Flash Storage
There are times where you need to store user related variables in some kind of permanent storage then relocate the user into another section of your application, be able to retrieve the data, use it and then clean it. All of these tedious operations are definitely doable but why reinvent the wheel if we can have the platform give us a tool for maintaing conversation variables across requests. The key point for Flash RAM is where will the data be stored so that it is unique per user. ColdFusion gives us several persistent scopes that we can use and we have also created several flash storages for this purpose. Since the ColdBox flash scope is based on an interface, the flash scope storage can be virtually anywhere. You will find all of these implementations in the following package: coldbox.system.web.flash. In order to choose what implementation to use in your application you need to tell the ColdBox.cfc which one to use via flash configuration structure:

Configuration

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// flash scope configuration
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flash = {
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scope = "session,client,cluster,cache,or full path",
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properties = {}, // constructor properties for the flash scope implementation
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inflateToRC = true, // automatically inflate flash data into the RC scope
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inflateToPRC = false, // automatically inflate flash data into the PRC scope
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autoPurge = true, // automatically purge flash data for you
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autoSave = true // automatically save flash scopes at end of a request and on relocations.
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};
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Below is a nice chart of all the keys in this configuration structure so you can alter behavior of the Flash RAM objects:
Key
Type
Required
Default
Description
scope
string or instantiation path
false
session
Determines what scope to use for Flash RAM. The available aliases are: session, client, cluster, cache or a custom instantiation path
properties
struct
false
{}
Properties that can be used inside the constructor of any Flash RAM implementation
inflateToRC
boolean
false
true
Whatever variables you put into the Flash RAM, they will also be inflated or copied into the request collection for you automatically.
inflateToPRC
boolean
false
false
Whatever variables you put into the Flash RAM, they will also be inflated or copied into the private request collection for you automatically
autoPurge
boolean
false
true
This is what makes the Flash RAM work, it cleans itself for you. Be careful when setting this to false as it then becomes your job to do the cleaning
autoSave
boolean
false
true
The Flash RAM saves itself at the end of requests and on relocations via setNextEvent(). If you do not want auto-saving, then turn it off and make sure you save manually

Core Flash Implementations

The included flash implementations for ColdBox are:
Name
Class
Description
Session
coldbox.system.web.flash.SessionFlash
Persists variables in session scope
Cluster
coldbox.system.web.flash.ClusterFlash
Persists variables in cluster scope via Railo only
Client
coldbox.system.web.flash.ClientFlash
Persists variables in client scope
Mock
coldbox.system.web.flash.MockFlash
Mocks the storage of Flashed variables. Great for unit/integration testing.
Cache
coldbox.system.web.flash.ColdboxCacheFlash
Persists variables in the ColdBox Cache

Configuration Properties

Each RAM implementation can also use properties in order to alter its behavior upon construction via the properties configuration struct. Below are the properties our core implementations can use:
Session Flash Settings
    none
Cluster Flash Settings
    none
Client Flash Settings
    none
Mock Flash Settings
    none
Cache Flash Settings
    cacheName : The cache provider name declared in CacheBox
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// flash scope configuration
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flash = {
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scope = "cache",
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properties = { cacheName="cluster" }
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};
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