Each sale and delivery moves the stock, and the owner gets one email when a product runs low.
For a shop that sells at the counter and online, and counts its own stock.
Start the small shop stock blueprint on Typestate
Asked you for the address the low-stock email goes to and the address your emails come from.
Started Small shop stock: 2 record types, 5 web endpoints.
5 actions are compiling.
Deployed to Sandbox. Try it at your Sandbox address.
Each step has 3 parts: who starts it, how it reaches your backend, and the action that answers.
The rule you will want to change first
When a sale takes a product under its low mark, the owner gets one email. The next email about it comes only after a delivery brings it back above the mark.
It lives in the action Record a Sale. Tell your agent how you want it instead: one sentence changes, and you read the change before it goes Live.
The map shows the records it keeps, the actions it runs and the services it calls.
What it keeps
What it does
What it reaches
One thing the shop sells, with its stock.
Only the shop's key reads and changes the stock.
Each change to the stock, and why.
Only the shop's key reads and writes the movements.
Open an action to read its steps: each sentence, with the calls that do it under it.
From the webPOST /products
Nametext, needed
Codetext, needed
On shelfa whole number, needed
Low marka whole number, needed
Find the Product whose sku is the given code.When one matches, refuse with "Another product has this code".
existing is
Find the first Product where
sku is input.code
when none carry on without one
When existing holds a value
Refuse "Another product has this code"
Create a Product with name, sku, stock and low_at set to the given name, code, number on the shelf and low mark, and low_told set to false.
Add a Product
set low_at to input.low_mark
set low_told to false
set name to input.name
set sku to input.code
set stock to input.on_shelf
Answer with that Product's id, name, sku, stock and low_at.
Answer
id is product.id
low_at is product.low_at
name is product.name
sku is product.sku
stock is product.stock
From the webPOST /sales
Codetext, needed
Solda whole number, needed
When the given number sold is less than 1, refuse with "Sell at least 1".
When input.sold is less than 1
Refuse "Sell at least 1"
Find the Product whose sku is the given code.When none matches, refuse with "No product has this code".
product is
Find the first Product where
sku is input.code
when none refuse "No product has this code"
When that Product's stock is less than the number sold, refuse with "Only {stock} are on the shelf".
When product.stock is less than input.sold
Refuse "Only {stock} are on the shelf"
Change that Product's stock to its stock minus the number sold, only if its stock is still at least the number sold, and refuse with "Only {stock} are on the shelf" if it is not.
Change the Product where
id is product.id
set stock to product.stock - input.sold
Create a Movement with product_id set to that Product's id, change set to minus the number sold, and reason set to sale.
Add a Movement
set change to 0 - input.sold
set product_id to product.id
set reason to "sale"
When that Product's new stock is below its low_at and its low_told is false, email the address in the OWNER_EMAIL setting with the subject "Running low" and the Product's name, with its sku, its new stock and its low_at, and change its low_told to true.
The owner is told once, so a busy day does not fill the inbox.
When sold_product.stock is less than product.low_at
and product.low_told is false
Send an email
to the setting OWNER_EMAIL
template "Record a Sale Email"
low_at product.low_at as a number
name product.name
sku product.sku
stock sold_product.stock as a number
Change the Product where
id is product.id
set low_told to true
Answer with the stock that is left.
Answer
stock is sold_product.stock
From the webPOST /deliveries
Codetext, needed
Numbera whole number, needed
Notetext, optional
When the given number is less than 1, refuse with "A delivery brings at least 1".
When input.number is less than 1
Refuse "A delivery brings at least 1"
Find the Product whose sku is the given code.When none matches, refuse with "No product has this code".
product is
Find the first Product where
sku is input.code
when none refuse "No product has this code"
Add the given number to that Product's stock.
Change the Product where
id is product.id
add input.number to stock
Create a Movement with product_id set to that Product's id, change set to the given number, reason set to delivery, and note set to the given note.
Add a Movement
set change to input.number
set note to input.note
set product_id to product.id
set reason to "delivery"
When that Product's new stock is at or above its low_at, change its low_told to false.
The owner is told again the next time it runs low.
When stocked.stock is at least product.low_at
Change the Product where
id is product.id
set low_told to false
Answer with the new stock.
Answer
stock is stocked.stock
From the webPOST /counts
Codetext, needed
Counta whole number, needed
Find the Product whose sku is the given code.When none matches, refuse with "No product has this code".
product is
Find the first Product where
sku is input.code
when none refuse "No product has this code"
The difference is the given count minus that Product's stock.
difference is input.count - product.stock
Create a Movement with product_id set to that Product's id, change set to the difference, and reason set to count.
Add a Movement
set change to difference
set product_id to product.id
set reason to "count"
Change that Product's stock to the given count.
Change the Product where
id is product.id
set stock to input.count
Answer with the difference.
Answer
difference is difference
From the webGET /stock
Low onlyyes or no, optional
List the Products, the ones furthest under their low_at first.When only the low ones are asked for, list only the Products whose stock is below their low_at.
all_products is
Find all Products
chosen is
each product of all_products where
input.low_only is false
or product.stock is less than product.low_at
ranked is
each product of chosen as
low_at is product.low_at
name is product.name
sku is product.sku
stock is product.stock
under is product.low_at - product.stock
sorted by under, highest first
For each Product, answer its name, sku, stock and low_at.
Answer
products is
each row of ranked as
low_at is row.low_at
name is row.name
sku is row.sku
stock is row.stock
| What it does | Who may call | Address |
|---|---|---|
| The shop adds a product. | you, with your key | POST /products |
| The till or the web shop records a sale. | you, with your key | POST /sales |
| The shop records a delivery. | you, with your key | POST /deliveries |
| The shop records a count. | you, with your key | POST /counts |
| The shop reads its stock. | you, with your key | GET /stock |
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