feat: Add message table to the database

This commit adds a new table called "message" to the database. The table includes columns for timestamp, sender, sender_name, session_id, text, id, flow_id, and files. The "message" table is created using Alembic migration. This addition allows for storing and retrieving messages in the application.

src/backend/base/langflow/alembic/versions/d066bfd22890_add_message_table.py

@@ -0,0 +1,52 @@
+"""Add message table
+
+Revision ID: 325180f0c4e1
+Revises: 631faacf5da2
+Create Date: 2024-06-23 21:29:28.220100
+
+"""
+
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+import sqlmodel
+from alembic import op
+
+from langflow.utils import migration
+
+# revision identifiers, used by Alembic.
+revision: str = "325180f0c4e1"
+down_revision: Union[str, None] = "631faacf5da2"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    conn = op.get_bind()
+    # ### commands auto generated by Alembic - please adjust! ###
+    if not migration.table_exists("message", conn):
+        op.create_table(
+            "message",
+            sa.Column("timestamp", sa.DateTime(), nullable=False),
+            sa.Column("sender", sqlmodel.sql.sqltypes.AutoString(), nullable=False),
+            sa.Column("sender_name", sqlmodel.sql.sqltypes.AutoString(), nullable=False),
+            sa.Column("session_id", sqlmodel.sql.sqltypes.AutoString(), nullable=False),
+            sa.Column("text", sqlmodel.sql.sqltypes.AutoString(), nullable=False),
+            sa.Column("id", sqlmodel.sql.sqltypes.GUID(), nullable=False),
+            sa.Column("flow_id", sqlmodel.sql.sqltypes.GUID(), nullable=True),
+            sa.Column("files", sa.JSON(), nullable=True),
+            sa.ForeignKeyConstraint(
+                ["flow_id"],
+                ["flow.id"],
+            ),
+            sa.PrimaryKeyConstraint("id"),
+        )
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    conn = op.get_bind()
+    # ### commands auto generated by Alembic - please adjust! ###
+    if migration.table_exists("message", conn):
+        op.drop_table("message")
+    # ### end Alembic commands ###

src/backend/base/langflow/base/models/model.py

@@ -119,7 +119,11 @@ class LCModelComponent(Component):
         return status_message
 
     def get_chat_result(
-        self, runnable: LanguageModel, stream: bool, input_value: str | Message, system_message: Optional[str] = None
+        self,
+        runnable: LanguageModel,
+        stream: bool,
+        input_value: str | Message,
+        system_message: Optional[str] = None,
     ):
         messages: list[Union[BaseMessage]] = []
         if not input_value and not system_message:

src/backend/base/langflow/services/database/models/__init__.py

@@ -1,7 +1,8 @@
 from .api_key import ApiKey
 from .flow import Flow
 from .folder import Folder
+from .message import MessageTable
 from .user import User
 from .variable import Variable
 
-__all__ = ["Flow", "User", "ApiKey", "Variable", "Folder"]
+__all__ = ["Flow", "User", "ApiKey", "Variable", "Folder", "MessageTable"]

src/backend/base/langflow/services/database/models/flow/model.py

@@ -3,7 +3,7 @@
 import re
 import warnings
 from datetime import datetime, timezone
-from typing import TYPE_CHECKING, Dict, Optional
+from typing import TYPE_CHECKING, Dict, List, Optional
 from uuid import UUID, uuid4
 
 import emoji
@@ -17,6 +17,7 @@ from langflow.schema import Data
 
 if TYPE_CHECKING:
     from langflow.services.database.models.folder import Folder
+    from langflow.services.database.models.message import MessageTable
     from langflow.services.database.models.user import User
 
 
@@ -141,6 +142,7 @@ class Flow(FlowBase, table=True):
     user: "User" = Relationship(back_populates="flows")
     folder_id: Optional[UUID] = Field(default=None, foreign_key="folder.id", nullable=True, index=True)
     folder: Optional["Folder"] = Relationship(back_populates="flows")
+    messages: List["MessageTable"] = Relationship(back_populates="flow")
 
     def to_data(self):
         serialized = self.model_dump()

src/backend/base/langflow/services/database/models/message/__init__.py

@@ -0,0 +1,3 @@
+from .model import MessageTable, MessageCreate, MessageRead, MessageUpdate
+
+__all__ = ["MessageTable", "MessageCreate", "MessageRead", "MessageUpdate"]

src/backend/base/langflow/services/database/models/message/model.py

@@ -0,0 +1,62 @@
+from datetime import datetime, timezone
+from typing import TYPE_CHECKING, List, Optional
+from uuid import UUID, uuid4
+
+from sqlmodel import JSON, Column, Field, Relationship, SQLModel
+
+if TYPE_CHECKING:
+    from langflow.schema.message import Message
+    from langflow.services.database.models.flow.model import Flow
+
+
+class MessageBase(SQLModel):
+    timestamp: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))
+    sender: str
+    sender_name: str
+    session_id: str
+    text: str
+    files: list[str] = Field(default_factory=list)
+
+    @classmethod
+    def from_message(cls, message: "Message", flow_id: str | None = None):
+        # first check if the record has all the required fields
+        if message.text is None or not message.sender or not message.sender_name:
+            raise ValueError("The message does not have the required fields (text, sender, sender_name).")
+        return cls(
+            sender=message.sender,
+            sender_name=message.sender_name,
+            text=message.text,
+            session_id=message.session_id,
+            files=message.files or [],
+            timestamp=message.timestamp,
+            flow_id=flow_id,
+        )
+
+
+class MessageTable(MessageBase, table=True):
+    __tablename__ = "message"
+    id: UUID = Field(default_factory=uuid4, primary_key=True)
+    flow_id: Optional[UUID] = Field(default=None, foreign_key="flow.id")
+    flow: "Flow" = Relationship(back_populates="messages")
+    files: List[str] = Field(sa_column=Column(JSON))
+
+    # Needed for Column(JSON)
+    class Config:
+        arbitrary_types_allowed = True
+
+
+class MessageRead(MessageBase):
+    id: UUID
+    flow_id: Optional[UUID] = Field()
+
+
+class MessageCreate(MessageBase):
+    pass
+
+
+class MessageUpdate(SQLModel):
+    text: Optional[str] = None
+    sender: Optional[str] = None
+    sender_name: Optional[str] = None
+    session_id: Optional[str] = None
+    files: Optional[list[str]] = None