User:Jules/emohyperlink

From XPUB & Lens-Based wiki

Etymology:
hyper + link
hupér, “over” (greek) over, above, excessive, existing in more than three spacial dimensions
→ antonym: hypo (under, deficient, less)

link: a unit in a connected series of units, a unit in a transportation or communication system, one of the rings or loops in a chain. A bond.
lien → latin ligamen
- what connect things physically
- chain used to attach a prisoner (plural)
- contract, union, engagement, between people (blood, wedding etc)
- dependency in which a woman keep a man away from mariage
- attach between musical notes (bar holding them all together) ♫ ♬
- hypertext way of transfer towards another web source
- reference to another file or folder appearing also as a file

Definition:
Text or graphic in an electric document that can be activated to display another document or trigger an action.
An hyperlink has an anchor (location within a certain type of document).
The term was coined in 1965 by Ted Nelson at the start of project Xanadu. Nelson had been inspired by “As we may think” a popular 1945 essay by Vannecar Bush (Memex: “trails” of related information)

<a href=”http://www.whatever.com” target=”_self or _blank”> </a>
Anchor Hyperlink Reference
Ancre de reference hyperlien avec ou sans cible

What happens when I click on a hyperlink?

According to anidrudhom.com, a lot of things I wasn't thinking about at first, as I was unfocused on brain and hand gestures.

1. Brain Sends signals to hand:
a) Brain sends signal to Skeletal muscles (muscles which are attached to bones) via motor neurons.
b) Muscles are made of muscle fibres which are made of two proteins Actin and Myosin.
c) The brain signals lead to activation of Myosin which attaches itself to muscle fibres made of Actin and pulls it. Many such Myosin and Actin sites bind to each other, Myosin pulling the muscle fibres made of Actin, which leads to muscle movement.
d) The muscle movement cause movement of hand which helps us to move computer mouse and click a button.

2. Mouse sends interrupts via USB to USB Host controller:
a) Optical mouse has a small camera on the bottom side which captures thousands of images per second.
b) A DSP Processor compares all those images and track the movement of the cursor.
c) Information like which button is clicked and X,Y location is packed into a packet (3 byte or 5 byte format).
d) An interrupt with that information is sent to the Host Controller via USB.

3. USB Host controller forwards the mouse click information to processor:
a) Host controller driver validates and processes that packet for working on it.
b) Operating System schedules the process which collects interrupt information from host controller.

4. Device Driver, X server and Compositing window manager resolve input information:
a) Device Driver takes control after interrupt is recognized from Interrupt Descriptor Table.
b) X server uses this device driver of mouse to collect input parameters sent by host controller and keeps them in a queue.
c) X server provide this information to a Composite window manager which is responsible for management of all the windowing GUI interface of operating system, and Composite window manager then takes care of window management based on input parameters given by X server. d) Since browser is an application program its Input and output functionality and window management is taken care by X server.

5. Now, Browser come into picture:
a) Browser gets the click event from X server and the event listener for that click event is invoked.
b) Browser parses the link and finds the host-name to which the query is to be sent.
c) Browsers take the help of OS APIs for sending and receiving packets over a socket.
d) Browser create a HTTP request for the server with required parameters in link. The HTTP request generated by browser is passed to OS for further processing.

6. Network card sends this request to the server: a) OS communicates with the network card for forwarding the packets to the server.
b) It registers a socket for every such session of communication. Socket address is a combination of IP address(to identify the machine) and port number(to identify the application).
c) Network card sends the packet to routers which communicate with other routers to send that information to server. Every router maintains a routing table which helps them in routing the packets.
d) The servers listen on the port at which the HTTP service is registered (80 by default) and they get the request packet.
e) Server processes the request packet and sends the reply.
f) Via the same routing mechanism the packet reaches the network card, which notify the arrival of the packet to processor using Interrupt moderation technique.

7. Browser receives HTML page and it generated GUI interface from it: a) Browser parses the HTML page and add its contents to the page which the user was viewing. Its important to know that browser creates new components on the page and adds the HTML page contents to them. However X server is notified of all these changes so that it can maintain the window information.

8. X server updates the video memory buffer with new contents:
a) The X server then gets the latest windowing information from Compositing window manager and it writes that information in the frame buffer which is present in Video RAM on the Video card.
b) CRTCs (CRT Controllers) in video card read contents of frame buffer at very high rate continuously.
c) Output controllers convert these contents of frame buffer to analog signals using D/A converters and send them to corresponding monitor/s.
d) Monitor receives these signal from VGA port and image is displayed on the screen which was there in frame buffer.

9. Eyes sees on the screen and send signals to brain:
a) Brain is connected to eyes by Optic Nerves and optic nerve attaches to Retina on the eye.
b) Light from monitor enters eyes through Pupil and is refracted by the eye lens(which help us to focus on the monitor) and an inverted image of it is formed on retina.
c) Information from Retina is sent back to brain via optic nerves which inverts it again to make it erect.


What is the opposite of a hyperlink?
Cul-de-sac? Enclave?

Why does such a thing exist?
Because there is all the technical infrastructure that supports it (DNS, TCP/IP, html language, webbrowser, OS, computer, mouse, user)
Because users want content to be contextualized in relation to other content

What could it be comparable to?
Underground system perhaps?
Locations are connected to each other regardless what's in-between geographically.
Mail system for the routing (addressing)