Dart/Flutter package that makes pretty easy and safe to get values from Map/Json

To safely and easily retrieve values from a map/json with useful and human friendly error messages. With little to no effort you can parse and guarantee the values type.

Features

Retriever has 2 main features when parsing values from a map:

1. Automatic error treatment:

  // This method will throw an error if the value is invalid
  Retriever.getString('key', map);

  // This method will return null if the value is invalid
  Retriever.getMaybeString('key', map);

2. Errors that realy help

  RetrieverFormatError: Found invalid format when parsing key.
       Key: "name"
       Expected: "Integer"
       Found: "String", value: "myExampleName".
       Object: "{
                --> name: myExampleName
                    ^^^^
                    age: 40
                }"

With retriever you can safely parse:

• String
• Integer
• Double
• Date
• Map

Getting started

Retriever has no dependencies other than dart it self, and all methods are static. This makes easy and performant to use.

Usage

Giving the following map.

  final map = {
    'name': 'myExampleName',
    'age': 40,
  };

You can retrieve a string from a Map, just like that.

  final string = Retriever.getString('name', map);
  print(string); // 'myExampleName'

If the key doesn’t exist or the value is not a valid, an error will be thrown. The errors are very helpful and human readable, showing exactly what’s going on.

  // Using getString on a "int" value will throw the following error
  Retriever.getString('age', map); // 'age' is a int. error will be thrown

  //  RetrieverFormatError: Found invalid format when parsing key.
  //       Key: "name"
  //       Expected: "Integer"
  //       Found: "String", value: "myExampleName".
  //       Object: "{
  //                --> name: myExampleName
  //                    ^^^^
  //                    age: 40
  //                }"

Additional information

Feel free to file an issue if you find a problem or make pull requests.

All contributions are welcome 🙂

GitHub

View Github