Add fileSize

Author: martijn00

CHANGELOG.md

@@ -8,7 +8,10 @@
 * Add uppercase
 * Add lowercase
 * Add file extension
+* Add max file size
 * Add notMatch
+* Add range
+* Add date range
 
 ## 10.0.2
 * Reland generated l10n files

README.md

@@ -54,6 +54,7 @@ Available built-in validators include:
 - `FormBuilderValidators.creditCardCVC()` - requires the field's value to be a valid credit card CVC number.
 - `FormBuilderValidators.colorCode()` - requires the field's value to be a valid color code.
 - `FormBuilderValidators.date()` - requires the field's value to be a valid date string.
+- `FormBuilderValidators.dateRange()` - requires the field's value to be a within a date range.
 - `FormBuilderValidators.email()` - requires the field's value to be a valid email address.
 - `FormBuilderValidators.equal()` - requires the field's value to be equal to the provided object.
 - `FormBuilderValidators.integer()` - requires the field's value to be an integer.
@@ -73,6 +74,7 @@ Available built-in validators include:
 - `FormBuilderValidators.uppercase()` - requires the field's value to be uppercase.
 - `FormBuilderValidators.lowercase()` - requires the field's value to be lowercase.
 - `FormBuilderValidators.fileExtension()` - requires the field's value to a valid file extension.
+- `FormBuilderValidators.fileSize()` - requires the field's to be less than the max size.
 
 ### Supported languages
 

lib/l10n/intl_en.arb

@@ -25,5 +25,7 @@
   "colorCodeErrorText": "Value should be a valid {colorCode} color code.",
   "uppercaseErrorText": "Value must be uppercase.",
   "lowercaseErrorText": "Value must be lowercase.",
-  "fileExtensionErrorText": "File extension must be {extensions}"
+  "fileExtensionErrorText": "File extension must be {extensions}",
+  "fileSizeErrorText": "File size must be less than {maxSize} while it is {fileSize}",
+  "dateRangeErrorText": "Date must be in range {min} - {max}"
 }

lib/src/form_builder_validators.dart

@@ -356,14 +356,54 @@ class FormBuilderValidators {
               : null;
 
   /// [FormFieldValidator] that requires the field's value to be a valid date string.
-  static FormFieldValidator<String> dateString({
+  static FormFieldValidator<String> date({
     String? errorText,
   }) =>
       (valueCandidate) => true == valueCandidate?.isNotEmpty &&
               !isDate(valueCandidate!)
           ? errorText ?? FormBuilderLocalizations.current.dateStringErrorText
           : null;
 
+  /// [FormFieldValidator] that requires the field's value to be a date within a certain range.
+  static FormFieldValidator<String> dateRange({
+    required String minDate,
+    required String maxDate,
+    String? errorText,
+  }) {
+    return compose<String>(
+      [
+        minDate.isNotEmpty
+            ? date(errorText: errorText)
+            : (valueCandidate) => null,
+        maxDate.isNotEmpty
+            ? date(errorText: errorText)
+            : (valueCandidate) => null,
+        (valueCandidate) {
+          if (valueCandidate == null || valueCandidate.isEmpty) {
+            return null;
+          }
+
+          final minDateTime = DateTime.tryParse(minDate);
+          final maxDateTime = DateTime.tryParse(maxDate);
+          final valueDateTime = DateTime.tryParse(valueCandidate);
+
+          if (minDateTime != null &&
+              valueDateTime!.isBefore(minDateTime) &&
+              maxDateTime != null &&
+              valueDateTime.isAfter(maxDateTime)) {
+            return errorText ??
+                FormBuilderLocalizations.current.dateRangeErrorText(
+                  minDate,
+                  maxDate,
+                );
+          }
+
+          return null;
+        },
+      ],
+    );
+  }
+
   /// [FormFieldValidator] that requires the field's value to be a valid phone number.
   static FormFieldValidator<String> phoneNumber({
     String? errorText,
@@ -404,6 +444,7 @@ class FormBuilderValidators {
           ? errorText ?? FormBuilderLocalizations.current.lowercaseErrorText
           : null;
 
+  /// [FormFieldValidator] that requires the field's value to be a valid file extension.
   static FormFieldValidator<File> fileExtension({
     required List<String> allowedExtensions,
     String? errorText,
@@ -416,4 +457,43 @@ class FormBuilderValidators {
                   FormBuilderLocalizations.current
                       .fileExtensionErrorText(allowedExtensions.join(', '))
               : null;
+
+  /// [FormFieldValidator] that restricts the size of an file to be less than or equal to the provided maximum size.
+  /// * [maxSize] is the maximum size in bytes.
+  static FormFieldValidator<File> fileSize({
+    required int maxSize,
+    String? errorText,
+  }) =>
+      (File? valueCandidate) => valueCandidate == null
+          ? null
+          : valueCandidate.existsSync() && valueCandidate.lengthSync() > maxSize
+              ? errorText ??
+                  FormBuilderLocalizations.current.fileSizeErrorText(
+                    formatBytes(valueCandidate.lengthSync()),
+                    formatBytes(maxSize),
+                  )
+              : null;
+
+  /// [FormFieldValidator] that applies another validator conditionally.
+  static FormFieldValidator<T> conditional<T>(
+    bool Function(T value) condition,
+    FormFieldValidator<T> validator,
+  ) =>
+      (T? valueCandidate) =>
+          condition(valueCandidate as T) ? validator(valueCandidate) : null;
+
+  /// [FormFieldValidator] that requires the field's value to be within a certain range.
+  static FormFieldValidator<T> range<T>(
+    num minValue,
+    num maxValue, {
+    bool inclusive = true,
+    String? errorText,
+  }) {
+    return compose<T>(
+      [
+        min(minValue, inclusive: inclusive, errorText: errorText),
+        max(maxValue, inclusive: inclusive, errorText: errorText),
+      ],
+    );
+  }
 }

lib/src/utils/helpers.dart

@@ -20,3 +20,16 @@ String fileExtensionFromPath(String path) {
   final splitter = path.split('.');
   return splitter.length > 1 ? splitter.last : "";
 }
+
+/// Helper function to format bytes into a human-readable string (e.g., KB, MB, GB).
+String formatBytes(int bytes) {
+  const suffixes = ['B', 'KB', 'MB', 'GB', 'TB'];
+  var i = 0;
+  double size = bytes.toDouble();
+  while (size > 1024 && i < suffixes.length - 1) {
+    size /= 1024;
+    i++;
+  }
+  // Truncate to 1 decimal place
+  return '${size.toStringAsFixed(1)}${suffixes[i]}';
+}