Introduction to Processes guide #4

WanjikuMac · 2019-02-05T16:06:26Z

churcho · 2019-02-08T10:40:36Z

Processes.md

+Using add_item we are modifying the state and all shows the maintenance of our system state, i.e you can add as many 
+items and the length of the state is maintained, which in our case is a list of 3 items so far.
+
+With the steps shown above, the chef can instantly perform updates and maintain the state of the menu, which the customer 


With the steps shown above, the restaurant is able to instantly perform updates and maintain the state of its menu, which the customer will then use to place their orders and eliminate the need of waiting for someone to take your order.

churcho · 2019-02-08T10:41:13Z

Processes.md

+
+Recently when I was working on Elixir processes, I remembered the restaurant incident and I thought, 
+processes can be used to hold state. Therefore, a restaurant menu can always be availed to customers on their table
+ (perhaps using a screen on the table), with the new delicacies/meals of the day list. The customers would then be able


(perhaps using a screen on the table or the restaurants mobile app)

churcho · 2019-02-08T10:43:28Z

Processes.md

+processes can be used to hold state. Therefore, a restaurant menu can always be availed to customers on their table
+ (perhaps using a screen on the table), with the new delicacies/meals of the day list. The customers would then be able
+to place orders directly to the kitchen, which would take way much less time. This would mean that the menu list has to 
+be flawless and everything listed on it should be available and the restaurant would have a way of tracking orders made


This would mean that the menu list has to be up to date with that exists in the kitchen stock inventory with every order updating the state appropriately.

churcho · 2019-02-08T10:43:45Z

Processes.md

+Maintain state.
+
+
+Let’s create a module Menuprocess.ex and see how we shall execute the process from the client in the menuserver.


MenuProcess.ex

churcho · 2019-02-08T10:44:51Z

Processes.md

+Return the current menu state
+Add items to the menu
+Handle wrong entries
+


Mention what start_link does with regards to spawning processes and PIDs

zacck-zz

Hey @WanjikuMac good progress on your write up, I left a few thoughts to help with some parts ... excited to see this over the hill

zacck-zz · 2019-02-08T14:08:43Z

Processes.md

@@ -1,4 +1,5 @@
 **Maintain and update processes**
+
 A few months ago, I walked into a restaurant with a friend to grab a meal. 
 The first thing we needed was a menu(to enable us place our orders) which was supposed to be brought by the waiter, 
 that process ended up taking over 30 min. As we were was waiting, I noticed some customers walk out without placing 


@WanjikuMac without placing what?

zacck-zz · 2019-02-08T14:11:09Z

Processes.md

-For the client requests to be handled on the server, start_link is called, the function menu_state is spawned to its own
-process then passed the initial state which in our case will change from an empty [] to an actual list of items to be 
-added to the menu. The function responsible for that is shown below;
+start_link begins a spawn linked to the current process with the given functions, the pid is registered using `Process.register`. For the client requests to be handled on the server, start_link is called, the function menu_state is spawned to its own process then passed the initial state which in our case will change from an empty [] to an actual list of items to be added to the menu. The function responsible for that is shown below;


This part is a little ambiguous, it's hard to tell if this is true for all processes or just this one in particular

zacck-zz · 2019-02-08T14:12:27Z

Processes.md

+   @spec start_link(any()) :: pid()
+    def start_link(initial_state \\ []) do
+     pid = spawn(__MODULE__, :menu_state, [initial_state])
+     Process.register(pid, :process)


I think using Process.register at this point of the reading is a red herring, I am not sure what purpose it serves

zacck-zz · 2019-02-08T14:13:16Z

Processes.md

+     pid 
+    end
+end 
+```

 Return the current menu state:


What returns the current menu context, I would try and provide more context to keep the reader involved

zacck-zz · 2019-02-08T14:14:35Z

Processes.md

+      send :process, {self(), :items}
+        receive do state -> inspect state end
+    end
+```

 Adding a list of items to our menu list is handled by a different function which takes in {self(), :additems, items}


show each functionality individually and demostrate it here too to show the reader the complete story

zacck-zz · 2019-02-08T14:15:28Z

Processes.md


-**add iex code**
+Fire up iex and excute the following commands.


I would sprinkle this demos around the articles as their code comes up rather than bunch them all up at the end

Introduction to Process article

10fcaff

WanjikuMac requested a review from churcho February 5, 2019 16:06

churcho suggested changes Feb 8, 2019

View reviewed changes

added the code and updated the literature

aafcc3e

zacck-zz requested changes Feb 8, 2019

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Introduction to Processes guide #4

Introduction to Processes guide #4

WanjikuMac commented Feb 5, 2019

churcho Feb 8, 2019

churcho Feb 8, 2019

churcho Feb 8, 2019

churcho Feb 8, 2019

churcho Feb 8, 2019

zacck-zz left a comment

zacck-zz Feb 8, 2019

zacck-zz Feb 8, 2019

zacck-zz Feb 8, 2019

zacck-zz Feb 8, 2019

zacck-zz Feb 8, 2019

zacck-zz Feb 8, 2019

		Maintain state.


		Let’s create a module Menuprocess.ex and see how we shall execute the process from the client in the menuserver.


		add iex code
		Fire up iex and excute the following commands.

Introduction to Processes guide #4

Are you sure you want to change the base?

Introduction to Processes guide #4

Conversation

WanjikuMac commented Feb 5, 2019

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

zacck-zz left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment