storage.md

ReplPad Storage

The ReplPad Storage module provides an API to the localStorage and sessionStorage objects in JavaScript. It has two main interfaces:

1. Through schemes specific to getting and setting to each object directly,

2. Through a filesystem scheme that attempts to simulate a desktop filesystem.

On initiating the module, these schemes are immediately available:

do %storage.reb

Storage Scheme

The Storage scheme maps each storage object to its own port. A port! for each object is created upon initiating the Storage module:

storage/local  ; maps to localStorage
storage/session  ; maps to sessionStorage

The storage scheme supports the following methods:

Method	Description	Example
poke	Used to set a key's value	poke storage/session "Key" "Value"
select	Used to retrieve a key's value	select storage/session "Key"
query	Returns a listing of an object's keys	query storage/session
clear	Clears all stored values of a given obect	clear storage/session

File Scheme

The File/Dir schemes replaces the inbuilt File/Dir schemes (which are redundant within the browser context) simulating the functionality of those schemes using localStorage and sessionStorage objects in place of the local filesystem. Upon initiating the Storage module, File/Dir schemes are ready to use:

probe read %/
change-dir %/tmp/
write %my-file.txt "Some Text"
probe read %my-file.txt
make-dir %dir/
change-dir %dir/
probe what-dir
probe read %../
write %hello.reb {Rebol [] print "Hello!"}
do %hello.reb

The localStorage object is mounted as %/ and the sessionStorage object is mounted as %/tmp/. Any files stored to %/tmp will be lost once the current browser session is closed.

The storage scheme supports the following methods, amongst others:

Method	Description	Example
create %folder/	Creates a new folder	; MAKE-DIR wraps CREATE make-dir %/folder/
write %file	Writes content to a given file	write %/folder/file.txt "Some Text"
read %file	Read a file's content (returns binary!)	read %/folder/file.txt
read %folder/	Read a folder's content (returns block!)	read %/folder/
delete %file	Deletes a file (returns the full path to a deleted file)	delete %/folder/file.txt
delete %folder/	Deletes a folder (so long as the folder is empty)	delete %/folder/