fix: adding better validation

src/backend/langflow/api/base.py

@@ -1,3 +1,4 @@
+from langflow.graph.utils import extract_input_variables_from_prompt
 from pydantic import BaseModel, validator
 
 
@@ -25,3 +26,12 @@ class CodeValidationResponse(BaseModel):
 
 class PromptValidationResponse(BaseModel):
     input_variables: list
+
+
+def validate_prompt(template: str):
+    input_variables = extract_input_variables_from_prompt(template)
+    if invalid := [variable for variable in input_variables if " " in variable]:
+        raise ValueError(
+            f"Invalid input variables: {invalid}. Please remove spaces from input variables"
+        )
+    return PromptValidationResponse(input_variables=input_variables)

src/backend/langflow/api/validate.py

@@ -5,6 +5,7 @@ from langflow.api.base import (
     CodeValidationResponse,
     Prompt,
     PromptValidationResponse,
+    validate_prompt,
 )
 from langflow.graph.utils import extract_input_variables_from_prompt
 from langflow.utils.logger import logger
@@ -29,8 +30,7 @@ def post_validate_code(code: Code):
 @router.post("/prompt", status_code=200, response_model=PromptValidationResponse)
 def post_validate_prompt(prompt: Prompt):
     try:
-        input_variables = extract_input_variables_from_prompt(prompt.template)
-        return PromptValidationResponse(input_variables=input_variables)
+        return validate_prompt(prompt.template)
     except Exception as e:
         logger.exception(e)
         return HTTPException(status_code=500, detail=str(e))