BNHtmlPdfKit.m

//
//  BNHtmlPdfKit.m
//
//  Created by Brent Nycum.
//  Copyright (c) 2013 Brent Nycum. All rights reserved.
//

#import "BNHtmlPdfKit.h"

#import "BNHtmlPdfKitPageRenderer.h"


#define PPI 72
#define BNSizeMakeWithPPI(width, height) CGSizeMake(width * PPI, height * PPI)


#pragma mark - BNHtmlPdfKit Class Extension

@interface BNHtmlPdfKit () <UIWebViewDelegate>

- (CGSize)_sizeFromPageSize:(BNPageSize)pageSize;

@property (nonatomic, copy) NSString *outputFile;
@property (nonatomic, strong) UIWebView *webView;

@end


#pragma mark - BNHtmlPdfKit Implementation

@implementation BNHtmlPdfKit

#pragma mark - Initializers

- (id)init {
    if (self = [super init]) {
        _pageSize = [BNHtmlPdfKit defaultPageSize];

		// Default 1/4" margins
		_topAndBottomMarginSize = 0.25f * 72.0f;
		_leftAndRightMarginSize = 0.25f * 72.0f;
    }
    return self;
}

- (id)initWithPageSize:(BNPageSize)pageSize {
	if (self = [super init]) {
		_pageSize = pageSize;

		// Default 1/4" margins
		_topAndBottomMarginSize = 0.25f * 72.0f;
		_leftAndRightMarginSize = 0.25f * 72.0f;
	}
	return self;
}

- (id)initWithCustomPageSize:(CGSize)pageSize {
	if (self = [super init]) {
		_pageSize = BNPageSizeCustom;
		_customPageSize = pageSize;

		// Default 1/4" margins
		_topAndBottomMarginSize = 0.25f * 72.0f;
		_leftAndRightMarginSize = 0.25f * 72.0f;

		_printHeader = YES;
		_printFooter = YES;
	}
	return self;
}

- (void)dealloc
{
	[[self class] cancelPreviousPerformRequestsWithTarget:self selector:@selector(_timeout) object:nil];

	[_webView setDelegate:nil];
	[_webView stopLoading];
}

#pragma mark - Methods

- (void)setWebView:(UIWebView *)webView {
	[[self class] cancelPreviousPerformRequestsWithTarget:self selector:@selector(_timeout) object:nil];

	[_webView setDelegate:nil];
	[_webView stopLoading];

	_webView = webView;
}

- (UIWebView *)createWebView {
	UIWebView *webView = [[UIWebView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];

	webView.scalesPageToFit = YES;
	webView.delegate = self;

	if ([webView respondsToSelector:@selector(setSuppressesIncrementalRendering:)]) {
		[webView setSuppressesIncrementalRendering:YES];
	}

	return webView;
}

- (CGSize)actualPageSize {
	return [self _sizeFromPageSize:self.pageSize];
}

- (void)saveHtmlAsPdf:(NSString *)html {
	[self saveHtmlAsPdf:html toFile:nil];
}

- (void)saveHtmlAsPdf:(NSString *)html toFile:(NSString *)file {
	UIWebView *webView = self.webView = [self createWebView];
	
	self.outputFile = file;

	[webView loadHTMLString:html baseURL:[NSURL URLWithString:@"http://localhost"]];
}

- (void)saveUrlAsPdf:(NSURL *)url {
	[self saveUrlAsPdf:url toFile:nil];
}

- (void)saveUrlAsPdf:(NSURL *)url toFile:(NSString *)file {
	[self saveRequestAsPdf:[NSURLRequest requestWithURL:url] toFile:file];
}

- (void)saveRequestAsPdf:(NSURLRequest *)request {
	[self saveRequestAsPdf:request toFile:nil];
}

- (void)saveRequestAsPdf:(NSURLRequest *)request toFile:(NSString *)file {
	UIWebView *webView = self.webView = [self createWebView];

	self.outputFile = file;

	[webView loadRequest:request];
}

- (void)saveDataAsPdf:(NSData *)data MIMEType:(NSString *)mimeType textEncodingName:(NSString *)textEncodingName {
	[self saveDataAsPdf:data MIMEType:mimeType textEncodingName:textEncodingName toFile:nil];
}

- (void)saveDataAsPdf:(NSData *)data MIMEType:(NSString *)mimeType textEncodingName:(NSString *)textEncodingName toFile:(NSString *)file {
	UIWebView *webView = self.webView = [self createWebView];

	self.outputFile = file;

	[webView loadData:data MIMEType:mimeType textEncodingName:textEncodingName baseURL:nil];
}

#pragma mark - Action methods

- (void)stopAction:(id)sender {
	[self.webView stopLoading];
}

#pragma mark - UIWebViewDelegate

- (void)webViewDidFinishLoad:(UIWebView *)webView {
	NSString	*readyState = [webView stringByEvaluatingJavaScriptFromString:@"document.readyState"];
	BOOL		complete	= [readyState isEqualToString:@"complete"];

	[[self class] cancelPreviousPerformRequestsWithTarget:self selector:@selector(_timeout) object:nil];

	if (complete) {
		[self _savePdf];
	}
	else {
		[self performSelector:@selector(_timeout) withObject:nil afterDelay:1.0f];
	}
}

-(void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error {
	id <BNHtmlPdfKitDelegate> delegate = self.delegate;

	if ([delegate respondsToSelector:@selector(htmlPdfKit:didFailWithError:)]) {
		[delegate htmlPdfKit:self didFailWithError:error];
	}

	self.webView = nil;
}

#pragma mark - Private Methods

- (CGSize)_sizeFromPageSize:(BNPageSize)pageSize {
	switch (pageSize) {
		case BNPageSizeLetter:
			return BNSizeMakeWithPPI(8.5f, 11.0f);
		case BNPageSizeGovernmentLetter:
			return BNSizeMakeWithPPI(8.0f, 10.5f);
		case BNPageSizeLegal:
			return BNSizeMakeWithPPI(8.5f, 14.0f);
		case BNPageSizeJuniorLegal:
			return BNSizeMakeWithPPI(8.5f, 5.0f);
		case BNPageSizeLedger:
			return BNSizeMakeWithPPI(17.0f, 11.0f);
		case BNPageSizeTabloid:
			return BNSizeMakeWithPPI(11.0f, 17.0f);
		case BNPageSizeA0:
			return BNSizeMakeWithPPI(33.11f, 46.81f);
		case BNPageSizeA1:
			return BNSizeMakeWithPPI(23.39f, 33.11f);
		case BNPageSizeA2:
			return BNSizeMakeWithPPI(16.54f, 23.39f);
		case BNPageSizeA3:
			return BNSizeMakeWithPPI(11.69f, 16.54f);
		case BNPageSizeA4:
			return BNSizeMakeWithPPI(8.26666667, 11.6916667);
		case BNPageSizeA5:
			return BNSizeMakeWithPPI(5.83f, 8.27f);
		case BNPageSizeA6:
			return BNSizeMakeWithPPI(4.13f, 5.83f);
		case BNPageSizeA7:
			return BNSizeMakeWithPPI(2.91f, 4.13f);
		case BNPageSizeA8:
			return BNSizeMakeWithPPI(2.05f, 2.91f);
		case BNPageSizeA9:
			return BNSizeMakeWithPPI(1.46f, 2.05f);
		case BNPageSizeA10:
			return BNSizeMakeWithPPI(1.02f, 1.46f);
		case BNPageSizeB0:
			return BNSizeMakeWithPPI(39.37f, 55.67f);
		case BNPageSizeB1:
			return BNSizeMakeWithPPI(27.83f, 39.37f);
		case BNPageSizeB2:
			return BNSizeMakeWithPPI(19.69f, 27.83f);
		case BNPageSizeB3:
			return BNSizeMakeWithPPI(13.90f, 19.69f);
		case BNPageSizeB4:
			return BNSizeMakeWithPPI(9.84f, 13.90f);
		case BNPageSizeB5:
			return BNSizeMakeWithPPI(6.93f, 9.84f);
		case BNPageSizeB6:
			return BNSizeMakeWithPPI(4.92f, 6.93f);
		case BNPageSizeB7:
			return BNSizeMakeWithPPI(3.46f, 4.92f);
		case BNPageSizeB8:
			return BNSizeMakeWithPPI(2.44f, 3.46f);
		case BNPageSizeB9:
			return BNSizeMakeWithPPI(1.73f, 2.44f);
		case BNPageSizeB10:
			return BNSizeMakeWithPPI(1.22f, 1.73f);
		case BNPageSizeC0:
			return BNSizeMakeWithPPI(36.10f, 51.06f);
		case BNPageSizeC1:
			return BNSizeMakeWithPPI(25.51f, 36.10f);
		case BNPageSizeC2:
			return BNSizeMakeWithPPI(18.03f, 25.51f);
		case BNPageSizeC3:
			return BNSizeMakeWithPPI(12.76f, 18.03f);
		case BNPageSizeC4:
			return BNSizeMakeWithPPI(9.02f, 12.76f);
		case BNPageSizeC5:
			return BNSizeMakeWithPPI(6.38f, 9.02f);
		case BNPageSizeC6:
			return BNSizeMakeWithPPI(4.49f, 6.38f);
		case BNPageSizeC7:
			return BNSizeMakeWithPPI(3.19f, 4.49f);
		case BNPageSizeC8:
			return BNSizeMakeWithPPI(2.24f, 3.19f);
		case BNPageSizeC9:
			return BNSizeMakeWithPPI(1.57f, 2.24f);
		case BNPageSizeC10:
			return BNSizeMakeWithPPI(1.10f, 1.57f);
		case BNPageSizeJapaneseB0:
			return BNSizeMakeWithPPI(40.55f, 57.32f);
		case BNPageSizeJapaneseB1:
			return BNSizeMakeWithPPI(28.66f, 40.55f);
		case BNPageSizeJapaneseB2:
			return BNSizeMakeWithPPI(20.28f, 28.66f);
		case BNPageSizeJapaneseB3:
			return BNSizeMakeWithPPI(14.33f, 20.28f);
		case BNPageSizeJapaneseB4:
			return BNSizeMakeWithPPI(10.12f, 14.33f);
		case BNPageSizeJapaneseB5:
			return BNSizeMakeWithPPI(7.17f, 10.12f);
		case BNPageSizeJapaneseB6:
			return BNSizeMakeWithPPI(5.04f, 7.17f);
		case BNPageSizeJapaneseB7:
			return BNSizeMakeWithPPI(3.58f, 5.04f);
		case BNPageSizeJapaneseB8:
			return BNSizeMakeWithPPI(2.52f, 3.58f);
		case BNPageSizeJapaneseB9:
			return BNSizeMakeWithPPI(1.77f, 2.52f);
		case BNPageSizeJapaneseB10:
			return BNSizeMakeWithPPI(1.26f, 1.77f);
		case BNPageSizeJapaneseB11:
			return BNSizeMakeWithPPI(0.87f, 1.26f);
		case BNPageSizeJapaneseB12:
			return BNSizeMakeWithPPI(0.63f, 0.87f);
		case BNPageSizeCustom:
			return self.customPageSize;
	}
	return CGSizeZero;
}

- (void)_timeout {
	[self _savePdf];
}

- (void)_savePdf {
	UIWebView *webView = self.webView;

	if (webView == nil) {
		return;
	}

	NSURLRequest *request = [webView request];
	NSURL *mainDocumentURL = [request mainDocumentURL];
	NSString *pageTitle = [webView stringByEvaluatingJavaScriptFromString:@"document.title"];
	NSBundle *bundle = [NSBundle bundleForClass:[self class]];
	NSURL *scriptURL = [bundle URLForResource:@"BNForceCSS" withExtension:@"js"];
	NSString *script = [NSString stringWithContentsOfURL:scriptURL
												encoding:NSUTF8StringEncoding
												   error:NULL];

	if (script != nil) {
		NSString *injectScriptTemplate =
		@"var bn_forceCSS_script = document.createElement('script');\n"
		@"bn_forceCSS_script.setAttribute(\"type\", \"text/javascript\");\n"
		@"bn_forceCSS_script.innerHTML = \"%@\"\n"
		@"document.getElementsByTagName('body')[0].appendChild(bn_forceCSS_script);\n";

		NSString *injectScript = [NSString stringWithFormat:injectScriptTemplate, script, nil];

		[webView stringByEvaluatingJavaScriptFromString:injectScript];
		[webView stringByEvaluatingJavaScriptFromString:@"bn_forceCSS()"];
	}

	UIPrintFormatter *formatter = webView.viewPrintFormatter;

	BNHtmlPdfKitPageRenderer *renderer = [[BNHtmlPdfKitPageRenderer alloc] init];

	renderer.pageTitle = [mainDocumentURL absoluteString];
	renderer.printFooter = self.printFooter;
	renderer.printHeader = self.printHeader;
	renderer.topAndBottomMarginSize = self.topAndBottomMarginSize;
	renderer.leftAndRightMarginSize = self.leftAndRightMarginSize;

	[renderer addPrintFormatter:formatter startingAtPageAtIndex:0];

	NSMutableData *currentReportData = [NSMutableData data];

    CGSize pageSize = [self actualPageSize];
    CGRect pageRect = CGRectMake(0, 0, pageSize.width, pageSize.height);

	UIGraphicsBeginPDFContextToData(currentReportData, pageRect, nil);

	[renderer prepareForDrawingPages:NSMakeRange(0, 1)];

	NSInteger pages = [renderer numberOfPages];

	for (NSInteger i = 0; i < pages; i++) {
		UIGraphicsBeginPDFPage();

		[renderer drawPageAtIndex:i inRect:renderer.paperRect];
	}

	UIGraphicsEndPDFContext();

	NSNumber *numberOfPages = [NSNumber numberWithInteger:pages];
    NSMutableDictionary *metadata = [NSMutableDictionary dictionary];

    [metadata setValue:numberOfPages forKey:@"numberOfPages"];
    [metadata setValue:mainDocumentURL forKey:@"mainDocumentURL"];
    [metadata setValue:pageTitle forKey:@"pageTitle"];

	id <BNHtmlPdfKitDelegate> delegate = self.delegate;

	if ([delegate respondsToSelector:@selector(htmlPdfKit:didSavePdfData:metadata:)]) {
		[delegate htmlPdfKit:self didSavePdfData:currentReportData metadata:metadata];
	}

	NSString *outputFile = self.outputFile;

	if (outputFile) {
		[currentReportData writeToFile:outputFile atomically:YES];

		if ([delegate respondsToSelector:@selector(htmlPdfKit:didSavePdfFile:)]) {
			[delegate htmlPdfKit:self didSavePdfFile:outputFile];
		}
	}

	self.webView = nil;
}

#pragma mark - Class Methods

+ (BNPageSize)defaultPageSize
{
	NSLocale *locale = [NSLocale currentLocale];
	BOOL useMetric = [[locale objectForKey:NSLocaleUsesMetricSystem] boolValue];
	BNPageSize pageSize = (useMetric ? BNPageSizeA4 : BNPageSizeLetter);

	return pageSize;
}

@end


@interface UIWebView (iOS_6)

- (void)setSuppressesIncrementalRendering:(BOOL)suppressesIncrementalRendering;

@end