Delete documents

In this tutorial we will update delete data from Dash Platform. Data is stored in the form of documents which are encapsulated in a state transition before being submitted to DAPI.

Prerequisites

• General prerequisites (Node.js / Dash SDK installed)

• A wallet mnemonic with some funds in it: Tutorial: Create and Fund a Wallet

• A configured client: Setup SDK Client

• Access to a previously created document (e.g., one created using the Submit Documents tutorial)

Code

const setupDashClient = require('../setupDashClient');

const client = setupDashClient();

const deleteNoteDocument = async () => {
  const { platform } = client;
  const identity = await platform.identities.get('an identity ID goes here');
  const documentId = 'an existing document ID goes here';

  // Retrieve the existing document
  const [document] = await client.platform.documents.get(
    'tutorialContract.note',
    { where: [['$id', '==', documentId]] },
  );

  // Sign and submit the document delete transition
  await platform.documents.broadcast({ delete: [document] }, identity);
  return document;
};

deleteNoteDocument()
  .then((d) => console.log('Document deleted:\n', d.toJSON()))
  .catch((e) => console.error('Something went wrong:\n', e))
  .finally(() => client.disconnect());

👍 Initializing the Client with a contract identity

The example above shows how access to contract documents via <contract name>.<contract document> syntax (e.g. tutorialContract.note) can be enabled by passing a contract identity to the constructor. Please refer to the Dash SDK documentation for details.

What’s happening

After we initialize the Client, we retrieve the document to be deleted via platform.documents.get using its id.

Once the document has been retrieved, we must submit it to DAPI. Documents are submitted in batches that may contain multiple documents to be created, replaced, or deleted. In this example, a single document is being deleted.

The platform.documents.broadcast method takes the document batch (e.g. {delete: [documents[0]]}) and an identity parameter. Internally, it creates a State Transition containing the previously created document, signs the state transition, and submits the signed state transition to DAPI.

📘 Wallet Sync

Since the SDK does not cache wallet information, lengthy re-syncs (5+ minutes) may be required for some Core chain wallet operations. See Wallet Operations for options.