JSON State (storing data)

See Uniteness for better way to JSON.

Saving arbitrary object as JSON to achieve persistence:

index.html file:

<script src="file_wrap.js"></script>
<script src="json.js"></script>
<script>

var state_filename = 'state.json';  
/* will become "/storage/state.json" */

// Load the state 
var state = JSON.parse( safe_file_get(state_filename, '[]') ); 
/* [] is default value is file is not found or smth bad happened*/
// so, basically we start with empty list

window.onload = function () {
    webserver = opera.io.webserver
    if (webserver)    {
        webserver.addEventListener('_index', start_page, false);
    };
};

function start_page(r) {
	// Append a number to end of list
    state.push( state.length );

    var o = r.connection.response;
	o.write('Current state: ' + state);

	// Save the state
	safe_file_put(state_filename, JSON.stringify(state) );

	o.close();
	
};
</script>

This is suboptimal, due to the fact that state is saved with each request, but so far I haven't found a way to do onUnload.

Don't forget to enable fileio library in config.xml.

In Uniteness

var db = new JSON_FILE('state_prices.json', []);
db.store.push({foo:"bar"})  // CREATE first(0) object
db.save()

Slava V. [about me]

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