source code converting EIP12UnsignedTx to Base64 encoded reduced Transaction
const unsignedTransaction = new TransactionBuilder(height)
.from(inputs)
.to(outputs)
.sendChangeTo(changeAddress)
.payMinFee()
.build()
.toEIP12Object();
const { inputs, dataInputs } = unsignedTransaction;
const [txId, ergoPayTx] = await getTxReducedB64Safe(unsignedTransaction,inputs,dataInputs);
const ergoPayUrl = `ergopay:${ergoPayTx}`; // turn this into a qr-code or open in browser to redirect to ergopay walletimport JSONBigInt from 'json-bigint';
const ergolib = import('ergo-lib-wasm-browser');
const DEFAULT_EXPLORER_API_ADDRESS = "https://api.ergoplatform.com/";
const explorerApiV1 = DEFAULT_EXPLORER_API_ADDRESS + 'api/v1';
export async function getTxReducedB64Safe(json, inputs, dataInputs) {
/*
* Name: getTxReducedB64Safe
* Type: async function
* Description: creates a ReducedTransaction object from a json transaction and encodes it with Base64
* Parameters:
* json: object
* inputs: object
* dataInputs: object (default [])
* Returns:
* Promise<any>
* Dependencies:
* getTxReduced: function
* byteArrayToBase64: function
* ErgoLib: import
* Comments:
* - returns an array of the transaction id and a ReducedTransaction object encoded with Base64
* - used to create a ReducedTransaction object
* - used to create a QR code
* - used to create a payment link
*/
let txId: string|null = null ;
let reducedTx;
try {
[txId, reducedTx] = await getTxReduced(json, inputs, dataInputs);
} catch (e) {
console.log("error", e);
}
// Reduced transaction is encoded with Base64
const txReducedBase64 = byteArrayToBase64(reducedTx.sigma_serialize_bytes());
const ergoPayTx = txReducedBase64.replace(/\//g, '_').replace(/\+/g, '-');
//console.log("getTxReducedB64Safe3", txId, ergoPayTx);
// split by chunk of 1000 char to generates the QR codes
return [txId, ergoPayTx];
}
export async function getUnspentBoxesByAddress(address: string, limit = 50) {
/*
* Name: getUnspentBoxesByAddress
* Type: async function
* Description: gets unspent boxes by address
* Parameters:
* address: string
* limit: number (default 50)
* Returns:
* Promise<any>
* Comments:
* - address must be a valid ergo address
* - limit is the maximum number of boxes to return
*/
//todo: add error handling
const data = await getRequestV1(`/boxes/unspent/byAddress/${address}?limit=${limit}`);
return data.items;
}
export async function currentHeight() {
/*
* Name: currentHeight
* Type: async function
* Description: gets the current height of the blockchain
* Parameters:
* none
* Returns:
* Promise<number>
* Todo:
* - add error handling
* - add caching
* - use node instead of explorer
*/
const url = '/blocks?limit=1';
const res = await get(explorerApiV1 + url);
const data = await res.json();
const height = data.items[0].height;
return height;
}
function byteArrayToBase64( byteArray ) {
/*
* Name: byteArrayToBase64
* Type: function
* Description: converts a byte array to a base64 string
* Parameters:
* byteArray: object
* Returns:
* string
* Dependencies:
* none
*/
var binary = '';
var len = byteArray.byteLength;
for (var i = 0; i < len; i++) {
binary += String.fromCharCode( byteArray[ i ] );
}
return window.btoa( binary );
}
async function getTxReduced(json, inputs, dataInputs): Promise<[string, any]>{
/*
* Name: getTxReduced
* Type: async function
* Description: creates a ReducedTransaction object from a json transaction
* Parameters:
* json: object
* inputs: object
* dataInputs: object (default [])
* Returns:
* Promise<any>
* Dependencies:
* getErgoStateContext: function
* ErgoLib: import
* Comments:
* - returns an array of the transaction id and a ReducedTransaction object
* - used to create a ReducedTransaction object
*/
const unsignedTx = (await ergolib).UnsignedTransaction.from_json(JSONBigInt.stringify(json));
console.log("unsignedTx", unsignedTx);
const inputBoxes = (await ergolib).ErgoBoxes.from_boxes_json(inputs);
console.log("inputBoxes", inputBoxes);
const inputDataBoxes = (await ergolib).ErgoBoxes.from_boxes_json(dataInputs);
console.log("inputDataBoxes xxxx", inputDataBoxes);
let ctx:any;
try {
ctx = await getErgoStateContext();
} catch (e) {
console.log("error", e);
}
const id = unsignedTx.id().to_str();
const reducedTx = (await ergolib).ReducedTransaction.from_unsigned_tx(unsignedTx, inputBoxes, inputDataBoxes, ctx);
return [id, reducedTx];
}
async function getErgoStateContext(): Promise<any> {
/*
* Name: getErgoStateContext
* Type: async function
* Description: gets the current state context of the ergo blockchain from the explorer
* Parameters:
* none
* Returns:
* Promise<any>
* Dependencies:
* getExplorerBlockHeaders: function
* ErgoLib: import
* Comments:
* - returns an ErgoStateContext object
* - used to create a ReducedTransaction object
*/
let explorerHeaders: any = [];
try {
explorerHeaders = await getExplorerBlockHeaders();
} catch (e) {
console.log("error", e);
}
console.log("explorerHeaders", explorerHeaders);
const block_headers = (await ergolib).BlockHeaders.from_json(explorerHeaders);
const pre_header = (await ergolib).PreHeader.from_block_header(block_headers.get(0));
const ctx = new (await ergolib).ErgoStateContext(pre_header, block_headers);
return ctx;
}
async function getExplorerBlockHeaders() {
/*
* Name: getExplorerBlockHeaders
* Type: async function
* Description: gets block headers from the explorer
* Parameters:
* none
* Returns:
* Promise<any>
* Comments:
* - returns an array of 10 most recent block headers
*/
let res: any = [];
let headers = [];
try {
res = await getRequestV1(`/blocks/headers`);
headers = res.items.slice(0, 10);
} catch (e) {
console.log("error", e);
}
return headers;
}
async function getRequestV1(url: string) {
/*
* Name: getRequestV1
* Type: function
* Description: makes a GET request to the explorer api
* Parameters:
* url: string
* Returns:
* Promise<any>
*/
const res = await get(explorerApiV1 + url);
const data = await res.json();
console.log("data:", data);
return data;
}
async function get(url: string, apiKey = '') {
return await fetch(url, {
headers: {
Accept: 'application/json',
'Content-Type': 'application/json',
api_key: apiKey,
},
});
}
async function post(url: string, body = {}, apiKey = '') {
return await fetch(url, {
method: 'POST',
headers: {
Accept: 'application/json',
'Content-Type': 'application/json',
api_key: apiKey,
},
body: JSON.stringify(body),
});
}