Links or How to Get There From Here

1
Links orHow to Get There From Here!

• John Sklar
• How The Web Works

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The Real Magic

• The real magic of the Web is that it does it all.
  
• Think of it as an internet Swiss Army Knife.

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It Is All About Protocols

• The internet has rules, file formats and browsers
  know them all.
• Thats why you can use the web to download files,
  upload files.
• And do almost any task you want.
• This is done with the basic URL

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Uniform Resource Locator

• http//faculty.stritch.edu/jmsklar/533/index.htm

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Uniform Resource Locator

• ftp//microsoft.com/pub/mouse/driver.zip

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Uniform Resource Locator

• mailtosomeone_at_someplace.edu

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Uniform Resource Locator

• file///c/path/home.htm

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Absolute URL Reference

• http//faculty.stritch.edu/jmsklar/533/index.htm

Absolute URLs contain the entire URL. They are
the compete address. If the file or page you are
after is on another server you must use and
absolute URL. An absolute URL will work from any
location.
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Relative URL Reference

• It is wasteful to use absolute URLs when the
  file you are after is in the same folder. It
  would be like sending a package to your neighbor
  by Fedex.
• Example
• Two files in the same folder, one called
  fileone.htm and the other index.htm. To call
  fileone.htm from index
• lta hreffileone.htmgtGo to fileonelt/agt

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Relative URL Reference

• Example
• Once in fileone.htm, to go back to index we
  simply need
• lta hrefindex.htmgtBack to the first file!lt/agt

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More on Relative URLs

• In 533 there is an index.htm
• To call the file index.htm in the htmlrat folder,
  we use this code
• lta hrefhtmlratgt
• or
• lta hrefhtmlrat/gt
• This calls the index.htm file in the folder
  htmlrat.

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More on Relative URLs

• If we want to go back to the 533/index.htm file
  from the htmlrat/index.htm file we need a
  different approach
• lta href../index.htmgt
• or
• lta href../gt

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More on Relative URLs

• If we want to call the play.htm file in the music
  folder, from the index.htm in the 533 folder, we
  use this code
• lta hrefcssdemo/music/play.htmgt

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More on Relative URLs

• To return to the index.htm in the 533 folder we
  use the code
• lta href../../gt
• Or
• lta href../../index.htmgt

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Organize in Folders

• If you organize your web pages in folders the
  navigation is easy and takes much less coding
• The great advantage is that the web pages are
  portable, wherever they are on the server they
  should work if they are placed in the same
  proximity.
• Of course all your folders on stritch are in the
  student/yourloginname folder

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Links Within the same Document

• We have used links to go from place to place and
  from file to file but we can jump within a file.
• Within the file place this code
• lta nameendinggtFinal Thoughtslt/agt
• Or
• lta id endinggtFinal Thoughtslt/agt
• Somewhere else in the document have a line like
  this
• lta href-endinggtSee my final thoughtslt/agt

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Links To an Anchor in Another Document

• If you know the anchor you can jump to a specific
  place in another file
• Within the file place this code in the file
  philosophy.htm
• lta nameendinggtFinal Thoughtslt/agt
• Or
• lta id endinggtFinal Thoughtslt/agt
• Then in another document you can get there with
  this
• lta href-philosophy.htmlendinggtSee my final
  thoughtslt/agt