API entity.compute() receiving params but method sees None - parameter passing issue

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1

I’m calling a view method in another workspace via entity.compute(), passing a dict with a temperature parameter at the top level. The dict arrives correctly (confirmed via debug logs), but inside the called method, params.get('temperature') returns None, causing the code to crash.

Setup:

  • Calling app (Heat Exchanger Designer): Uses API to call Food Properties workspace

  • Called app (Food Properties): Has a @TableView method that should receive temperature parameter

Code in calling app:

# Prepare params dict with temperature

params_dict = entity_params.toDict() # Convert Munch to dict

params_dict[‘temperature’] = 65.0 # Add temperature parameter

# Call remote entity method

result = entity.compute(

method_name="calculate_properties_for_heat_exchanger",

params=params_dict

Debugging shows the following:

DEBUG: Calling Food Properties API for sample 2 (Water (TEST)) at 65.0°C
DEBUG: Calling entity.compute with params keys = [‘foods’, ‘temperature’]
DEBUG: Full params_dict structure:
{ “fat_wt”: 0, “density”: 1000, “porosity”: 0, “food_name”: “Water (TEST)”, “dry_matter”: 0, “food_group”: “Other”, “protein_wt”: 0, “minerals_wt”: 0, “temperature”: 65.0, “specific_heat”: 4.18, “viscosity_files”: “<viktor.api_v1.FileResource object at 0x00000275BA1474D0>”, “carbohydrates_wt”: 0, “manual_viscosity”: 0.001, “heat_conductivity”: 0.5, “concentration_factor”: 1, “rheological_behavior”: “Newtonian”, “enable_viscosity_upload”: false, “food_composition_boolean”: true } ]

},
“temperature”: 65.0
}
DEBUG: Error in entity computation: Computation failed with an error (type: error_code, details: )

Code in called app (Food Properties controller):

@vkt.TableView("Properties for Heat Exchanger")

def calculate_properties_for_heat_exchanger(self, params, \*\*kwargs):

    """Display food properties formatted for heat exchanger calculations

    

    Can be called remotely via API with temperature parameter.

    """

    \# Get temperature parameter (for API calls) - use attribute access for Munch objects

    temperature = getattr(params, 'temperature') or params.foods.food_samples\[0\].get('temperature')

            

    try:

        food_samples_params = params.foods.food_samples

        if not food_samples_params:

            return {"error": "No food samples defined"}

        

        \# Use the temperature parameter to calculate properties

        foods = \[Food(sample, temperature) for sample in food_samples_params\]

    except AttributeError:

        return {"error": "Please configure food samples first"}

// Existing code not relevant for this issue

    \# Build table data for heat exchanger

    table_rows = \[\]

    

    \# Properties relevant for heat exchanger design

    hex_props = \[

        ("Temperature (°C)", "temperature", 1, None),

        ("Density (kg/m³)", "total_concentration_kgm3", 1, None),

        ("Specific Heat (kJ/kg·K)", "specific_heat", 3, None),

        ("Thermal Conductivity (W/m·K)", "heat_conductivity", 4, None),

        ("Viscosity (mPa·s)", "viscosity", 3, "viscosity_special"),  # mPa·s with 3 decimals

        ("Concentration Factor", "concentration_factor", 2, None),

    \]



    for prop_name, prop_key, decimals, special_handling in hex_props:

        row = {"Property": prop_name}

        for i, food in enumerate(foods):

            sample_param = food_samples_params\[i\]

            try:

                if prop_key == "temperature":

                    \# Use the temperature parameter directly

                    row\[sample_names\[i\]\] = f"{temperature:.{decimals}f}"

// Existing code not relevant for this issue

    df = pd.DataFrame(table_rows)

    

    \# Create column headers

    column_headers = \[vkt.TableHeader("Property", align="left")\]

    for name in sample_names:

        column_headers.append(vkt.TableHeader(name, align="center"))

    

    return vkt.TableResult(df, column_headers=column_headers)

When entity.compute() passes a dict with params={'foods': {...}, 'temperature': 65.0}, what type does the receiving controller’s params argument become? How should I access the temperature key in the called method?

Should I use:

  • params.get('temperature') (dict method)

  • params.temperature (attribute access for Munch)

  • getattr(params, 'temperature', None) (safe attribute access)

What’s the proper way to pass and retrieve custom parameters via entity.compute() API?

I tried multiple ways with some help of Claude, but i keep running into the same issue that temperature keeps returning None.

2

Called with @MSEP, and this issue was solved. After some trying all is up and running and the difficulty was likely due to not matching the structure of a dynamic array (which is a list of dicts) in the params that were sent into the compute method.

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