chore: import upstream snapshot with attribution

python/semantic_kernel/template_engine/blocks/text_block.py

@@ -0,0 +1,59 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+import logging
+from typing import TYPE_CHECKING, ClassVar, Optional
+
+from pydantic import field_validator
+
+from semantic_kernel.template_engine.blocks.block import Block
+from semantic_kernel.template_engine.blocks.block_types import BlockTypes
+
+if TYPE_CHECKING:
+    from semantic_kernel.functions.kernel_arguments import KernelArguments
+    from semantic_kernel.kernel import Kernel
+
+logger: logging.Logger = logging.getLogger(__name__)
+
+
+class TextBlock(Block):
+    """A block with text content."""
+
+    type: ClassVar[BlockTypes] = BlockTypes.TEXT
+
+    @field_validator("content", mode="before")
+    @classmethod
+    def content_strip(cls, content: str):
+        """Strip the content of the text block.
+
+        Overload strip method, text blocks are not stripped.
+        """
+        return content
+
+    @classmethod
+    def from_text(
+        cls,
+        text: str | None = None,
+        start_index: int | None = None,
+        stop_index: int | None = None,
+    ):
+        """Create a text block from a string."""
+        if text is None:
+            return cls(content="")
+        if start_index is not None and stop_index is not None:
+            if start_index > stop_index:
+                raise ValueError(f"start_index ({start_index}) must be less than stop_index ({stop_index})")
+
+            if start_index < 0:
+                raise ValueError(f"start_index ({start_index}) must be greater than 0")
+
+            text = text[start_index:stop_index]
+        elif start_index is not None:
+            text = text[start_index:]
+        elif stop_index is not None:
+            text = text[:stop_index]
+
+        return cls(content=text)
+
+    def render(self, *_: tuple[Optional["Kernel"], Optional["KernelArguments"]]) -> str:
+        """Render the text block."""
+        return self.content