News article example (API Gateway models and mapping templates)

The following sections provide examples of models and mapping templates that could be used for a sample news article API in API Gateway. For more information about models and mapping templates in API Gateway, see PetStore mapping template.

Original data (news article example)

The following is the original JSON data for the news article example:

{
  "count": 1,
  "items": [
    {
      "last_updated_date": "2015-04-24",
      "expire_date": "2016-04-25",
      "author_first_name": "John",
      "description": "Sample Description",
      "creation_date": "2015-04-20",
      "title": "Sample Title",
      "allow_comment": "1",
      "author": {
        "last_name": "Doe",
        "email": "[e-mail]",
        "first_name": "John"
      },
      "body": "Sample Body",
      "publish_date": "2015-04-25",
      "version": "1",
      "author_last_name": "Doe",
      "parent_id": 2345678901,
      "article_url": "http://www.example.com/articles/3456789012"
    }
  ],
  "version": 1
}

Input model (news article example)

The following is the input model that corresponds to the original JSON data for the news article example:

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "title": "NewsArticleInputModel",
  "type": "object",
  "properties": {
    "count": { "type": "integer" },
    "items": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "last_updated_date": { "type": "string" },
          "expire_date": { "type": "string" },
          "author_first_name": { "type": "string" },
          "description": { "type": "string" },
          "creation_date": { "type": "string" },
          "title": { "type": "string" },
          "allow_comment": { "type": "string" },
          "author": {
            "type": "object",
            "properties": {
              "last_name": { "type": "string" },
              "email": { "type": "string" },
              "first_name": { "type": "string" }
            }
          },
          "body": { "type": "string" },
          "publish_date": { "type": "string" },
          "version": { "type": "string" },
          "author_last_name": { "type": "string" },
          "parent_id": { "type": "integer" },
          "article_url": { "type": "string" }
        }
      }
    },
    "version": { "type": "integer" }
  }
}

Input mapping template (news article example)

The following is the input mapping template that corresponds to the original JSON data for the news article example:

#set($inputRoot = $input.path('$'))
{
  "count": $inputRoot.count,
  "items": [
#foreach($elem in $inputRoot.items)
    {
      "last_updated_date": "$elem.last_updated_date",
      "expire_date": "$elem.expire_date",
      "author_first_name": "$elem.author_first_name",
      "description": "$elem.description",
      "creation_date": "$elem.creation_date",
      "title": "$elem.title",
      "allow_comment": "$elem.allow_comment",
      "author": {
        "last_name": "$elem.author.last_name",
        "email": "$elem.author.email",
        "first_name": "$elem.author.first_name"
      },
      "body": "$elem.body",
      "publish_date": "$elem.publish_date",
      "version": "$elem.version",
      "author_last_name": "$elem.author_last_name",
      "parent_id": $elem.parent_id,
      "article_url": "$elem.article_url"
    }#if($foreach.hasNext),#end

#end
  ],
  "version": $inputRoot.version
}

Transformed data (news article example)

The following is one example of how the original news article example JSON data could be transformed for output:

{
  "count": 1,
  "items": [
    {
      "creation_date": "2015-04-20",
      "title": "Sample Title",
      "author": "John Doe",
      "body": "Sample Body",
      "publish_date": "2015-04-25",
      "article_url": "http://www.example.com/articles/3456789012"
    }
  ],
  "version": 1
}

Output model (news article example)

The following is the output model that corresponds to the transformed JSON data format:

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "title": "NewsArticleOutputModel",
  "type": "object",
  "properties": {
    "count": { "type": "integer" },
    "items": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "creation_date": { "type": "string" },
          "title": { "type": "string" },
          "author": { "type": "string" },
          "body": { "type": "string" },
          "publish_date": { "type": "string" },
          "article_url": { "type": "string" }
        }
      }
    },
    "version": { "type": "integer" }
  }
}

Output mapping template (news article example)

The following is the output mapping template that corresponds to the transformed JSON data format. The template variables here are based on the original, not transformed, JSON data format:

#set($inputRoot = $input.path('$'))
{
  "count": $inputRoot.count,
  "items": [
#foreach($elem in $inputRoot.items)
    {
      "creation_date": "$elem.creation_date",
      "title": "$elem.title",
      "author": "$elem.author.first_name $elem.author.last_name",
      "body": "$elem.body",
      "publish_date": "$elem.publish_date",
      "article_url": "$elem.article_url"
    }#if($foreach.hasNext),#end

#end
  ],
  "version": $inputRoot.version
}