Function transact

src/utils/Transaction.js:635–671

(doc, f, origin = null, local = true)

 * @function
 */
export const transact = (doc, f, origin = null, local = true) => {
  const transactionCleanups = doc._transactionCleanups
  let initialCall = false
  /**
   * @type {any}
   */
  let result = null
  if (doc._transaction === null) {
    initialCall = true
    doc._transaction = new Transaction(doc, origin, local)
    transactionCleanups.push(doc._transaction)
    if (transactionCleanups.length === 1) {
      doc.emit('beforeAllTransactions', [doc])
    }
    doc.emit('beforeTransaction', [doc._transaction, doc])
  }
  try {
    result = f(doc._transaction)
  } finally {
    if (initialCall) {
      const finishCleanup = doc._transaction === transactionCleanups[0]
      doc._transaction = null
      if (finishCleanup) {
        // The first transaction ended, now process observer calls.
        // Observer call may create new transactions for which we need to call the observers and do cleanup.
        // We don't want to nest these calls, so we execute these calls one after
        // another.
        // Also we need to ensure that all cleanups are called, even if the
        // observes throw errors.
        // This file is full of hacky try {} finally {} blocks to ensure that an
        // event can throw errors and also that the cleanup is called.
        cleanupTransactions(transactionCleanups, 0)
      }
    }
  }
  return result
}