JSDoc: Source: uci.js

'use strict';
+'require rpc';
+
+/**
+ * @class uci
+ * @memberof LuCI
+ * @hideconstructor
+ * @classdesc
+ *
+ * The `LuCI.uci` class utilizes {@link LuCI.rpc} to declare low level
+ * remote UCI `ubus` procedures and implements a local caching and data
+ * manipulation layer on top to allow for synchroneous operations on
+ * UCI configuration data.
+ */
+return L.Class.extend(/** @lends LuCI.uci.prototype */ {
+	__init__: function() {
+		this.state = {
+			newidx:  0,
+			values:  { },
+			creates: { },
+			changes: { },
+			deletes: { },
+			reorder: { }
+		};
+
+		this.loaded = {};
+	},
+
+	callLoad: rpc.declare({
+		object: 'uci',
+		method: 'get',
+		params: [ 'config' ],
+		expect: { values: { } }
+	}),
+
+
+	callOrder: rpc.declare({
+		object: 'uci',
+		method: 'order',
+		params: [ 'config', 'sections' ]
+	}),
+
+	callAdd: rpc.declare({
+		object: 'uci',
+		method: 'add',
+		params: [ 'config', 'type', 'name', 'values' ],
+		expect: { section: '' }
+	}),
+
+	callSet: rpc.declare({
+		object: 'uci',
+		method: 'set',
+		params: [ 'config', 'section', 'values' ]
+	}),
+
+	callDelete: rpc.declare({
+		object: 'uci',
+		method: 'delete',
+		params: [ 'config', 'section', 'options' ]
+	}),
+
+	callApply: rpc.declare({
+		object: 'uci',
+		method: 'apply',
+		params: [ 'timeout', 'rollback' ]
+	}),
+
+	callConfirm: rpc.declare({
+		object: 'uci',
+		method: 'confirm'
+	}),
+
+
+	/**
+	 * Generates a new, unique section ID for the given configuration.
+	 *
+	 * Note that the generated ID is temporary, it will get replaced by an
+	 * identifier in the form `cfgXXXXXX` once the configuration is saved
+	 * by the remote `ubus` UCI api.
+	 *
+	 * @param {string} config
+	 * The configuration to generate the new section ID for.
+	 *
+	 * @returns {string}
+	 * A newly generated, unique section ID in the form `newXXXXXX`
+	 * where `X` denotes a hexadecimal digit.
+	 */
+	createSID: function(conf) {
+		var v = this.state.values,
+		    n = this.state.creates,
+		    sid;
+
+		do {
+			sid = "new%06x".format(Math.random() * 0xFFFFFF);
+		} while ((n[conf] && n[conf][sid]) || (v[conf] && v[conf][sid]));
+
+		return sid;
+	},
+
+	/**
+	 * Resolves a given section ID in extended notation to the internal
+	 * section ID value.
+	 *
+	 * @param {string} config
+	 * The configuration to resolve the section ID for.
+	 *
+	 * @param {string} sid
+	 * The section ID to resolve. If the ID is in the form `@typename[#]`,
+	 * it will get resolved to an internal anonymous ID in the forms
+	 * `cfgXXXXXX`/`newXXXXXX` or to the name of a section in case it points
+	 * to a named section. When the given ID is not in extended notation,
+	 * it will be returned as-is.
+	 *
+	 * @returns {string|null}
+	 * Returns the resolved section ID or the original given ID if it was
+	 * not in extended notation. Returns `null` when an extended ID could
+	 * not be resolved to existing section ID.
+	 */
+	resolveSID: function(conf, sid) {
+		if (typeof(sid) != 'string')
+			return sid;
+
+		var m = /^@([a-zA-Z0-9_-]+)\[(-?[0-9]+)\]$/.exec(sid);
+
+		if (m) {
+			var type = m[1],
+			    pos = +m[2],
+			    sections = this.sections(conf, type),
+			    section = sections[pos >= 0 ? pos : sections.length + pos];
+
+			return section ? section['.name'] : null;
+		}
+
+		return sid;
+	},
+
+	/* private */
+	reorderSections: function() {
+		var v = this.state.values,
+		    n = this.state.creates,
+		    r = this.state.reorder,
+		    tasks = [];
+
+		if (Object.keys(r).length === 0)
+			return Promise.resolve();
+
+		/*
+		 gather all created and existing sections, sort them according
+		 to their index value and issue an uci order call
+		*/
+		for (var c in r) {
+			var o = [ ];
+
+			if (n[c])
+				for (var s in n[c])
+					o.push(n[c][s]);
+
+			for (var s in v[c])
+				o.push(v[c][s]);
+
+			if (o.length > 0) {
+				o.sort(function(a, b) {
+					return (a['.index'] - b['.index']);
+				});
+
+				var sids = [ ];
+
+				for (var i = 0; i < o.length; i++)
+					sids.push(o[i]['.name']);
+
+				tasks.push(this.callOrder(c, sids));
+			}
+		}
+
+		this.state.reorder = { };
+		return Promise.all(tasks);
+	},
+
+	/* private */
+	loadPackage: function(packageName) {
+		if (this.loaded[packageName] == null)
+			return (this.loaded[packageName] = this.callLoad(packageName));
+
+		return Promise.resolve(this.loaded[packageName]);
+	},
+
+	/**
+	 * Loads the given UCI configurations from the remote `ubus` api.
+	 *
+	 * Loaded configurations are cached and only loaded once. Subsequent
+	 * load operations of the same configurations will return the cached
+	 * data.
+	 *
+	 * To force reloading a configuration, it has to be unloaded with
+	 * {@link LuCI.uci#unload uci.unload()} first.
+	 *
+	 * @param {string|string[]} config
+	 * The name of the configuration or an array of configuration
+	 * names to load.
+	 *
+	 * @returns {Promise<string[]>}
+	 * Returns a promise resolving to the names of the configurations
+	 * that have been successfully loaded.
+	 */
+	load: function(packages) {
+		var self = this,
+		    pkgs = [ ],
+		    tasks = [];
+
+		if (!Array.isArray(packages))
+			packages = [ packages ];
+
+		for (var i = 0; i < packages.length; i++)
+			if (!self.state.values[packages[i]]) {
+				pkgs.push(packages[i]);
+				tasks.push(self.loadPackage(packages[i]));
+			}
+
+		return Promise.all(tasks).then(function(responses) {
+			for (var i = 0; i < responses.length; i++)
+				self.state.values[pkgs[i]] = responses[i];
+
+			if (responses.length)
+				document.dispatchEvent(new CustomEvent('uci-loaded'));
+
+			return pkgs;
+		});
+	},
+
+	/**
+	 * Unloads the given UCI configurations from the local cache.
+	 *
+	 * @param {string|string[]} config
+	 * The name of the configuration or an array of configuration
+	 * names to unload.
+	 */
+	unload: function(packages) {
+		if (!Array.isArray(packages))
+			packages = [ packages ];
+
+		for (var i = 0; i < packages.length; i++) {
+			delete this.state.values[packages[i]];
+			delete this.state.creates[packages[i]];
+			delete this.state.changes[packages[i]];
+			delete this.state.deletes[packages[i]];
+
+			delete this.loaded[packages[i]];
+		}
+	},
+
+	/**
+	 * Adds a new section of the given type to the given configuration,
+	 * optionally named according to the given name.
+	 *
+	 * @param {string} config
+	 * The name of the configuration to add the section to.
+	 *
+	 * @param {string} type
+	 * The type of the section to add.
+	 *
+	 * @param {string} [name]
+	 * The name of the section to add. If the name is omitted, an anonymous
+	 * section will be added instead.
+	 *
+	 * @returns {string}
+	 * Returns the section ID of the newly added section which is equivalent
+	 * to the given name for non-anonymous sections.
+	 */
+	add: function(conf, type, name) {
+		var n = this.state.creates,
+		    sid = name || this.createSID(conf);
+
+		if (!n[conf])
+			n[conf] = { };
+
+		n[conf][sid] = {
+			'.type':      type,
+			'.name':      sid,
+			'.create':    name,
+			'.anonymous': !name,
+			'.index':     1000 + this.state.newidx++
+		};
+
+		return sid;
+	},
+
+	/**
+	 * Removes the section with the given ID from the given configuration.
+	 *
+	 * @param {string} config
+	 * The name of the configuration to remove the section from.
+	 *
+	 * @param {string} sid
+	 * The ID of the section to remove.
+	 */
+	remove: function(conf, sid) {
+		var n = this.state.creates,
+		    c = this.state.changes,
+		    d = this.state.deletes;
+
+		/* requested deletion of a just created section */
+		if (n[conf] && n[conf][sid]) {
+			delete n[conf][sid];
+		}
+		else {
+			if (c[conf])
+				delete c[conf][sid];
+
+			if (!d[conf])
+				d[conf] = { };
+
+			d[conf][sid] = true;
+		}
+	},
+
+	/**
+	 * A section object represents the options and their corresponding values
+	 * enclosed within a configuration section, as well as some additional
+	 * meta data such as sort indexes and internal ID.
+	 *
+	 * Any internal metadata fields are prefixed with a dot which is isn't
+	 * an allowed character for normal option names.
+	 *
+	 * @typedef {Object<string, boolean|number|string|string[]>} SectionObject
+	 * @memberof LuCI.uci
+	 *
+	 * @property {boolean} .anonymous
+	 * The `.anonymous` property specifies whether the configuration is
+	 * anonymous (`true`) or named (`false`).
+	 *
+	 * @property {number} .index
+	 * The `.index` property specifes the sort order of the section.
+	 *
+	 * @property {string} .name
+	 * The `.name` property holds the name of the section object. It may be
+	 * either an anonymous ID in the form `cfgXXXXXX` or `newXXXXXX` with `X`
+	 * being a hexadecimal digit or a string holding the name of the section.
+	 *
+	 * @property {string} .type
+	 * The `.type` property contains the type of the corresponding uci
+	 * section.
+	 *
+	 * @property {string|string[]} *
+	 * A section object may contain an arbitrary number of further properties
+	 * representing the uci option enclosed in the section.
+	 *
+	 * All option property names will be in the form `[A-Za-z0-9_]+` and
+	 * either contain a string value or an array of strings, in case the
+	 * underlying option is an UCI list.
+	 */
+
+	/**
+	 * The sections callback is invoked for each section found within
+	 * the given configuration and receives the section object and its
+	 * associated name as arguments.
+	 *
+	 * @callback LuCI.uci~sectionsFn
+	 *
+	 * @param {LuCI.uci.SectionObject} section
+	 * The section object.
+	 *
+	 * @param {string} sid
+	 * The name or ID of the section.
+	 */
+
+	/**
+	 * Enumerates the sections of the given configuration, optionally
+	 * filtered by type.
+	 *
+	 * @param {string} config
+	 * The name of the configuration to enumerate the sections for.
+	 *
+	 * @param {string} [type]
+	 * Enumerate only sections of the given type. If omitted, enumerate
+	 * all sections.
+	 *
+	 * @param {LuCI.uci~sectionsFn} [cb]
+	 * An optional callback to invoke for each enumerated section.
+	 *
+	 * @returns {Array<LuCI.uci.SectionObject>}
+	 * Returns a sorted array of the section objects within the given
+	 * configuration, filtered by type of a type has been specified.
+	 */
+	sections: function(conf, type, cb) {
+		var sa = [ ],
+		    v = this.state.values[conf],
+		    n = this.state.creates[conf],
+		    c = this.state.changes[conf],
+		    d = this.state.deletes[conf];
+
+		if (!v)
+			return sa;
+
+		for (var s in v)
+			if (!d || d[s] !== true)
+				if (!type || v[s]['.type'] == type)
+					sa.push(Object.assign({ }, v[s], c ? c[s] : undefined));
+
+		if (n)
+			for (var s in n)
+				if (!type || n[s]['.type'] == type)
+					sa.push(Object.assign({ }, n[s]));
+
+		sa.sort(function(a, b) {
+			return a['.index'] - b['.index'];
+		});
+
+		for (var i = 0; i < sa.length; i++)
+			sa[i]['.index'] = i;
+
+		if (typeof(cb) == 'function')
+			for (var i = 0; i < sa.length; i++)
+				cb.call(this, sa[i], sa[i]['.name']);
+
+		return sa;
+	},
+
+	/**
+	 * Gets the value of the given option within the specified section
+	 * of the given configuration or the entire section object if the
+	 * option name is omitted.
+	 *
+	 * @param {string} config
+	 * The name of the configuration to read the value from.
+	 *
+	 * @param {string} sid
+	 * The name or ID of the section to read.
+	 *
+	 * @param {string} [option]
+	 * The option name to read the value from. If the option name is
+	 * omitted or `null`, the entire section is returned instead.
+	 *
+	 * @returns {null|string|string[]|LuCI.uci.SectionObject}
+	 * - Returns a string containing the option value in case of a
+	 *   plain UCI option.
+	 * - Returns an array of strings containing the option values in
+	 *   case of `option` pointing to an UCI list.
+	 * - Returns a {@link LuCI.uci.SectionObject section object} if
+	 *   the `option` argument has been omitted or is `null`.
+	 * - Returns `null` if the config, section or option has not been
+	 *   found or if the corresponding configuration is not loaded.
+	 */
+	get: function(conf, sid, opt) {
+		var v = this.state.values,
+		    n = this.state.creates,
+		    c = this.state.changes,
+		    d = this.state.deletes;
+
+		sid = this.resolveSID(conf, sid);
+
+		if (sid == null)
+			return null;
+
+		/* requested option in a just created section */
+		if (n[conf] && n[conf][sid]) {
+			if (!n[conf])
+				return undefined;
+
+			if (opt == null)
+				return n[conf][sid];
+
+			return n[conf][sid][opt];
+		}
+
+		/* requested an option value */
+		if (opt != null) {
+			/* check whether option was deleted */
+			if (d[conf] && d[conf][sid]) {
+				if (d[conf][sid] === true)
+					return undefined;
+
+				for (var i = 0; i < d[conf][sid].length; i++)
+					if (d[conf][sid][i] == opt)
+						return undefined;
+			}
+
+			/* check whether option was changed */
+			if (c[conf] && c[conf][sid] && c[conf][sid][opt] != null)
+				return c[conf][sid][opt];
+
+			/* return base value */
+			if (v[conf] && v[conf][sid])
+				return v[conf][sid][opt];
+
+			return undefined;
+		}
+
+		/* requested an entire section */
+		if (v[conf])
+			return v[conf][sid];
+
+		return undefined;
+	},
+
+	/**
+	 * Sets the value of the given option within the specified section
+	 * of the given configuration.
+	 *
+	 * If either config, section or option is null, or if `option` begins
+	 * with a dot, the function will do nothing.
+	 *
+	 * @param {string} config
+	 * The name of the configuration to set the option value in.
+	 *
+	 * @param {string} sid
+	 * The name or ID of the section to set the option value in.
+	 *
+	 * @param {string} option
+	 * The option name to set the value for.
+	 *
+	 * @param {null|string|string[]} value
+	 * The option value to set. If the value is `null` or an empty string,
+	 * the option will be removed, otherwise it will be set or overwritten
+	 * with the given value.
+	 */
+	set: function(conf, sid, opt, val) {
+		var v = this.state.values,
+		    n = this.state.creates,
+		    c = this.state.changes,
+		    d = this.state.deletes;
+
+		sid = this.resolveSID(conf, sid);
+
+		if (sid == null || opt == null || opt.charAt(0) == '.')
+			return;
+
+		if (n[conf] && n[conf][sid]) {
+			if (val != null)
+				n[conf][sid][opt] = val;
+			else
+				delete n[conf][sid][opt];
+		}
+		else if (val != null && val !== '') {
+			/* do not set within deleted section */
+			if (d[conf] && d[conf][sid] === true)
+				return;
+
+			/* only set in existing sections */
+			if (!v[conf] || !v[conf][sid])
+				return;
+
+			if (!c[conf])
+				c[conf] = {};
+
+			if (!c[conf][sid])
+				c[conf][sid] = {};
+
+			/* undelete option */
+			if (d[conf] && d[conf][sid])
+				d[conf][sid] = d[conf][sid].filter(function(o) { return o !== opt });
+
+			c[conf][sid][opt] = val;
+		}
+		else {
+			/* only delete in existing sections */
+			if (!(v[conf] && v[conf][sid] && v[conf][sid].hasOwnProperty(opt)) &&
+			    !(c[conf] && c[conf][sid] && c[conf][sid].hasOwnProperty(opt)))
+			    return;
+
+			if (!d[conf])
+				d[conf] = { };
+
+			if (!d[conf][sid])
+				d[conf][sid] = [ ];
+
+			if (d[conf][sid] !== true)
+				d[conf][sid].push(opt);
+		}
+	},
+
+	/**
+	 * Remove the given option within the specified section of the given
+	 * configuration.
+	 *
+	 * This function is a convenience wrapper around
+	 * `uci.set(config, section, option, null)`.
+	 *
+	 * @param {string} config
+	 * The name of the configuration to remove the option from.
+	 *
+	 * @param {string} sid
+	 * The name or ID of the section to remove the option from.
+	 *
+	 * @param {string} option
+	 * The name of the option to remove.
+	 */
+	unset: function(conf, sid, opt) {
+		return this.set(conf, sid, opt, null);
+	},
+
+	/**
+	 * Gets the value of the given option or the entire section object of
+	 * the first found section of the specified type or the first found
+	 * section of the entire configuration if no type is specfied.
+	 *
+	 * @param {string} config
+	 * The name of the configuration to read the value from.
+	 *
+	 * @param {string} [type]
+	 * The type of the first section to find. If it is `null`, the first
+	 * section of the entire config is read, otherwise the first section
+	 * matching the given type.
+	 *
+	 * @param {string} [option]
+	 * The option name to read the value from. If the option name is
+	 * omitted or `null`, the entire section is returned instead.
+	 *
+	 * @returns {null|string|string[]|LuCI.uci.SectionObject}
+	 * - Returns a string containing the option value in case of a
+	 *   plain UCI option.
+	 * - Returns an array of strings containing the option values in
+	 *   case of `option` pointing to an UCI list.
+	 * - Returns a {@link LuCI.uci.SectionObject section object} if
+	 *   the `option` argument has been omitted or is `null`.
+	 * - Returns `null` if the config, section or option has not been
+	 *   found or if the corresponding configuration is not loaded.
+	 */
+	get_first: function(conf, type, opt) {
+		var sid = null;
+
+		this.sections(conf, type, function(s) {
+			if (sid == null)
+				sid = s['.name'];
+		});
+
+		return this.get(conf, sid, opt);
+	},
+
+	/**
+	 * Sets the value of the given option within the first found section
+	 * of the given configuration matching the specified type or within
+	 * the first section of the entire config when no type has is specified.
+	 *
+	 * If either config, type or option is null, or if `option` begins
+	 * with a dot, the function will do nothing.
+	 *
+	 * @param {string} config
+	 * The name of the configuration to set the option value in.
+	 *
+	 * @param {string} [type]
+	 * The type of the first section to find. If it is `null`, the first
+	 * section of the entire config is written to, otherwise the first
+	 * section matching the given type is used.
+	 *
+	 * @param {string} option
+	 * The option name to set the value for.
+	 *
+	 * @param {null|string|string[]} value
+	 * The option value to set. If the value is `null` or an empty string,
+	 * the option will be removed, otherwise it will be set or overwritten
+	 * with the given value.
+	 */
+	set_first: function(conf, type, opt, val) {
+		var sid = null;
+
+		this.sections(conf, type, function(s) {
+			if (sid == null)
+				sid = s['.name'];
+		});
+
+		return this.set(conf, sid, opt, val);
+	},
+
+	/**
+	 * Removes the given option within the first found section of the given
+	 * configuration matching the specified type or within the first section
+	 * of the entire config when no type has is specified.
+	 *
+	 * This function is a convenience wrapper around
+	 * `uci.set_first(config, type, option, null)`.
+	 *
+	 * @param {string} config
+	 * The name of the configuration to set the option value in.
+	 *
+	 * @param {string} [type]
+	 * The type of the first section to find. If it is `null`, the first
+	 * section of the entire config is written to, otherwise the first
+	 * section matching the given type is used.
+	 *
+	 * @param {string} option
+	 * The option name to set the value for.
+	 */
+	unset_first: function(conf, type, opt) {
+		return this.set_first(conf, type, opt, null);
+	},
+
+	/**
+	 * Move the first specified section within the given configuration
+	 * before or after the second specified section.
+	 *
+	 * @param {string} config
+	 * The configuration to move the section within.
+	 *
+	 * @param {string} sid1
+	 * The ID of the section to move within the configuration.
+	 *
+	 * @param {string} [sid2]
+	 * The ID of the target section for the move operation. If the
+	 * `after` argument is `false` or not specified, the section named by
+	 * `sid1` will be moved before this target section, if the `after`
+	 * argument is `true`, the `sid1` section will be moved after this
+	 * section.
+	 *
+	 * When the `sid2` argument is `null`, the section specified by `sid1`
+	 * is moved to the end of the configuration.
+	 *
+	 * @param {boolean} [after=false]
+	 * When `true`, the section `sid1` is moved after the section `sid2`,
+	 * when `false`, the section `sid1` is moved before `sid2`.
+	 *
+	 * If `sid2` is null, then this parameter has no effect and the section
+	 * `sid1` is moved to the end of the configuration instead.
+	 *
+	 * @returns {boolean}
+	 * Returns `true` when the section was successfully moved, or `false`
+	 * when either the section specified by `sid1` or by `sid2` is not found.
+	 */
+	move: function(conf, sid1, sid2, after) {
+		var sa = this.sections(conf),
+		    s1 = null, s2 = null;
+
+		sid1 = this.resolveSID(conf, sid1);
+		sid2 = this.resolveSID(conf, sid2);
+
+		for (var i = 0; i < sa.length; i++) {
+			if (sa[i]['.name'] != sid1)
+				continue;
+
+			s1 = sa[i];
+			sa.splice(i, 1);
+			break;
+		}
+
+		if (s1 == null)
+			return false;
+
+		if (sid2 == null) {
+			sa.push(s1);
+		}
+		else {
+			for (var i = 0; i < sa.length; i++) {
+				if (sa[i]['.name'] != sid2)
+					continue;
+
+				s2 = sa[i];
+				sa.splice(i + !!after, 0, s1);
+				break;
+			}
+
+			if (s2 == null)
+				return false;
+		}
+
+		for (var i = 0; i < sa.length; i++)
+			this.get(conf, sa[i]['.name'])['.index'] = i;
+
+		this.state.reorder[conf] = true;
+
+		return true;
+	},
+
+	/**
+	 * Submits all local configuration changes to the remove `ubus` api,
+	 * adds, removes and reorders remote sections as needed and reloads
+	 * all loaded configurations to resynchronize the local state with
+	 * the remote configuration values.
+	 *
+	 * @returns {string[]}
+	 * Returns a promise resolving to an array of configuration names which
+	 * have been reloaded by the save operation.
+	 */
+	save: function() {
+		var v = this.state.values,
+		    n = this.state.creates,
+		    c = this.state.changes,
+		    d = this.state.deletes,
+		    r = this.state.reorder,
+		    self = this,
+		    snew = [ ],
+		    pkgs = { },
+		    tasks = [];
+
+		if (n)
+			for (var conf in n) {
+				for (var sid in n[conf]) {
+					var r = {
+						config: conf,
+						values: { }
+					};
+
+					for (var k in n[conf][sid]) {
+						if (k == '.type')
+							r.type = n[conf][sid][k];
+						else if (k == '.create')
+							r.name = n[conf][sid][k];
+						else if (k.charAt(0) != '.')
+							r.values[k] = n[conf][sid][k];
+					}
+
+					snew.push(n[conf][sid]);
+					tasks.push(self.callAdd(r.config, r.type, r.name, r.values));
+				}
+
+				pkgs[conf] = true;
+			}
+
+		if (c)
+			for (var conf in c) {
+				for (var sid in c[conf])
+					tasks.push(self.callSet(conf, sid, c[conf][sid]));
+
+				pkgs[conf] = true;
+			}
+
+		if (d)
+			for (var conf in d) {
+				for (var sid in d[conf]) {
+					var o = d[conf][sid];
+					tasks.push(self.callDelete(conf, sid, (o === true) ? null : o));
+				}
+
+				pkgs[conf] = true;
+			}
+
+		if (r)
+			for (var conf in r)
+				pkgs[conf] = true;
+
+		return Promise.all(tasks).then(function(responses) {
+			/*
+			 array "snew" holds references to the created uci sections,
+			 use it to assign the returned names of the new sections
+			*/
+			for (var i = 0; i < snew.length; i++)
+				snew[i]['.name'] = responses[i];
+
+			return self.reorderSections();
+		}).then(function() {
+			pkgs = Object.keys(pkgs);
+
+			self.unload(pkgs);
+
+			return self.load(pkgs);
+		});
+	},
+
+	/**
+	 * Instructs the remote `ubus` UCI api to commit all saved changes with
+	 * rollback protection and attempts to confirm the pending commit
+	 * operation to cancel the rollback timer.
+	 *
+	 * @param {number} [timeout=10]
+	 * Override the confirmation timeout after which a rollback is triggered.
+	 *
+	 * @returns {Promise<number>}
+	 * Returns a promise resolving/rejecting with the `ubus` RPC status code.
+	 */
+	apply: function(timeout) {
+		var self = this,
+		    date = new Date();
+
+		if (typeof(timeout) != 'number' || timeout < 1)
+			timeout = 10;
+
+		return self.callApply(timeout, true).then(function(rv) {
+			if (rv != 0)
+				return Promise.reject(rv);
+
+			var try_deadline = date.getTime() + 1000 * timeout;
+			var try_confirm = function() {
+				return self.callConfirm().then(function(rv) {
+					if (rv != 0) {
+						if (date.getTime() < try_deadline)
+							window.setTimeout(try_confirm, 250);
+						else
+							return Promise.reject(rv);
+					}
+
+					return rv;
+				});
+			};
+
+			window.setTimeout(try_confirm, 1000);
+		});
+	},
+
+	/**
+	 * An UCI change record is a plain array containing the change operation
+	 * name as first element, the affected section ID as second argument
+	 * and an optional third and fourth argument whose meanings depend on
+	 * the operation.
+	 *
+	 * @typedef {string[]} ChangeRecord
+	 * @memberof LuCI.uci
+	 *
+	 * @property {string} 0
+	 * The operation name - may be one of `add`, `set`, `remove`, `order`,
+	 * `list-add`, `list-del` or `rename`.
+	 *
+	 * @property {string} 1
+	 * The section ID targeted by the operation.
+	 *
+	 * @property {string} 2
+	 * The meaning of the third element depends on the operation.
+	 * - For `add` it is type of the section that has been added
+	 * - For `set` it either is the option name if a fourth element exists,
+	 *   or the type of a named section which has been added when the change
+	 *   entry only contains three elements.
+	 * - For `remove` it contains the name of the option that has been
+	 *   removed.
+	 * - For `order` it specifies the new sort index of the section.
+	 * - For `list-add` it contains the name of the list option a new value
+	 *   has been added to.
+	 * - For `list-del` it contains the name of the list option a value has
+	 *   been removed from.
+	 * - For `rename` it contains the name of the option that has been
+	 *   renamed if a fourth element exists, else it contains the new name
+	 *   a section has been renamed to if the change entry only contains
+	 *   three elements.
+	 *
+	 * @property {string} 4
+	 * The meaning of the fourth element depends on the operation.
+	 * - For `set` it is the value an option has been set to.
+	 * - For `list-add` it is the new value that has been added to a
+	 *   list option.
+	 * - For `rename` it is the new name of an option that has been
+	 *   renamed.
+	 */
+
+	/**
+	 * Fetches uncommitted UCI changes from the remote `ubus` RPC api.
+	 *
+	 * @method
+	 * @returns {Promise<Object<string, Array<LuCI.uci.ChangeRecord>>>}
+	 * Returns a promise resolving to an object containing the configuration
+	 * names as keys and arrays of related change records as values.
+	 */
+	changes: rpc.declare({
+		object: 'uci',
+		method: 'changes',
+		expect: { changes: { } }
+	})
+});
+