Minim
A library for interacting with Refract elements.
Install
$ npm install minim
About
In working with the XML-based DOM, there is a limitation on what types are available in the document. Element attributes may only be strings, and element values can only be strings, mixed types, and nested elements.
JSON provides additional types, which include objects, arrays, booleans, and nulls. A plain JSON document, though, provides no structure and no attributes for each property and value in the document.
Refract is a JSON structure for JSON documents to make a more flexible document object model. In Refract, each element has three components:
- Name of the element
- Metadata
- Attributes
- Content (which can be of different elements depending on the element)
An element ends up looking like this:
const element = {
element: 'string',
content: 'bar'
};
Usage
Converting JavaScript Values into Elements
var minim = require('minim').namespace();
var arrayElement = minim.toElement([1, 2, 3]);
var refract = minim.toRefract(arrayElement);
The refract
variable above has the following JSON value.
{
"element": "array",
"content": [
{
"element": "number",
"content": 1
},
{
"element": "number",
"content": 2
},
{
"element": "number",
"content": 3
}
]
}
Converting Serialized Refract into Elements
Serialized Refract can be converted back to Minim elements to make a roundtrip.
var arrayElement1 = minim.toElement([1, 2, 3]);
var refracted = minim.toRefract(arrayElement1);
var arrayElement2 = minim.fromRefract(refracted);
Note that due to optional refracting in meta
, anything that looks like an element in the given serialization will be loaded as such.
Extending elements
You can extend elements using the extend
static method.
var StringElement = minim.getElementClass('string');
var NewElement = StringElement.extend({
constructor: function() {
this.__super();
},
customMethod: function() {
}
})
Element Attributes
Each Minim element provides the following attributes:
- element (string) - The name of the element
- meta (object) - The element's metadata
- attributes (object) - The element's attributes
- content - The element's content, e.g. a list of other elements.
Additionally, convenience attributes are exposed on the element:
- id (StringElement) - Shortcut for
.meta.get('id')
. - name (StringElement) - Shortcut for
.meta.get('name')
. - classes (ArrayElement) - Shortcut for
.meta.get('classes')
. - title (StringElement) - Shortcut for
.meta.get('title')
. - description (StringElement) - Shortcut for
.meta.get('description')
.
Element Methods
Each Minim element provides the following methods.
toValue
The toValue
method returns the JSON value of the Minim element.
var arrayElement = minim.toElement([1, 2, 3]);
var arrayValue = arrayElement.toValue();
toRef
The toRef
method returns a RefElement referencing the element.
var ref = element.toRef();
toRef
accepts an optional path.
var ref = element.toRef('attributes');
toEmbeddedRefract
The toEmbeddedRefract
method returns the Embedded Refract value of the Minim element.
var stringElement = minim.toElement("foobar");
stringElement.attributes.set('a', 'b');
var embedded = stringElement.toEmbeddedRefract();
equals
Allows for testing equality with the content of the element.
var stringElement = minim.toElement("foobar");
stringElement.equals('abcd');
clone
Creates a clone of the given instance.
var stringElement = minim.toElement("foobar");
var stringElementClone = stringElement.clone();
findRecursive
Recursively find an element. Returns an ArrayElement containing all elements
that match the given element name.
const strings = element.findRecursive('string');
You may pass multiple element names to findRecursive
. When multiple element
names are passed down, minim will only find an element that is found within
the other given elements. For example, we can pass in member
and string
so
that we are recursively looking for all string
elements that are found within a
member
element:
const stringInsideMembers = element.findRecursive('member', 'string');
children
The children
property returns an ArrayElement
containing all of the direct children elements.
var arrayElement = minim.toElement(['a', [1, 2], 'b', 3]);
var numbers = arrayElement.children(function(el) {
return el.element === 'number';
}).toValue();
recursiveChildren
The recursiveChildren
property returns an ArrayElement
containing all of the children elements recursively.
var arrayElement = minim.toElement(['a', [1, 2], 'b', 3]);
var children = arrayElement.recursiveChildren;
children.toValue();
Chaining
var evenNumbers = array
.recursiveChildren
.findByElement('number')
.filter((element) => element.toValue() % 2)
Minim Elements
Minim supports the following primitive elements
NullElement
This is an element for representing the null
value.
StringElement
This is an element for representing string values.
set
The set
method sets the value of the StringElement
instance.
var stringElement = minim.toElement('');
stringElement.set('foobar');
var value = stringElement.toValue()
NumberElement
This is an element for representing number values.
set
The set
method sets the value of the NumberElement
instance.
var numberElement = minim.toElement(0);
numberElement.set(4);
var value = numberElement.toValue()
BooleanElement
This is an element for representing boolean values.
set
The set
method sets the value of the BooleanElement
instance.
var booleanElement = minim.toElement(false);
booleanElement.set(true);
var value = booleanElement.toValue()
ArrayElement
This is an element for representing arrays.
Iteration
The array element is iterable if the environment supports the iteration protocol. You can then use the element in for ... of
loops, use the spread operator, yield*
, and destructuring assignment.
const arrayElement = minim.toElement(['a', 'b', 'c']);
for (let item of arrayElement) {
console.log(item);
}
get
The get
method returns the item of the ArrayElement
instance at the given index.
var arrayElement = minim.toElement(['a', 'b', 'c']);
var value = arrayElement.get(0)
getValue
The getValue
method returns the value of the item of the ArrayElement
instance at the given index.
var arrayElement = minim.toElement(['a', 'b', 'c']);
var value = arrayElement.getValue(0)
getIndex
The getIndex
method returns the item of the array at a given index.
var arrayElement = minim.toElement(['a', 'b', 'c']);
var value = arrayElement.getIndex(0)
set
The set
method sets the value of the ArrayElement
instance.
var arrayElement = minim.toElement([]);
arrayElement.set(0, 'z');
var value = arrayElement.get(0)
remove
The remove
method removes an item (specified by index) from the ArrayElement
instance.
var arrayElement = minim.toElement(['a', 'b', 'c']);
arrayElement.remove(0);
var value = arrayElement.get(0)
map
The map
method may be used to map over an array. Each item given is a Minim instance.
var arrayElement =minim.toElement(['a', 'b', 'c']);
var newArray = arrayElement.map(function(item) {
return item.element;
});
filter
The filter
method may be used to filter a Minim array. This method returns a Minim array itself rather than a JavaScript array instance.
var arrayElement = minim.toElement(['a', 'b', 'c']);
var newArray = arrayElement.filter(function(item) {
return item.toValue() === 'a'
});
reduce
The reduce
method may be used to reduce over a Minim array or object. The method takes a function and an optional beginning value.
var numbers = minim.toElement([1, 2, 3, 4]);
var total = numbers.reduce(function(result, item) {
return result.toValue() + item.toValue();
});
The reduce
method also takes an initial value, which can either be a value or Minim element.
var numbers = minim.toElement([1, 2, 3, 4]);
var total = numbers.reduce(function(result, item) {
return result.toValue() + item.toValue();
}, 10);
The reduce
method also works with objects:
var objNumbers = minim.toElement({a: 1, b:2, c:3, d:4});
var total = objNumbers.reduce(function(result, item) {
return result.toValue() + item.toValue();
}, 10);
The function passed to reduce
can accept up to five optional parameters and depends on whether you are using an array element or object element:
Array
result
: the reduced value thus faritem
: the current item in the arrayindex
: the zero-based index of the current item in the arrayarrayElement
: the array element which contains item
(e.g. numbers
above)
Object
result
: the reduced value thus faritem
: the value element of the current item in the objectkey
: the key element of the current item in the objectmemberElement
: the member element which contains key
and value
objectElement
: the object element which contains memberElement
(e.g. objNumbers
above)
forEach
The forEach
method may be used to iterate over a Minim array.
var arrayElement = minim.toElement(['a', 'b', 'c']);
arrayElement.forEach(function(item) {
console.log(item.toValue())
});
shift
The shift
method may be used to remove an item from the start of a Minim array.
var arrayElement = minim.toElement(['a', 'b', 'c']);
var element = arrayElement.shift();
console.log(element.toValue());
unshift
The unshift
method may be used to inserts items to the start of a Minim array.
var arrayElement = minim.toElement(['a', 'b', 'c']);
arrayElement.unshift('d');
console.log(arrayElement.toValue());
push
The push
method may be used to add items to a Minim array.
var arrayElement = minim.toElement(['a', 'b', 'c']);
arrayElement.push('d');
console.log(arrayElement.toValue());
find
The find
method traverses the entire descendent element tree and returns an ArrayElement
of all elements that match the conditional function given.
var arrayElement = minim.toElement(['a', [1, 2], 'b', 3]);
var numbers = arrayElement.find(function(el) {
return el.element === 'number'
}).toValue();
findByClass
The findByClass
method traverses the entire descendent element tree and returns an ArrayElement
of all elements that match the given class.
findByElement
The findByElement
method traverses the entire descendent element tree and returns an ArrayElement
of all elements that match the given element name.
getById
Search the entire tree to find a matching ID.
elTree.getById('some-id');
contains
Test to see if a collection contains the value given. Does a deep equality check.
var arrayElement = minim.toElement(['a', [1, 2], 'b', 3]);
arrayElement.contains('a');
length
Returns the amount of items in the array element.
arrayElement.length;
isEmpty
Returns whether the array element is empty.
if (arrayElement.isEmpty) {
console.log("We have an empty array");
}
first
Returns the first element in the collection.
var arrayElement = minim.toElement(['a', [1, 2], 'b', 3]);
arrayElement.first;
second
Returns the second element in the collection.
var arrayElement = minim.toElement(['a', [1, 2], 'b', 3]);
arrayElement.second;
last
Returns the last element in the collection.
var arrayElement = minim.toElement(['a', [1, 2], 'b', 3]);
arrayElement.last;
ObjectElement
This is an element for representing objects. Objects store their items as an ordered array, so they inherit most of the methods above from the ArrayElement
.
get
The get
method returns the ObjectElement
instance at the given name.
See getKey
and getMember
for ways to get more instances around a key-value pair.
var objectElement = minim.toElement({ foo: 'bar' });
var value = objectElement.get('foo')
getValue
The getValue
method returns the value of the ObjectElement
instance at the given name.
var objectElement = minim.toElement({ foo: 'bar' });
var value = objectElement.getValue('foo')
getKey
The getKey
method returns the key element of a key-value pair.
var objectElement = minim.toElement({ foo: 'bar' });
var key = objectElement.getKey('foo')
getMember
The getMember
method returns the entire member for a key-value pair.
var objectElement = minim.toElement({ foo: 'bar' });
var member = objectElement.getMember('foo')
var key = member.key;
var value = member.value;
set
The set
method sets the value of the ObjectElement
instance.
var objectElement = minim.toElement({});
objectElement.set('foo', 'hello world');
var value = objectElement.get('foo')
keys
The keys
method returns an array of keys.
var objectElement = minim.toElement({ foo: 'bar' });
var keys = objectElement.keys()
remove
The remove
method removes a key from the ObjectElement
instance.
var objectElement = minim.toElement({ foo: 'bar' });
objectElement.remove('foo');
var keys = objectElement.keys()
You can use elementa.meta.remove() or element.attributes.remove() because of this.
values
The values
method returns an array of keys.
var objectElement = minim.toElement({ foo: 'bar' });
var values = objectElement.values()
items
The items
method returns an array of key value pairs which can make iteration simpler.
const objectElement = minim.toElement({ foo: 'bar' });
for (let [key, value] of objectElement.items()) {
console.log(key, value);
}
map, filter, reduce, and forEach
The map
, filter
, and forEach
methods work similar to the ArrayElement
map function, but the callback receives the value, key, and member element instances. The reduce
method receives the reduced value, value, key, member, and object element instances.
See getMember
to see more on how to interact with member elements.
const objectElement = minim.toElement({ foo: 'bar' });
const values = objectElement.map((value, key, member) => {
return [key.toValue(), value.toValue()];
});
Namespace
Namespace Methods
toRefract
The toRefract
method returns the Refract value of the Minim element.
Note that if any element in meta
has metadata or attributes defined that would be lost by calling toValue()
then that element is also converted to refract.
var arrayElement = namespace.toElement([1, 2, 3]);
var refract = namespace.toRefract();
Customizing Namespaces
Minim allows you to register custom elements. For example, if the element name you wish to handle is called category
and it should be handled like an array:
var minim = require('minim').namespace();
var ArrayElement = minim.getElementClass('array');
minim.register('category', ArrayElement);
var elements = minim.fromRefract({
element: 'category',
meta: {},
attributes: {},
content: [
{
element: 'string',
meta: {},
attributes: {},
content: 'hello, world'
}
]
});
console.log(elements.get(0).content);
minim.unregister('category');
Creating Namespace Plugins
It is also possible to create plugin modules that define elements for custom namespaces. Plugin modules should export a single namespace
function that takes an options
object which contains an existing namespace to which you can add your elements:
var minim = require('minim').namespace();
var plugin = {
namespace: function(options) {
var base = options.base;
var ArrayElement = base.getElementClass('array');
base.register('category', ArrayElement);
return base;
}
}
minim.use(plugin);
The load
property may be used in addition to the namespace
property when a plugin is not implementing a namespace.
var minim = require('minim').namespace();
var plugin = {
load: function(options) {
return base;
}
}
minim.use(plugin);
Chaining
Methods may also be chained when using getters and setters.
var objectElement = minim.toElement({})
.set('name', 'John Doe')
.set('email', 'john@example.com')
.set('id', 4)