PART 7.1 - Links and URLs both Absolute and Relative

We are located on the Museum Web Site in the folder "docentclass"

• A link is the connection made between documents on the Internet.

  • A LINK Contains

  • The URL (Uniform Resource Locator) i.e. the PATH NAME to the document that you want to link to.
  • Some descriptive text so that the viewer can decide whether the referred to document is of interest
    • In these notes represents a block of text or a file that we want to link TO
  • Yes there is syntax to do all of these things
    
    

We will discuss the following today:

1. Absolute URLs
2. Relative URL's for named blocks of text in the same file
3. Relative URL's for files in one folder
4. Relative URL's between folders on a web site

   
   ABSOLUTE URLs

• Absolute URLs

  • They are known as a full URLs
  • They define the location of a file in absolute terms using the full path name and the correct grammar
  • So what are the steps along the path?

    Decide what protocol to use

    • If you want to have the server recognize HTML then the protocol that you want the server to use is:
      
      • http:// (Hypertext Transfer Protocol)
    • If you want to upload or downoad a file from some web site the protocol to use is:
      
      • ftp:// (File Transfer Protocol)
        

       

      Where do I want to go?

    • What computer out of all of the 10's of millions of computers do you, OH MASTER, want me to link to?

    You want to link to a specific Domain name

    www.somedomain.com (our domain name is www.sjmusart.org)

    • Once I get to that domain what folder should I look for?
      
      
    • Folder name i.e. /"folderIwant"/ (in our case "docentclass") notice the ubiquitous forward slash /
      • The forward slash / indicates the end of one path item and the start of the next one
        
      • The / at the end of the path statement asks for the index page located in the last folder in the path name
        
        
    • You know that folders contain files
      • The file that you usually, not always, look for is the index file, named aptly, index.html or occasionally index.htm
        • This is also referred to as the home page

         

  • To Summarize the absolute URL to our site (path name to our site) is:
    • http://www.sjmusart.org/docentclass/
  • This full path name gets you to
    • The proper protocol http:// for understanding Hypertext Mark Up Files
    • We will also use the ftp:// protocol (File Transfer Protocol) to upload our pages to the Internet later
    • The Museum web site - www.sjmusart.org
    • Into the folder docentclass
    • And to the file index.html
    • So why don't we put index.html at the end of the path name?
    • And what does the forward slash / do?

RELATIVE URLs in the same folder

• A relative URL relates the folders and files on your own web site to each other

• You can link to a section within a document or to any document on your web site using relative links

  • You don't need a server type, or a domain name to access a file or folder on your own site
    • On our site web site all files are in the folder "docentcouncil"
      
    • So the relative URL is simply "somefile.html"
      

  
  

  • The server recognizes that to get to "somefile.html" it must look in the folder containing the linking document to find the linked document
    • If the file is not there you will know. The error messages will pop up in many different forms

  ---

  Relative URLs between folders on our own web site

• In the case where we create subfolders under "docentclass" that we want to link to

• Then "docentclass" is the "parent folder"

  • Then there could be another file that you want to link to say "someotherfile.html"
    
    
    • If "someotherfile.html" is in a subfolder then that folder becomes the "childfolder"
      • If "someotherfile.html" is in a subfolder of "childfolder" that folder becomes the "grandchildfolder"
        • Etc. etc to quote the Yul Brunner version of "Anna and the King of Siam"
          
          
    • For example to get to the picture "image.jpg" in the "graphics" (child) folder from "docentclass" (parent) folder
      • the pathname is /graphics/image.jpg
    • To link to a file in the parent folder from a child folder
    "
    • the path name is ../"filename.html" where filename.html is the file that you want in the parent folder
    • from a grandchild folder to a parent folder ../../filename.html
      • ../ is the server code for stepping up one folder on the server
      • ../../ = how many folders?

      
      HTML is a tag based language. So where are the tags?