# PublicResolver

​Source​PublicResolver implements a general-purpose Domains resolver that is suitable for most standard Domains use-cases. The public resolver permits updates to Domains records by the owner of the corresponding name.The public resolver implements the following EIPs:

While the `PublicResolve`r provides a convenient default implementation, many resolver implementations and versions exist. Callers must not assume that a domain uses the current version of the public resolver, or that all of the methods described here are present. To check if a resolver supports a feature, see Check Interface Support.<br>

**Check Interface Support**

```javascript
function supportsInterface(bytes4 interfaceID) external pure returns (bool)
```

Domains use ERC165 for interface detection. ERC 165 requires that supporting contracts implement a function, `supportsInterface`, which takes an interface ID and returns a boolean value indicating if this interface is supported or not.

Interface IDs are calculated as the exclusive-or of the four-byte function identifiers of each function included in the interface. For example, `addr(bytes32`) has the function ID 0x3b3b57de. Because it is the only function in the Ethereum Address interface, its interface ID is also 0x3b3b57de, and so calling `supportsInterface(0x3b3b57de)` will return true for any resolver that supports `addr()`.ERC 165 has an interface ID of 0x01ffc9a7, so `supportsInterface(0x01ffc9a7)` will always return true for any ERC165 supporting contract (and hence for any resolver).Note that the public resolver does not expose explicit interfaces for setter functions, so there are no automated means to check for support for a given setter function.

**Get Ethereum Address**

```javascript
function addr(bytes32 node) external view returns (address)
```

Returns the Ethereum address associated with the provided `node`, or 0 if none.\
\
This function has interface ID 0x3b3b57de.

**Set Ethereum Address**

```javascript
function setAddr(bytes32 node, address addr) external;
```

Sets the Ethereum address associated with the provided `node` to `addr.`

Only callable by the owner of `node.`

Emits the following event:

```javascript
event AddrChanged(bytes32 indexed node, address a);
```

**Get Blockchain Address**

```javascript
function addr(bytes32 node, uint coinType) external view returns(bytes memory);
```

Returns the Blockchain address associated with the provided `node` and `node`, or 0 if none.

This function has interface ID 0xf1cb7e06.

This function is specified in EIP 2304.

The return value is the cryptocurrency address in its native binary format and each blockchain address has a different encoding and decoding method.

For example, the Bitcoin address `1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa` base58check decodes to the 21 bytes `0062e907b15cbf27d5425399ebf6f0fb50ebb88f18` then scriptPubkey encodes to 25 bytes `76a91462e907b15cbf27d5425399ebf6f0fb50ebb88f1888ac` whereas the BNB address `bnb1grpf0955h0ykzq3ar5nmum7y6gdfl6lxfn46h2` Bech32 decodes to the binary representation `40c2979694bbc961023d1d27be6fc4d21a9febe6.`

To convert the binary representation into the address, use `function setAddr(bytes32 node, uint coinType, bytes calldata a) external;ByCoinType[SYMBOL].encoder(binary) of address-encoder`.

A zero-length string will be returned if the specified coin ID does not exist on the specified node.

**Set Blockchain Address**

function setAddr(bytes32 node, uint coinType, bytes calldata a) external;

Sets the blockchain address associated with the provided `node` and `coinType` to `addr.`

`coinType` is the cryptocurrency coin type index from SLIP44.

To convert the address into the binary representation, use `formatsByName[SYMBOL].decoder(text)` of address-encoder

Only callable by the owner of node.

Emits the following event:

```javascript
event AddressChanged(bytes32 indexed node, uint coinType, bytes newAddress);
```

**Get Canonical Name**

```javascript
function name(bytes32 node) external view returns (string memory);
```

Returns the canonical Domains name associated with the provided `node`. Used exclusively for reverse resolution.

This function has interface ID 0x691f3431.

**Set Canonical Name**

```javascript
function setName(bytes32 node, string calldata name) external;
```

Sets the canonical Domains name for the provided `node` to `name`.

Only callable by the owner of `node.`

Emits the following event:

```javascript
event NameChanged(bytes32 indexed node, string name);
```

**Get Content Hash**

```javascript
function contenthash(bytes32 node) external view returns (bytes memory);
```

Returns the content hash for `node`, if one exists. Values are formatted as machine-readable multicodecs, as specified in EIP 1577.

`contenthash` is used to store IPFS and Swarm content hashes, which permit resolving Domains addresses to distributed content (eg, websites) hosted on these distributed networks.

This function has interface ID 0xbc1c58d1.

**Set Content Hash**

```javascript
function setContenthash(bytes32 node, bytes calldata hash) external;
```

Sets the content hash for the provided `node` to `hash.`

Only callable by the owner of `node.`

Values are formatted as machine-readable multi codecs, as specified in EIP 1577.

Emits the following event:

```javascript
event ContenthashChanged(bytes32 indexed node, bytes hash);
```

**Get Contract ABI**

```
ABI(bytes32 node, uint256 contentTypes) external view returns (uint256, bytes memory);
```

Returns a matching ABI definition for the provided node, if one exists. contentTypes is the bitwise-OR of the encodings that the caller can accept. If multiple content types are specified, the resolver will select one to return. Currently supported content types are:

| Content Type ID | Description                                               |
| --------------- | --------------------------------------------------------- |
| 1               | JSON                                                      |
| 2               | zlib-compressed JSON                                      |
| 4               | [<mark style="color:red;">CBOR</mark>](https://cbor.io/)​ |
| 8               | URI                                                       |

ABI returns a two-tuple of the content type ID and the ABI data. If no data of the appropriate content type ID was found, 0 is returned for the content type ID, and the ABI data will be the empty string.This function has interface ID 0x2203ab56.

**Set Contract ABI**

```javascript
function setABI(bytes32 node, uint256 contentType, bytes calldata data) external
```

Sets or updates ABI data for node. contentType specifies the content type ID (see[ <mark style="color:red;">Get Contract ABI</mark>](https://tomi-domain-name-service.gitbook.io/titled/publicresolver#get-contract-abi) for valid values); exactly one type ID must be specified. data contains the encoded ABI data. To clear ABI data for a name, specify the empty string for data.

Only callable by the owner of node.

Emits the following event:

```javascript
event ABIChanged(bytes32 indexed node, uint256 indexed contentType);
```

**Get Public Key**

```javascript
function pubkey(bytes32 node) external view returns (bytes32 x, bytes32 y)
```

Returns the ECDSA SECP256k1 public key for `node,` as a 2-tuple (x, y). If no public key is set, (0, 0) is returned.

This function has interface ID 0xc8690233.

**Set Public Key**

```javascript
function setPubkey(bytes32 node, bytes32 x, bytes32 y) external
```

Sets the ECDSA SECP256k1 public key for `node` to `(x, y).`

Only callable by the owner of `node.`

Emits the following event:

```javascript
event PubkeyChanged(bytes32 indexed node, bytes32 x, bytes32 y);
```

**Get Text Data**

function text(bytes32 node, string calldata key) external view returns (string memory)Retrieves text metadata for `node`. Each name may have multiple pieces of metadata, identified by a unique string `key`. If no text data exists for `node` with the `key` key, the empty string is returned.Standard values for key are:

| key         | Meaning                                                                                                                                                   |
| ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------- |
| email       | An email address                                                                                                                                          |
| url         | A URL                                                                                                                                                     |
| avatar      | A URL to an image used as an avatar or logo                                                                                                               |
| description | A description of the name                                                                                                                                 |
| notice      | A notice regarding this name                                                                                                                              |
| keywords    | A list of comma-separated keywords, ordered by most significant first; clients that interpresent this field may choose a threshold beyond which to ignore |

In addition, anyone may specify vendor-specific keys, which must be prefixed with vnd.. The following vendor-specific keys are currently known:key

| key         | Meaning         |
| ----------- | --------------- |
| com.twitter | Twitter handle  |
| com.github  | Github username |

**Set Text Data**

function setText(bytes32 node, string calldata key, string calldata value) externalSets text metadata for `node` with the unique `key` key to `value,` overwriting anything previously stored for `node` and `key.` To clear a text field, set it to the empty string.Only callable by the owner of `node`. Emits the following event:event TextChanged(bytes32 indexed node, string indexedKey, string key);

**Multicall**

```javascript
function multicall(bytes[] calldata data) external returns(bytes[] memory results)
```

Permits users to set multiple records in a single operation.

Use the `encodeABI` function to encode your contract calls and pass it to data.

The frontend usage will be as follows:

```javascript
var addrSet = resolver.contract.methods['setAddr(bytes32,address)'](node, accounts[1]).encodeABI();
var textSet = resolver.contract.methods.setText(node, "url", "https://tomi.com//").encodeABI();
var tx = await resolver.multicall([addrSet, textSet], {from: accounts[0]});
```