Amber and local store, asJSON?

Question

I want to save an Adered ( on-line IDE ) OrderedCollection in a local web browser repository and get it later.

Creating a Test Data Object

| coll hcoll | coll := OrderedCollection new. coll add: 'abc'. coll add: 'xon'. hcoll := HashedCollection new. hcoll at: 'en' put: 'English'. hcoll at: 'fr' put: 'French'. hcoll at: 'ge' put: 'German'. coll add: hcoll. 

Saving the test data object to localStorage

localStorage is the keystore in the browser. Values ​​must be strings.

 localStorage setItem: 'coll' value: coll asJSONString. "We set coll to nil to indicate that we are going to retrieve it back from the localStorage" coll := nil. 

Return stored value

a printIt next

 localStorage getItem: 'coll' 

gives

  '["abc","xon",{"en":"English","fr":"French","ge":"German"}]' 

This is a JSON string.

How do I return an OrderedCollection column?

Use browser parser JSON

 JSON parse: (localStorage getItem: 'coll') 

PrintIt result

 an Array ('abc' 'xon' [object Object]) 

and

 (JSON parse: (localStorage getItem: 'coll')) class 

is an

 Array 

The third element of the array

 ((JSON parse: (localStorage getItem: 'coll')) at: 3) class 

is an

 JSObjectProxy 

Question

How do I get a Smalltalk view for an arbitrary JSON object (containing JavaScript arrays and objects, ordered characters and hashes, dictionaries in Smalltalk)?

Note

http://www.json.org

JSON is built on two structures:

• A collection of name / value pairs. In different languages, this is implemented as an object, a dictionary, a hash table, or an associative array.
• An ordered list of values. In many languages, this is implemented as an array, list, or sequence.

Answer 1

A printIt

  SmalltalkImage current readJSObject: (JSON parse: (localStorage getItem: 'coll')) 

returns

  an Array ('abc' 'xon' a Dictionary ('en' -> 'English' , 'fr' -> 'French' , 'ge' -> 'German')) 

A comment

 (JSON parse: (localStorage getItem: 'coll')) 

provides a JSProxyObject, which is then converted to Amber objects using the #readJSObject: method. This method simply redirects the call to the underlying JavaScript method.