engchina / cfmgo

A MongoDB integration package for Cloud Foundry

cfmgo

A MongoDB integration package for Cloud Foundry

Overview

cfmgo is a package to assist you in connecting Go applications running on Cloud Foundry to MongoDB.

Usage

go get github.com/cloudnativego/cfmgo

appEnv, _ := cfenv,Current() //relies on github.com/cloudfoundry-community/go-cfenv
serviceName := os.Getenv("DB_NAME")
serviceURIName := os.Getenv("DB_URI")
serviceURI := cfmgo.GetServiceBinding(serviceName, serviceURIName, appEnv)
collection := cfmgo.Connect(cfmgo.NewCollectionDialer, serviceURI, "my-collection")

cfmgo/params

params is a package that extracts query parameters from a request to be used in cfmgo.Collection.Find() operations.

Example

func ListInventoryItemsHandler(collection cfmgo.Collection) http.HandlerFunc {
	return func(w http.ResponseWriter, req *http.Request) {
		collection.Wake()

		params := params.Extract(req.URL.Query())

		items := make([]RedactedInventoryItem, 0)

		if count, err := collection.Find(params, &items); err == nil {
			Formatter().JSON(w, http.StatusOK, wrapper.Collection(&items, count))
		} else {
			Formatter().JSON(w, http.StatusNotFound, wrapper.Error(err.Error()))
		}
	}
}

cfmgo/wrapper

wrapper is a simple helper to wrap API response data and errors in a consistent structure.

//ResponseWrapper provides a standard structure for API responses.
type ResponseWrapper struct {
	//Status indicates the result of a request as "success" or "error"
	Status string `json:"status"`
	//Data holds the payload of the response
	Data interface{} `json:"data,omitempty"`
	//Message contains the nature of an error
	Message string `json:"message,omitempty"`
	//Count contains the number of records in the result set
	Count int `json:"count,omitempty"`
}

Examples

wrapper.Error(err) yields:

{
"status": "error",
"message": "error message text"
}

wrapper.One(&someRecord) yields:

{
"status": "success",
"data": {
	"id": 1,
	"name": "fluffy"
	}
}

wrapper.Collection(&someResults, count) yields:

{
"status": "success",
"data": [
	{
	"id": 1,
	"name": "fluffy"
	},
	{
	"id": 2,
	"name": "thiggy"
	}
	],
"count": 2
}

Note: count represents the total number of matching records from the query, not the number of records returned in the result set. That number is governed by limit.