property-manager
v2.0.0
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make it easier to manage the properties/attributes of your class.
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property-manager
make it easier to manage the properties/attributes of your class.
Features:
- Inherited properties with class.
- Assign properties from a plain object(JSON Object).
- Clone object.
- Compare object whether is the same.
- Export properties to a plain object(JSON Object).
- Declare properties with type and default value.
- Supports
arrayOf
property with type - Supports property with
template
(the property value is determined by the template content):template
{string | (this) => string}
:- the template string, eg,
'${author}-${uuid()}'
- or customize template function,
function() {return this.author + '-' + uuid()}
- the template string, eg,
imports
:{Object}
the optional functions could be used in the template string.- NOTE: the template property is readonly by default. You can make it writeable. Once a new value has been written, the template will be no useful unless the new value is null or undefined.
- Supports
We often need to manage the properties of an object, consider the following:
- Set the options to the properties of object when the object was created
var myObj = new MyObject({opt1:value1, opt2:value2})
- Assign the options value from another object:
myObj.assign({opt1:v1, opt2:v2})
- Clone an object:
var newObj = myObj.clone()
- Compare two objects whether is the same by their options(assigned properties).
myObj.isSame(anotherObj)
- Export the properties as a plain object or JSON to make recreate the object easier in the future.
- There are some internal attributes should not be exported.
- The empty or default value of an attribute should not be exported.
- the meaningful(non-english) name should be exported and assigned.
myObj.toObject()
andmyObj.toJSON()
JSON.stringify(myObj)
- Problem: how to assign an object value of a property?
- replace the standard
assignPropertyTo()
method. - define the attribute's
assign(value, dest, src, name)
method on the$attributes
.- the custom attribute's
assign
the value. return the changed value.
- the custom attribute's
- replace the standard
- Problem: how to decide which property should be assign value or get default value of an attribute?
- define all attributes on this object even though the value is null.
- no default value feature.
- define a simple
$attributes
property to manage this:{attrName: {value:'defaultValue'}, ...}
- define a complex
$attributes
(useProperties
class) to manage attributes.
- define all attributes on this object even though the value is null.
So we have these classes: SimplePropertyManager,NormalPropertyManager and AdvancePropertyManager.
first the rules of the properties:
- exported attributes means they are the JSON.stringify(aObj) attributes only.
- The non-enumerable attributes can not be exported and assigned.
- The enumerable attributes beginning with '$' can not be exported. but can be assigned.
undefined
value can not be exported.- the readonly(writable is false) attributes can not be assigned.
- the assignment order of properties is the order of defined properties.
You can inherit from it
SimplePropertyManager
: /lib/simple- use the object's property descriptor directly.
- so do not support default value.
- do not support object value assignment hook function.
- do not support meaningful(non-english) name.
NormalPropertyManager
: /lib/normal- use the
$attributes
plain object to hold the declaration properties - support default value.
- support object value assignment hook function.
- support meaningful(non-english) name.
- use the
AdvancePropertyManager
: /lib/advance- use the
$attributes
to hold the declaration properties - the
$attributes
is an instance ofProperties
class. - so you can custom your
Properties
class inherited from. - support default value.
- support object value assignment hook function.
- support meaningful(non-english) name.
- support type check if possible.
- use the
The $attributes
holds all attributes(like the property descriptor) of an object.
The key
is the property name. the value is the property descriptor:
name
(String): the non-english name to export, Defaults to thekey
name.value
: the property's default value if exists. Defaults toundefined
.type
(String): the property's type name. defaults to undefined.enumerable
(Boolean): defaults to true- true if and only if this property shows up during enumeration of the properties on the corresponding object.
configurable
(Boolean): defaults to true- true if and only if the type of this property descriptor may be changed and if the property may be deleted from the corresponding object.
writable
(Boolean): defaults to true- true if and only if the value associated with the property may be changed with an assignment operator.
assign
(Function(value, dest, src, name)):the custom attribute assignment function. justreturn
the changed value. defaults to undefined. It means do not assign this value if returnundefined
- Note: It only used on assign the options from another object.
- It's no effect if the assign the property individually. use the property descriptor
set
to do so. - Wrap it as smart-assign feature(only on Advance Property Manager):
- automatically add a hidden internal property with prefix
- automatically add descriptor
get
function to read the property - automatically add descriptor
set
function to assign the property(call theassign
descriptor).
- only available on Normal and Advance Property Manager:
assigned
(Boolean): whether the property can be assigned. defaults: undefined- if undefined then
=enumerable isn't false and (writable isn't false or isFunction(set))
- if undefined then
- Smart Assign Support only available on AdvancePropertyManager
assigned
(Boolean|String): enable smart-assign support when the assigned is string- it uses the
nonExported1stChar+name
as the internal property name if the string is empty - the
assigned
string is the internal property name if it's non-empty.
exported
(Boolean): whether the property can be exported. defaults: undefined- if
undefined
then=enumerable isn't false and the first char isn't "$"
- if
alias
(String|ArrayOf String): add the alias(es) to the property. It used via assignment from options.clone
(Boolean): Whether clone default property value if the value is an object when initializing. defaults to true.skipDefault
(Boolean): Whether to skip default values when exporting. defaults to true.
'$attributes': {
'attrName': {
name: 'exportedName',
value: 123,
enumerable: false,
type: 'String',
configurable: true,
writable: true,
assign: function(value, dest, src, name)
get: ...,
set: ....
}
}
Or inject it as an ability
these methods will be added(replaced):
initialize(options)
: overwrite this for assign options from constructor?- apply the initialized value of the properties to the object if possible.
- then call
assign
method.
assign(options)
: assign the options' attributes to this object.- how to decide which attribute should be assign?
- I need an attributes manage class? or just a simple attributes list?
- or define all attributes even the value is null when initialize
- this must be an optional feature.
assignPropertyTo(dest, options, attributeName, value)
: assign an attribute to dest.- you can override it to determine howto assign an object value.
assignProperty(options, attributeName, value)
: assign an atrribute. called byassign
assignTo(dest)
: assign the attributes to thisdest
object.mergeTo(dest)
: merge the attributes itself todest
object.- do not overwrite the already exist attributes of the
dest
.
- do not overwrite the already exist attributes of the
isSame(obj)
: compare theobj
's attributes whether is the same value with itself.clone(options)
: create a new object with the same attributes' value.toObject(options)
: convert it as plain object.- do not export the non-enumerable attributes or beginning with '$'
- do not export the attribute's value is null
- do not export the attribute's value is default value.
- where to get the default value?
toJSON()
: this will call thetoObject()
to return.
Note: you should specify the position of the argument if the first argument is not the options
Usage
Make your class manage the properties
there are three ways to make your class manage the attributes.
- Class inherits from
- inherits from PropertyManager directly.
- Ability to hook on any class
- You need confirm these method names are not be used.
The
$attributes
is used via normal and advance PropertyManager. thenonExported1stChar
is used to change the first char of non-exported property, defaults to '$'. It must be exist. The first four methods must be exist. others are optional. But be care of their dependencies.- $attributes (unless use simple PropertyManager)
- nonExported1stChar
- assign
- assignPropertyTo
- getProperties
- defineProperties
- clone (optional)
- mergeTo
- initialize (optional)
- getProperties
- assign
- assignProperty (optional)
- assignPropertyTo
- mergeTo (optional)
- getProperties
- assignPropertyTo
- exportTo (optional)
- mergeTo
- assignTo (optional)
- getProperties
- assignPropertyTo
- toObject (optional)
- exportTo
- toJSON (optional)
- toObject
- isSame (optional)
- mergeTo
- You need confirm these method names are not be used.
The
- Decorator: property-manager-decorator
Class Inherits
there are three PropertyManager class to use, the default is NormalPropertyManager
.
// var inherits = require('inherits-ex/lib/inherits');
// var PropertyManager = require('property-manager');
// var PropertyManager = require('property-manager/lib/normal');
// var SimplePropertyManager = require('property-manager/lib/simple');
// var AdvancePropertyManager = require('property-manager/lib/advance');
import {inherits} from 'inherits-ex'
import {SimplePropertyManager, NormaPropertyManager, AdvancePropertyManager} from 'property-manager'
const ProperManager = NormaPropertyManager
//# Only for Normal or Advance PropertyManager
var defineProperties = ProperManager.defineProperties
class MyClass extends ProperManager {
constructor(name, options) {
super()
this.name = name
// if you use the SimplePropertyManager
// you should define your properties here:
//this.defineProperties({
// 'attr1': {value:123}
// 'hidden': {value:1, enumerable: false},
// '$dontExport': {value:3, enumerable: true}
//})
// initialize ProperManager
this.initialize(options)
}
}
/*
function MyClass(name, options) {
this.name = name;
// if you use the SimplePropertyManager
// you should define your properties here:
//this.defineProperties({
// 'attr1': {value:123}
// 'hidden': {value:1, enumerable: false},
// '$dontExport': {value:3, enumerable: true}
//})
PropertyManager.call(this, options);
}
inherits(MyClass, PropertyManager);
*/
// Only for normal and advance property manager
defineProperties(MyClass, {
'attr1': {value:123},
'hidden': {value:1, enumerable: false},
'$dontExport': {value:3, enumerable: true},
'custom': {
value: {},
assign: function(value, dest, src, name) {
if (value == null) {
value = {};
}
value.exta = 123;
return value;
}
}
});
/*
function MyClassEx() {
MyClassEx.__super__.constructor.apply(this, arguments)
}
inherits(MyClassEx, MyClass);
*/
class MyClassEx extends MyClass {}
// Inherited properties from MyClass
defineProperties(MyClassEx, {'extra': {value: 'extra'}});
Ability to hook on any class
Inject PropertyManger ability into any class via the PropertyAbility
function.
PropertyAbility(target:Function|Object, options?)
If there is no parameter then it is the default normal
property manager.
options:
name
:{'simple' | 'advance' | 'normal' | 'abstract'}
Selected PropertyManger, defaultnormal
optionsPosition
:{number}
, optional attribute option parameter position, used when the constructor needs to import Json object attributes.exclude
:{string[]}
A list of attribute capability method names that do not need to be injected, the default is empty.
// var PropertyAbility = require('property-manager/ability');
import {PropertyAbility} from 'property-manager'
class MyClass {
constructor(name, options) {
// if you use the SimplePropertyManager
// you should define your properties here:
//this.defineProperties({
// 'attr1': {value:123}
// 'hidden': {value:1, enumerable: false},
// '$dontExport': {value:3, enumerable: false}
//})
this.name = name;
// initialize PropertyManager
this.initialize.apply(this, arguments);
}
}
/*
function MyClass(name, options) {
// if you use the SimplePropertyManager
// you should define your properties here:
//this.defineProperties({
// 'attr1': {value:123}
// 'hidden': {value:1, enumerable: false},
// '$dontExport': {value:3, enumerable: false}
//})
this.name = name;
this.initialize.apply(this, arguments);
}
*/
// add the property manager ability to MyClass
// the default is normal property manager
// PropertyAbility(MyClass)
// you can specified the property manager 'simple', 'advance', 'normal':
// PropertyAbility(MyClass, 'simple')
// PropertyAbility(MyClass, {name: 'simple'})
// and you can specified the options position in the arguments
// the first argument(arguments[0]) is `name`, and the second(arguments[1]) is the options
PropertyAbility(MyClass, {optionsPosition: 1});
// you can exclude some non-core methods:
//PropertyAbility(MyClass, {optionsPosition:1, exclude: ['assignTo', ...]})
// You can define your properties here to:
var defineProperties = MyClass.defineProperties;
//only for normal, advance property manager
defineProperties(MyClass, {
'attr1': {value: 123},
'hidden': {value: 1, enumerable: false},
'$dontExport': {value: 3, enumerable: true},
'date': {
assign(value, dest, src, name, {isExported}) {
let result;
if (isExported) {
result = value.toISOString()
} else if (!(value instanceof Date)) {
result = new Date(value)
}
return result;
}
},
'custom': {
value: {},
assign: function(value, dest, src, name, opts) {
if (value == null) {
value = {};
}
value.exta = 123;
return value;
}
}
});
class MyClassEx extends MyClass {}
/*
function MyClassEx() {
MyClassEx.__super__.constructor.apply(this, arguments)
}
inherits(MyClassEx, MyClass);
*/
// Inherited properties from MyClass
defineProperties(MyClassEx, {'extra': {value: 'extra'}});
Use the attributes
It's very simple, and it is no different from the use of ordinary object properties. Defining properties is also similar to Object.defineProperties
.
Now the MyClass
class should have these attributes:
attr1
: can be exported and assignedhidden
: can not be exported and assigned$dontExport
: can be assigned, can not be exported.date
: can be exported and assignedcustom
: can be exported and assigned, the value be changed byassign
function in the property descriptor.
the MyClassEx
inherits from MyClass
(NOTE: only for normal or advance property manager)
extra
: can be exported and assigned.- others inherited from
MyClass
var assert = require('assert');
var my = new MyClass('aName', {
attr1: 3,
hidden: 11222,
$dontExport: 1,
custom: {
b: 12
}
});
assert.deepEqual(my.mergeTo(), {
attr1: 3,
$dontExport: 1,
custom: {
b: 12,
exta: 123
}
});
// the `hidden` can not be assigned and exported
assert.equal(my.hidden, 1);
// the `$dontExport` can not be exported
assert.deepEqual(my.toObject(), {
attr1: 3
});
assert.equal(JSON.stringify(my), '{"attr1":3,"custom":{"b":12,"exta":123}}');
var obj = my.clone();
// compare each assigned properties.
assert.ok(obj.isSame(my));
assert.deepEqual(obj.mergeTo(), {
attr1: 3,
$dontExport: 1,
custom: {
b: 12,
exta: 123
}
});
var myEx = new MyClassEx('theClassEx', {attr1: 3, hidden:11222, $dontExport: 1, custom:{b:12}})
assert.deepEqual(myEx.mergeTo(), {extra:'extra', attr1:3, $dontExport:1, custom:{b:12, exta: 123}})
API
Changes
More recent changes see: CHANGELOG.md
v2
- ES6 Class
- ESM support
- NodeJS >= 8
v1.4.0
- feat: add the readonly to smart assigned property
@Properties
class Phone extends AdvancePropertyManager {
@Prop({
writable: false,
exported: true,
assigned: '',
}) id!: string;
}
- BROKEN CHANGE: DO NOT EXPORT the readonly property by default unless exported is true.
@Properties
class Phone extends AdvancePropertyManager {
@Prop({
writable: false,
exported: true,
}) id!: string;
}
v1.0.0
- add the array with type supports.
import { arrayOf } from 'property-manager/lib/array';
import AdvancePropertyManager from 'property-manager/lib/advance';
import { PropertyManager as Properties, Property as Prop } from 'property-manager-decorator';
@Properties
class Phone extends AdvancePropertyManager {
@Prop() value!: string;
@Prop() codeNum!: string;
@Prop() kind!: string;
constructor(initValue?) {
super(initValue);
}
}
@Properties
class Contact extends AdvancePropertyManager {
@Prop({type: String}) name!: string;
@Prop({type: arrayOf(Phone)}) phones!: Phone[];
constructor(initValue?) {
super(initValue);
}
}
- BROKEN change
toObject
method params to(options?: IMergeOptions)
- BROKEN change
assign
method params to(src, options?: IMergeOptions)
- BROKEN change
assignTo
method params to(dest, options?: IMergeOptions)
- BROKEN change
assignPropertyTo
andassignProperty
method params to(dest, src, name: string, value, attrs?, options?: IMergeOptions)
- BROKEN change
exportTo
method params to(dest, options?: IExportOptions)
- BROKEN change
mergeTo
method params to(dest, options?: IMergeOptions)
- add
skipNull
andskipUndefined
option toIExportOptions
andIMergeOptions
- add
- add the
extends(attrs: Object, nonExported1stChar)
method to theProperties
- return a new
Properties
instance to extends properties from current instance.
- return a new
- add the inherited properties supports for
AdvancePropertyManager.defineProperties
- change the
recreate
argument default value ofdefineProperties
tofalse
forAdvancePropertyManager
andNormalPropertyManager
- set all methods and non-properties of
Properties
to be non-enumerable.
v0.13.0
- add typed property for
AdvancePropertyManager
andNormalPropertyManager
function CustomType(value) {
if (!(this instanceof CustomType)) return new CustomType(value)
try {
value = JSON.parse(value)
} catch(err) {
this.value = value
}
}
const attrs = {
prop1: {type: CustomType, value: 111}
}
class TypedPM extends AdvancePropertyManager {
constructor(opts) {
super(opts)
}
}
TypedPM.defineProperties(attrs)
const obj = new TypedPM()
console.log(obj.prop1 instanceof CustomType)
v0.11.0
- add the
skipExists
option to theProperties.assignTo
andProperties.assignPropertyTo
- the options to the
Properties.assignTo(dest, src, options)
exclude
(String|Array)skipDefault
(Boolean)skipExists
(Boolean)skipReadOnly
(Boolean)exported
(Boolean)
v0.10.0
- add the alias property descriptor(Normal&Advance):
- You can define one or more aliases to assign from other object(options)
alias
(String|ArrayOf String)
- Smart assignment property supports(AdvancePropertyManager):
- broken: SMART_ASSIGN constant deprecated.
assigned
descriptor (Boolean|String):String
means SMART_ASSIGN.- it's the internal property name of the smart assignment if it's string
- the internal property name is the property name with prefix(
nonExported1stChar
) if it's an empty string
- broken: remove
attrsName
property(fixed to '$attributes')
- add the helper function: properties/define-properties.
v0.9.0
- clone default property value if the value is an object when initializing
- the object instances will share the same one of property value if the default value of property is an object.
- howto create a new object instance when initializing default value.
- Solution 1: the
value
descriptor could be a function to create new object instance:- Problem1: it will be only available for normal and advance property manager
value: function (){return Object.create()}
- Problem2: the value can not be a function now.
- Problem1: it will be only available for normal and advance property manager
- Solution 2: check the value whether is object. if so, clone it when initializing.
- use this solution. but if someone wish all instance share the same value.
- add a descriptor to control whethe enable this. but simple can not support the custom descriptor.
clone
(Boolean): defaults to true.
- the object instances will share the same one of property value if the default value of property is an object.
- Smart assignment property supports:
- assign property descriptor (Function(value, dest, src, name)):
- It only used to assign the options from another object.
- It's no effect if the assign the property individually. should use the property descriptor
set
to do so. - maybe I should wrap it:
- add a hidden internal property with prefix(
nonExported1stChar
) - add descriptor
get
function to read the property - add descriptor
set
function to assign the property(call theassign
descriptor).
- add a hidden internal property with prefix(
- need a descriptor to control whethe enable this.
assigned
: AdvancePropertyManager::SMART_ASSIGN = 2
- enabled:
!get and !set and assigned is AdvancePropertyManager::SMART_ASSIGN
- only available for advance property manager.
- note: only
value
argument is passed intoassign
descriptor when assignment the property individually.
- assign property descriptor (Function(value, dest, src, name)):
v0.8.0
- add the property writable check: do not assign the readonly property.
- Normal, Advance
- add the
assigned
,exported
(Boolean) to property descriptor directly.assigned
: enumerable isnt false and (writable isnt false or isFunction(set)).exported
: enumerable isnt false and the first char isnt "$"
- add the
PropertyManager::nonExported1stChar
(Char), defaults to '$'- note: the
exported
descriptor is higher prior thannonExported1stChar
.
- note: the
nonExported1stChar
option to the property manager ability.
v0.7.0
- broken the arguments order of assign function in property descriptor are changed:
- attr.assign(value, dest, src, name, opts) instead of assign(dest, src, value, name)
License
MIT