reading-notes

Sending Form Data

Client/server architecture

• client sends request to server
• server answers the request

HTML form is a convenient way to send data to a server.

• action
  • defines where data gets sent
  • value = valid relative or absolute url

  <form action="">

• method
• defines how data is sent
• two methods GET and POST
• GET
  • asks server to send back resource
• POST
  • browser talks to server
  • asks for response
  • takes in data provided and uses it in response
• Viewing HTTP requests
  • never displayed to user
  • use GET when data is not sensitive
  • use POST when it is sensitive
  • use POST for larger files
• Retrieving data
  • server receives a string
  • string is parsed
  • data is retrived as a list of key/value pairs
  • can be accessed with different platforms and frameworks.
    • PHP
    • Python
    • Django
    • Express
• Special requirements when sending files
  • files are binary data
  • other data is text data
  • HTTP is generally for text
    • method = POST
    • enctype = multipart/form-data

  - input type="file"

• Security Issues
  • HTML forms most common place to attack server
  • sanitize all daya that comes back to server
  • escape dangerous characters
  • limit incoming data
  • sandbox uploaded files

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