From dfabcb84fdf949f540301dad7b6bef2718466140 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Musab=20G=C3=BCltekin?= <gultekinmusab@gmail.com>
Date: Sun, 14 Jul 2019 03:30:59 +0300
Subject: [PATCH] JSON renamed to JSONLine. JSON List support added.

---
 README.md           | 16 +++---------
 export/json.go      | 60 +++++++++++++++++++++++++++++++++++++++++++--
 export/json_test.go | 23 ++++++++++++++---
 3 files changed, 81 insertions(+), 18 deletions(-)

diff --git a/README.md b/README.md
index 147addd..fcd5ff2 100644
--- a/README.md
+++ b/README.md
@@ -21,26 +21,16 @@ See scraper [Options](https://godoc.org/github.com/geziyor/geziyor#Options) for
 ## Status
 The project is in **development phase**. Thus, we highly recommend you to use Geziyor with go modules.
 
-## Examples
-Simple usage 
+## Usage
 
-```go
-geziyor.NewGeziyor(&geziyor.Options{
-    StartURLs: []string{"http://api.ipify.org"},
-    ParseFunc: func(g *geziyor.Geziyor, r *client.Response) {
-        fmt.Println(string(r.Body))
-    },
-}).Start()
-```
-
-Advanced usage
+This example extracts all quotes from *quotes.toscrape.com* and exports to JSON file.
 
 ```go
 func main() {
     geziyor.NewGeziyor(&geziyor.Options{
         StartURLs: []string{"http://quotes.toscrape.com/"},
         ParseFunc: quotesParse,
-        Exporters: []export.Exporter{export.JSON{}},
+        Exporters: []export.Exporter{&export.JSON{}},
     }).Start()
 }
 
diff --git a/export/json.go b/export/json.go
index 55cab72..cbaf938 100644
--- a/export/json.go
+++ b/export/json.go
@@ -1,6 +1,7 @@
 package export
 
 import (
+	"bytes"
 	"encoding/json"
 	"github.com/geziyor/geziyor/internal"
 	"log"
@@ -8,7 +9,7 @@ import (
 )
 
 // JSON exports response data as JSON streaming file
-type JSON struct {
+type JSONLine struct {
 	FileName   string
 	EscapeHTML bool
 	Prefix     string
@@ -16,7 +17,7 @@ type JSON struct {
 }
 
 // Export exports response data as JSON streaming file
-func (e *JSON) Export(exports chan interface{}) {
+func (e *JSONLine) Export(exports chan interface{}) {
 
 	// Create or append file
 	file, err := os.OpenFile(internal.DefaultString(e.FileName, "out.json"), os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
@@ -37,3 +38,58 @@ func (e *JSON) Export(exports chan interface{}) {
 		}
 	}
 }
+
+// JSON exports response data as JSON
+type JSON struct {
+	FileName   string
+	EscapeHTML bool
+	Prefix     string
+	Indent     string
+}
+
+// Export exports response data as JSON
+func (e *JSON) Export(exports chan interface{}) {
+
+	// Create or append file
+	file, err := os.OpenFile(internal.DefaultString(e.FileName, "out.json"), os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
+	if err != nil {
+		log.Printf("Output file creation error: %v\n", err)
+		return
+	}
+	defer file.Close()
+
+	file.Write([]byte("[\n"))
+
+	// Export data as responses came
+	for res := range exports {
+		data, err := jsonMarshalLine(res, e.EscapeHTML, e.Prefix, e.Indent)
+		if err != nil {
+			log.Printf("JSON encoding error on exporter: %v\n", err)
+			continue
+		}
+		file.Write(data)
+	}
+
+	// Override on last comma
+	stat, err := file.Stat()
+	if err != nil {
+		file.Write([]byte("]\n"))
+		return
+	}
+	file.WriteAt([]byte("\n]\n"), stat.Size()-2)
+}
+
+// jsonMarshalLine behaves like json.Marshal but supports escapeHTML and indenting
+func jsonMarshalLine(t interface{}, escapeHTML bool, prefix string, indent string) ([]byte, error) {
+	buffer := &bytes.Buffer{}
+	encoder := json.NewEncoder(buffer)
+	encoder.SetEscapeHTML(escapeHTML)
+	encoder.SetIndent(prefix, indent)
+
+	buffer.Write([]byte("	"))         // Tab char
+	err := encoder.Encode(t)          // Write actual data
+	buffer.Truncate(buffer.Len() - 1) // Remove last newline char
+	buffer.Write([]byte(",\n"))       // Write comma and newline char
+
+	return buffer.Bytes(), err
+}
diff --git a/export/json_test.go b/export/json_test.go
index b743579..17110fd 100644
--- a/export/json_test.go
+++ b/export/json_test.go
@@ -8,8 +8,8 @@ import (
 	"time"
 )
 
-func TestJSONExporter_Export(t *testing.T) {
-	exporter := &JSON{
+func TestJSONLineExporter_Export(t *testing.T) {
+	exporter := &JSONLine{
 		FileName: "out.json",
 		Indent:   " ",
 	}
@@ -19,9 +19,26 @@ func TestJSONExporter_Export(t *testing.T) {
 
 	exports <- map[string]string{"key": "value"}
 	close(exports)
-	time.Sleep(time.Millisecond)
+	time.Sleep(time.Millisecond) // Wait for writing to disk
 
 	contents, err := ioutil.ReadFile(exporter.FileName)
 	assert.NoError(t, err)
 	assert.Equal(t, "{\n \"key\": \"value\"\n}\n", string(contents))
 }
+
+func TestJSONExporter_Export(t *testing.T) {
+	exporter := &JSON{
+		FileName: "out.json",
+	}
+	_ = os.Remove(exporter.FileName)
+	exports := make(chan interface{})
+	go exporter.Export(exports)
+
+	exports <- map[string]string{"key": "value"}
+	close(exports)
+	time.Sleep(time.Millisecond) // Wait for writing to disk
+
+	contents, err := ioutil.ReadFile(exporter.FileName)
+	assert.NoError(t, err)
+	assert.Equal(t, "[\n\t{\"key\":\"value\"}\n]\n", string(contents))
+}