Add support for File Input element type

README.md

@@ -89,6 +89,7 @@ Here's the list of types of components and corresponding classes:
 | rich_text_preformatted     | RichTextPreformatted     |
 | rich_text_quote            | RichTextQuote            |
 | rich_text_section          | RichTextSection          |
+| file_input                 | FileInput                |
 
 ### Composition objects
 

blockkit/blocks.py

@@ -12,6 +12,7 @@
     DatePicker,
     DatetimePicker,
     ExternalSelect,
+    FileInput,
     Image,
     MultiChannelsSelect,
     MultiConversationsSelect,
@@ -154,6 +155,7 @@ def __init__(
     DatetimePicker,
     TimePicker,
     NumberInput,
+    FileInput
 ]
 
 

blockkit/elements.py

@@ -23,6 +23,7 @@
     validate_datetime,
     validate_text_length,
     validate_time,
+    validate_integer_size,
     validator,
 )
 
@@ -51,6 +52,7 @@
     "RichTextQuote",
     "RichTextSection",
     "RichTextList",
+    "FileInput"
 ]
 
 
@@ -717,3 +719,27 @@ def __init__(
         indent: Optional[int] = None,
     ):
         super().__init__(elements=elements, style=style, indent=indent)
+
+class FileInput(FocusableElement):
+    type: str = "file_input"
+    filetypes: Optional[List[str]] = Field(None)
+    maxfiles: Optional[int] = Field(None)
+
+    def __init__(
+        self,
+        *,
+        action_id: Optional[str] = None,
+        filetypes: Optional[List[str]] = None,
+        maxfiles: Optional[int] = None,
+        focus_on_load: Optional[bool] = None,
+    ):
+        super().__init__(
+            action_id=action_id,
+            filetypes=filetypes,
+            maxfiles=maxfiles,
+            focus_on_load=focus_on_load,
+        )
+
+    _validate_maxfiles = validator(
+        "maxfiles", validate_integer_size, min=1, max=10
+    )

blockkit/validators.py

@@ -53,3 +53,16 @@ def validate_datetime(v: Union[int, datetime]) -> Optional[int]:
             _ = datetime.fromtimestamp(v)
             return v
     return v
+
+def validate_integer_size(v: int, min: int, max: int) -> Optional[int]:
+    if v is not None:
+        if v<max and v>min:
+            return v
+        elif v<min:
+            e = ValueError(f"Minimum value is {min}")
+            raise e
+        elif v>max:
+            e = ValueError(f"Maximum value is {max}")
+            raise e
+
+    return v

tests/test_elements.py

@@ -12,6 +12,7 @@
     DatePicker,
     DatetimePicker,
     ExternalSelect,
+    FileInput,
     Image,
     MultiChannelsSelect,
     MultiConversationsSelect,
@@ -1557,3 +1558,21 @@ def test_timepicker_excessive_action_id_raises_exception():
 def test_timepicker_excessive_placeholder_raises_exception():
     with pytest.raises(ValidationError):
         TimePicker(placeholder=PlainText(text="p" * 151))
+
+def test_builds_fileinput():
+    assert FileInput(
+        action_id="action_id",
+        filetypes=["file"],
+        maxfiles=1,
+        focus_on_load=True
+    ).build() == {
+        "type": "file_input",
+        "action_id": "action_id",
+        "filetypes": ["file"],
+        "maxfiles": 1,
+        "focus_on_load": True
+    }
+
+def test_fileinput_excessive_maxfiles_raises_exception():
+    with pytest.raises(ValidationError):
+        FileInput(maxfiles=11)