#29-custompattern

examples/api/custom-pattern/README.md

@@ -0,0 +1,46 @@
+# Gateway using Custom-Pattern
+This recipe is a gateway using the custom pattern. It uses counter activity to keep the track of number of successful
+and failed HTTP calls.
+
+Example:
+#Counter Activity
+| Name   |  Type   | Description   |
+|:-----------|:--------|:--------------|
+| counterName | string, required:true | The name of the counter |
+| op | string | Counter operation, 'get' is the default operation |
+
+
+## Installation
+* Install [Go](https://golang.org/)
+
+## Setup
+```bash
+git clone https://github.com/project-flogo/microgateway
+cd microgateway/examples/api/custom-pattern
+```
+
+## Testing
+Start the gateway:
+```bash
+go run main.go
+```
+In another terminal start the server:
+```bash
+go run main.go -server
+
+### Request is successful
+Run the following command:
+```bash
+curl --request GET http://localhost:9096/endpoint
+```
+
+You should see on successful call:
+```json
+{"Error-Calls":0,"Success-Calls":1}
+```
+
+Similarly, on unsuccessful call...or in case of error:
+You should see on successful call:
+```json
+{"Error-Calls":1,"Success-Calls":0}
+```

examples/api/custom-pattern/main.go

@@ -0,0 +1,146 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"html"
+	"io/ioutil"
+	"net/http"
+
+	_ "github.com/project-flogo/contrib/activity/counter"
+	_ "github.com/project-flogo/contrib/activity/rest"
+	"github.com/project-flogo/core/engine"
+	_ "github.com/project-flogo/microgateway/activity/circuitbreaker"
+	"github.com/project-flogo/microgateway/examples"
+)
+
+var (
+	server = flag.Bool("server", false, "run the test server")
+)
+
+const reply = `{
+	"name": "sally"
+}`
+
+const pattern = `{
+  "name": "CustomPattern",
+  "steps": [
+    {
+      "service": "HttpBackend",
+      "halt": "($.HttpBackend.error != nil) && !error.isneterror($.HttpBackend.error)"
+    },
+    {
+      "if": "$.HttpBackend.error == nil",
+      "service": "SuccessCounter"
+    },
+    {
+      "if": "$.HttpBackend.error != nil",
+      "service": "ErrorCounter"
+    },
+    {
+      "service": "GetCounterSuccess"
+    },
+    {
+      "service": "GetCounterError"
+    }
+  ],
+  "responses": [
+    {
+      "if" : "$.GetCounterSuccess.error == nil",
+      "error": false,
+      "output": {
+        "code": 200,
+        "data": {
+        	"Success-Calls": "=$.GetCounterSuccess.outputs.value",
+        	"Error-Calls": "=$.GetCounterError.outputs.value"
+        }
+      }
+    },
+    {
+      "error": true,
+      "output": {
+        "code": 400,
+        "data": "Error"
+      }
+    }
+  ],
+  "services": [
+    {
+      "name": "HttpBackend",
+      "description": "Make an http call to your backend",
+      "ref": "github.com/project-flogo/contrib/activity/rest",
+      "settings": {
+        "method": "GET",
+        "uri": "http://localhost:1234/pets"
+      }
+    },
+    {
+      "name": "SuccessCounter",
+      "description": "Increment counter on successful call",
+      "ref": "github.com/project-flogo/contrib/activity/counter",
+      "settings": {
+        "counterName": "SuccessCounter",
+        "op": "increment"
+      }
+    },
+    {
+      "name": "ErrorCounter",
+      "description": "Increment counter on error call",
+      "ref": "github.com/project-flogo/contrib/activity/counter",
+      "settings": {
+        "counterName": "ErrorCounter",
+        "op": "increment"
+      }
+    },
+    {
+      "name": "GetCounterSuccess",
+      "description": "Get success counter",
+      "ref": "github.com/project-flogo/contrib/activity/counter",
+      "settings": {
+        "counterName": "SuccessCounter"
+      }
+    },
+    {
+      "name": "GetCounterError",
+      "description": "Get error counter",
+      "ref": "github.com/project-flogo/contrib/activity/counter",
+      "settings": {
+        "counterName": "ErrorCounter"
+      }
+    }
+  ]
+}`
+
+func main() {
+	flag.Parse()
+
+	if *server {
+		http.HandleFunc("/pets", func(w http.ResponseWriter, r *http.Request) {
+			fmt.Printf("url: %q\n", html.EscapeString(r.URL.Path))
+			defer r.Body.Close()
+			body, err := ioutil.ReadAll(r.Body)
+			if err != nil {
+				panic(err)
+			}
+			fmt.Println(string(body))
+			w.Header().Set("Content-Type", "application/json")
+			_, err = w.Write([]byte(reply))
+			if err != nil {
+				panic(err)
+			}
+		})
+
+		err := http.ListenAndServe(":1234", nil)
+		if err != nil {
+			panic(err)
+		}
+
+		return
+	}
+
+	e, err := examples.CustomPattern("CustomPattern", pattern)
+	if err != nil {
+		panic(err)
+	}
+	engine.RunEngine(e)
+}

examples/api/default-channel-pattern/main.go

@@ -1,15 +1,13 @@
 package main
 
 import (
-
+	_ "github.com/project-flogo/contrib/activity/channel"
 	"github.com/project-flogo/core/engine"
-	"github.com/project-flogo/microgateway/examples"
 	_ "github.com/project-flogo/microgateway/activity/circuitbreaker"
 	_ "github.com/project-flogo/microgateway/activity/jwt"
-	_ "github.com/project-flogo/contrib/activity/channel"
+	"github.com/project-flogo/microgateway/examples"
 )
 
-
 func main() {
 
 	e, err := examples.DefaultChannelPattern()

examples/examples.go

@@ -10,6 +10,7 @@ import (
 	"github.com/project-flogo/core/engine/channels"
 	"github.com/project-flogo/microgateway"
 	microapi "github.com/project-flogo/microgateway/api"
+	"github.com/project-flogo/microgateway/internal/pattern"
 )
 
 // BasicGatewayExample returns a Basic Gateway API example
@@ -226,3 +227,30 @@ func DefaultChannelPattern() (engine.Engine, error) {
 
 	return api.NewEngine(app)
 }
+
+// CustomPattern returns an engine configured for given pattern name
+func CustomPattern(patternName string, custompattern string) (engine.Engine, error) {
+	err := pattern.Register(patternName, custompattern)
+	if err != nil {
+		panic(err)
+	}
+	app := api.NewApp()
+
+	trg := app.NewTrigger(&trigger.Trigger{}, &trigger.Settings{Port: 9096})
+	handler, err := trg.NewHandler(&trigger.HandlerSettings{
+		Method: "GET",
+		Path:   "/endpoint",
+	})
+	if err != nil {
+		panic(err)
+	}
+
+	_, err = handler.NewAction(&microgateway.Action{}, map[string]interface{}{
+		"pattern": patternName,
+	})
+	if err != nil {
+		panic(err)
+	}
+
+	return api.NewEngine(app)
+}

examples/examples_test.go

@@ -10,12 +10,12 @@ import (
 	"testing"
 	"time"
 
+	_ "github.com/project-flogo/contrib/activity/channel"
 	_ "github.com/project-flogo/contrib/activity/rest"
-	_ "github.com/project-flogo/microgateway/activity/ratelimiter"
-	_ "github.com/project-flogo/microgateway/activity/circuitbreaker"
 	"github.com/project-flogo/core/engine"
+	_ "github.com/project-flogo/microgateway/activity/circuitbreaker"
 	_ "github.com/project-flogo/microgateway/activity/jwt"
-	_ "github.com/project-flogo/contrib/activity/channel"
+	_ "github.com/project-flogo/microgateway/activity/ratelimiter"
 	"github.com/project-flogo/microgateway/api"
 	test "github.com/project-flogo/microgateway/internal/testing"
 	"github.com/stretchr/testify/assert"
@@ -258,7 +258,6 @@ func TestDefaultHttpPatternJSON(t *testing.T) {
 	testDefaultHTTPPattern(t, e)
 }
 
-
 func testDefaultChannelPattern(t *testing.T, e engine.Engine) {
 	defer api.ClearResources()
 

internal/pattern/DefaultHttpPattern.json

@@ -152,4 +152,4 @@
       }
     }
   ]
-}
+}

internal/pattern/pattern.go

@@ -4,20 +4,50 @@ package pattern
 
 import (
 	"encoding/json"
-
+	"fmt"
 	"github.com/project-flogo/microgateway/api"
 )
 
+var patternMap = make(map[string][]byte)
+
+func init() {
+	patterns := []string{"DefaultChannelPattern", "DefaultHttpPattern"}
+	for i := range patterns {
+		patternName := patterns[i] + ".json"
+		JSON, err := Asset(patternName)
+		if err != nil {
+			fmt.Println("Error from Asset function")
+		}
+		patternMap[patternName] = JSON
+	}
+}
+
 // Load loads a pattern
 func Load(pattern string) (*api.Microgateway, error) {
-	patternJSON, err := Asset(pattern + ".json")
-	if err != nil {
-		return nil, err
-	}
+	patternJSON := []byte{}
+	patternJSON = getPattern(pattern)
 	pDef := &api.Microgateway{}
-	err = json.Unmarshal(patternJSON, pDef)
+	err := json.Unmarshal(patternJSON, pDef)
 	if err != nil {
 		return nil, err
 	}
 	return pDef, nil
 }
+
+//Registers a pattern
+func Register(patternName string, pattern string) error {
+	patternFileName := patternName + ".json"
+	if _, ok := patternMap[patternFileName]; !ok {
+		patternMap[patternFileName] = []byte(pattern)
+	}
+	return nil
+}
+
+//Returns a registered pattern
+func getPattern(pattern string) []byte {
+	patternFileName := pattern + ".json"
+	if _, ok := patternMap[patternFileName]; ok {
+		return patternMap[patternFileName]
+	}
+	return nil
+}