Support events listening

[justkawal]

Supports events runtime subscription:

Steps:

• When listening to events fetched latest runtime metadata very first time only
• Decodes the metadata and creates a scale_codec
• After the scale codec is created reuses the same instance to decode the events on the fly.

[codecov[bot]]

Codecov Report

Merging #344 (204dd2f) into create-tx (97926a5) will decrease coverage by 0.05%. The diff coverage is 0.00%.

Additional details and impacted files

[](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio) ```diff @@ Coverage Diff @@ ## create-tx #344 +/- ## ============================================= - Coverage 45.35% 45.31% -0.05% ============================================= Files 139 140 +1 Lines 8109 8117 +8 ============================================= Hits 3678 3678 - Misses 4431 4439 +8 ``` | [Flag](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio) | Coverage Δ | | |---|---|---| | [polkadart](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio) | `17.81% <0.00%> (-0.13%)` | :arrow_down: | | [polkadart_cli](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio) | `12.29% <ø> (ø)` | | | [polkadart_keyring](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio) | `94.25% <ø> (ø)` | | | [polkadart_scale_codec](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio) | `54.93% <ø> (ø)` | | | [ss58](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio) | `96.87% <ø> (ø)` | | | [substrate_bip39](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio) | `64.34% <ø> (ø)` | | | [substrate_metadata](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio) | `87.61% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio#carryforward-flags-in-the-pull-request-comment) to find out more. | [Files](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio) | Coverage Δ | | |---|---|---| | [packages/polkadart/lib/apis/author.dart](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio#diff-cGFja2FnZXMvcG9sa2FkYXJ0L2xpYi9hcGlzL2F1dGhvci5kYXJ0) | `0.00% <ø> (ø)` | | | [...ges/polkadart/lib/extrinsic/extrinsic\_payload.dart](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio#diff-cGFja2FnZXMvcG9sa2FkYXJ0L2xpYi9leHRyaW5zaWMvZXh0cmluc2ljX3BheWxvYWQuZGFydA==) | `0.00% <ø> (ø)` | | | [...kages/polkadart/lib/extrinsic/signing\_payload.dart](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio#diff-cGFja2FnZXMvcG9sa2FkYXJ0L2xpYi9leHRyaW5zaWMvc2lnbmluZ19wYXlsb2FkLmRhcnQ=) | `0.00% <ø> (ø)` | | | [...ges/polkadart/lib/primitives/extrinsic\_status.dart](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio#diff-cGFja2FnZXMvcG9sa2FkYXJ0L2xpYi9wcmltaXRpdmVzL2V4dHJpbnNpY19zdGF0dXMuZGFydA==) | `0.00% <ø> (ø)` | | | [packages/polkadart/lib/provider.dart](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio#diff-cGFja2FnZXMvcG9sa2FkYXJ0L2xpYi9wcm92aWRlci5kYXJ0) | `1.90% <ø> (+0.15%)` | :arrow_up: | | [...ges/polkadart/lib/primitives/runtime\_metadata.dart](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio#diff-cGFja2FnZXMvcG9sa2FkYXJ0L2xpYi9wcmltaXRpdmVzL3J1bnRpbWVfbWV0YWRhdGEuZGFydA==) | `0.00% <0.00%> (ø)` | | | [packages/polkadart/lib/apis/state.dart](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio#diff-cGFja2FnZXMvcG9sa2FkYXJ0L2xpYi9hcGlzL3N0YXRlLmRhcnQ=) | `0.00% <0.00%> (ø)` | | | [...ackages/polkadart/lib/primitives/event\_record.dart](https://app.codecov.io/gh/leonardocustodio/polkadart/pull/344?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Leonardo+Custodio#diff-cGFja2FnZXMvcG9sa2FkYXJ0L2xpYi9wcmltaXRpdmVzL2V2ZW50X3JlY29yZC5kYXJ0) | `0.00% <0.00%> (ø)` | |