Scrapy CrawlSpider doesn't crawl the first landing page

Question

I am new to Scrapy and I am working on a scraping exercise and I am using the CrawlSpider. Although the Scrapy framework works beautifully and it follows the relevant links, I can't seem to make the CrawlSpider to scrape the very first link (the home page / landing page). Instead it goes directly to scrape the links determined by the rule but doesn't scrape the landing page on which the links are. I don't know how to fix this since it is not recommended to overwrite the parse method for a CrawlSpider. Modifying follow=True/False also doesn't yield any good results. Here is the snippet of code:

class DownloadSpider(CrawlSpider):
    name = 'downloader'
    allowed_domains = ['bnt-chemicals.de']
    start_urls = [
        "http://www.bnt-chemicals.de"        
        ]
    rules = (   
        Rule(SgmlLinkExtractor(aloow='prod'), callback='parse_item', follow=True),
        )
    fname = 1

    def parse_item(self, response):
        open(str(self.fname)+ '.txt', 'a').write(response.url)
        open(str(self.fname)+ '.txt', 'a').write(','+ str(response.meta['depth']))
        open(str(self.fname)+ '.txt', 'a').write('\n')
        open(str(self.fname)+ '.txt', 'a').write(response.body)
        open(str(self.fname)+ '.txt', 'a').write('\n')
        self.fname = self.fname + 1

Answer 1

Just change your callback to parse_start_url and override it:

from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor

class DownloadSpider(CrawlSpider):
    name = 'downloader'
    allowed_domains = ['bnt-chemicals.de']
    start_urls = [
        "http://www.bnt-chemicals.de",
    ]
    rules = (
        Rule(SgmlLinkExtractor(allow='prod'), callback='parse_start_url', follow=True),
    )
    fname = 0

    def parse_start_url(self, response):
        self.fname += 1
        fname = '%s.txt' % self.fname

        with open(fname, 'w') as f:
            f.write('%s, %s\n' % (response.url, response.meta.get('depth', 0)))
            f.write('%s\n' % response.body)

Answer 2

There's a number of ways of doing this, but one of the simplest is to implement parse_start_url and then modify start_urls

from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
from scrapy.selector import HtmlXPathSelector

class DownloadSpider(CrawlSpider):
    name = 'downloader'
    allowed_domains = ['bnt-chemicals.de']
    start_urls = ["http://www.bnt-chemicals.de/tunnel/index.htm"]
    rules = (
        Rule(SgmlLinkExtractor(allow='prod'), callback='parse_item', follow=True),
        )
    fname = 1

    def parse_start_url(self, response):
        return self.parse_item(response)


    def parse_item(self, response):
        open(str(self.fname)+ '.txt', 'a').write(response.url)
        open(str(self.fname)+ '.txt', 'a').write(','+ str(response.meta['depth']))
        open(str(self.fname)+ '.txt', 'a').write('\n')
        open(str(self.fname)+ '.txt', 'a').write(response.body)
        open(str(self.fname)+ '.txt', 'a').write('\n')
        self.fname = self.fname + 1