62 lines
1.6 KiB
Markdown
62 lines
1.6 KiB
Markdown
---
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title: Use DBOS Decorators with Classes
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impact: MEDIUM
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impactDescription: Enables stateful workflow patterns with class instances
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tags: classes, dbos_class, instance, oop
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---
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## Use DBOS Decorators with Classes
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DBOS decorators work with class methods. Workflow classes must inherit from `DBOSConfiguredInstance`.
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**Incorrect (missing class setup):**
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```python
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class MyService:
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def __init__(self, url):
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self.url = url
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@DBOS.workflow() # Won't work without proper setup
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def fetch_data(self):
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return self.fetch()
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```
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**Correct (proper class setup):**
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```python
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from dbos import DBOS, DBOSConfiguredInstance
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@DBOS.dbos_class()
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class URLFetcher(DBOSConfiguredInstance):
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def __init__(self, url: str):
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self.url = url
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# instance_name must be unique and passed to super()
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super().__init__(instance_name=url)
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@DBOS.workflow()
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def fetch_workflow(self):
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return self.fetch_url()
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@DBOS.step()
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def fetch_url(self):
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return requests.get(self.url).text
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# Instantiate BEFORE DBOS.launch()
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example_fetcher = URLFetcher("https://example.com")
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api_fetcher = URLFetcher("https://api.example.com")
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if __name__ == "__main__":
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DBOS.launch()
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print(example_fetcher.fetch_workflow())
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```
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Requirements:
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- Class must be decorated with `@DBOS.dbos_class()`
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- Class must inherit from `DBOSConfiguredInstance`
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- `instance_name` must be unique and passed to `super().__init__()`
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- All instances must be created before `DBOS.launch()`
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Steps can be added to any class without these requirements.
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Reference: [Python Classes](https://docs.dbos.dev/python/tutorials/classes)
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