Cache tags in Laravel - Step-by-Step Execution

Concept Flow - Cache tags

Store item with tags

↓

Cache saves item under tags

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Retrieve item by tags

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Check if item exists

Yes No↓

Return item

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Flush all items with tag

↓

Tagged items removed

Cache tags let you group cached items by labels. You can store, retrieve, or clear all items with the same tag easily.

Execution Sample

Laravel

Cache::tags(['users', 'settings'])->put('user_1', 'John', 3600);
$value = Cache::tags(['users'])->get('user_1');
Cache::tags(['users'])->flush();

Stores 'John' under 'user_1' with tags 'users' and 'settings', retrieves it by 'users' tag, then clears all 'users' tagged cache.

Execution Table

Step	Action	Tags Used	Key	Value	Cache State
1	Put item	['users', 'settings']	user_1	'John'	{user_1: 'John' tagged with users, settings}
2	Get item	['users']	user_1	'John'	{user_1: 'John' tagged with users, settings}
3	Flush tag	['users']	-	-	{}
4	Get item after flush	['users']	user_1	null	{}

💡 Cache is empty after flushing 'users' tag, so retrieval returns null.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4
Cache contents	{}	{user_1: 'John' tagged with users, settings}	{user_1: 'John' tagged with users, settings}	{}	{}
Retrieved value	null	'John'	'John'	null	null

Key Moments - 2 Insights

Why does flushing the 'users' tag remove the cached item even though it also has the 'settings' tag?

Because cache tags group items, flushing any tag removes all items tagged with it regardless of other tags. See step 3 in execution_table where flushing 'users' clears the item.

What happens if you try to get a cached item with a tag that was not used when storing it?

The item won't be found because tags filter cache keys. You must use at least one tag that matches the stored tags. Step 2 shows retrieval with 'users' tag works because it matches stored tags.

Visual Quiz - 3 Questions

Look at the execution table, what is the cache state after step 1?

A {}

B {user_1: 'John' tagged with users, settings}

C {user_1: 'John' tagged with users}

D null

💡 Hint

Check the 'Cache State' column in row for step 1.

At which step does the cache become empty?

A Step 2

B Step 4

C Step 3

D Never

💡 Hint

Look at the 'Cache State' column and see when it changes to {}.

If you flush the 'settings' tag instead of 'users' at step 3, what happens to the cache?

A Cache is emptied

B Cache still contains the item

C Cache contains a different item

D Error occurs

💡 Hint

Since the item is tagged with both 'users' and 'settings', flushing either tag removes it.

Concept Snapshot

Cache tags group cached items by labels.
Use Cache::tags(['tag1', 'tag2'])->put(key, value, ttl) to store.
Retrieve with Cache::tags(['tag1'])->get(key).
Flush all items with a tag using Cache::tags(['tag1'])->flush().
Flushing a tag removes all items with that tag, even if they have other tags.

Full Transcript

Cache tags in Laravel let you label cached items with one or more tags. When you store an item, you specify tags. Later, you can retrieve the item by using any of its tags. You can also clear all cached items that share a tag by flushing that tag. For example, storing 'John' under key 'user_1' with tags 'users' and 'settings' means the item belongs to both groups. Retrieving with tag 'users' finds it. Flushing 'users' tag removes it from cache, even though it also had 'settings' tag. This grouping helps manage cache efficiently by clearing related items together.