B4X
Must-Match Patterns

You may restrict the spider to only follow links that match any one of a set of "must-match" wildcard patterns. The AddMustMatchPattern can be called repeatedly to add must-match patterns.
Chilkat B4X Downloads

Download Chilkat for B4X
B4X
Dim success As Boolean = False

Dim spider As ChilkatSpider
spider.Initialize("spider")

'  --------------------------------------------------------------------
'  Note: The URLs in this example are no longer valid.
'  You should replace the URLs with URLs from a site of your
'  own choosing -- preferably your own site if testing.
'  (Google's Directory no longer exists.)
'  --------------------------------------------------------------------

'  First, we'll get the outbound links for a page in the
'  Google directory.  Then we'll add some must-match
'  and then re-fetch, to see it work...

spider.InitializeSpider("directory.google.com")
spider.AddUnspidered("http://directory.google.com/Top/Recreation/Outdoors/Hiking/Backpacking/")

success = spider.CrawlNext

'  Display the outbound links
Dim i As Int
Dim url As String
For i = 0 To spider.NumOutboundLinks - 1
    Log(spider.GetOutboundLink(i))
Next

'  The output:
'  http://www.backpacker.com
'  http://www.cmc.org
'  http://www.backpacking.net
'  http://www.thebackpacker.com/
'  http://www.rei.com/online/store/LearnShareArticlesList?categoryId=Camping
'  http://www.trailspace.com/
'  http://www.catskillhikes.com/
'  http://gorp.away.com/gorp/location/asia/nepal/favpicks.htm
'  http://www.backpackinglight.com/cgi-bin/backpackinglight/index.html
'  http://www.yetizone.com/
'  http://www.backpackingfun.com
'  http://www.freezerbagcooking.com/
'  http://www.spadout.com/backpacking/
'  http://sierrabackpacker.com
'  http://www.abovecalifornia.com/
'  http://www.personal.psu.edu/faculty/r/p/rpc1/bbb/
'  http://www.thebackpackersguide.com
'  http://www.journeywest.com/WB/index.html
'  http://www.johann-sandra.com/backpackdir.htm
'  http://www.geocities.com/amytys/
'  http://www.cloudwalkersbasecamp.com
'  http://www.netbackpacking.com
'  http://members.tripod.com/~stooges/
'  http://www.thebackpackingsite.com
'  http://www.thruhikers.com/
'  http://www.redcompservices.com/AT/
'  http://members.aol.com/CMorHiker/backpack
'  http://mywebpages.comcast.net/midwestpacker/
'  http://www.midwesthiker.com/
'  http://www.WeBackpack.com
'  http://www.michiganhiker.com
'  http://www.host33.com/backpack/
'  http://www.wilderness-backpacking.com
'  http://www.thetravelmonkey.net
'  http://dmoz.org/cgi-bin/add.cgi?where=Recreation/Outdoors/Hiking/Backpacking
'  http://dmoz.org/about.html
'  http://dmoz.org/cgi-bin/apply.cgi?where=Recreation/Outdoors/Hiking/Backpacking
'  http://dmoz.org
'  http://dmoz.org/profiles/cdog.html
'  http://dmoz.org/profiles/justinwp.html

'  Do it again, but this time with avoid patterns.
spider.InitializeSpider("directory.google.com")
spider.AddUnspidered("http://directory.google.com/Top/Recreation/Outdoors/Hiking/Backpacking/")

'  Add some must-match patterns:
spider.AddMustMatchPattern("*.com/*")
spider.AddMustMatchPattern("*.net/*")

'  Add some avoid-patterns:
spider.AddAvoidOutboundLinkPattern("*.mypages.*")
spider.AddAvoidOutboundLinkPattern("*.personal.*")
spider.AddAvoidOutboundLinkPattern("*.comcast.*")
spider.AddAvoidOutboundLinkPattern("*.aol.*")
spider.AddAvoidOutboundLinkPattern("*~*")

success = spider.CrawlNext

Log("-----------------------")

'  Display the outbound links
For i = 0 To spider.NumOutboundLinks - 1
    Log(spider.GetOutboundLink(i))
Next

'  Output:
'  http://www.thebackpacker.com/
'  http://www.rei.com/online/store/LearnShareArticlesList?categoryId=Camping
'  http://www.trailspace.com/
'  http://www.catskillhikes.com/
'  http://gorp.away.com/gorp/location/asia/nepal/favpicks.htm
'  http://www.backpackinglight.com/cgi-bin/backpackinglight/index.html
'  http://www.yetizone.com/
'  http://www.freezerbagcooking.com/
'  http://www.spadout.com/backpacking/
'  http://www.abovecalifornia.com/
'  http://www.journeywest.com/WB/index.html
'  http://www.johann-sandra.com/backpackdir.htm
'  http://www.geocities.com/amytys/
'  http://www.thruhikers.com/
'  http://www.redcompservices.com/AT/
'  http://www.midwesthiker.com/
'  http://www.host33.com/backpack/