The document provides steps to install Hyperledger Composer and create a sample business network for managing savings accounts. It involves: 1. Installing Hyperledger Composer and the development environment. 2. Using the Yeoman generator to scaffold a new business network project. 3. Defining the domain model, transactions, and permissions for savings accounts. 4. Implementing the transaction processor logic to adjust account balances. 5. Packaging and deploying the business network to test it in the Composer Playground.

1. Install​ ​Hyperledger​ ​Composer
1. Start​ ​with​ ​the​ ​​Install​ ​Index​​ ​for​ ​Hyperledger​ ​Composer.
2. Ensure​ ​you​ ​have​ ​the​ ​​prerequisites​​ ​installed.
3. Install​ ​​playground​ ​locally​.
4. Install​ ​the​ ​​development​ ​environment​.
Creating​ ​the​ ​BNA​ ​File
1. yo​​hyperledger-composer
Welcome​ ​to​ ​the​ ​Hyperledger​ ​Composer​ ​project​ ​generator
?​ ​​Please​ ​select​ ​the​ ​type​ ​of​ ​project:​​ ​Business​ ​Network
You​ ​can​ ​run​ ​this​ ​generator​ ​using:​ ​'yo​ ​hyperledger-composer:businessnetwork'
Welcome​ ​to​ ​the​ ​business​ ​network​ ​generator
?​ ​​Business​ ​network​ ​name:​​ ​code-camp-network
?​ ​​Description:​​ ​Example​ ​network​ ​for​ ​the​ ​Distributed:Health​ ​Code​ ​Camp
?​ ​​Author​ ​name:​ ​​​ ​Tracy​ ​Kuhrt
?​ ​​Author​ ​email:​​ ​tkuhrt@linuxfoundation.org
?​ ​​License:​​ ​Apache-2.0
?​ ​​Namespace:​​ ​org.hyperledger.healthcare.bank
​ ​​ ​​ ​create​ ​index.js
​ ​​ ​​ ​create​ ​package.json
​ ​​ ​​ ​create​ ​README.md
​ ​​ ​​ ​create​ ​models/org.hyperledger.healthcare.bank.cto
​ ​​ ​​ ​create​ ​.eslintrc.yml
​ ​​ ​​ ​create​ ​test/logic.js
​ ​​ ​​ ​create​ ​lib/logic.js
2. Contents​ ​of​ ​​code-camp-network​​ ​directory:
./code-camp-network:
↳eslintrc.yml
↳README.md
↳lib
​​​​​​↳logic.js​​-​​Contains​​the​​transaction​​logic
↳package.json
↳index.js
↳models
​​​​​​↳org.hyperledger.healthcare.bank.cto​​-​​Contains​​the​​business​​model
↳test
​​​​​​↳logic.js

3. 3. Modify​ ​​code-camp-network/models/org.hyperledger.healthcare.bank.cto​​ ​to​ ​contain​ ​the
following​ ​source​ ​code:
/**
​​*​​Define​​the​​assets,​​participants,​​and​​transactions​​that​​are
​​*​​part​​of​​the​​business​​network.
​​*/
namespace​​org.hyperledger.healthcare.bank
/**
​​*​​The​​type​​of​​accounts​​that​​we​​maintain​​(FSA,​​HSA)
​​*/
enum​​SavingsAccountType​​{
​​​​o​​FSA
​​​​o​​HSA
}
/**
​​*​​The​​status​​of​​the​​account​​(open​​or​​closed)
​​*/
enum​​SavingsAccountStatus​​{
​​​​o​​OPEN
​​​​o​​CLOSED
}
/**
​​*​​The​​type​​of​​adjustment​​made​​to​​the​​account
​​*/
enum​​AdjustmentType​​{
​​​​o​​DEBIT
​​​​o​​CREDIT
}
asset​​SavingsAccount​​identified​​by​​accountId​​{
​​​​o​​String​​accountId
​​​​-->​​Customer​​owner
​​​​o​​Double​​balance
​​​​o​​SavingsAccountType​​accountType
​​​​o​​SavingsAccountStatus​​accountStatus
}
participant​​Customer​​identified​​by​​customerId​​{
​​​​o​​String​​customerId
​​​​o​​String​​firstName

4. ​​​​o​​String​​lastName
}
transaction​​AdjustAccount​​{
​​​​-->​​SavingsAccount​​account
​​​​o​​AdjustmentType​​adjustment
​​​​o​​Double​​amount
}
event​​AccountAdjustedEvent​​{
​​​​-->​​SavingsAccount​​account
​​​​o​​Double​​oldBalance
​​​​o​​Double​​newBalance
}
4. Implement​ ​the​ ​transaction​ ​processor.​ ​Modify​ ​​code-camp-network/lib/logic.js​​ ​to​ ​contain​ ​the
following​ ​source​ ​code:
/*
​​*​​Licensed​​under​​the​​Apache​​License,​​Version​​2.0​​(the​​"License");
​​*​​you​​may​​not​​use​​this​​file​​except​​in​​compliance​​with​​the​​License.
​​*​​You​​may​​obtain​​a​​copy​​of​​the​​License​​at
​​*
​​*​​http://www.apache.org/licenses/LICENSE-2.0
​​*
​​*​​Unless​​required​​by​​applicable​​law​​or​​agreed​​to​​in​​writing,​​software
​​*​​distributed​​under​​the​​License​​is​​distributed​​on​​an​​"AS​​IS"​​BASIS,
​​*​​WITHOUT​​WARRANTIES​​OR​​CONDITIONS​​OF​​ANY​​KIND,​​either​​express​​or​​implied.
​​*​​See​​the​​License​​for​​the​​specific​​language​​governing​​permissions​​and
​​*​​limitations​​under​​the​​License.
​​*/
/**
​​*​​Adjust​​the​​account.
​​*​​@param​​{org.hyperledger.healthcare.bank.AdjustAccount}​​tx​​The​​sample
transaction​​instance.
​​*​​@transaction
​​*/
function​​AdjustAccount(tx)​​{
​​​​​​​​//​​Save​​the​​old​​balance​​of​​the​​account.
​​​​​​​​var​​oldBalance​​=​​tx.account.balance;

5. ​​​​​​​​//​​Update​​the​​account​​balance.
​​​​​​​​if​​(tx.adjustment​​==​​'DEBIT')​​{
​​​​​​​​​​​​if​​(tx.amount​​>​​tx.account.balance)​​{
​​​​​​​​​​​​​​​​throw​​new​​Error('Insufficient​​funds');
​​​​​​​​​​​​}​​else​​{
​​​​​​​​​​​​​​​​tx.account.balance​​-=​​tx.amount;
​​​​​​​​​​​​}
​​​​​​​​}​​else​​if​​(tx.adjustment​​==​​'CREDIT')​​{
​​​​​​​​​​​​tx.account.balance​​+=​​tx.amount;
​​​​​​​​}​​else​​{
​​​​​​​​​​​​throw​​new​​Error('Unknown​​adjustment​​type');
​​​​​​​​}
​​​​​​​​//​​Get​​the​​asset​​registry​​for​​the​​asset.
​​​​​​​​return
getAssetRegistry('org.hyperledger.healthcare.bank.SavingsAccount')
​​​​​​​​​​​​​​​​.then(function​​(accountRegistry)​​{
​​​​​​​​​​​​​​​​​​​​​​​​//​​Update​​the​​account​​in​​the​​account​​registry.
​​​​​​​​​​​​​​​​​​​​​​​​return​​accountRegistry.update(tx.account);
​​​​​​​​​​​​​​​​})
​​​​​​​​​​​​​​​​.then(function​​()​​{
​​​​​​​​​​​​​​​​​​​​​​​​//​​Emit​​an​​event​​for​​the​​modified​​asset.
​​​​​​​​​​​​​​​​​​​​​​​​var​​event​​=
getFactory().newEvent('org.hyperledger.healthcare.bank',
'AccountAdjustedEvent');
​​​​​​​​​​​​​​​​​​​​​​​​event.account​​=​​tx.account;
​​​​​​​​​​​​​​​​​​​​​​​​event.oldBalance​​=​​oldBalance;
​​​​​​​​​​​​​​​​​​​​​​​​event.newBalance​​=​​tx.account.balance;
​​​​​​​​​​​​​​​​​​​​​​​​emit(event);
​​​​​​​​​​​​​​​​});
}
5. Set​ ​up​ ​permissions.​ ​Modify​ ​​code-camp-network/permissions.acl​​ ​to​ ​contain​ ​the​ ​following:
/**
​​*​​Sample​​access​​control​​list.
​​*/
rule​​EverybodyCanReadEverything​​{

6. ​​​​​​​​description:​​"Allow​​all​​participants​​read​​access​​to​​all​​resources"
​​​​​​​​participant:​​"org.hyperledger.healthcare.bank.Customer"
​​​​​​​​operation:​​READ
​​​​​​​​resource:​​"org.hyperledger.healthcare.bank.*"
​​​​​​​​action:​​ALLOW
}
rule​​EverybodyCanSubmitTransactions​​{
​​​​​​​​description:​​"Allow​​all​​participants​​to​​submit​​transactions"
​​​​​​​​participant:​​"org.hyperledger.healthcare.bank.Customer"
​​​​​​​​operation:​​CREATE
​​​​​​​​resource:​​"org.hyperledger.healthcare.bank.AdjustAccount"
​​​​​​​​action:​​ALLOW
}
rule​​OwnerHasFullAccessToTheirAssets​​{
​​​​​​​​description:​​"Allow​​all​​participants​​full​​access​​to​​their​​accounts"
​​​​​​​​participant(p):​​"org.hyperledger.healthcare.bank.Customer"
​​​​​​​​operation:​​ALL
​​​​​​​​resource(r):​​"org.hyperledger.healthcare.bank.SavingsAccount"
​​​​​​​​condition:​​(r.owner.getIdentifier()​​===​​p.getIdentifier())
​​​​​​​​action:​​ALLOW
}
rule​​SystemACL​​{
​​​​description:​​​​"System​​ACL​​to​​permit​​all​​access"
​​​​participant:​​"org.hyperledger.composer.system.Participant"
​​​​operation:​​ALL
​​​​resource:​​"org.hyperledger.composer.system.**"
​​​​action:​​ALLOW
}
6. Run​ ​the​ ​following​ ​command​ ​from​ ​the​ ​​code-camp-network​​ ​directory:
composer​​archive​​create​​-t​​dir​​-n​​.​​-a​​./dist/code-camp-network.bna

7. Steps​ ​to​ ​set​ ​up​ ​code​ ​camp​ ​network
1. Download​ ​BNA​ ​file:​ ​​http://bit.ly/code-camp-network​​ ​(or​ ​use​ ​the​ ​one​ ​created​ ​above)
2. Open​ ​Composer​ ​Playground​ ​in​ ​browser:​ ​​http://composer-playground.mybluemix.net
3. Click​ ​on​ ​the​ ​button​ ​to​ ​​Deploy​​a​​new​​business​​network
4. Fill​ ​in​ ​the​ ​​1.​ ​BASIC​ ​INFORMATION​ ​​section:
Give​ ​your​ ​new​ ​Business​ ​Network​ ​a​ ​name: code-camp-network
Describe​ ​what​ ​your​ ​Business​ ​Network​ ​will​ ​be
used​ ​for:
Demo​​for​​Distributed:Health​​Code
Camp
5. Under​ ​​2.​ ​MODEL​ ​NETWORK​ ​STARTER​ ​TEMPLATE,​ ​​click​ ​​Drop​​here​​to​​upload​​or
browse​​ ​button
6. Choose​ ​the​ ​BNA​ ​file​ ​downloaded​ ​in​ ​step​ ​1​ ​and​ ​click​ ​​Open
7. Click​ ​the​ ​​Deploy​​ ​button

8. Test​ ​the​ ​Network
To​ ​test​ ​this​ ​Business​ ​Network​ ​Definition​ ​select​ ​​Test​​ ​at​ ​the​ ​top​ ​of​ ​the​ ​screen:
Create​ ​a​ ​​Customer​​ ​participant
1. Select​ ​​Customer​​ ​on​ ​the​ ​left-hand​ ​side​ ​of​ ​the​ ​screen
2. Click​ ​the​ ​​Create​​Participant​​ ​button​ ​on​ ​the​ ​upper​ ​right-hand​ ​corner​ ​of​ ​the​ ​screen
3. Enter​ ​the​ ​following​ ​information
{
​​​​"$class":​​"org.hyperledger.healthcare.bank.Customer",
​​​​"customerId":​​"tracy",
​​​​"firstName":​​"Tracy",
​​​​"lastName":​​"Kuhrt"
}
4. Click​ ​the​ ​​Create​​New​​ ​button
Create​ ​a​ ​​SavingsAccount​​ ​asset
In​ ​this​ ​section,​ ​we​ ​will​ ​create​ ​a​ ​​SavingsAccount​​ ​asset​ ​and​ ​assign​ ​the​ ​owner​ ​to​ ​the​ ​​Customer​​ ​participant
created​ ​above.
1. Select​ ​​SavingsAccount​​ ​on​ ​the​ ​left-hand​ ​side​ ​of​ ​the​ ​screen
2. Click​ ​the​ ​​Create​​Asset​​ ​button​ ​on​ ​the​ ​upper​ ​right-hand​ ​corner​ ​of​ ​the​ ​screen
3. Enter​ ​the​ ​following​ ​information
{
​​​​"$class":​​"org.hyperledger.healthcare.bank.SavingsAccount",
​​​​"accountId":​​"tracy_account",
​​​​"owner":​​"resource:org.hyperledger.healthcare.bank.Customer#tracy",
​​​​"balance":​​500,
​​​​"accountType":​​"FSA",
​​​​"accountStatus":​​"OPEN"
}

9. 4. Click​ ​the​ ​​Create​​New​​ ​button
Submit​ ​an​ ​​AdjustAccount​​ ​transaction
In​ ​this​ ​section,​ ​we​ ​will​ ​submit​ ​a​ ​transaction​ ​to​ ​debit​ ​the​ ​​SavingsAccount​​ ​asset​ ​created​ ​above
1. Click​ ​the​ ​​Submit​​Transaction​​ ​button​ ​in​ ​the​ ​lower​ ​left-hand​ ​corner
2. Ensure​ ​the​ ​​AdjustAccount​​ ​transaction​ ​is​ ​selected​ ​(NOTE:​ ​This​ ​is​ ​the​ ​only​ ​transaction​ ​in​ ​our​ ​sample
network)
3. Enter​ ​the​ ​following​ ​information
{
​​"$class":​​"org.hyperledger.healthcare.bank.AdjustAccount",
​​"account":
"resource:org.hyperledger.healthcare.bank.SavingsAccount#tracy_account",
​​"adjustment":​​"DEBIT",
​​"amount":​​5
}
4. Click​ ​​Submit
Verify​ ​Data
After​ ​submitting​ ​this​ ​transaction,​ ​you​ ​should​ ​now​ ​see​ ​the​ ​transaction​ ​in​ ​the​ ​Transaction​ ​Registry​ ​and​ ​that​ ​an
AccountAdjustedEvent​​ ​has​ ​been​ ​emitted.
1. Click​ ​on​ ​the​ ​​All​​Transactions​​ ​on​ ​the​ ​left-hand​ ​side​ ​of​ ​the​ ​screen​ ​to​ ​see​ ​a​ ​list​ ​of​ ​all​ ​the​ ​transactions.
2. Click​ ​the​ ​​View​​Record​​ ​next​ ​to​ ​the​ ​most​ ​recent​ ​​AdjustAccount​​ ​transaction.​ ​You​ ​should​ ​see​ ​the
following​ ​information
{
​ ​"$class":​ ​"org.hyperledger.healthcare.bank.AdjustAccount",
​ ​"account":​ ​"resource:org.hyperledger.healthcare.bank.SavingsAccount#tracy_account",
​ ​"adjustment":​ ​"DEBIT",
​ ​"amount":​ ​5,
​ ​"transactionId":​ ​"b4676d5f-05a1-42eb-bbfb-77becc13544b",
​ ​"timestamp":​ ​"2017-09-16T00:53:51.507Z"
}

10. 3. Click​ ​the​ ​​Event​​ ​for​ ​this​ ​transaction.​ ​You​ ​should​ ​see​ ​the​ ​following​ ​information
{
​​"$class":​​"org.hyperledger.healthcare.bank.AccountAdjustedEvent",
​​"account":
"resource:org.hyperledger.healthcare.bank.SavingsAccount#tracy_account",
​​"oldBalance":​​500,
​​"newBalance":​​495,
​​"eventId":​​"13c7144b-e77e-48ad-96d4-d09ee8c718a4#0",
​​"timestamp":​​"2017-09-10T17:02:14.338Z"
}
4. Check​ ​the​ ​​SavingsAccount​​ ​record​ ​for​ ​​tracy_account​.​ ​​As​ ​a​ ​result,​ ​the​ ​balance​ ​of​ ​the​ ​​tracy_account
SavingsAccount​​ ​should​ ​now​ ​reflect​ ​the​ ​updated​ ​balance​ ​in​ ​the​ ​Asset​ ​Registry.