schematics

a library to validate data using schemas expressed as Crystal classes

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     schematics:
       github: qequ/schematics
   

2. Run shards install

Usage

require "schematics"

Instantiate a new Schema class and define the fields you want to validate:

    schema = Schema.new(String)
    schema.validate("hello") # => true

You can also validate complex arrays

    schema = Schema.new(Array(String))
    schema.validate(["hello", "world"]) # => true

    schema = Schema.new([Array(String), Int32, [[Bool]]])
    schema.validate([["hello", "world"], 1, [[true]]]) # => true

Hashes

Validating hashes with basic types:

schema = Schema.new(Hash(String, Int32))
schema.validate({"a" => 1, "b" => 2}) # => true

Hashes with different key types should fail:

schema = Schema.new(Hash(String, Int32))
schema.validate({"a" => 1, 1 => 2}) # => false

Nested hashes:

schema = Schema.new(Hash(String, Hash(String, Int32)))
schema.validate({"a" => {"b" => 1}, "c" => {"d" => 2}}) # => true

Hashes with mixed types:

schema = Schema.new(Hash(String, Array(Int32)))
schema.validate({"a" => [1,2,3], "b" => [4,5,6]}) # => true

Structs

You can validate data against a struct:

struct Person
property name : String
property age : Int32

def initialize(@name : String, @age : Int32)
end
end

schema = Schema.new(Person)
person_instance = Person.new(name: "John", age: 30)
schema.validate(person_instance) # => true

For more examples and advanced use cases, check the specs.

Development

Until this version Schematics only validates Basic data types (int, string, bool, etc) and Arrays of those types or nested arrays.

Upcoming versions should parse more complex types like Hashes, Structs, etc.

TODO

• Add support for Hashes
• Add support for Structs
• Add support for custom types
• Add support for custom validations

Contributing

1. Fork it (https://github.com/qequ/schematics/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Alvaro Frias Garay - creator and maintainer