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362a075 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 | # SPDX-FileCopyrightText: 2022-present deepset GmbH <info@deepset.ai>
#
# SPDX-License-Identifier: Apache-2.0
from typing import Dict, List
from haystack import Document, component
from haystack.utils.filters import document_matches_filter
@component
class MetadataRouter:
"""
Routes documents to different connections based on their metadata fields.
Specify the routing rules in the `init` method.
If a document does not match any of the rules, it's routed to a connection named "unmatched".
### Usage example
```python
from haystack import Document
from haystack.components.routers import MetadataRouter
docs = [Document(content="Paris is the capital of France.", meta={"language": "en"}),
Document(content="Berlin ist die Haupststadt von Deutschland.", meta={"language": "de"})]
router = MetadataRouter(rules={"en": {"field": "meta.language", "operator": "==", "value": "en"}})
print(router.run(documents=docs))
# {'en': [Document(id=..., content: 'Paris is the capital of France.', meta: {'language': 'en'})],
# 'unmatched': [Document(id=..., content: 'Berlin ist die Haupststadt von Deutschland.', meta: {'language': 'de'})]}
```
"""
def __init__(self, rules: Dict[str, Dict]):
"""
Initializes the MetadataRouter component.
:param rules: A dictionary defining how to route documents to output connections based on their metadata.
Keys are output connection names, and values are dictionaries of
[filtering expressions](https://docs.haystack.deepset.ai/docs/metadata-filtering) in Haystack.
For example:
```python
{
"edge_1": {
"operator": "AND",
"conditions": [
{"field": "meta.created_at", "operator": ">=", "value": "2023-01-01"},
{"field": "meta.created_at", "operator": "<", "value": "2023-04-01"},
],
},
"edge_2": {
"operator": "AND",
"conditions": [
{"field": "meta.created_at", "operator": ">=", "value": "2023-04-01"},
{"field": "meta.created_at", "operator": "<", "value": "2023-07-01"},
],
},
"edge_3": {
"operator": "AND",
"conditions": [
{"field": "meta.created_at", "operator": ">=", "value": "2023-07-01"},
{"field": "meta.created_at", "operator": "<", "value": "2023-10-01"},
],
},
"edge_4": {
"operator": "AND",
"conditions": [
{"field": "meta.created_at", "operator": ">=", "value": "2023-10-01"},
{"field": "meta.created_at", "operator": "<", "value": "2024-01-01"},
],
},
}
```
"""
self.rules = rules
component.set_output_types(self, unmatched=List[Document], **{edge: List[Document] for edge in rules})
def run(self, documents: List[Document]):
"""
Routes the documents.
If a document does not match any of the rules, it's routed to a connection named "unmatched".
:param documents: A list of documents to route.
:returns: A dictionary where the keys are the names of the output connections (including `"unmatched"`)
and the values are lists of routed documents.
"""
unmatched_documents = []
output: Dict[str, List[Document]] = {edge: [] for edge in self.rules}
for document in documents:
cur_document_matched = False
for edge, rule in self.rules.items():
if "operator" not in rule:
raise ValueError(
"Invalid filter syntax. "
"See https://docs.haystack.deepset.ai/docs/metadata-filtering for details."
)
if document_matches_filter(rule, document):
output[edge].append(document)
cur_document_matched = True
if not cur_document_matched:
unmatched_documents.append(document)
output["unmatched"] = unmatched_documents
return output
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