where¶

The 'where' filter is designed to select elements from an array that match a specific condition based on a property value. It functions similarly to a "filter" or "where" clause in SQL or other query languages.

Functionality

Arrays of Objects: Takes an array of objects as input.
Property and Value: Requires a property name (string) and a target value to filter by.
Matching: Evaluates each object in the array, keeping only those where the specified property matches the target value.
Output: Returns a new array containing only the objects that satisfied the condition.

Syntax

    {{ array_variable | where: property_name, target_value }}

Arguments

property_name: A string representing the name of the property to check for each object.
target_value: The value that the specified property should match for an object to be included in the result.

Code Samples

Example 1: Filtering by a String Property

    {% assign products = [{ "name": "Product A", "category": "Electronics" }, 
                          { "name": "Product B", "category": "Clothing" }, 
                          { "name": "Product C", "category": "Electronics" }] %}

    {{ products | where: "category", "Electronics" }}

Output:

[{"name": "Product A", "category": "Electronics"}, {"name": "Product C","category": "Electronics"}]

Example 2: Filtering by a Number Property

    {% assign users = [{ "name": "Alice", "age": 30 }, 
                       { "name": "Bob", "age": 25 }, 
                       { "name": "Charlie", "age": 35 }] %}

    {{ users | where: "age", 30 }}

Output:

[{"name": "Alice", "age": 30}]

Example 3: Filtering with Boolean Values (Implicit True)

    {% assign tasks = [{ "name": "Task 1", "completed": true }, 
                       { "name": "Task 2", "completed": false }, 
                       { "name": "Task 3", "completed": true }] %}

    {{ tasks | where: "completed" }}

Output:

[{"name": "Task 1", "completed": true}, {"name": "Task 3", "completed": true}]

Outliers and Special Cases¶

Empty Arrays: If the input array is empty, the where filter returns an empty array.
Non-Array Input: If the input is not an array of objects, the where filter returns the original input value unchanged.
Invalid Property: If the specified property_name does not exist on the objects, the filter may return an error or unexpected results (depending on Experience Builder's error handling).
Type Coercion: Be mindful of data types when specifying the target_value. Experience Builder might perform type coercion if the types don't match exactly (e.g., comparing a string "30" with a number 30 might still be considered a match).

Key Points¶

The where filter is a powerful tool for filtering and extracting specific subsets of data from arrays of objects.
It allows you to create dynamic and conditional content based on object properties.
Pay attention to data types to ensure accurate filtering.
Consider using the map filter in conjunction with where for more complex filtering scenarios.