formatNumber

def formatNumber = { attrs ->
		if (!attrs.containsKey('number'))
			throwTagError("Tag [formatNumber] is missing required attribute [number]")
    	def number = attrs.get('number')
    	if (number == null) return null
        def formatName = attrs.get('formatName')
        def format = attrs.get('format')
        def type = attrs.get('type')
        def locale = resolveLocale(attrs.get('locale'))
        if(type==null) {
	        if(!format && formatName) {
	            format = messageHelper(formatName,null,null,locale)
	            if(!format) throwTagError("Attribute [formatName] of Tag [formatNumber] specifies a format key [$formatName] that does not exist within a message bundle!")
	        }
	        else if (!format) {
	            format = messageHelper( "number.format", { messageHelper( "default.number.format", "0", null, locale) } ,null ,locale)
	        }
        }
        DecimalFormatSymbols dcfs = locale ? new DecimalFormatSymbols( locale ) : new DecimalFormatSymbols()
        DecimalFormat decimalFormat
        if(!type) {
        	decimalFormat = new java.text.DecimalFormat( format, dcfs )
        } else {
        	if(type=='currency') {
        		decimalFormat = NumberFormat.getCurrencyInstance(locale)
            } else if (type=='number') {
        		decimalFormat = NumberFormat.getNumberInstance(locale)
        	} else if (type=='percent') {
        		decimalFormat = NumberFormat.getPercentInstance(locale)
        	} else {
        		throwTagError("Attribute [type] of Tag [formatNumber] specifies an unknown type. Known types are currency, number and percent.")
        	}
        }
        // ensure formatting accuracy
        decimalFormat.setParseBigDecimal(true)
        if(attrs.get('currencyCode') != null) {
        	Currency currency=Currency.getInstance(attrs.get('currencyCode') as String)
        	decimalFormat.setCurrency(currency)
        }
        if(attrs.get('currencySymbol') != null) {
        	dcfs = decimalFormat.getDecimalFormatSymbols()
        	dcfs.setCurrencySymbol(attrs.get('currencySymbol') as String)
        	decimalFormat.setDecimalFormatSymbols(dcfs)
        }
        if(attrs.get('groupingUsed') != null) {
			if(attrs.get('groupingUsed') instanceof Boolean) {
				decimalFormat.setGroupingUsed(attrs.get('groupingUsed'))
			} else {
				// accept true, y, 1, yes
				decimalFormat.setGroupingUsed(attrs.get('groupingUsed').toString().toBoolean() || attrs.get('groupingUsed').toString()=='yes')
			}
        }
        if(attrs.get('maxIntegerDigits') != null) {
        	decimalFormat.setMaximumIntegerDigits(attrs.get('maxIntegerDigits') as Integer)
        }
        if(attrs.get('minIntegerDigits') != null) {
        	decimalFormat.setMinimumIntegerDigits(attrs.get('minIntegerDigits') as Integer)
        }
        if(attrs.get('maxFractionDigits') != null) {
        	decimalFormat.setMaximumFractionDigits(attrs.get('maxFractionDigits') as Integer)
        }
        if(attrs.get('minFractionDigits') != null) {
        	decimalFormat.setMinimumFractionDigits(attrs.get('minFractionDigits') as Integer)
        }
        if(attrs.get('roundingMode') != null) {
        	def roundingMode=attrs.get('roundingMode')
        	if(!(roundingMode instanceof RoundingMode)) {
        		roundingMode = RoundingMode.valueOf(roundingMode)
        	}
        	decimalFormat.setRoundingMode(roundingMode)
        }
        if(!(number instanceof Number)) {
        	number = decimalFormat.parse(number as String)
        }
        def formatted
        try {
        	formatted=decimalFormat.format(number)
        } catch(ArithmeticException e) {
        	// if roundingMode is UNNECESSARY and ArithemeticException raises, just return original number formatted with default number formatting
        	formatted=NumberFormat.getNumberInstance(locale).format(number)
        }
        return formatted
    }
    def resolveLocale(localeAttr) {
         def locale = localeAttr
         if(locale != null && !(locale instanceof Locale)) {
         	locale=StringUtils.parseLocaleString(locale as String)
         }
         if(locale==null) {
         	locale=RCU.getLocale(request)
         	if(locale==null) {
         		locale=Locale.getDefault()
         	}
         }    
         return locale
    }