elewa-academy / planning-calc-mvclh

Planning an MVC-LH calculator

More practice with MVC-LH, reverse-engineering/tdd, & story-focues development.

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A user can ...

1. add two numbers & see result
2. subract two numbers & see result
3. chain operations (ie. use last result instead of 2 args)
4. general purpose controller method
5. multiply two numbers & see result
6. divide two numbers & see result
7. provide an expected value and see if they were right
8. see a history of all operations
9. clear the history of all operations
10. reset last_result

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story	UI	handler	controller	model	logic	view
1: +	two inputs, add button, output area	call_add: reads, cleans & passes on inputs	add: passes two numbers through logic.add & calls view		add: adds two numbers & returns the result	render: draws result to the UI
2: -	subtract button	call_subtract: reads, cleans & passes on inputs	subtract: passes two numbers through logic.subtract & calls view		subtract: subtracts two numbers & returns the result
3: chain			refactor call_add & call_subtract to read from model when needed, and write new result to model	set_last_result, read_last_result
4: generalize	both buttons call the new generalized handler method	operate: reads operation, a, b. calls controller	operate: args - operation(str), a(num), b(num). uses indicated operation & reads/writes last_result
5: *	mulitply button				multiply: multiplies 2 numbers and returns result
6: /	divide button				divide: divides 2 numbers and returns result
7: expected values	expected input field, test_it check-box, results output field	test: reads input, operation & expected value. passes on to controller	test: caries out the indicated operation, then compares the result & expected. calls view.render & view.render_test		test: takes args, exected & actual, returns pass/fail message	render_test: draws pass/fail message in test space
8: history of operations	button to read history, space to display it	read_history: calls controller	read_history: reads history and passes to view. refactor operate to save each call to the model as a string	add_call, read_all_calls		render_history: renders an array of strings to the history space
9: clear history	"clear call history" button	clear_call_history: calls controller	clear_call_history: clears the model's call history	clear_call_history
10: set last_result	a "set last_result" input field & button	set_last_result: calls the model	set_last_result: resets it to the new value

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