Add convenience method to get formatted value from ‘FieldValue’ (#27)

* Add convenience method to get formatted value from ‘FieldValue’

* Add ‘InvalidFieldValueException’

* Fix ‘formatNumberGrouping’ extension function

* Add extension functions for unformatted number value

src/main/kotlin/it/facile/form/Exceptions.kt

@@ -0,0 +1,5 @@
+package it.facile.form
+
+import it.facile.form.storage.FieldValue
+
+class InvalidFieldValueException(fieldValue: FieldValue, override val message: String?) : Exception("Invalid FieldValue: $fieldValue")

src/main/kotlin/it/facile/form/ui/utils/FormatterUtil.kt

@@ -1,5 +1,6 @@
 package it.facile.form.ui.utils
 
+import it.facile.form.storage.FieldValue
 import java.text.DecimalFormat
 import java.text.DecimalFormatSymbols
 import java.text.ParseException
@@ -20,4 +21,21 @@ fun String.formatNumberGrouping(separator: Char): String {
     }
 
     return decimalFormat.format(number)
-}
+}
+
+fun FieldValue.Text.formatNumberGrouping(separator: Char) = text.formatNumberGrouping(separator)
+
+fun String.getUnformattedNumberWithGrouping(separator: Char): Number? {
+    val symbols = DecimalFormatSymbols(Locale.ITALY).apply { groupingSeparator = separator }
+    val decimalFormat = DecimalFormat("###,###.###", symbols)
+
+    val stringWithoutSeparator = this.replace(separator.toString(), "")
+
+    return try {
+        decimalFormat.parse(stringWithoutSeparator)
+    } catch (pe: ParseException) {
+        return null
+    }
+}
+
+fun FieldValue.Text.getUnformattedNumberWithGrouping(separator: Char) = text.getUnformattedNumberWithGrouping(separator)