEqualToString:FOR_START]) { if (args && [args count] >= 3) { // Determine which type of loop this is. BOOL isRange = YES; if ([[args objectAtIndex:1] isEqualToString:FOR_TYPE_ENUMERATOR]) { isRange = NO; } BOOL reversed = NO; if ([args count] == 4 && [[args objectAtIndex:3] isEqualToString:FOR_REVERSE]) { reversed = YES; } // Determine if we have acceptable parameters. NSObject *loopEnumObject = nil; BOOL valid = NO; NSString *startArg = [args objectAtIndex:0]; NSString *endArg = [args objectAtIndex:2]; NSInteger startIndex, endIndex; if (isRange) { // Check to see if either the arg itself is numeric, or it corresponds to a numeric variable. valid = [self argIsNumeric:startArg intValue:&startIndex checkVariables:YES]; if (valid) { valid = [self argIsNumeric:endArg intValue:&endIndex checkVariables:YES]; if (valid) { // Check startIndex and endIndex are sensible. valid = (startIndex <= endIndex); } } } else { startIndex = 0; // Check that endArg is a collection. NSObject *obj = [engine resolveVariable:endArg]; if (obj && [obj respondsToSelector:@selector(objectEnumerator)] && [obj respondsToSelector:@selector(count)]) { endIndex = [(NSArray *)obj count]; if (endIndex > 0) { loopEnumObject = obj; valid = YES; } } } if (valid) { *blockStarted = YES; // Set up for-stack frame for this loop. NSMutableDictionary *stackFrame = [NSMutableDictionary dictionaryWithObjectsAndKeys: [NSValue valueWithRange:markerRange], STACK_START_MARKER_RANGE, [NSValue valueWithRange:*nextRange], STACK_START_REMAINING_RANGE, nil]; [forStack addObject:stackFrame]; // Set up variables for the block. NSInteger currentIndex = (reversed) ? endIndex : startIndex; NSMutableDictionary *loopVars = [NSMutableDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithInteger:startIndex], FOR_LOOP_START_INDEX, [NSNumber numberWithInteger:endIndex], FOR_LOOP_END_INDEX, [NSNumber numberWithInteger:currentIndex], FOR_LOOP_CURR_INDEX, [NSNumber numberWithBool:reversed], FOR_REVERSE, nil]; NSMutableDictionary *blockVars = [NSMutableDictionary dictionaryWithObjectsAndKeys: loopVars, FOR_LOOP_VARS, nil]; // Add enumerator variable if appropriate. if (!isRange) { NSEnumerator *enumerator; if (reversed && [loopEnumObject respondsToSelector:@selector(reverseObjectEnumerator)]) { enumerator = [(NSArray *)loopEnumObject reverseObjectEnumerator]; } else { enumerator = [(NSArray *)loopEnumObject objectEnumerator]; } [stackFrame setObject:enumerator forKey:FOR_STACK_ENUMERATOR]; [stackFrame setObject:startArg forKey:FOR_STACK_ENUM_VAR]; [blockVars setObject:[enumerator nextObject] forKey:startArg]; } // Add parentLoop if it exists. if (blockInfo) { NSDictionary *parentLoop; parentLoop = (NSDictionary *)[engine resolveVariable:FOR_LOOP_VARS]; // in case parent loop isn't in the first parent stack-frame. if (parentLoop) { [loopVars setObject:parentLoop forKey:FOR_PARENT_LOOP]; } } *newVariables = blockVars; } else { // Disable output for this block. *blockStarted = YES; NSMutableDictionary *stackFrame = [NSMutableDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithBool:YES], FOR_STACK_DISABLED_OUTPUT, [NSValue valueWithRange:markerRange], STACK_START_MARKER_RANGE, [NSValue valueWithRange:*nextRange], STACK_START_REMAINING_RANGE, nil]; [forStack addObject:stackFrame]; *outputEnabled = NO; } } } else if ([marker isEqualToString:FOR_END]) { // Decide whether to loop back or terminate. if ([self currentBlock:blockInfo matchesTopOfStack:forStack]) { NSMutableDictionary *frame = [forStack lastObject]; // Check to see if this was a block with an invalid looping condition. NSNumber *disabledOutput = (NSNumber *)[frame objectForKey:FOR_STACK_DISABLED_OUTPUT]; if (disabledOutput && [disabledOutput boolValue]) { *outputEnabled = YES; *blockEnded = YES; [forStack removeLastObject]; } // This is the same loop that's on top of our stack. Check to see if we need to loop back. BOOL loop = NO; NSDictionary *blockVars = [blockInfo objectForKey:BLOCK_VARIABLES_KEY]; if ([blockVars count] == 0) { *blockEnded = YES; return nil; } NSMutableDictionary *loopVars = [[[blockVars objectForKey:FOR_LOOP_VARS] mutableCopy] autorelease]; BOOL reversed = [[loopVars objectForKey:FOR_REVERSE] boolValue]; NSEnumerator *loopEnum = [frame objectForKey:FOR_STACK_ENUMERATOR]; NSObject *newEnumValue = nil; NSInteger currentIndex = [[loopVars objectForKey:FOR_LOOP_CURR_INDEX] integerValue]; if (loopEnum) { // Enumerator type. newEnumValue = [loopEnum nextObject]; if (newEnumValue) { loop = YES; } } else { // Range type. if (reversed) { NSInteger minIndex = [[loopVars objectForKey:FOR_LOOP_START_INDEX] integerValue]; if (currentIndex > minIndex) { loop = YES; } } else { NSInteger maxIndex = [[loopVars objectForKey:FOR_LOOP_END_INDEX] integerValue]; if (currentIndex < maxIndex) { loop = YES; } } } if (loop) { // Set remainingRange from stack dict *nextRange = [[frame objectForKey:STACK_START_REMAINING_RANGE] rangeValue]; // Set new currentIndex if (reversed) { currentIndex--; } else { currentIndex++; } [loopVars setObject:[NSNumber numberWithInteger:currentIndex] forKey:FOR_LOOP_CURR_INDEX]; // Set new val for enumVar if specified NSMutableDictionary *newVars = [NSMutableDictionary dictionaryWithObjectsAndKeys: loopVars, FOR_LOOP_VARS, nil]; if (newEnumValue) { [newVars setObject:newEnumValue forKey:[frame objectForKey:FOR_STACK_ENUM_VAR]]; } *newVariables = newVars; } else { // Don't need to do much here, since: // 1. Each blockStack frame for a "for" has its own currentLoop dict. // 2. Parent loop's enum-vars are still in place in the parent stack's vars. // End block. *blockEnded = YES; [forStack removeLastObject]; } // Return immediately. return nil; } *blockEnded = YES; } else if ([marker isEqualToString:SECTION_START]) { if (args && [args count] == 1) { *blockStarted = YES; // Set up for-stack frame for this section. NSMutableDictionary *stackFrame = [NSMutableDictionary dictionaryWithObjectsAndKeys: [NSValue valueWithRange:markerRange], STACK_START_MARKER_RANGE, nil]; [sectionStack addObject:stackFrame]; } } else if ([marker isEqualToString:SECTION_END]) { if ([self currentBlock:blockInfo matchesTopOfStack:sectionStack]) { // This is the same section that's on top of our stack. Remove from stack. [sectionStack removeLastObject]; } *blockEnded = YES; } else if ([marker isEqualToString:IF_START]) { if (args && ([args count] == 1 || [args count] == 3)) { *blockStarted = YES; // Determine appropriate values for outputEnabled and for our if-stack frame. BOOL elseEncountered = NO; BOOL argTrue = NO; if ([args count] == 1) { argTrue = [self argIsTrue:[args objectAtIndex:0]]; } else if ([args count] == 2 && [[[args objectAtIndex:0] lowercaseString] isEqualToString:@"not"]) { // e.g. if not x argTrue = ![self argIsTrue:[args objectAtIndex:1]]; } else if ([args count] == 3) { // Assumed to be of the form: operand comparison operand, e.g. x == y NSString *firstArg = [args objectAtIndex:0]; NSString *secondArg = [args objectAtIndex:2]; BOOL firstTrue = [self argIsTrue:firstArg]; BOOL secondTrue = [self argIsTrue:secondArg]; NSInteger num1, num2; BOOL firstNumeric, secondNumeric; firstNumeric = [self argIsNumeric:firstArg intValue:&num1 checkVariables:YES]; secondNumeric = [self argIsNumeric:secondArg intValue:&num2 checkVariables:YES]; if (!firstNumeric) { num1 = ([engine resolveVariable:firstArg]) ? 1 : 0; } if (!secondNumeric) { num2 = ([engine resolveVariable:secondArg]) ? 1 : 0; } NSString *op = [[args objectAtIndex:1] lowercaseString]; if ([op isEqualToString:@"and"] || [op isEqualToString:@"&&"]) { argTrue = (firstTrue && secondTrue); } else if ([op isEqualToString:@"or"] || [op isEqualToString:@"||"]) { argTrue = (firstTrue || secondTrue); } else if ([op isEqualToString:@"="] || [op isEqualToString:@"=="]) { argTrue = (num1 == num2); } else if ([op isEqualToString:@"!="] || [op isEqualToString:@"<>"]) { argTrue = (num1 != num2); } else if ([op isEqualToString:@">"]) { argTrue = (num1 > num2); } else if ([op isEqualToString:@"<"]) { argTrue = (num1 < num2); } else if ([op isEqualToString:@">="]) { argTrue = (num1 >= num2); } else if ([op isEqualToString:@"<="]) { argTrue = (num1 <= num2); } else if ([op isEqualToString:@"\%"]) { argTrue = ((num1 % num2) > 0); } } BOOL shouldDisableOutput = *outputEnabled; if (shouldDisableOutput && !argTrue) { *outputEnabled = NO; } // Create variables. NSMutableDictionary *ifVars = [NSMutableDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithBool:argTrue], IF_ARG_TRUE, [NSNumber numberWithBool:shouldDisableOutput], DISABLE_OUTPUT, [NSNumber numberWithBool:elseEncountered], IF_ELSE_SEEN, nil]; // Set up for-stack frame for this if-statement. NSMutableDictionary *stackFrame = [NSMutableDictionary dictionaryWithObjectsAndKeys: [NSValue valueWithRange:markerRange], STACK_START_MARKER_RANGE, ifVars, IF_VARS, nil]; [ifStack addObject:stackFrame]; } } else if ([marker isEqualToString:ELSE]) { if ([self currentBlock:blockInfo matchesTopOfStack:ifStack]) { NSMutableDictionary *frame = [[ifStack lastObject] objectForKey:IF_VARS]; BOOL elseSeen = [[frame objectForKey:IF_ELSE_SEEN] boolValue]; BOOL argTrue = [[frame objectForKey:IF_ARG_TRUE] boolValue]; BOOL modifyOutput = [[frame objectForKey:DISABLE_OUTPUT] boolValue]; if (!elseSeen) { if (modifyOutput) { // Only make changes if we've not already seen an 'else' for this block, // and if we're modifying output state at all. *outputEnabled = !argTrue; // either turning it off, or turning it back on. } // Note that we've now seen the else marker. [frame setObject:[NSNumber numberWithBool:YES] forKey:IF_ELSE_SEEN]; } } } else if ([marker isEqualToString:IF_END]) { if ([self currentBlock:blockInfo matchesTopOfStack:ifStack]) { NSMutableDictionary *frame = [[ifStack lastObject] objectForKey:IF_VARS]; BOOL modifyOutput = [[frame objectForKey:DISABLE_OUTPUT] boolValue]; if (modifyOutput) { // If we're modifying output, it was enabled when this block started. // Thus, it should be enabled after the block ends. // If it's already enabled, this will have no harmful effect. *outputEnabled = YES; } // End block. [ifStack removeLastObject]; *blockEnded = YES; } *blockEnded = YES; } else if ([marker isEqualToString:NOW]) { return [NSDate date]; } else if ([marker isEqualToString:COMMENT_START]) { // Work out if we need to start a block. if (!args || [args count] == 0) { *blockStarted = YES; // Determine appropriate values for outputEnabled and for our stack frame. BOOL shouldDisableOutput = *outputEnabled; if (shouldDisableOutput) { *outputEnabled = NO; } // Set up for-stack frame for this if-statement. NSMutableDictionary *stackFrame = [NSMutableDictionary dictionaryWithObjectsAndKeys: [NSValue valueWithRange:markerRange], STACK_START_MARKER_RANGE, [NSNumber numberWithBool:shouldDisableOutput], DISABLE_OUTPUT, nil]; [commentStack addObject:stackFrame]; } } else if ([marker isEqualToString:COMMENT_END]) { // Check this is block on top of stack. if ([self currentBlock:blockInfo matchesTopOfStack:commentStack]) { NSMutableDictionary *frame = [commentStack lastObject]; BOOL modifyOutput = [[frame objectForKey:DISABLE_OUTPUT] boolValue]; if (modifyOutput) { // If we're modifying output, it was enabled when this block started. // Thus, it should be enabled after the block ends. // If it's already enabled, this will have no harmful effect. *outputEnabled = YES; } // End block. [commentStack removeLastObject]; *blockEnded = YES; } *blockEnded = YES; } else if ([marker isEqualToString:LOAD]) { if (args && [args count] > 0) { for (NSString *className in args) { Class class = NSClassFromString(className); if (class && [(id)class isKindOfClass:[NSObject class]]) { if ([class conformsToProtocol:@protocol(MGTemplateFilter)]) { // Instantiate and load filter. NSObject <MGTemplateFilter> *obj = [[[class alloc] init] autorelease]; [engine loadFilter:obj]; } else if ([class conformsToProtocol:@protocol(MGTemplateMarker)]) { // Instantiate and load marker. NSObject <MGTemplateMarker> *obj = [[[class alloc] initWithTemplateEngine:engine] autorelease]; [engine loadMarker:obj]; } } } } } else if ([marker isEqualToString:CYCLE]) { if (args && [args count] > 0) { // Check to see if it's an existing cycle. NSString *rangeKey = NSStringFromRange(markerRange); NSMutableDictionary *cycle = [cycles objectForKey:rangeKey]; if (cycle) { NSArray *vals = [cycle objectForKey:CYCLE_VALUES]; NSInteger currIndex = [[cycle objectForKey:CYCLE_INDEX] integerValue]; currIndex++; if (currIndex >= [vals count]) { currIndex = 0; } [cycle setObject:[NSNumber numberWithInteger:currIndex] forKey:CYCLE_INDEX]; return [vals objectAtIndex:currIndex]; } else { // New cycle. Create and output appropriately. cycle = [NSMutableDictionary dictionaryWithCapacity:2]; [cycle setObject:[NSNumber numberWithInteger:0] forKey:CYCLE_INDEX]; [cycle setObject:args forKey:CYCLE_VALUES]; [cycles setObject:cycle forKey:rangeKey]; return [args objectAtIndex:0]; } } } else if ([marker isEqualToString:SET]) { if (args && [args count] == 2 && *outputEnabled) { // Set variable arg1 to value arg2. NSDictionary *newVar = [NSDictionary dictionaryWithObject:[args objectAtIndex:1] forKey:[args objectAtIndex:0]]; if (newVar) { *newVariables = newVar; } } } return nil; } - (BOOL)currentBlock:(NSDictionary *)blockInfo matchesTopOfStack:(NSMutableArray *)stack { if (blockInfo && [stack count] > 0) { // end-tag should always have blockInfo, and correspond to a stack frame. NSDictionary *frame = [stack lastObject]; NSRange stackSectionRange = [[frame objectForKey:STACK_START_MARKER_RANGE] rangeValue]; NSRange thisSectionRange = [[blockInfo objectForKey:BLOCK_START_MARKER_RANGE_KEY] rangeValue]; if (NSEqualRanges(stackSectionRange, thisSectionRange)) { return YES; } } return NO; } - (BOOL)argIsTrue:(NSString *)arg { BOOL argTrue = NO; if (arg) { NSObject *val = [engine resolveVariable:arg]; if (val) { if ([val isKindOfClass:[NSNumber class]]) { argTrue = [(NSNumber *)val boolValue]; } else { argTrue = YES; } } } return argTrue; } - (BOOL)argIsNumeric:(NSString *)arg intValue:(NSInteger *)val checkVariables:(BOOL)checkVars { BOOL numeric = NO; NSInteger value = 0; if (arg && [arg length] > 0) { if ([[arg substringToIndex:1] isEqualToString:@"0"] || [arg integerValue] != 0) { numeric = YES; value = [arg integerValue]; } else if (checkVars) { // Check to see if arg is a variable with an intValue. NSObject *argObj = [engine resolveVariable:arg]; NSString *argStr = [NSString stringWithFormat:@"%@", argObj]; if (argObj && [argObj respondsToSelector:@selector(integerValue)] && [self argIsNumeric:argStr intValue:&value checkVariables:NO]) { // avoid recursion numeric = YES; } } } if (val) { *val = value; } return numeric; } - (void)engineFinishedProcessingTemplate { // Clean up stacks etc. [forStack release]; forStack = [[NSMutableArray alloc] init]; [sectionStack release]; sectionStack = [[NSMutableArray alloc] init]; [ifStack release]; ifStack = [[NSMutableArray alloc] init]; [commentStack release]; commentStack = [[NSMutableArray alloc] init]; cycles = [[NSMutableDictionary alloc] init]; } @end