Update plugin interface with some breaking changes

src/ios/APPPrinter.h

@@ -23,11 +23,12 @@
 
 @interface APPPrinter : CDVPlugin <UIPrintInteractionControllerDelegate>
 
-// Find out whether printing is supported on this platform
 - (void) check:(CDVInvokedUrlCommand *)command;
-// Displays system interface for selecting a printer
+
+- (void) utis:(CDVInvokedUrlCommand *)command;
+
 - (void) pick:(CDVInvokedUrlCommand *)command;
-// Prints the content
+
 - (void) print:(CDVInvokedUrlCommand *)command;
 
 @end

src/ios/APPPrinter.m

@@ -42,22 +42,30 @@
 - (void) check:(CDVInvokedUrlCommand *)command
 {
     [self.commandDelegate runInBackground:^{
-        BOOL res = NO;
-
-        if (command.arguments.count == 0)
-        {
-            res = UIPrintInteractionController.isPrintingAvailable;
-        }
-        else
-        {
-            res = [APPPrinterItem canPrintURL:command.arguments[0]];
-        }
+        BOOL res = [APPPrinterItem canPrintURL:command.arguments[0]];
 
         [self sendResultWithMessageAsBool:res
                                callbackId:command.callbackId];
     }];
 }
 
+/*
+ * List all printable document types (utis).
+ */
+- (void) utis:(CDVInvokedUrlCommand *)command
+{
+    [self.commandDelegate runInBackground:^{
+        NSSet *utis = UIPrintInteractionController.printableUTIs;
+
+        CDVPluginResult* result =
+        [CDVPluginResult resultWithStatus:CDVCommandStatus_OK
+                            messageAsArray:utis.allObjects];
+
+        [self.commandDelegate sendPluginResult:result
+                                    callbackId:command.callbackId];
+    }];
+}
+
 /**
  * Displays system interface for selecting a printer.
  */

src/ios/APPPrinterItem.h

@@ -23,6 +23,6 @@
 
 + (id) ItemFromURL:(NSString *)url;
 
-+ (BOOL) canPrintURL:(NSString *)url;
++ (BOOL) canPrintURL:(nullable NSString *)url;
 
 @end

src/ios/APPPrinterItem.m

@@ -45,9 +45,12 @@
  *
  * @return true if its able to render the content of the file.
  */
-+ (BOOL) canPrintURL:(NSString *)url
++ (BOOL) canPrintURL:(nullable NSString *)url
 {
-    if (![NSURL URLWithString:url]) return YES;
+    if (![NSURL URLWithString:url])
+    {
+        return UIPrintInteractionController.isPrintingAvailable;
+    }
 
     id item = [self ItemFromURL:url];
 

src/ios/APPPrinterUnit.h

@@ -21,6 +21,6 @@
 
 @interface APPPrinterUnit : NSObject
 
-+ (double) convert:(NSString *)unit;
++ (double) convert:(nullable NSString *)unit;
 
 @end

src/ios/APPPrinterUnit.m

@@ -23,8 +23,11 @@
 
 @implementation APPPrinterUnit
 
-+ (double) convert:(NSString *)unit
++ (double) convert:(nullable NSString *)unit
 {
+    if ([unit isEqual:[NSNull null]])
+        return 1.0;
+
     if ([unit isEqualToString:@"in"])
         return 72.0;