Usage: *
* // Create manually, or require 'settings' from the container.
* // This is the manual version:
* var settings = plugins.catalog.getObject('settings');
* // Add a new setting
* settings.addSetting({ name:'foo', ... });
* // Display the default value
* alert(settings.get('foo'));
* // Alter the value, which also publishes the change etc.
* settings.set('foo', 'bar');
* // Reset the value to the default
* settings.resetValue('foo');
*
* @constructor
*/
function Settings(persister) {
/**
* Storage for deactivated values
*/
this._deactivated = {};
/**
* Storage for the setting values
*/
this._values = {};
this._settings = {};
if (persister) {
this.setPersister(persister);
}
/**
* Event that tells people when a setting has changed.
*/
// TODO: Fix events
// this.settingChange = new Event({ keyElement: 0 });
};
Settings.prototype = {
/**
* Function to add to the list of available settings.
* Example usage: *
* var settings = plugins.catalog.getObject('settings');
* settings.addSetting({
* name: 'tabsize', // For use in settings.get('X')
* type: 'number', // To allow value checking.
* defaultValue: 4 // Default value for use when none is directly set
* });
*
* @param {object} settingSpec Object containing name/type/defaultValue members.
*/
addSetting: function(settingSpec) {
if (!settingSpec.name) {
console.error('Setting.name == undefined. Ignoring.', settingSpec);
return;
}
if (!settingSpec.defaultValue === undefined) {
console.error('Setting.defaultValue == undefined', settingSpec);
return;
}
var type = types.getType(settingSpec.type);
if (!type) {
console.error('Missing type', settingSpec);
return;
}
/*
// The value can be
// 1) the value of a setting that is not activated at the moment
// OR
// 2) the defaultValue of the setting.
var value = this._deactivated[settingSpec.name] ||
settingSpec.defaultValue;
*/
var setting = { type: type, spec: settingSpec };
this._settings[settingSpec.name] = setting;
},
removeSetting: function(name) {
delete this._settings[name];
},
getSettingNames: function() {
return Object.keys(this._settings);
},
/**
* A Persister is able to store settings. It is an object that defines
* two functions:
* loadInitialValues(settings) and persistValue(settings, key, value).
*/
setPersister: function(persister) {
this._persister = persister;
if (persister) {
persister.loadInitialValues(this);
}
},
/**
* Read accessor
*/
get: function(key) {
return this._values[key];
},
/**
* Override observable.set(key, value) to provide type conversion and
* validation.
*/
set: function(key, value) {
var setting = this._settings[key];
if (!setting) {
console.warn('Setting not defined: ', key, value);
}
this._values[key] = value;
if (persister) {
persister.persistValue(this, key, value);
}
// Inform subscriptions of the change
// TODO: fix events
// this.settingChange(key, converted);
return this;
},
/**
* Reset the value of the key setting to it's default
*/
resetValue: function(key) {
var setting = this._settings[key];
if (setting) {
this.set(key, setting.spec.defaultValue);
} else {
console.log('ignore resetValue on ', key);
}
},
resetAll: function() {
this.getSettingNames().forEach(function(key) {
this.resetValue(key);
}.bind(this));
},
/**
* Retrieve a list of the known settings and their values
*/
_list: function() {
var reply = [];
this.getSettingNames().forEach(function(setting) {
reply.push({
'key': setting,
'value': this.get(setting)
});
}.bind(this));
return reply;
},
/**
* Prime the local cache with the defaults.
*/
_loadDefaultValues: function() {
this._loadFromObject(this._getDefaultValues());
},
/**
* Utility to load settings from an object
*/
_loadFromObject: function(data) {
// We iterate over data rather than keys so we don't forget values
// which don't have a setting yet.
for (var key in data) {
if (data.hasOwnProperty(key)) {
var setting = this._settings[key];
if (setting) {
var value = setting.type.fromString(data[key]);
this.set(key, value);
} else {
this.set(key, data[key]);
}
}
}
},
/**
* Utility to grab all the settings and export them into an object
*/
_saveToObject: function() {
return this.getSettingNames().map(function(key) {
return this._settings[key].type.toString(this.get(key));
}.bind(this));
},
/**
* The default initial settings
*/
_getDefaultValues: function() {
return this.getSettingNames().map(function(key) {
return this._settings[key].spec.defaultValue;
}.bind(this));
}
};
exports.settings = new Settings(new MemoryPersister());
/**
* Save the settings in a cookie
* This code has not been tested since reboot
* @constructor
*/
function CookiePersister() {
};
CookiePersister.prototype = {
loadInitialValues: function(settings) {
settings._loadDefaultValues();
var data = cookie.get('settings');
settings._loadFromObject(JSON.parse(data));
},
persistValue: function(settings, key, value) {
try {
var stringData = JSON.stringify(settings._saveToObject());
cookie.set('settings', stringData);
} catch (ex) {
console.error('Unable to JSONify the settings! ' + ex);
return;
}
}
};
exports.CookiePersister = CookiePersister;
});