Adding more info to Schema and JSONParser

[Sajjon]

In a fork of this repo I have added some more metadata helpful in our stencil templates,

In Schema:

  let isOptional: Bool
  let isMutable: Bool
  let jsonKey: String?
  var hasCustomJsonKey: Bool {
    return jsonKey != nil
  }

Inside JsonParser:

  public var customKeyProperties: [SchemaProperty] {
    return properties.filter { $0.hasCustomJsonKey }
  }

  public var nonCustomKeyProperties: [SchemaProperty] {
    return properties.filter { !$0.hasCustomJsonKey }
  }
  
  public var nonOptionalProperties: [SchemaProperty] {
    return properties.filter { !$0.isOptional }
  }
  
  public var nonOptionalProperties: [SchemaProperty] {
    return properties.filter { $0.isOptional }
  }
  
  public var immutableProperties: [SchemaProperty] {
    return properties.filter { !$0.isMutable }
  }
  
  public var mutableProperties: [SchemaProperty] {
    return properties.filter { $0.isMutable }
  }

I added these arrays allowing for filtering on properties since stencil does not support filtering. Only map.

Here are some use cases for these filtered properties;

CustomStringConvertible

If I declare a protocol in my template.stencil and let that protocol, let's call it MyModel as CustomStringConvertible, we can then give it a default implementation of var description: String that we can override. We don't want to print optional properties without unwrapping them, so we want to first iterate through all nonoptional properties and then unwrap all optional. So we need the nonOptionalProperties and the nonOptionalProperties computed properties, an ugly example of usage:

public extension {{ protocol }} {
    var description: String {
var nonOptional = ""
nonOptional = "{% for p in spec.nonOptionalProperties %}{{p.name}}: `\({{p.name}})`{% if not forloop.last %}, {% endif %}{% endfor %}"
{% if spec.optionalProperties.count > 0 %}
    {% for p in spec.optionalProperties %}
        if let value = {{ p.name }} {
            nonOptional.append(", {{ p.name }}: `\(value)`")
        }
    {% endfor %}
{% endif %}

return nonOptional
    }
}

CodingKeys

Or let's say we want to make MyModel conform to Codable with default implementations, then we want to separate between those properties who have a custom jsonKey and those who have not:

enum {{ codingKeys }}: String, CodingKey {

    //MARK: Custom JSON key cases
{% for customKeyCase in spec.customKeyProperties %}
    case {{ customKeyCase.name }} = "{{ customKeyCase.jsonKey }}"
{% endfor %}

    //MARK: Standard cases
{% if spec.nonCustomKeyProperties.count > 0 %}
    case {% for case in spec.nonCustomKeyProperties %}{{ case.name }}{% if not forloop.last %}, {% endif %}{% endfor %}
{% endif %}
}

Which result in e.g. this Swift code for a Hotel model:

enum HotelCodingKeys: String, CodingKey {

    //MARK: Custom JSON key cases
    case location = "geolocation"

    //MARK: Standard cases
    case name, propertyCode, image, phoneNumber, address
}

For this template:

{
  "title": "Hotel",
  "concreteType": "struct",
  "properties": {
    "name": {"type": "string"},
    "propertyCode": {"type": "string"},
    "image": {"type": "string"},
    "phoneNumber": {"type": "string"},
    "address": {"$ref": "address.json"},
    "location": {"$ref": "location.json", "jsonKey": "geolocation"}
  }
}

I have already implemented this in a fork, do you feel like this is something that you want part of this repo? If so I can create a PR?

[hebertialmeida]

Overal I think this is interesting and useful for me too, could you create the PR and I will test it and we continue the improvements.

Couple things:

1. You propose to remove the required (from JSON Schema) property and add isOptional?
2. Did you disable SwiftLint? It is important to enforce the code style/convention...

Thank you for working on this!

[hebertialmeida]

Do you still have this fork?

[Sajjon]

@hebertialmeida sorry for slow response, I just created this PR, not mergable, so that you can copy paste/Git cherry pick if you find anything interesting.

#8

[hebertialmeida]

Cool, that will be useful