80 lines
1.6 KiB
Markdown
80 lines
1.6 KiB
Markdown
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# Signal Subscriptions
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This package implements subscriptions mechanics using [`signal`](../../signal) package.
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It defines 3 new RPC methods in the `eth` namespace and 2 signals.
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## Methods
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###`eth_subscribeSignal`
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Creates a new filter and subscribes to its changes via signals.
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Parameters: receives the method name and parameters for the filter that is created.
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Example 1:
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```json
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{
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"jsonrpc": "2.0",
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"id": 1,
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"method": "eth_subscribeSignal",
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"params": ["eth_newPendingTransactionFilter", []]
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}
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```
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Example 2:
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```json
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{
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"jsonrpc": "2.0",
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"id": 2,
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"method": "eth_subscribeSignal",
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"params": [
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"shh_newMessageFilter",
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[{ "symKeyID":"abcabcabcabc", "topics": ["0x12341234"] }]
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]
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}
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```
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Supported filters: `shh_newMessageFilter`, `eth_newFilter`, `eth_newBlockFilter`, `eth_newPendingTransactionFilter`
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(see [Ethereum documentation](https://github.com/ethereum/wiki/wiki/JSON-RPC) for respective parameters).
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Returns: error or `subscriptionID`.
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###`eth_unsubscribeSignal`
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Unsubscribes and removes one filter by its ID.
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NOTE: Unsubscribing from a filter removes it.
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Parameters: `subscriptionID` obtained from `eth_subscribeSignal`
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Returns: error if something went wrong while unsubscribing.
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## Signals
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1. Subscription data received
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```json
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{
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"type": "subscriptions.data",
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"event": {
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"subscription_id": "shh_0x01",
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"data": {
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<whisper envelope 01>,
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<whisper envelope 02>,
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...
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}
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}
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```
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2. Subscription error received
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```json
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{
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"type": "subscriptions.error",
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"event": {
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"subscription_id": "shh_0x01",
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"error_message": "can not find filter with id: 0x01"
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}
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}
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```
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