Step Configuration ⑤ - Attachment Step

Configuring the Attachment Handling Step (`attachment_step`)

Description: In the DP2 system, attachment_step is designed for processing and saving attachments extracted from the detail page (detail_step). These attachments often include images, PDF files, or other multimedia content. The following tutorial will guide you on how to configure attachment_step to properly process and save these attachments.

Prepare Attachment Data

In the data_in field, you need to provide relevant information about the attachments. This typically includes the task’s unique identifier (task_fp), the DP2 ID (dp2_id), title (title), link (link), and file type (type).

Set the Project Name

Use {STU}.attachments as the project name in the project_name field, where {STU} is your study template’s unique identifier.

Specify the Attachment Link

Use {link} as a placeholder in the url field, which will be replaced with the attachment’s link during runtime.

Configure the API Request

Set type to one-off, indicating this is a single-use task. Set fetch_method to direct, indicating direct data fetching. Set method to GET, as attachments are typically downloaded via GET requests.

Handle Attachment Download

In the data_out field, use jpath {key:key} to extract the attachment’s OSS key. This will be used for subsequent database updates.

Update Database Records

Specify the database URL, table name, unique identifier (where), and the data to be updated in the api field. Here, we use data.oss_keys.{row_idx}.key to update the attachment OSS key in the database.

Sample Configuration

Below is a sample attachment_step configuration for reference:

{
  "data_in": {
    "jpath": "attachments",
    "data_for_test": {
      "attachments": [
        {
          "task_fp": "b23166330ad46c070a293085a2b340b6",
          "dp2_id": 123456,
          "title": "Example Product",
          "link": "https://example.com/upload/2021-09-06/example.JPG",
          "type": "jpg"
        }
      ]
    }
  },
  "project_name": "{STU}.attachments",
  "url": "{link}",
  "type": "one-off",
  "priority": 2,
  "fetch_method": "direct",
  "method": "GET",
  "status": 1,
  "charset": "UTF-8",
  "add_only": 1,
  "excluded_workers": "{excluded_workers}",
  "interval": 5184000,
  "data_out": {
    "note": "jpath only extracts key, masks the attachment task's own dp2_id",
    "note2": "Writes the corresponding oss address into oss_keys, separated from the attachments field",
    "jpath": "{key:key}",
    "api": {
      "url": "http://api2.example.com/save/v2",
      "table": "company.example.drugs",
      "where": {
        "uniqueId": "{dp2_id}"
      },
      "data": {
        "data.oss_keys.{row_idx}.key": "{key}"
      }
    }
  },
  "pf_id": 1792
}

With this configuration, you can ensure that attachment data is correctly downloaded and saved to the database. Configuring the attachment_step requires precise mapping of attachment information and ensuring they are correctly associated with records in the database. Before running live, do not forget to conduct testing to verify the setup works as intended and to catch any issues before they affect your data collection process.