# SubstrateClient

This is a library of interfaces for communicating with Substrate nodes. It provides application developers the ability to query a node and interact with the Substrate chains using Ruby.

## Installation

Add this line to your application's Gemfile:

```ruby
gem 'substrate_client'
```

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install substrate_client

## Usage

### Supported rpc methods

#### rpc method list

```ruby
require "substrate_client"

client = SubstrateClient.new("wss://kusama-rpc.polkadot.io/")
puts client.method_list
```
The rpc methods can be dynamically called by its name, so the methods returned by this method can all be used.

#### hard-coded rpc method

But, in order to show the parameters more clearly, some important or frequently used methods are hard-coded:

- chain_get_finalised_head

  Get hash of the last finalized block in the canon chain

  

- chain_get_head

- chain_get_header(block_hash = nil)

  Retrieves the header for a specific block

  

- chain_get_block(block_hash = nil)

  Get header and body of a relay chain block

  

- chain_get_block_hash(block_id)

  Get the block hash for a specific block

  

- chain_get_runtime_version(block_hash = nil)

  Get the runtime version for a specific block

  

- state_get_metadata(block_hash = nil)

  Returns the runtime metadata by block

  

- state_get_storage(storage_key, block_hash = nil)

  Retrieves the storage for a key

  

- system_name

- system_version

  

- chain_subscribe_all_heads(&callback)

  Retrieves the newest header via subscription. This will return data continuously until you unsubscribe the subscription.

  ```ruby
  subscription = client.chain_subscribe_new_heads do |data| 
    p data 
  end
  ```

- chain_unsubscribe_all_heads(subscription)

  Unsubscribe newest header subscription.

  ```ruby
  client.chain_unsubscribe_all_heads(subscription)
  ```

  

- chain_subscribe_new_heads(&callback)

  Retrieves the best header via subscription. This will return data continuously until you unsubscribe the subscription.

  ```ruby
  subscription = client.chain_subscribe_new_heads do |data|
    p data
  end
  ```

- chain_unsubscribe_new_heads(subscription)

  Unsubscribe the best header subscription.

  ```ruby
  client.chain_unsubscribe_new_heads(subscription)
  ```



- chain_subscribe_finalized_heads(&callback)

  Retrieves the best finalized header via subscription. This will return data continuously until you unsubscribe the subscription.

  ```ruby
  subscription = client.chain_subscribe_finalized_heads do |data|
    p data
  end
  ```

- chain_unsubscribe_finalized_heads(subscription)

  Unsubscribe the best finalized header subscription.

  ```ruby
  client.chain_unsubscribe_finalized_heads(subscription)
  ```

  

- state_subscribe_runtime_version(&callback)

  Retrieves the runtime version via subscription. 

- state_unsubscribe_runtime_version(subscription)

  Unsubscribe the runtime version subscription.

  

- state_subscribe_storage(keys, &callback)

  Subscribes to storage changes for the provided keys until unsubscribe.

  ```ruby
  subscription = client.state_subscribe_storage ["0x26aa394eea5630e07c48ae0c9558cef780d41e5e16056765bc8461851072c9d7"] do |data| 
  	p data 
  end
  ```

- state_unsubscribe_storage(subscription)

  Unsubscribe storage changes.

  
### Cutom methods based on rpc methods

These methods will encode the parameters and decode the returned data

- get_block_number(block_hash)

- get_metadata(block_hash)

- get_block(block_hash=nil)

- get_block_events(block_hash)

- subscribe_block_events(&callback)

- get_storage(module_name, storage_name, params = nil, block_hash = nil)

  ```ruby
  client.get_storage("Sudo", "Key")
  client.get_storage("Balances", "TotalIssuance")
  client.get_storage("System", "Account", ["0xd43593c715fdd31c61141abd04a99fd6822c8558854ccde39a5684e7a56da27d"])
  client.get_storage("ImOnline", "AuthoredBlocks", [2818, "0x749ddc93a65dfec3af27cc7478212cb7d4b0c0357fef35a0163966ab5333b757"])
  ```

- compose_call(module_name, call_name, params, block_hash=nil)

  ```ruby
  compose_call "Balances", "Transfer", { dest: "0x586cb27c291c813ce74e86a60dad270609abf2fc8bee107e44a80ac00225c409", value: 1_000_000_000_000 }
  ```



## Development

After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).

## Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/substrate_client. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [Contributor Covenant](http://contributor-covenant.org) code of conduct.

## License

The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).

## Code of Conduct

Everyone interacting in the SubstrateClient project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](https://github.com/[USERNAME]/substrate_client/blob/master/CODE_OF_CONDUCT.md).