Resource

Router provides REST Api layer. Internally it uses the Views in order to communicate with database and add extra layer to handle http requests in order to read and filter data. It can be configured programmatically or by reading external configuration from yaml file.

In the yaml file, following sections can be configured:

Section	Description	Type	Required
Routes	configuration for specific route	[]Route	true
Resource	configuration of Views, Connectors and Parameters shared across the Routes	Resource	false
Compression	Compression configuraion that will be used for all Routes unless Route Compression is configured	Compression	false
Cors	Cors configuraion that will be used for all Routes unless Route Cors is configured	Cors	false
APIURI		string	true
SourceURL		string	false
With		[]string	false

Cors

In order to enable the web browser cross-origin requests, the Cors need to be configured. If any of the section is not specified, corresponding Http header will not be added to the Cors preflight request:

Section	Description	Type	Required
AllowCredentials	Access-Control-Allow-Credentials header value	bool	false
AllowHeaders	Access-Control-Allow-Headers header value	[]string	false
AllowMethods	Access-Control-Allow-Methods header value	[]string	false
AllowOrigins	Access-Control-Allow-Origin header value	[]string	false
ExposeHeaders	Access-Control-Expose-Headers header value	[]string	false
MaxAge	Access-Control-Max-Age header value	int	false

Compression

In order to compress data if response exceed given size, Compression configuration need to be specified:

Section	Description	Type	Required	Default value
MinSizeKb	Minimum size in KB after when response should be compressed	int	false	0

Route

Route configures specific URL handler for given http method. The Compression and Cors can be configured on the router level, but can also be overridden on the Route level. In the Route section, following properties can be configured.

Section	Description	Type	Required	Default value
URI	Url pattern that Requests will be matched with. The path variables have to be put between brackets i.e. /users/{userId}	string	true	""
View	View definition used to fetch data from database	View	true	null
Method	Http method used to match http requests	enum: GET, POST	true	""
Service	The service type used to handle the requests.	enum: Reader	false	GET -> Reader, Post -> ""
Cors	Cors configuration specific for the Route	Cors	false	null
Cardinality	Indicates whether single object should be returned or the array of objects.	enum: ONE, MANY	false	MANY
CaseFormat	Configures the output JSON field names format.	enum: CaseFormat	false	uppercamel
OmitEmpty	Removes zero values from the output. Examples of removable values: 0, "", false, [], null	boolean	false	false
Style	Indicates whether response body should be wrapped with status code and error message (Comprehensive) or just returned as is	enum: Basic, Comprehensive	false	Basic
Field	ResponseBody field for Comprehensive Style	string in the UperCamelCase format	false	ResponseBody
Namespace	Mapping between Selector prefix into the View name	string -> string map / pairs	false	null
Visitor	Interceptor that can execute some logic before or/and after data was fetched from database. In order to use Visitors, Visitor need to be created programmatically and passed to the Configuration	Visitor	false	null
View	View configuration used to fetch data from database	View	true	null
Compression	Route specific Compression configuration	Compression	false	null
Cache	Route specific Cache configuration	Cache	false	null
Exclude	Fields that will be excluded from response.	Field paths in format: CammelCase.CammelCase.OutputCase, i.e. - Employees.Departments.id	false	[]string{}
NormalizeExclude	In order to use Excluded path using only CammelCase NormalizeExclude needs to be set to false.	bool	false	true

Cache

Cache caches the database result for the main view specified on the Route level. It uses the Selectors to produce entry key. The cache key is produced using the Selectors. If two http requests produces the same Selectors, and one happen after the other in time shorter than specified, the data will be read from the cache:

Section	Description	Type	Required
TimeToLiveMs	Cache entry time after when entry will be invalidated	int	true
StorageURL	URL of the stored cache entries	string	true

Visitor

Visitor intercepts regular reader flow. Visitor executes regular golang code so in order to use them they have to be registered before Resource is initialized. It can implement following interfaces:

• BeforeFetch - executes before data is fetched from the database.

BeforeFetch(response http.ResponseWriter, request *http.Request) (responseClosed bool, err error)

• AfterFetch - executes after data is fetched from the database.

AfterFetch(data interface{}, response http.ResponseWriter, request *http.Request) (responseClosed bool, err error)

Section	Description	Type	Required
Name	Visitor name, has to match visitors map key provided programmatically	string	true

Examples

For examples see test cases