Middleware support added. HTML Parsing disable option added.

Goroutine leaks will be tested using leaktest lib.

.travis.yml

@@ -4,6 +4,9 @@ go:
   - 1.11.x
   - tip
 
+env:
+  - GO111MODULE=on
+
 before_install:
   - go get -t -v ./...
 

README.md

@@ -16,7 +16,7 @@ Geziyor is a blazing fast web crawling and web scraping framework. It can be use
 See scraper [Options](https://godoc.org/github.com/geziyor/geziyor#Options) for all custom settings. 
 
 ## Status
-Since the project is in **development phase**, **API may change in time**. Also, we highly recommend you to use Geziyor with go modules.
+Since the project is in **development phase**, **API may change in time**. Thus, we highly recommend you to use Geziyor with go modules.
 
 ## Usage
 Simple usage 

exporter/csv.go

@@ -49,12 +49,11 @@ func (e *CSVExporter) Export(response *geziyor.Response) {
 				values = append(values, fmt.Sprint(val.Index(i)))
 			}
 
-		// TODO: Map type support is incomplete. Ordering is wrong. Needs to be sorted by map keys (CSV headers).
-		case reflect.Map:
-			iter := val.MapRange()
-			for iter.Next() {
-				values = append(values, fmt.Sprint(iter.Value()))
-			}
+			//case reflect.Map:
+			//	iter := val.MapRange()
+			//	for iter.Next() {
+			//		values = append(values, fmt.Sprint(iter.Value()))
+			//	}
 		}
 
 		// Write to file

geziyor.go

@@ -23,9 +23,13 @@ import (
 
 // Exporter interface is for extracting data to external resources
 type Exporter interface {
-	Export(response *Response)
+	Export(r *Response)
 }
 
+// RequestMiddleware called before requests made.
+// Set request.Cancelled = true to cancel request
+type RequestMiddleware func(g *Geziyor, r *Request)
+
 // Geziyor is our main scraper type
 type Geziyor struct {
 	Opt Options
@@ -41,6 +45,7 @@ type Geziyor struct {
 		sync.RWMutex
 		visitedURLS []string
 	}
+	requestMiddlewaresBase []RequestMiddleware
 }
 
 func init() {
@@ -69,6 +74,7 @@ func NewGeziyor(opt Options) *Geziyor {
 			Timeout: time.Second * 180, // Google's timeout
 		},
 		Opt:                    opt,
+		requestMiddlewaresBase: []RequestMiddleware{defaultHeadersMiddleware},
 	}
 
 	if opt.Cache != nil {
@@ -168,6 +174,14 @@ func (g *Geziyor) do(req *Request, callback func(resp *Response)) {
 		return
 	}
 
+	// Request Middlewares
+	for _, middlewareFunc := range g.requestMiddlewaresBase {
+		middlewareFunc(g, req)
+	}
+	for _, middlewareFunc := range g.Opt.RequestMiddlewares {
+		middlewareFunc(g, req)
+	}
+
 	// Do request normal or Chrome and read response
 	var response *Response
 	var err error
@@ -180,7 +194,7 @@ func (g *Geziyor) do(req *Request, callback func(resp *Response)) {
 		return
 	}
 
-	if response.isHTML() {
+	if !g.Opt.ParseHTMLDisabled && response.isHTML() {
 		response.DocHTML, _ = goquery.NewDocumentFromReader(bytes.NewReader(response.Body))
 	}
 
@@ -216,12 +230,6 @@ func (g *Geziyor) doRequestClient(req *Request) (*Response, error) {
 
 	g.delay()
 
-	// Modify Request
-	req.Header.Set("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8")
-	req.Header.Set("Accept-Charset", "utf-8")
-	req.Header.Set("Accept-Language", "en")
-	req.Header.Set("User-Agent", g.Opt.UserAgent)
-
 	log.Println("Fetching: ", req.URL.String())
 
 	// Do request

geziyor_test.go

@@ -3,6 +3,7 @@ package geziyor_test
 import (
 	"fmt"
 	"github.com/PuerkitoBio/goquery"
+	"github.com/fortytw2/leaktest"
 	"github.com/fpfeng/httpcache"
 	"github.com/geziyor/geziyor"
 	"github.com/geziyor/geziyor/exporter"
@@ -21,6 +22,7 @@ func TestSimple(t *testing.T) {
 }
 
 func TestSimpleCache(t *testing.T) {
+	defer leaktest.Check(t)()
 	gez := geziyor.NewGeziyor(geziyor.Options{
 		StartURLs: []string{"http://api.ipify.org"},
 		Cache:     httpcache.NewMemoryCache(),
@@ -34,6 +36,7 @@ func TestSimpleCache(t *testing.T) {
 }
 
 func TestQuotes(t *testing.T) {
+	defer leaktest.Check(t)()
 	geziyor.NewGeziyor(geziyor.Options{
 		StartURLs: []string{"http://quotes.toscrape.com/"},
 		ParseFunc: quotesParse,
@@ -56,7 +59,7 @@ func quotesParse(r *geziyor.Response) {
 
 	// Next Page
 	if href, ok := r.DocHTML.Find("li.next > a").Attr("href"); ok {
-		go r.Geziyor.Get(r.JoinURL(href), quotesParse)
+		r.Geziyor.Get(r.JoinURL(href), quotesParse)
 	}
 }
 

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/PuerkitoBio/goquery v1.5.0
 	github.com/chromedp/cdproto v0.0.0-20190429085128-1aa4f57ff2a9
 	github.com/chromedp/chromedp v0.3.0
+	github.com/fortytw2/leaktest v1.3.0
 	github.com/fpfeng/httpcache v0.0.0-20181220155740-6b8f16a92be3
 	golang.org/x/net v0.0.0-20190522155817-f3200d17e092
 	golang.org/x/text v0.3.2 // indirect

go.sum

@@ -6,6 +6,8 @@ github.com/chromedp/cdproto v0.0.0-20190429085128-1aa4f57ff2a9 h1:ARnDd2vEk91rLN
 github.com/chromedp/cdproto v0.0.0-20190429085128-1aa4f57ff2a9/go.mod h1:xquOK9dIGFlLaIGI4c6IyfLI/Gz0LiYYuJtzhsUODgI=
 github.com/chromedp/chromedp v0.3.0 h1:7/pwrXFRq6/ym3sxCykm90DMoyw6VKXY48DgGRgUURA=
 github.com/chromedp/chromedp v0.3.0/go.mod h1:EktsZcC2iycVrRhC9fDmshBpCK9lNnZYi6x2q9uE7zI=
+github.com/fortytw2/leaktest v1.3.0 h1:u8491cBMTQ8ft8aeV+adlcytMZylmA5nnwwkRZjI8vw=
+github.com/fortytw2/leaktest v1.3.0/go.mod h1:jDsjWgpAGjm2CA7WthBh/CdZYEPF31XHquHwclZch5g=
 github.com/fpfeng/httpcache v0.0.0-20181220155740-6b8f16a92be3 h1:yoJ3JExhshZwcfvvQLLRqKICf4/p4gZ/mDzdQV1hRWQ=
 github.com/fpfeng/httpcache v0.0.0-20181220155740-6b8f16a92be3/go.mod h1:QThlC5qj7EJa+O2HqbxzVGWLspJQHQLVsKmBtbg9ak8=
 github.com/gobwas/httphead v0.0.0-20180130184737-2c6c146eadee h1:s+21KNqlpePfkah2I+gwHF8xmJWRjooY+5248k6m4A0=

options.go

@@ -47,12 +47,18 @@ type Options struct {
 	// For extracting data
 	Exporters []Exporter
 
+	// Called before requests made to manipulate requests
+	RequestMiddlewares []RequestMiddleware
+
 	// Max body reading size in bytes
 	MaxBodySize int64
 
 	// Charset Detection disable
 	CharsetDetectDisabled bool
 
+	// If true, HTML parsing is disabled to improve performance.
+	ParseHTMLDisabled bool
+
 	// Revisiting same URLs is disabled by default
 	URLRevisitEnabled bool
 }

request.go

@@ -10,3 +10,17 @@ type Request struct {
 	Meta     map[string]interface{}
 	Rendered bool
 }
+
+func defaultHeadersMiddleware(g *Geziyor, r *Request) {
+	r.Header = headerSetDefault(r.Header, "Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8")
+	r.Header = headerSetDefault(r.Header, "Accept-Charset", "utf-8")
+	r.Header = headerSetDefault(r.Header, "Accept-Language", "en")
+	r.Header = headerSetDefault(r.Header, "User-Agent", g.Opt.UserAgent)
+}
+
+func headerSetDefault(header http.Header, key string, value string) http.Header {
+	if header.Get(key) == "" {
+		header.Set(key, value)
+	}
+	return header
+}