# Geziyor
Geziyor is a blazing fast web crawling and web scraping framework. It can be used to crawl websites and extract structured data from them. Geziyor is useful for a wide range of purposes such as data mining, monitoring and automated testing. 

[![GoDoc](https://godoc.org/github.com/geziyor/geziyor?status.svg)](https://godoc.org/github.com/geziyor/geziyor)
[![report card](https://goreportcard.com/badge/github.com/geziyor/geziyor)](http://goreportcard.com/report/geziyor/geziyor)
[![Code Coverage](https://img.shields.io/codecov/c/github/geziyor/geziyor/master.svg)](https://codecov.io/github/geziyor/geziyor?branch=master)

## Features
- **JS Rendering**
- 5.000+ Requests/Sec
- Caching (Memory/Disk/LevelDB)
- Automatic Data Exporting (JSON, CSV, or custom)
- Metrics (Prometheus, Expvar, or custom)
- Limit Concurrency (Global/Per Domain)
- Request Delays (Constant/Randomized)
- Cookies, Middlewares, robots.txt
- Automatic response decoding to UTF-8

See scraper [Options](https://godoc.org/github.com/geziyor/geziyor#Options) for all custom settings. 

## Status
We highly recommend you to use Geziyor with go modules.

## 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{}},
    }).Start()
}

func quotesParse(g *geziyor.Geziyor, r *client.Response) {
    r.HTMLDoc.Find("div.quote").Each(func(i int, s *goquery.Selection) {
        g.Exports <- map[string]interface{}{
            "text":   s.Find("span.text").Text(),
            "author": s.Find("small.author").Text(),
        }
    })
    if href, ok := r.HTMLDoc.Find("li.next > a").Attr("href"); ok {
        g.Get(r.JoinURL(href), quotesParse)
    }
}
```

See [tests](https://github.com/geziyor/geziyor/blob/master/geziyor_test.go) for more usage examples.

## Documentation

### Installation

    go get -u github.com/geziyor/geziyor

If you want to make JS rendered requests, make sure you have Chrome installed.

**NOTE**: macOS limits the maximum number of open file descriptors.
If you want to make concurrent requests over 256, you need to increase limits.
Read [this](https://wilsonmar.github.io/maximum-limits/) for more.

### Making Normal Requests

Initial requests start with ```StartURLs []string``` field in ```Options```. 
Geziyor makes concurrent requests to those URLs.
After reading response, ```ParseFunc func(g *Geziyor, r *Response)``` called.

```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()
```

If you want to manually create first requests, set ```StartRequestsFunc```.
```StartURLs``` won't be used if you create requests manually.  
You can make requests using ```Geziyor``` [methods](https://godoc.org/github.com/geziyor/geziyor#Geziyor):

```go
geziyor.NewGeziyor(&geziyor.Options{
    StartRequestsFunc: func(g *geziyor.Geziyor) {
    	g.Get("https://httpbin.org/anything", g.Opt.ParseFunc)
        g.Head("https://httpbin.org/anything", g.Opt.ParseFunc)
    },
    ParseFunc: func(g *geziyor.Geziyor, r *client.Response) {
        fmt.Println(string(r.Body))
    },
}).Start()
``` 

### Making JS Rendered Requests

JS Rendered requests can be made using ```GetRendered``` method. 
By default, geziyor uses local Chrome application CLI to start Chrome browser. Set ```BrowserEndpoint``` option to use different chrome instance. Such as, "ws://localhost:3000"

```go
geziyor.NewGeziyor(&geziyor.Options{
    StartRequestsFunc: func(g *geziyor.Geziyor) {
        g.GetRendered("https://httpbin.org/anything", g.Opt.ParseFunc)
    },
    ParseFunc: func(g *geziyor.Geziyor, r *client.Response) {
        fmt.Println(string(r.Body))
    },
    //BrowserEndpoint: "ws://localhost:3000",
}).Start()
```

### Extracting Data

We can extract HTML elements using ```response.HTMLDoc```. HTMLDoc is Goquery's [Document](https://godoc.org/github.com/PuerkitoBio/goquery#Document).

HTMLDoc can be accessible on Response if response is HTML and can be parsed using Go's built-in HTML [parser](https://godoc.org/golang.org/x/net/html#Parse)
If response isn't HTML, ```response.HTMLDoc``` would be ```nil```.  

```go
geziyor.NewGeziyor(&geziyor.Options{
    StartURLs: []string{"http://quotes.toscrape.com/"},
    ParseFunc: func(g *geziyor.Geziyor, r *client.Response) {
        r.HTMLDoc.Find("div.quote").Each(func(_ int, s *goquery.Selection) {
            log.Println(s.Find("span.text").Text(), s.Find("small.author").Text())
        })
    },
}).Start()
```

### Exporting Data

You can export data automatically using exporters. Just send data to ```Geziyor.Exports``` chan.
[Available exporters](https://godoc.org/github.com/geziyor/geziyor/export)

```go
geziyor.NewGeziyor(&geziyor.Options{
    StartURLs: []string{"http://quotes.toscrape.com/"},
    ParseFunc: func(g *geziyor.Geziyor, r *client.Response) {
        r.HTMLDoc.Find("div.quote").Each(func(_ int, s *goquery.Selection) {
            g.Exports <- map[string]interface{}{
                "text":   s.Find("span.text").Text(),
                "author": s.Find("small.author").Text(),
            }
        })
    },
    Exporters: []export.Exporter{&export.JSON{}},
}).Start()
```


### Custom Requests - Passing Metadata To Callbacks

You can create custom requests with ```client.NewRequest```

Use that request on ```geziyor.Do(request, callback)``` 

```go
geziyor.NewGeziyor(&geziyor.Options{
    StartRequestsFunc: func(g *geziyor.Geziyor) {
        req, _ := client.NewRequest("GET", "https://httpbin.org/anything", nil)
        req.Meta["key"] = "value"
        g.Do(req, g.Opt.ParseFunc)
    },
    ParseFunc: func(g *geziyor.Geziyor, r *client.Response) {
        fmt.Println("This is our data from request: ", r.Request.Meta["key"])
    },
}).Start()
```

## Benchmark

**8748 request per seconds** on *Macbook Pro 15" 2016*

See [tests](https://github.com/geziyor/geziyor/blob/master/geziyor_test.go) for this benchmark function:

```bash
>> go test -run none -bench Requests -benchtime 10s
goos: darwin
goarch: amd64
pkg: github.com/geziyor/geziyor
BenchmarkRequests-8   	  200000	    108710 ns/op
PASS
ok  	github.com/geziyor/geziyor	22.861s
```