关于getSchema函数调用时机、调用者及Google Data Studio Connector函数流程文档的咨询

Great questions about Google Data Studio Connector's getSchema function—let me break this down clearly for you:

1. When does the getSchema function get called? #

• Right after your connector finishes its authentication flow (if auth is required). If your connector doesn’t need authentication, it runs immediately when a user adds the connector to their Data Studio report.
• It also triggers whenever the user makes a configuration change that impacts the data structure—for example, switching between different tables in a database connector, or updating a filter that alters which fields are available.
• Additionally, if you use the setCredentials method to update authentication credentials after the initial setup, getSchema will re-run to pull the updated schema that matches the new permissions.

2. Caller, Execution Flow, and Related Documentation #

• Calling主体 (Caller): The getSchema function is invoked directly by the Google Data Studio frontend runtime. You never need to call it manually in your connector code—the platform handles triggering it at the right moments.
• Execution Flow Overview: Here’s a typical lifecycle sequence for most Data Studio connectors:
  1. A user starts adding your connector to their Data Studio report.
  2. If authentication is required, the connector runs isAuthValid first. If auth is invalid, getAuthType and authorize are called to walk the user through the auth process.
  3. Once auth is valid (or no auth is needed), getConfig runs to let the user set connector-specific parameters (like picking a dataset or date range).
  4. After the user confirms their configuration, getSchema is called to retrieve the full data structure—including field names, data types, and any calculated fields.
  5. Finally, getData runs to fetch the actual data based on the schema and the user’s report selections.
• Documentation Notes: Google’s official Data Studio Connector docs cover the execution flow and each function’s responsibilities in detail. While there’s no single dedicated "flow chart" page, the core function reference and connector development guide walk through the entire lifecycle from initialization to data fetching, explaining when each function is triggered and how they interact.

内容的提问来源于stack exchange，提问作者Philip Hall