Using Steem-API with Ruby Part 2 — Print Account Balances
utopian-io·@krischik·
0.000 HBDUsing Steem-API with Ruby Part 2 — Print Account Balances
## Repository
### steem-ruby
* Project Name: Steem Ruby
* Repository: [https://github.com/steemit/steem-ruby](https://github.com/steemit/steem-ruby)
### radiator
* Project Name: Radiator
* Repository: [https://github.com/inertia186/radiator](https://github.com/inertia186/radiator)
* Official Tutorial: [https://developers.steem.io/tutorials-ruby/getting_started](https://developers.steem.io/tutorials-ruby/getting_started)
## What Will I Learn?
This tutorial shows how to interact with the Steem blockchain and Steem database using Ruby. When using Ruby you have two APIs available to chose: **steem-api** and **radiator** which differentiates in how return values and errors are handled:
* **steem-api** uses closures and exceptions and provides low level computer readable data.
* **radiator** uses classic function return values and provides high level human readable data.
Since both APIs have advantages and disadvantages I have provided sample code for both APIs so you can decide which is more suitable for you.
In this 2nd part you learn the use of the classes `Steem::Type::Amount` and `Radiator::Type::Amount` and how to handle account balances using them.
## Requirements
You should have basic knowledge of Ruby programming you need to install at least Ruby 2.5 as well as the following ruby gems:
```sh
gem install bundler
gem install colorize
gem install steem-ruby
gem install radiator
```
If there is anything not clear you can ask in the comments.
**Note:** Both steem-ruby and radiator provide a file called `steem.rb`. This means that:
1. When you install both APIs you need to tell ruby which one to use.
2. You can't use both APIs in the same script.
## Difficulty
Provided you have some programming experience this tutorial is **basic level**.
## Tutorial Contents
In this second part of the tutorial I demonstrate how to print out account balances from a list of accounts passed on command line. The data will be formatted and a simple calculation is performed to show how you can use arithmetic on account balances.
As mentioned there will be two examples showing the differences. Both `…::Amount` classes have there weaknesses which I compensate by introducing an extended `Amount` class making the rest of the code identical.
You might notice that Steem Power is output in VESTS. In a future part I will show you how to convert VEST value into STEEM value.
## Implementation using steem-ruby
Steem-ruby keeps balance data in low level structures which is rather cumbersome to use. Here an example:
```
"sbd_balance"=>{"amount"=>"8716549", "precision"=>3, "nai"=>"@@000000013"},
```
The constructor `Steem::Type::Amount` class will parse the structure for you and make the data within more accessible and printable. Let's look in detail how to use `Steem::Type::Amount`:
-----
Make the script executable under Unix. Of course you need to add the correct path to your ruby executable.
```ruby
#!/opt/local/bin/ruby
```
Use the "steem.rb" file from the steem-ruby gem. This is only needed if you have both steem-api and radiator installed.
```ruby
gem "steem-ruby", :require => "steem"
require 'pp'
require 'colorize'
require 'steem'
```
Steem-ruby comes with a helpful `Steem::Type::Amoun` class to handle account balances. However `Steem::Type::Amoun` won't let you access the actual amount as float which is quite cumbersome when you want to make calculations.
This class expands `Steem::Type::Amoun` to add the missing functions.
```ruby
class Amount < Steem::Type::Amount
```
Return amount as float to be used for calculations
```ruby
def to_f
return @amount.to_f
end # to_f
```
Operator to add two balances for the users convenience
```ruby
def +(right)
return (if right.is_a?(Numeric) then
@amount.to_f + right
else
@amount.to_f + right.to_f
end)
end
```
Operator to subtract two balances for the users convenience
```ruby
def -(right)
return (if right.is_a?(Numeric) then
@amount.to_f - right
else
@amount.to_f - right.to_f
end)
end
end # Amount
```
Print account information for an array of accounts
```ruby
def print_account_balances (accounts)
accounts.each do |account|
```
Create an amount instances for each balance to be used for further processing
```ruby
_balance = Amount.new account.balance
_savings_balance = Amount.new account.savings_balance
_sbd_balance = Amount.new account.sbd_balance
_savings_sbd_balance = Amount.new account.savings_sbd_balance
_vesting_shares = Amount.new account.vesting_shares
_delegated_vesting_shares = Amount.new account.delegated_vesting_shares
_received_vesting_shares = Amount.new account.received_vesting_shares
```
Calculate actual vesting by adding and subtracting delegation.
```ruby
_actual_vesting = _vesting_shares - (_delegated_vesting_shares + _received_vesting_shares)
```
Pretty print out the balances. Note that for a quick printout Steem::Type::Amount provides a simple to_s method. But this method won't align the decimal point
```ruby
puts ("Account: " + account.name).colorize(:blue)
puts " Steem = %1$15.3f %2$s" % [_balance.to_f, _balance.asset]
puts " Steem Savings = %1$15.3f %2$s" % [_savings_balance.to_f, _savings_balance.asset]
puts " SBD = %1$15.3f %2$s" % [_sbd_balance.to_f, _sbd_balance.asset]
puts " SBD Savings = %1$15.3f %2$s" % [_savings_sbd_balance.to_f, _savings_sbd_balance.asset]
puts " Steem Power = %1$18.6f %2$s" % [_vesting_shares.to_f, _vesting_shares.asset]
puts " Delegated Steem = %1$18.6f %2$s" % [_delegated_vesting_shares.to_f, _delegated_vesting_shares.asset]
puts " Received Steem = %1$18.6f %2$s" % [_received_vesting_shares.to_f, _received_vesting_shares.asset]
puts " Actual Power = %1$18.6f VESTS" % _actual_vesting
end
return
end # Print_Account_Balances
if ARGV.length == 0 then
puts """
Steem-Dump-Balances — Dump account balances.
Usage:
Steem-Dump-Balances account_name …
"""
else
```
Read arguments from command line
```ruby
Account_Names = ARGV
```
Create instance to the steem database API
```ruby
Database_Api = Steem::DatabaseApi.new
```
Request account information from the Steem database and print out the accounts balances found using a new function or print out error information when an error occurred.
```ruby
Database_Api.find_accounts(accounts: Account_Names) do |result|
Accounts = result.accounts
if Accounts.length == 0 then
puts "No accounts found.".yellow
else
```
Print out the actual account balances.
```ruby
print_account_balances Accounts
end
rescue => error
puts "Error reading accounts:".red
pp error
end
end
```
-----
**Hint:** Follow this link on Github for the complete script with syntax highlighting: [Steem-Dump-Balances.rb on GitHub](https://github.com/krischik/SteemRubyTutorial/blob/master/Scripts/Steem-Dump-Balances.rb).
The output of the command (for the steem account) looks like this:
## Steem-Print-Accounts.rb using radiator
Radiator keeps the amount data inside a string which nice for printing but still cumbersome for any further processing:
```
"sbd_balance"=>"8716.549 SBD",
```
Luckily we don't need to parse the string ourself. The constructor `Radiator::Type::Amount` class will do that for you and provides the same functionality then `Radiator::Type::Amount`. Let's look in detail how to use `Radiator::Type::Amount`:
-----
Make the script executable under Unix. Of course you need to add the correct path to your ruby executable.
```ruby
#!/opt/local/bin/ruby
```
use the "steem.rb" file from the radiator gem. This is only needed if you have both steem-api and radiator installed.
```ruby
gem "radiator", :require => "steem"
require 'pp'
require 'colorize'
require 'radiator'
```
steem-ruby comes with a helpful `Radiator::Type::Amount` class to handle account balances. However `Radiator::Type::Amount` won't let you access any attributes which makes using the class quite cumbersome.
This class expands `Radiator::Type::Amount` to add the missing functions making it super convenient.
```ruby
class Amount < Radiator::Type::Amount
```
add the missing attribute reader.
```ruby
attr_reader :amount, :precision, :asset, :value
```
return amount as float to be used for calculations
```ruby
def to_f
return @amount.to_f
end # to_f
```
Operator to add two balances for the users convenience
```ruby
def +(right)
return (if right.is_a?(Numeric) then
@amount.to_f + right
else
@amount.to_f + right.to_f
end)
end
```
Operator to subtract two balances for the users convenience
```ruby
def -(right)
return (if right.is_a?(Numeric) then
@amount.to_f - right
else
@amount.to_f - right.to_f
end)
end
end # Amount
```
Print account information for an array of accounts
```ruby
def print_account_balances (accounts)
accounts.each do |account|
```
Create an amount instances for each balance to be used for further processing
```ruby
_balance = Amount.new account.balance
_savings_balance = Amount.new account.savings_balance
_sbd_balance = Amount.new account.sbd_balance
_savings_sbd_balance = Amount.new account.savings_sbd_balance
_vesting_shares = Amount.new account.vesting_shares
_delegated_vesting_shares = Amount.new account.delegated_vesting_shares
_received_vesting_shares = Amount.new account.received_vesting_shares
```
calculate actual vesting by adding and subtracting delegation.
```ruby
_actual_vesting = _vesting_shares - (_delegated_vesting_shares + _received_vesting_shares)
```
Pretty print out the balances. Note that for a quick printout Radiator::Type::Amount provides a simple `to_s` method. But this code will create a nicer output.
```ruby
puts ("Account: " + account.name).colorize(:blue)
puts " Steem = %1$15.3f %2$s" % [_balance.to_f, _balance.asset]
puts " Steem Savings = %1$15.3f %2$s" % [_savings_balance.to_f, _savings_balance.asset]
puts " SBD = %1$15.3f %2$s" % [_sbd_balance.to_f, _sbd_balance.asset]
puts " SBD Savings = %1$15.3f %2$s" % [_savings_sbd_balance.to_f, _savings_sbd_balance.asset]
puts " Steem Power = %1$18.6f %2$s" % [_vesting_shares.to_f, _vesting_shares.asset]
puts " Delegated Steem = %1$18.6f %2$s" % [_delegated_vesting_shares.to_f, _delegated_vesting_shares.asset]
puts " Received Steem = %1$18.6f %2$s" % [_received_vesting_shares.to_f, _received_vesting_shares.asset]
puts " Actual Power = %1$18.6f VESTS" % _actual_vesting
end
return
end # Print_Account_Balances
if ARGV.length == 0 then
puts """
Steem-Print-Balances — Print account balances.
Usage:
Steem-Print-Balances account_name …
"""
else
```
Read arguments from command line
```ruby
Account_Names = ARGV
```
Create instance to the steem database API
```ruby
Database_Api = Radiator::DatabaseApi.new
```
Request account information from the Steem database and print out the accounts balances found using a new function or print out error information when an error occurred.
```ruby
Result = Database_Api.get_accounts(Account_Names)
if Result.key?('error') then
puts "Error reading accounts:".red
pp Result.error
elsif Result.result.length == 0 then
puts "No accounts found.".yellow
else
print_account_balances Result.result
end
end
```
-----
**Hint:** Follow this link to Github for the complete script with syntax highlighting: [Steem-Print-Balances.rb on GitHub](https://github.com/krischik/SteemRubyTutorial/blob/master/Scripts/Steem-Print-Balances.rb).
The output of the command (for the steem account) look identical to the previous output:
# Curriculum
## First tutorial
* [Using Steem-API with Ruby Part 1](https://steemit.com/@krischik/using-steem-api-with-ruby-part-1)
## Previous tutorial
* [Using Steem-API with Ruby Part 1](https://steemit.com/@krischik/using-steem-api-with-ruby-part-1)
## Next tutorial
* [Using Steem-API with Ruby Part 3](https://steemit.com/@krischik/using-steem-api-with-ruby-part-3)
## Proof of Work
* [SteemRubyTutorial on GitHub](https://github.com/krischik/SteemRubyTutorial)
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