Retrieving terms by ID, slug, or name in WordPress using get_term_by

The WordPress get_term_by function is used to retrieve a single term from a specific taxonomy based on a given field and value. This can be useful for fetching specific terms based on custom criteria, such as fetching a category by its name or fetching a tag by its slug.

By using the get_term_by function, developers can easily retrieve the term they need without having to manually query the database or loop through all terms in a taxonomy to find the desired one.

Parameters Accepted by get_term_by Function

The get_term_by function accepts the following parameters:

  • $field (string, required): Either ‘slug’, ‘name’, ‘term_id’ (or ‘id’, ‘ID’), or ‘term_taxonomy_id’.
  • $value (string/int, required): The term value to search for.
  • $taxonomy (string, optional, default value: ”): The taxonomy name. This parameter is optional if $field is ‘term_taxonomy_id’.
  • $output (string, optional, default value: OBJECT): The required return type. It can be OBJECT, ARRAY_A, or ARRAY_N, which correspond to a WP_Term object, an associative array, or a numeric array, respectively.
  • $filter (string, optional, default value: ‘raw’): Specifies how to sanitize term fields. The default value is ‘raw’.

Value Returned by get_term_by Function

The get_term_by function returns a WP_Term instance or array on success, depending on the $output value. It returns false if the specified $taxonomy does not exist or if the $term was not found.

Examples

How to get a term by ID

<?php
$term_id = 5;
$taxonomy = 'category';
$term = get_term_by('id', $term_id, $taxonomy);
?>

The code snippet retrieves a term from a specific taxonomy by its ID using the get_term_by function. It assigns the term to the variable $term.

How to get a term by slug

<?php
$term_slug = 'news';
$taxonomy = 'category';
$term = get_term_by('slug', $term_slug, $taxonomy);
?>

This code snippet fetches a term from a specific taxonomy by its slug using the get_term_by function. It stores the retrieved term in the variable $term.

How to check if a term exists before retrieving it

<?php
$term_name = 'Technology';
$taxonomy = 'category';

if (term_exists($term_name, $taxonomy)) {
 $term = get_term_by('name', $term_name, $taxonomy);
}

This code snippet first checks if a term with the name ‘Technology’ exists in the specified taxonomy using the term_exists function. If it does exist, it retrieves the term using the get_term_by function and assigns it to the variable $term.

Conclusion

The get_term_by function is an useful component for retrieving term data from the database in WordPress. It allows developers to easily access specific term information based on various parameters, such as the term’s name, slug, or ID. By understanding the different parameters and options available for this function, developers can efficiently retrieve the exact term data they need for their projects.

When using the get_term_by function, it’s important to consider the potential return values and handle them accordingly in the code. Additionally, developers should be mindful of the potential performance implications when using this function, especially when dealing with large datasets or frequent queries.

The get_term_by function provides a valuable way to interact with term data in WordPress, and with proper usage and understanding, it can greatly enhance the development process for WordPress projects.

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