Submit Documents
Submit data to Dash Platform
Overview
In this tutorial we will submit some data to an application on Dash Platform. Data is stored in the form of documents which are encapsulated in a state transition before being submitted to DAPI.
Prerequisites
- node.js (v12+)
- Basic familiarity with JavaScript asychronous functions using async/await
- The Dash JavaScript SDK is initialized (covered in Connecting to EvoNet)
Code
Initializing the Client with a contract identity
The example below 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.
const Dash = require('dash');
const clientOpts = {
network: 'evonet',
wallet: {
mnemonic: 'a Dash wallet mnemonic with evonet funds goes here',
},
apps: {
tutorialContract: {
contractId: 'Q894cs83D8REQNo7mAetj1wPJK2W3svrwqaN61aP25W',
},
},
};
const client = new Dash.Client(clientOpts);
const submitNoteDocument = async () => {
const platform = client.platform;
const identity = await platform.identities.get('an identity ID goes here');
const docProperties = {
message: 'Tutorial Test @ ' + new Date().toUTCString(),
};
// Create the note document
const noteDocument = await platform.documents.create(
'tutorialContract.note',
identity,
docProperties,
);
const documentBatch = {
create: [noteDocument], // Document(s) to create
replace: [], // Document(s) to update
delete: [], // Document(s) to delete
};
// Sign and submit the document(s)
return platform.documents.broadcast(documentBatch, identity);
};
submitNoteDocument()
.then((d) => console.log(d))
.catch((e) => console.error('Something went wrong:\n', e))
.finally(() => client.disconnect());
What's happening
After we initialize the Client, we create a document that matches the structure defined by the data contract of the application being referenced (e.g. a note
document for the contract registered in the data contract tutorial). The platform.documents.create
method takes three arguments: a document locator, an identity, and the document data. The document locator consists of an application name (e.g. tutorialContract
) and the document type being created (e.g. note
). The document data should contain values for each of the properties defined for it in the data contract (e.g. message
for the tutorial contract's note).
Once the document has been created, we still need to 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 created. The documentBatch
object defines the action to be completed for the document (the empty action arrays - replace
and delete
in this example - may be excluded and are shown for reference only here).
The platform.documents.broadcast
method then takes the document batch 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.
Updated almost 4 years ago