|
|
--- |
|
|
|
|
|
contentType: explanation |
|
|
--- |
|
|
|
|
|
# Choose your node building approach |
|
|
|
|
|
n8n has two node-building styles, declarative and programmatic. |
|
|
|
|
|
You should use the declarative style for most nodes. This style: |
|
|
|
|
|
* Uses a JSON-based syntax, making it simpler to write, with less risk of introducing bugs. |
|
|
* Is more future-proof. |
|
|
* Supports integration with REST APIs. |
|
|
|
|
|
The programmatic style is more verbose. You must use the programmatic style for: |
|
|
|
|
|
* Trigger nodes |
|
|
* Any node that isn't REST-based. This includes nodes that need to call a GraphQL API and nodes that use external dependencies. |
|
|
* Any node that needs to transform incoming data. |
|
|
* Full versioning. Refer to [Node versioning](/integrations/creating-nodes/build/reference/node-versioning.md) for more information on types of versioning. |
|
|
|
|
|
## Data handling differences |
|
|
|
|
|
The main difference between the declarative and programmatic styles is how they handle incoming data and build API requests. The programmatic style requires an `execute()` method, which reads incoming data and parameters, then builds a request. The declarative style handles this using the `routing` key in the `operations` object. Refer to [Node base file](/integrations/creating-nodes/build/reference/node-base-files/index.md) for more information on node parameters and the `execute()` method. |
|
|
|
|
|
## Syntax differences |
|
|
|
|
|
To understand the difference between the declarative and programmatic styles, compare the two code snippets below. This example creates a simplified version of the SendGrid integration, called "FriendGrid." The following code snippets aren't complete: they emphasize the differences in the node building styles. |
|
|
|
|
|
In programmatic style: |
|
|
|
|
|
```js |
|
|
import { |
|
|
IExecuteFunctions, |
|
|
INodeExecutionData, |
|
|
INodeType, |
|
|
INodeTypeDescription, |
|
|
IRequestOptions, |
|
|
} from 'n8n-workflow'; |
|
|
|
|
|
// Create the FriendGrid class |
|
|
export class FriendGrid implements INodeType { |
|
|
description: INodeTypeDescription = { |
|
|
displayName: 'FriendGrid', |
|
|
name: 'friendGrid', |
|
|
. . . |
|
|
properties: [ |
|
|
{ |
|
|
displayName: 'Resource', |
|
|
. . . |
|
|
}, |
|
|
{ |
|
|
displayName: 'Operation', |
|
|
name: 'operation', |
|
|
type: 'options', |
|
|
displayOptions: { |
|
|
show: { |
|
|
resource: [ |
|
|
'contact', |
|
|
], |
|
|
}, |
|
|
}, |
|
|
options: [ |
|
|
{ |
|
|
name: 'Create', |
|
|
value: 'create', |
|
|
description: 'Create a contact', |
|
|
}, |
|
|
], |
|
|
default: 'create', |
|
|
description: 'The operation to perform.', |
|
|
}, |
|
|
{ |
|
|
displayName: 'Email', |
|
|
name: 'email', |
|
|
. . . |
|
|
}, |
|
|
{ |
|
|
displayName: 'Additional Fields', |
|
|
// Sets up optional fields |
|
|
}, |
|
|
], |
|
|
}; |
|
|
|
|
|
async execute(this: IExecuteFunctions): Promise<INodeExecutionData[][]> { |
|
|
let responseData; |
|
|
const resource = this.getNodeParameter('resource', 0) as string; |
|
|
const operation = this.getNodeParameter('operation', 0) as string; |
|
|
//Get credentials the user provided for this node |
|
|
const credentials = await this.getCredentials('friendGridApi') as IDataObject; |
|
|
|
|
|
if (resource === 'contact') { |
|
|
if (operation === 'create') { |
|
|
// Get email input |
|
|
const email = this.getNodeParameter('email', 0) as string; |
|
|
// Get additional fields input |
|
|
const additionalFields = this.getNodeParameter('additionalFields', 0) as IDataObject; |
|
|
const data: IDataObject = { |
|
|
email, |
|
|
}; |
|
|
|
|
|
Object.assign(data, additionalFields); |
|
|
|
|
|
// Make HTTP request as defined in https://sendgrid.com/docs/api-reference/ |
|
|
const options: IRequestOptions = { |
|
|
headers: { |
|
|
'Accept': 'application/json', |
|
|
'Authorization': `Bearer ${credentials.apiKey}`, |
|
|
}, |
|
|
method: 'PUT', |
|
|
body: { |
|
|
contacts: [ |
|
|
data, |
|
|
], |
|
|
}, |
|
|
url: `https://api.sendgrid.com/v3/marketing/contacts`, |
|
|
json: true, |
|
|
}; |
|
|
responseData = await this.helpers.httpRequest(options); |
|
|
} |
|
|
} |
|
|
// Map data to n8n data |
|
|
return [this.helpers.returnJsonArray(responseData)]; |
|
|
} |
|
|
} |
|
|
``` |
|
|
|
|
|
In declarative style: |
|
|
|
|
|
```js |
|
|
import { INodeType, INodeTypeDescription } from 'n8n-workflow'; |
|
|
|
|
|
// Create the FriendGrid class |
|
|
export class FriendGrid implements INodeType { |
|
|
description: INodeTypeDescription = { |
|
|
displayName: 'FriendGrid', |
|
|
name: 'friendGrid', |
|
|
. . . |
|
|
// Set up the basic request configuration |
|
|
requestDefaults: { |
|
|
baseURL: 'https://api.sendgrid.com/v3/marketing' |
|
|
}, |
|
|
properties: [ |
|
|
{ |
|
|
displayName: 'Resource', |
|
|
. . . |
|
|
}, |
|
|
{ |
|
|
displayName: 'Operation', |
|
|
name: 'operation', |
|
|
type: 'options', |
|
|
displayOptions: { |
|
|
show: { |
|
|
resource: [ |
|
|
'contact', |
|
|
], |
|
|
}, |
|
|
}, |
|
|
options: [ |
|
|
{ |
|
|
name: 'Create', |
|
|
value: 'create', |
|
|
description: 'Create a contact', |
|
|
// Add the routing object |
|
|
routing: { |
|
|
request: { |
|
|
method: 'POST', |
|
|
url: '=/contacts', |
|
|
send: { |
|
|
type: 'body', |
|
|
properties: { |
|
|
email: {{$parameter["email"]}} |
|
|
} |
|
|
} |
|
|
} |
|
|
}, |
|
|
// Handle the response to contact creation |
|
|
output: { |
|
|
postReceive: [ |
|
|
{ |
|
|
type: 'set', |
|
|
properties: { |
|
|
value: '={{ { "success": $response } }}' |
|
|
} |
|
|
} |
|
|
] |
|
|
} |
|
|
}, |
|
|
], |
|
|
default: 'create', |
|
|
description: 'The operation to perform.', |
|
|
}, |
|
|
{ |
|
|
displayName: 'Email', |
|
|
. . . |
|
|
}, |
|
|
{ |
|
|
displayName: 'Additional Fields', |
|
|
// Sets up optional fields |
|
|
}, |
|
|
], |
|
|
} |
|
|
// No execute method needed |
|
|
} |
|
|
``` |
|
|
|