chore(core/workflow/utils/variable_template_parser): Refactor VariableTemplateParser class for better readability and maintainability. (#5328)

api/core/workflow/utils/variable_template_parser.py

 
 class VariableTemplateParser:
     """
+    A class for parsing and manipulating template variables in a string.
+
     Rules:
 
     1. Template variables must be enclosed in `{{}}`.
     2. The template variable Key can only be: #node_id.var1.var2#.
     3. The template variable Key cannot contain new lines or spaces, and must comply with rule 2.
+
+    Example usage:
+
+    template = "Hello, {{#node_id.query.name#}}! Your age is {{#node_id.query.age#}}."
+    parser = VariableTemplateParser(template)
+
+    # Extract template variable keys
+    variable_keys = parser.extract()
+    print(variable_keys)
+    # Output: ['#node_id.query.name#', '#node_id.query.age#']
+
+    # Extract variable selectors
+    variable_selectors = parser.extract_variable_selectors()
+    print(variable_selectors)
+    # Output: [VariableSelector(variable='#node_id.query.name#', value_selector=['node_id', 'query', 'name']),
+    #          VariableSelector(variable='#node_id.query.age#', value_selector=['node_id', 'query', 'age'])]
+
+    # Format the template string
+    inputs = {'#node_id.query.name#': 'John', '#node_id.query.age#': 25}}
+    formatted_string = parser.format(inputs)
+    print(formatted_string)
+    # Output: "Hello, John! Your age is 25."
     """
 
     def __init__(self, template: str):
         self.variable_keys = self.extract()
 
     def extract(self) -> list:
+        """
+        Extracts all the template variable keys from the template string.
+
+        Returns:
+            A list of template variable keys.
+        """
         # Regular expression to match the template rules
         matches = re.findall(REGEX, self.template)
 
         return list(set(first_group_matches))
 
     def extract_variable_selectors(self) -> list[VariableSelector]:
+        """
+        Extracts the variable selectors from the template variable keys.
+
+        Returns:
+            A list of VariableSelector objects representing the variable selectors.
+        """
         variable_selectors = []
         for variable_key in self.variable_keys:
             remove_hash = variable_key.replace('#', '')
         return variable_selectors
 
     def format(self, inputs: dict, remove_template_variables: bool = True) -> str:
+        """
+        Formats the template string by replacing the template variables with their corresponding values.
+
+        Args:
+            inputs: A dictionary containing the values for the template variables.
+            remove_template_variables: A boolean indicating whether to remove the template variables from the output.
+
+        Returns:
+            The formatted string with template variables replaced by their values.
+        """
         def replacer(match):
             key = match.group(1)
             value = inputs.get(key, match.group(0))  # return original matched string if key not found
 
     @classmethod
     def remove_template_variables(cls, text: str):
+        """
+        Removes the template variables from the given text.
+
+        Args:
+            text: The text from which to remove the template variables.
+
+        Returns:
+            The text with template variables removed.
+        """
         return re.sub(REGEX, r'{\1}', text)