Flutter工具集插件dartlang_utils的使用

Flutter工具集插件dartlang_utils的使用

标题

Flutter工具集插件dartlang_utils的使用

内容

Utils package for Dart.

一个包含实用工具和扩展类的Dart包。

Features

• 无null安全的布尔检查，用于true、false、not true和not false
• 随机字符串生成
• 字符串相似度函数：汉明距离和Levenshtein距离
• 字符串缩写功能
• 方便在iterable.reduce中使用的函数
• 对列表中的每个元素进行操作，同时提供当前元素和索引

Getting Started

将此包添加到您的pubspec.yaml文件中：

dartlang_utils: ^0.2.0

在你的Dart文件中导入库。有单独的导入路径用于utils和扩展。因此，如果你想只使用utils或扩展方法，只需导入你想要的其中一个。

如果你想使用utils，请导入以下文件：

import 'package:dartlang_utils/dartlang_utils.dart';

如果你想使用extension methods，请导入以下Dart文件：

import 'package:dartlang_utils/dartlang_extensions.dart';

如果你想只使用特定的utils或扩展方法，请使用show关键字：

import 'package:dartlang_utils/dartlang_utils.dart' show StringUtils;
import 'package:dartlang_utils/dartlang_extensions.dart' show BooleanExtensions;

Featured Utils

目前此包包含以下utils：

• StringUtils
• MathUtils

Featured Extensions

目前此包包含以下扩展：

• BooleanExtensions
• ListExtensions
• NumberExtensions
• StringExtensions
• NullableStringExtensions

More will follow soon, if you miss any function you can open an issue or a PR

StringUtils

目前支持以下操作：

/// Null safe check if string is empty.
bool isEmpty(String? str)

/// Null safe check if string is blank.
bool isBlank(String? str)

/// Null safe trim operation on a string.
String? trim(String? str)

/// Returns the string itself or a default if the string is `null`.
String defaultString(String? str, String defaultStr)

/// Returns the string itself or a default if the string is `null` or empty.
String defaultIfEmpty(String? str, String defaultStr

/// Returns the string itself or a default if the string is `null` or blank.
String defaultIfBlank(String? str, String defaultStr

/// Null safe check if a string starts with [prefix].
bool startsWith(String? str, Pattern prefix, [int index = 0])

/// Null safe check if a string starts with any of [prefixes].
bool startsWithAny(String? str, List<Pattern> prefixes, [int index = 0])

/// Null safe check if a string contains [searchPattern].
bool contains(String? str, Pattern searchPattern,[int startIndex = 0])

/// Null safe check if a string contains any of [searchPatterns].
bool containsAny(String? str, List<Pattern> searchPatterns, [int startIndex = 0])

/// Abbreviates a string with [maxWidth] using dots.
/// Example: StringUtils.abbreviate('0124567890', 6)  = '012...'
String abbreviate(String str, int maxWidth, {int offset = 0})

/// Null safe comparison of two strings according their lexical order.
int compare(String? str1, String? str2)

/// Creates a random alpha numeric string.
String random({int? length, bool includeNumeric = true})
    
/// String similarity:
/// Calculates the hamming distance between two strings.
/// The hamming distance is the number of positions where two strings have
/// different chars.
int hammingDistance(String str1, String str2)

/// String similarity:
/// Calculates the levenshtein distance between two strings.
/// The levenshtein distance is the number of deletions, insertions or
/// substitutions needed to transform one string into the other.
int levenshteinDistance(String str1, String str2)

MathUtils

目前支持以下操作：

  /// Returns the minimum element of [list].
  static T minOf<T extends num>(List<T> list)

  /// Convinience method to sum up two numbers.
  /// Can be used e.g. in [Iterable.reduce]: myIterable.reduce(MathUtils.mult)
  static T sum<T extends num>(T n1, T n2)

  /// Convinience method to multiply two numbers.
  /// Can be used e.g. in [Iterable.reduce]: myIterable.reduce(MathUtils.mult)
  static T mult<T extends num>(T n1, T n2)

BooleanExtensions

目前支持以下操作：

  /// Returns [true] if the value is not null and true.
  /// Otherwise [false] is returned.
  bool get isTrue 

  /// Returns [true] if the value is not null and false.
  /// Otherwise [false] is returned.
  bool get isFalse

  /// Returns [true] if the value is null or false.
  /// Otherwise [false] is returned.
  bool get isNotTrue

  /// Returns [true] if the value is null and true.
  /// Otherwise [false] is returned.
  bool get isNotFalse

ListExtensions

目前支持以下操作：

/// Counts the elements for whichs the predicate holdss.
int countWhere(bool Function(T) test)

/// For each method with provides not only the element but the index as well.
void forEachIndexed(void Function(T element, int index) f)

/// Return a random element of the list.
T random([int? seed])

NumberExtensions

目前支持以下操作：

/// Determines if [this] is between [a ] and [ b ] whereas the bounds are inclusive.
bool between(int a, int b)

StringExtensions

目前支持以下操作：

/// Abbreviates a String using dots.
String abbreviate(int maxWidth, {int offset = 0})

NullsafeStringExtensions

目前支持以下操作：

/// Returns the string itself if not null otherwise the other string.
String or(String other) 

/// Null safe check if the string starts with any of given prefixes.
bool startsWithAny(List<Pattern> prefixes, [int index = 0])

/// Null safe check if a string contains any of [searchPatterns].
bool containsAny(List<Pattern> searchPatterns, [int startIndex = 0])

/// Null safe check if string is blank.
bool get isBlank 

示例代码

import 'package:dartlang_utils/dartlang_utils.dart' show StringUtils;

void main() {
  var shortend = StringUtils.abbreviate('This is an example.', 7);
  print(shortend);
}