Remove need for slice when setting cache tags. Require cache key for get/set ops.

README.md

@@ -887,7 +887,7 @@ err := c.Cache.
 ```go
 err := c.Cache.
     Set().
-    Group("my-group")
+    Group("my-group").
     Key("my-key").
     Data(myData).
     Save(ctx)
@@ -899,7 +899,7 @@ err := c.Cache.
 err := c.Cache.
     Set().
     Key("my-key").
-    Tags([]string{"tag1", "tag2"})
+    Tags("tag1", "tag2").
     Data(myData).
     Save(ctx)
 ```
@@ -910,7 +910,7 @@ err := c.Cache.
 err := c.Cache.
     Set().
     Key("my-key").
-    Expiration(time.Hour * 2)
+    Expiration(time.Hour * 2).
     Data(myData).
     Save(ctx)
 ```
@@ -945,7 +945,7 @@ This will flush all cache entries that were tagged with the given tags.
 ```go
 err := c.Cache.
     Flush().
-    Tags([]string{"tag1"}).
+    Tags("tag1", "tag2").
     Exec(ctx)
 ```
 
@@ -965,7 +965,7 @@ While it's ideal to use cache control headers on your static files so browsers c
 
 For example, to render a file located in `static/picture.png`, you would use:
 ```go
-<img src="{{File "picture.png"}"/>
+<img src="{{File "picture.png"}}"/>
 ```
 
 Which would result in:

controller/controller.go

@@ -138,7 +138,7 @@ func (c *Controller) cachePage(ctx echo.Context, page Page, html *bytes.Buffer)
 		Set().
 		Group(middleware.CachedPageGroup).
 		Key(key).
-		Tags(page.Cache.Tags).
+		Tags(page.Cache.Tags...).
 		Expiration(page.Cache.Expiration).
 		Data(cp).
 		Save(ctx.Request().Context())

controller/controller_test.go

@@ -166,7 +166,7 @@ func TestController_RenderPage(t *testing.T) {
 		// Clear the tag
 		err = c.Cache.
 			Flush().
-			Tags([]string{p.Cache.Tags[0]}).
+			Tags(p.Cache.Tags[0]).
 			Exec(context.Background())
 		require.NoError(t, err)
 

services/cache.go

@@ -2,6 +2,7 @@ package services
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"time"
 
@@ -124,13 +125,17 @@ func (c *cacheSet) Expiration(expiration time.Duration) *cacheSet {
 }
 
 // Tags sets the cache tags
-func (c *cacheSet) Tags(tags []string) *cacheSet {
+func (c *cacheSet) Tags(tags ...string) *cacheSet {
 	c.tags = tags
 	return c
 }
 
 // Save saves the data in the cache
 func (c *cacheSet) Save(ctx context.Context) error {
+	if c.key == "" {
+		return errors.New("no cache key specified")
+	}
+
 	opts := &store.Options{
 		Expiration: c.expiration,
 		Tags:       c.tags,
@@ -161,6 +166,10 @@ func (c *cacheGet) Type(expectedType interface{}) *cacheGet {
 
 // Fetch fetches the data from the cache
 func (c *cacheGet) Fetch(ctx context.Context) (interface{}, error) {
+	if c.key == "" {
+		return nil, errors.New("no cache key specified")
+	}
+
 	return marshaler.New(c.client.cache).Get(
 		ctx,
 		c.client.cacheKey(c.group, c.key),
@@ -181,7 +190,7 @@ func (c *cacheFlush) Group(group string) *cacheFlush {
 }
 
 // Tags sets the cache tags
-func (c *cacheFlush) Tags(tags []string) *cacheFlush {
+func (c *cacheFlush) Tags(tags ...string) *cacheFlush {
 	c.tags = tags
 	return c
 }

services/cache_test.go

@@ -73,14 +73,14 @@ func TestCacheClient(t *testing.T) {
 		Group(group).
 		Key(key).
 		Data(data).
-		Tags([]string{"tag1"}).
+		Tags("tag1").
 		Save(context.Background())
 	require.NoError(t, err)
 
 	// Flush the tag
 	err = c.Cache.
 		Flush().
-		Tags([]string{"tag1"}).
+		Tags("tag1").
 		Exec(context.Background())
 	require.NoError(t, err)