Intro

This is a opensource website (backend/frontend) written by a bunch of people for our capstone class at the university for a company called www.masteringdecisions.com. The tool is used to help in making decisions. I wrote the backend portion of this project, API and all code is documented.

Backend

This is the backend written in Golang. This verison is almost complete. It's almost same as our initial design. I will explain briefly explain how the api works. There are also javascript examples written in webtest/ to show how to do various things.

Installing and building

First make sure go is installed and configured then type

go get

to get the dependencies

go build
./gobackend

Code documentation, and testing

Run

godoc -http=localhost:6969

open the link in a browser find gobackend package and read the documentation. To test the code just run the following

./run_tests.sh

This command will run all testing and create a system.html file that can be previewed a the browser, to see which code is covered.

Pages

As defined in main.go

	// Roots of pages for the frontend
	/////////////////////////
	routes.GET("/", HRootHome)
	routes.GET("/login.html", HRootLogin)
	routes.GET("/logout.html", HRootLogout)
	routes.GET("/ballot.html", HRootBallot)
	routes.GET("/decision/:decision_id", HRootDecision)

These are the only pages required to change, no html nothing. Those pages are found in static/page_*.js :)

API

For all API below if the header accept json then json objects are sent as mentioned below, if the accept header wants html then the same objects are passed to static file that runs a javascript file with that name found in static/ folder. eg : Requestion html from GET /persons will give an html reply that will run the file static/persons_list.js

person

These are the things we can do with person, under this table is description of some of the things we need to send or the things we receive back.

Description	URL	Method	Wants	Gives
Create a user	/person	POST	p1	p2
Get all persons	/persons	GET	nothing	array of p2
Get person info	/person/:person_id/info	GET	nothing	p2
Get person's decisions	/person/:person_id/decisions	GET	nothing	a persons decisions
Delete a person	/person/:person_id	DELETE	nothing	s1
Update a user	/person/:person_id	PUT	p1	p2

Wants/Gives

p1 = {"email":<str>,"pw_hash":<str>,"name_first":<str>,"name_last":<str>}
p2 = {"person_id":<int>, "email":<str>,"pw_hash":<str>,"name_first":<str>,"name_last":<str>}
s1 = {"result": "deleted"}

What we actually return is {"somehting": object} for example :

• Get person will return

{"person": p1 object}

• Get persons will return

{"persons": array of p1 object}

and so on..

decision

These are the things we can do with decision. Things like creating a decision, configuring it's criterions, creating ballots, doing voting on the ballots, and gather statistics.

Description	URL	Method	Wants	Gives
Create a decision	/decision	POST	d1	d2
Get all decisions	/decisions	GET	nothing	array of d2
Decision update	/decision/:decision_id	PUT	d1	d2
Get a decision info	/decision/:decision_id/info	GET	nothing	d2
Get a decision statistics	/decision/:decision_id/stats	GET	nothing	s1
Delete a decision	/decision/:decision_id	DELETE	nothing	r1
Create a ballot for decision	/decision/:decision_id/ballot	POST	b1	b2
Create a ballot without inv.	/decision/:decision_id/ballot_silent	POST	b1	b2
List ballots in a decision	/decision/:decision_id/ballots	GET	nothing	array of b2
Show a ballot info	/decision/:decision_id/ballot/:ballot_id/info	GET	nothing	b2
Delete a ballot	/decision/:decision_id/ballot/:ballot_id	DELETE	nothing	r1
Update a ballot	/decision/:decision_id/ballot/:ballot_id	PUT	b1	b2
Create a decision criterion	/decision/:decision_id/criterion	POST	c1	c2
List all criterions	/decision/:decision_id/criterions	GET	nothing	array of c2
Get a criterion info	/decision/:decision_id/criterion/:criterion_id/info	GET	nothing	c2
Update a criterion	/decision/:decision_id/criterion/:criterion_id	PUT	c1	c2
Delete a criterion	/decision/:decision_id/criterion/:criterion_id	DELETE	nothing	r1
Ballot votes in a criterion	/decision/:decision_id/ballot/:ballot_id/alternative/:alternative_id/criterion/:criterion_id/vote/:weight	GET	nothing	v2
Update Ballot vote	/decision/:decision_id/ballot/:ballot_id/alternative/:alternative_id/criterion/:criterion_id/vote/:weight	PUT	nothing	v2
Show ballot votes	/decision/:decision_id/ballot/:ballot_id/votes	GET	nothing	array of v2
Delete a vote in ballot	/decision/:decision_id/ballot/:ballot_id/alternative/:alternative_id/criterion/:criterion_id/vote	DELETE	nothing	r1
Create an alternative	/decision/:decision_id/alternative	POST	a1	a1
Show all alternatives	/decision/:decision_id/alternatives	GET	nothing	array of a1
Show info of one alternative	/decision/:decision_id/alternative/:alternative_id/info	GET	nothing	a1
Delete an alternative	/decision/:decision_id/alternative/:alternative_id	DELETE	nothing	r1
Update an alternative	/decision/:decision_id/alternative/:alternative_id	PUT	a1	a1
More ballot information	/decision/:decision_id/ballot/:ballot_id	GET	nothing	b3
Ballot rate a criterion	/decision/:decision_id/ballot/:ballot_id/criterion/:criterion_id/vote/:rating	GET	nothing	k1
Get criterion ratings	/decision/:decision_id/criterion/:criterion_id/votes	GET	nothing	array of k1
Delete a rating on an altern.	/decision/:decision_id/ballot/:ballot_id/criterion/:criterion_id/vote	DELETE	nothign	r1
Update criterion rating	/decision/:decision_id/ballot/:ballot_id/criterion/:criterion_id/vote/:rating	PUT	nothing	k1
Decision duplicate	/decision/:decision_id/duplicate	GET	nothing	d2

Wants/Gives

a1 = {"name": <str>, "description":<optional-str>, "cost":<optiona-int> }
d1 = {"person_id":<int>, "name":<str>, "description":<str>, "stage":<int>, "criterion_vote_style":<str>, "alternative_vote_style":<str>, "client_settings":<str>}
d2 = {"decision_id":<int>, "person_id":<int>, "name":<str>, "description":<str>, "stage":<int>, "criterion_vote_style":<str>, "alternative_vote_style":<str>, "client_settings":<str>}
s1 = "undecided yet"
b1 = {"name":<str>, "email":<str>, "sent":<bool-opt>}
b2 = {"ballot_id":<int>, "decision_id":<int>, "secret":<str>, "name":<str>, "email":<str>, "sent":<bool-opt>}
b3 = {"ballot": b1, "ratings": array of v2}
c1 = {"name":<str>, "description":<optional-str>}
c2 = {"criterion_id":<int>, "description":<optional-str>, "decision_id":<int>, "name":<str>}
v1 = {"weight":<int>}
v2 = {"criterion_id":<int>, "ballot_id":<int>, "weight":<int>}
r1 = {"result": "deleted"}
k1 = {"criterion_id": <int>, "ballot_id":<int>, "rating":<int> }

What we actually return is {"somehting": object} for example :

• Get decision will return

{"decision": d1 object}

• Get decisions will return

{"decisions": array of d1 object}

and so on..

Authentication

Authentication is implemented as middlewares applied to routes, currently they are applied to 0 routes to make it easier for the front-end to start writing their code. The login you get a cookie and this cookie is checked..etc

Description	URL	Method	Wants	Gives
Login	/login	POST	l1	l2
Logout	/logout	GET	Nothing	Nothing
Get person_id of current logged in user	/whoami	GET	Nothing	g1

Wants/Gives

l1 = {"email":<str>, "password":<str>}
l2 = {"error":<str>} or {"status":<str>}
g1 = {"person_id": <int>} or {"error": <str> }

Permissions

In here I list the permissions and who can do what. They are three types of permissions.

• Admin : Only authenticated admin is allowed
• All : Only authenticated persons (admin or facilitator)
• None : Anyone

This list contains the routes that have permissions on them, anything not listed in here is considered to have a None permission.

Action	URL	Who is allowed
Person Creation	/person	admin
Person Delete	/person/:pid	admin
Person Update	/person/:pid	all
Decision Creation	/decision/:did	all
Decision Delete	/decision/:did	all
Decision Update	/decision/:did	all
Decision Dupl.	/decision/:did/duplicate	all
Alt. Creation		all
Alt. Delete		all
Alt. Update		all
Blt. Creation
Blt. Delete
Blt. Update
Crt. Creation
Crt. Delete
Crt. Update
Vt. Delete
Vt. Update
Rt. Delete
Rt. Update

Features

• Cross-platform
• Fully concurrent
• SecureCookie Authentication
• Logging
• ...