How to Use Dynamic Formula Expressions in Steersman's Dynamic BoMs

Steersman’s Dynamic BoM customization uses condition statements to determine when a component or rule should apply to a configured product.

This guide explains how to write clear and reliable Dynamic BoM conditions, including how to compare configuration values, combine multiple requirements, group and and or logic, and avoid common formatting mistakes.

What Is a Dynamic BoM Condition?

A Dynamic BoM condition is a single-line expression that returns either True or False.

• True means the component or rule applies.
• False means the component or rule does not apply.

For example:

finish_code == 'premium'

This condition returns True when the configured finish is premium.

- Dynamic BoM condition fields are intended for single-line expressions. They should not contain full Python scripts, loops, imports, or function definitions.

Understanding the Parts of a Condition

A condition normally compares a variable from the product configuration to a value.

finish_code == 'premium'

In this example:

• finish_code is the variable.
• == means “is equal to.”
• 'premium' is the value being checked.

The variables available to a condition are determined by the attributes you have configured on the Product. The condition does not create or define the variables. You can find the list of available variables and values in the “Variables” tab of the Dynamic BoM.

Variable Names Are Case-Sensitive

Variable names in the condition statement must match exactly how they are written in the “Variables” tab.

For example, these are treated as three different variable names:

beam_length
Beam_Length
BEAM_LENGTH

Copy the variable name exactly as it appears in Odoo.

Place Text/String Values in Quotes

Text/String values must be placed inside single quotes.

Correct

color_code == 'blue'

Incorrect

color_code == blue

Numeric values should not be placed in quotes unless the value is stored as text/String.

panel_count == 4

Put the Variable First

For readability, place the variable first and the value second.

Recommended

wiring == 'hardwire'

Harder to read

'hardwire' == wiring

Both expressions may work, but the variable-first format is easier for another person to read and verify.

Comparison Operators

The following operators can be used to compare values:

- Use == when comparing values. Do not use a single equals sign.

Correct

color_code == 'blue'

Incorrect

color_code = 'blue'

Combining Multiple Requirements

Boolean operators allow a condition to include multiple requirements.

The most commonly used Boolean operators are:

• and
• or
• not

Use and When Every Requirement Must Be True

Use and when all parts of the condition must be true.

finish_code == 'premium' and panel_count >= 4

This condition applies only when:

1. The finish is premium.
2. The panel count is at least four.

Both requirements must be true.

Use or When Either Requirement May Be True

Use or when at least one part of the condition must be true.

color_code == 'red' or color_code == 'blue'

This condition applies when the selected color is either red or blue.

Use not to Reverse a Condition

Use not when a condition should apply when a Boolean value is false.

not is_outdoor

This condition returns True when is_outdoor is false.

Use in for Several Accepted Values

When one variable can match several acceptable values, use in.

color_code in ('red', 'blue', 'green')

This is easier to read than repeating the same variable:

color_code == 'red' or color_code == 'blue' or color_code == 'green'

Place a comma between each accepted value.

Use not in to Exclude Several Values

Use not in when a variable must not match any of the listed values.

finish_code not in ('archived', 'unavailable')

This condition applies when the finish is neither archived nor unavailable.

Checking Numeric Ranges

Use a chained comparison when a numeric value must fall within a range.

24 <= beam_length <= 48

This condition returns True when beam_length is at least 24 and no more than 48.

Another example:

1.5 <= thickness <= 3.0

Grouping and and or Logic

When a condition contains both and and or, always use parentheses to show how the condition should be evaluated.

This is one of the most important rules for formatting Dynamic BoM conditions.

Without parentheses, the condition may apply to configurations that were not intended.

Example: One Requirement and Several Accepted Finishes

Hard to read and potentially incorrect

wiring == 'hardwire' and hardware_finish == 'satin_brass' or hardware_finish == 'patina_brass'

This expression may allow patina_brass regardless of the selected wiring because the or portion is not grouped with the hardwire requirement.

Recommended

wiring == 'hardwire' and hardware_finish in ('satin_brass', 'patina_brass')

This condition clearly requires:

1. The wiring to be hardwire.
2. The hardware finish to be either satin_brass or patina_brass.

Example: Two Sizes and One Required Finish

Correct grouping

(size == 'duo' or size == 'trio') and hardware_finish == 'black'

This condition means:

• The size must be duo or trio.
• The hardware finish must be black.

Clearer version using in

size in ('duo', 'trio') and hardware_finish == 'black'

Example: Either of Two Complete Cases

Sometimes a component should apply for either of two complete configurations.

(finish_code == 'premium' and color_code == 'blue') or (finish_code == 'standard' and color_code == 'green')

This condition applies when either of the following is true:

1. The finish is premium and the color is blue.
2. The finish is standard and the color is green.

Each complete case is placed inside its own parentheses.

How to Determine the Correct Grouping

Write the business rule as a sentence before writing the condition.

For example:

- Apply the component when the size is duo or trio, and the hardware finish is black.

The first complete idea is:

The size is duo or trio.

The second complete idea is:

The hardware finish is black.

The formatted condition is:

(size == 'duo' or size == 'trio') and hardware_finish == 'black'

The clearer version is:

size in ('duo', 'trio') and hardware_finish == 'black'

Place parentheses around each phrase that must be evaluated as one complete idea.

Common Condition Patterns

The following patterns can be copied and adapted.

Replace the example variables and values with those configured for the product.

Always apply

True

Never apply

False

Apply for one selected option

variable == 'value'

Example:

color_code == 'blue'

Apply for any listed option

variable in ('value_1', 'value_2')

Example:

size in ('duo', 'trio')

Exclude listed options

variable not in ('value_1', 'value_2')

Example:

finish_code not in ('archived', 'unavailable')

Require all conditions

condition_a and condition_b

Example:

wiring == 'hardwire' and is_outdoor

Allow either condition

condition_a or condition_b

Example:

color_code == 'red' or color_code == 'blue'

Apply within a numeric range

minimum <= numeric_variable <= maximum

Example:

24 <= beam_length <= 48

Require an option and a numeric range

option_condition and range_condition

Example:

finish_code == 'premium' and 24 <= beam_length <= 48

Allow either of two complete cases

(case_a) or (case_b)

Example:

(size == 'duo' and color_code == 'black') or (size == 'trio' and color_code == 'white')

Boolean Values

Boolean values must begin with a capital letter:

True
False

Check whether a Boolean variable is true

is_outdoor

This can also be written as:

is_outdoor == True

The shorter version is normally easier to read.

Check whether a Boolean variable is false

not is_outdoor

This can also be written as:

is_outdoor == False

Common Formatting Mistakes

Using one equals sign

Incorrect:

color_code = 'blue'

Correct:

color_code == 'blue'

Leaving text unquoted

Incorrect:

color_code == blue

Correct:

color_code == 'blue'

Using a lowercase Boolean

Incorrect:

is_outdoor == true

Correct:

is_outdoor == True

Or:

is_outdoor

Mixing and and or without grouping

Unclear:

size == 'duo' or size == 'trio' and color_code == 'black'

Correct:

(size == 'duo' or size == 'trio') and color_code == 'black'

Clearer:

size in ('duo', 'trio') and color_code == 'black'

Repeating the same variable

Harder to read:

color_code == 'red' or color_code == 'blue' or color_code == 'green'

Recommended:

color_code in ('red', 'blue', 'green')

Worked Example

Business rule

Apply the component when wiring is hardwire and either the hardware finish or shade finish is one of the approved brass or metal finishes.

Formatted condition

wiring == 'hardwire' and (hardware_finish in ('satin_brass', 'patina_brass', 'blackened_brass', 'pewter') or shade_finish in ('satin_brass', 'patina_brass', 'blackened_brass', 'pewter'))

How the condition works

The first requirement is:

wiring == 'hardwire'

The and operator means that the wiring requirement must be true.

Inside the parentheses are two acceptable finish groups:

hardware_finish in ('satin_brass', 'patina_brass', 'blackened_brass', 'pewter')

Or:

shade_finish in ('satin_brass', 'patina_brass', 'blackened_brass', 'pewter')

The parentheses keep the two finish groups together. An approved finish cannot bypass the hardwire requirement.

Before saving a condition, confirm that:

• The condition is written on one line.
• The condition returns True or False.
• Variable names match the Odoo configuration exactly.
• Text values are placed inside quotes.
• The comparison operator is ==, not =.
• True, False, and None begin with capital letters.
• Several acceptable values for one variable use in where practical.
• Conditions containing both and and or use explicit parentheses.
• Each grouped case matches the intended business rule.
• The condition has been tested with matching and nonmatching configurations.
• Another person can read the condition and explain what it does.