@iceylan/restorm
Advanced tools
Provides a robust interface for managing access to RESTful resources in JavaScript.
Restorm is a lightweight JavaScript library designed to streamline the process of handling RESTful services within client-side applications. With Restorm, we can easily model data on the client side and interact with RESTful APIs by adhering to predefined rules and conventions.
This library simplifies the communication process between the client and server, abstracting away the complexities of HTTP requests and allowing developers to focus on building robust, scalable applications. Whether you're fetching data, creating new resources, or updating existing ones, Restorm provides a well known interface for performing CRUD operations while ensuring compliance with RESTful principles.
With its intuitive design and flexible configuration options, Restorm empowers developers to efficiently integrate RESTful services into their JavaScript applications, enhancing productivity and promoting best practices in web development.
To install Restorm, you can use npm:
npm install @iceylan/restorm
Set up on src/models.
// base-model.js
import { Model } from "@iceylan/restorm";
export default class BaseModel extends Model
{
baseUrl = "https://yourdomain.com/api/v1.0";
}
// post.js
import { BaseModel } from ".";
export default class Post extends BaseModel
{
resource = "posts";
}
After preparing our models, we can create RESTful requests with them.
There are two ways to get a list of resources.
all - Get all resources as collection under any circumstance.get - Get all resources as collection or a single resource model.The all method creates a request to access all resources under the root directory of endpoint.
It will make sure that even the response has only one resource, the resolved promise will be fulfilled with a collection and that collection will be filled with instance(s) of the model(s).
If the response is empty, the promise will be fulfilled with an empty collection.
const posts = await Post.all();
GET /api/v1.0/posts
We can safely use Collection and Array specific methods on the result.
const latestPostTitle = posts.map( post => post.title ).last();
If we are sure that the endpoint is kind of a multiple resource returner or we are aware that we should have to deal with the results either as a collection or a single model then we can use get method.
The method will detect the returned resource's type and returns a promise that will be fulfilled with an instance of collection of models or an instance of model.
import { Collection } from "@iceylan/restorm";
const result = await Post.where( conditions ).get();
if( result instanceof Collection )
{
result.forEach( post =>
console.log( post.id )
);
}
GET /api/v1.0/posts
The Collection extends native Array. So we can say that collections a specialized type of array. We will learn more about it in the next sections.
We could easily use Array approach as well to accomplish the same result.
if( Array.isArray( result ))
{
result.forEach( post =>
console.log( post.id )
);
}
There are three methods that enable us to obtain a single resource.
first - Get the first resource in a resource collection.find - Find a specific resource based on the primary key.get - Get all resources as collection or a single resource model.The first method creates a request to the root directory of resources with filtering criteria, and it requests the first item of the results found.
The returned promise will be fulfilled with an instance created from the Post model.
const post = await Post.first();
GET /api/v1.0/posts?limit=1
The find method creates a request to access a resource under the root directory of resources using a primary key.
const post = await Post.find( 1 );
GET /api/v1.0/posts/1
The get method creates a request to access all resources under the root directory of restful endpoint with filtering criteria. The results may be a single resource or an array of resources.
get will autodetect the returned resource type and return a promise that will be fulfilled with an instance of the model or collection of models.
const result = await Post.where( conditions ).get();
if( result instanceof Post )
{
console.log( result.title );
}
GET /api/v1.0/posts
The with method is used to include related resource to a model. This process is known as eager loading. We can provide as many relationship names as arguments to the method or as an array.
We can directly include a related resource by its name to the model:
const posts = await Post
.with( "comments", "author" )
// or
.with([ "comments", "author" ])
.all();
GET /api/v1.0/posts?with=comments,author
With that, the API endpoint will return the posts with their comments and authors.
Even including nested relationships is possible. That means we can include the related resources of the related resources and so on.
const posts = await Post.with( "author", "comments.author" ).all();
GET /api/v1.0/posts?with=author,comments.author
The API endpoint should return the following response:
[
{
"id": 1,
"post": "lorem ipsum",
"author":
{
"id": 1,
"name": "John Doe"
},
"comments":
[
{
"id": 1,
"comment": "lorem ipsum",
"author":
{
"id": 1,
"name": "Jane Doe"
}
}
]
}
]
To list specific resources, we add filters with where and various methods like whereNull, whereNotNull, whereBetween, whereNotBetween, whereIn, whereNotIn to accomplish this.
All the alternative methods listed above are implemented by where method under the hood.
where method has 3 arguments. target, operator and filter. The first one is the name of the field, the second one is the operator and the third one is the filtering criteria. The operator is an optional one.
We can directly filter represented resources by models:
const articles = await Post.where( "type", "article" ).all();
GET /api/v1.0/posts?filter[type]=eq:article
If no operator is specified, the given criteria value type will be checked. If the given value is an array, the operator will be assumed as in and the filtering attempt will be transformed into a whereIn. If the given value is not an array, the operator will be assumed as equal and items that match exactly the given value will be filtered out.
These three filters are equal to each other:
Post.where( "type", "article" );
Post.where( "type", "=", "article" );
Post.where( "type", "equal", "article" );
These are also equal to each other:
Post.where( "id", [ 10, 20, 30 ]);
// or more explicitly
Post.where( "id", "in" [ 10, 20, 30 ]);
// or with the dedicated method
Post.whereIn( "id", [ 10, 20, 30 ]);
Restorm supports the following comparison operators in the where methods:
| Operator | Alternative | Encapsulating Method | Description |
|---|---|---|---|
equal | = | where | match exactly |
notequal | != <> | where | don't match the given value |
less | < | where | smaller than the given value |
great | > | where | greater than the given value |
lesseq | <= | where | equal or smaller than the given value |
greateq | >= | where | equal or greater than the given value |
between | >< | where whereBetween | fall between two given values |
notbetween | >!< | where whereNotBetween | don't fall between two given values |
in | ... | where whereIn | match exactly with the given multiple values |
notin | .!. | where whereNotIn | don't match with the given multiple values |
like | ~ | where | match if the given value containing |
notlike | !~ | where | don't contain the given value |
null | =n | where whereNull | match if it's empty |
notnull | !n | where whereNotNull | don't match if it's not empty |
If the related resource that we included in by with method is kind of multiple (i.e., one-to-many), for example comments of a post, we can also indirectly add filters to these sub-resources (comments) to reduce the returned results.
const articles = await Post
.where( "type", "article" )
.with( "comments" )
.where( "comments.state", "approved" )
// or
.where([ "comments", "state" ], "approved" )
.all();
GET /api/v1.0/posts?with=comments&filter[type]=eq:article&filter[comments.state]=eq:approved
We could also use operators with them.
Post.where( "comments.state", "notin", [ "owner-removed", "banned" ]);
// or with dedicated method
Post.whereNotIn( "comments.state", [ "owner-removed", "banned" ]);
GET /api/v1.0/posts?filter[comments.state]=nin:owner-removed,banned
With that filter, we could get all the comments that if their state not owner-removed and not banned.
We can perform these operations in a more organized and concise manner through object syntax, providing a cleaner and more streamlined usage. For example, if we are using something like vue.js or react.js, we can manage operations on reactive objects and directly pass this object to the where method.
const conditions =
{
type: "article",
"comments.state": "approved"
// or
[ relationName + "." + fieldName ]: "approved",
// or
comments:
{
state: "approved"
},
}
const articles = await Post.with( "comments" ).where( conditions ).all();
GET /api/v1.0/posts?with=comments&filter[type]=eq:article&filter[comments.state]=eq:approved
As you noticed, we doesn't have a way to apply operators on object syntax currently. The operator is defaultly assumed to be equal for the object syntax. Maybe we can improve it in the future.
We can also add multiple values for a filter.
const posts = await Post.where( "type", [ "article", "news" ]).get();
This request will get all the posts of the article and news types.
GET /api/v1.0/posts?filter[type]=in:article,news
The orderBy method is used to obtain results sorted by a specific field of resource.
We can directly subject a model to sorting like this:
const posts = await Post.orderBy( "updated_at", "desc" ).get();
GET /api/v1.0/posts?sort[updated_at]=desc
We may also want to sort on two different fields simultaneously.
const posts = await Post
.orderBy( "updated_at", "asc" )
.orderBy( "created_at", "desc" )
.get();
GET /api/v1.0/posts?sort[updated_at]=asc&sort[created_at]=desc
We can also subject the related model to the sorting process.
const posts = await Post
.with( "comments.replies" )
.orderBy( "comments.id", "desc" );
// or with array syntax
.orderBy([ "comments", "id" ], "desc" );
// or we can go further and sort on nested relationships
.orderBy( "comments.replies.created_at", "desc" );
.all();
GET /api/v1.0/posts?with=comments.replies&sort[comments.id]=desc&sort[comments.replies.created_at]=desc
We can use object syntax to organize sorting operations.
const sorting =
{
updated_at: "desc",
created_at: "asc",
"comments.id": "desc",
// or
[ relationName + "." + fieldName ]: "desc",
// or
comments:
{
id: "desc",
replies:
{
created_at: "desc"
}
}
}
const posts = await Post.with( "comments" ).orderBy( sorting ).get();
GET /api/v1.0/posts?with=comments&sort[updated_at]=desc&sort[created_at]=asc&sort[comments.id]=desc&sort[comments.replies.created_at]=desc
The select method is used to select specific fields from the model.
const posts = await Post.select([ "id", "title", "author_id" ]).get();
GET /api/v1.0/posts?field[]=id,title,author_id
We can also select fields from the related resources. First argument of the select method is the name of the related resource. We can provide relation name as a string with dot notation or as an array and the field names should be provided as an array.
const posts = Post
.select( "comments", [ "id", "author_id", "comment" ])
.select([ "comments", "author" ], [ "id", "username" ])
// or
.select( "comments.author", [ "id", "username" ])
.get();
GET /api/v1.0/posts?field[comments]=id,author_id,comment&field[comments.author]=id,username
We can use object syntax to organize field selection operations. To select fields directly from the model, we should define an empty key or relation name as a key and provide an array of fields to selected as the value.
const selections =
{
// resource fields
"": [ "id", "title", "author_id" ],
// related resource fields
comments: [ "id", "author_id", "comment" ],
// deeply related resource fields
"comments.author": [ "id", "username" ],
// or
comments:
{
author: [ "id", "username" ]
}
}
const posts = Post.select( selections ).all();
GET /api/v1.0/posts?field[]=id,title,author_id&field[comments]=id,author_id,comment&field[comments.author]=id,username
Pagination is a process of dividing a large set of data into smaller and more manageable chunks. Restorm provides basic and advanced pagination support.
We can accomplish this process manually by using the page and limit methods. With two of these methods, we can get the desired paginated results.
So, let's see how we can use these methods.
The page method is used to specify the page number.
const posts = await Post.page( 2 ).all();
GET /api/v1.0/posts?page=2
The limit method is used to specify the number of items per page.
const posts = await Post.limit( 10 ).all();
GET /api/v1.0/posts?limit=10
If the limit value we are going to use is the same most of the time, we can define it in the model instead of using the limit method every time.
class Post extends BaseModel
{
itemsPerPage = 10;
}
const posts = await Post.all();
GET /api/v1.0/posts?limit=10
We defined a default limit on Post level. The query would give us the first 10 posts.
const [ firstPage, secondPage ] = await Promise.all(
[
Post.page( 1 ).all(),
Post.page( 2 ).all()
]);
GET /api/v1.0/posts?limit=10&page=1
GET /api/v1.0/posts?limit=10&page=2
We requested the first and second page and got the first and second 10 posts simultaneously.
As you realized, we paginated resources without knowing the total number of items and pages. It's kind of a blind process but more performant than if we knew them upfront.
The paginate method can handle the pagination process that we have been doing manually and adds some extra features to it.
This method returns a LengthAwarePaginator instance which it extends our Collection class. We will see soon what collections can do but for now, that makes it an advanced collection that can be used to get the total number of items, current page, items per page, total number of pages, request the next page with ease and of course get the items.
const paginator = await Post.paginate();
GET /api/v1.0/posts?limit=10&page=1&paginate=length-aware
The LengthAwarePaginator has a property named page which holds a Page instance. If the Rest API that we are requesting has included pagination metadata in its responses, this information is abstracted with the Page class, and we can access it through the paginator.
Let's now explore what these useful pagination information are.
The currentPage property holds the current page number.
const { currentPage } = paginator.page;
The from property holds the starting item number.
const { from } = paginator.page;
The lastPage property holds the last page number.
const { lastPage } = paginator.page;
The perPage property holds the number of items per page.
const { perPage } = paginator.page;
The to property holds the ending item number.
const { to } = paginator.page;
The total property holds the total number of items.
const { total } = paginator.page;
The end property is a flag that indicates if the pagination is at the end and there are no more items to be fetched. It's a read-only property. The value of this property is calculated from the currentPage and lastPage properties.
const { end } = paginator.page;
Nowadays, RESTful APIs can provide various types of pagination metadata depending on the frameworks, libraries, and who created the API. The Page class normalizes this metadatas into a consistent format. But we need to specify which information corresponds to which attribute and distribute them properly.
We achieve this by defining a static method called $pluckPaginations on our models. Restorm invokes this method by passing the body of the response sent by the Restful API and the Page instance through the argument tunnel. We should then use these objects to ensure the necessary distribution.
For example, while our post data may be provided through Django and user data may be powered by Laravel. In those kind of cases, we can define the mentioned function individually in the Post model and the User model. Otherwise if all the data is being fed by the same framework, we can write it once in the BaseModel.
// models/base-model.js
import { Model } from "restorm";
class BaseModel extends Model
{
static $pluckPaginations( page, responseBody )
{
page.currentPage = responseBody.current_page;
page.lastPage = responseBody.last_page;
page.perPage = responseBody.per_page;
page.total = responseBody.total;
page.from = responseBody.from;
page.to = responseBody.to;
}
}
Paginators allows us to query the next page of resources that we are currently working on. We can do this by calling the next method on the paginator instance.
There is no need to track the current page number, increase it etc. as Restorm will handle this for us.
Additionally, Restorm keeps track of whether requests have been completed or not. When the next method is called, if there is still a pending request awaiting response, the call is ignored. We don't need to deal with such matters.
await paginator.next();
paginator.forEach( post =>
console.log( post.title )
);
GET /api/v1.0/posts?limit=10&page=2&paginate=length-aware
We used same paginator instance to access fetched resources as models placed on it.
Sometimes, we might want to add a constraint to our query. To do this, we can use the when method. The first argument is a boolean expression, and the second is a callback function. The callback will receive query builder instance and the condition flag's value as arguments.
The main advantage of using when method is that it allows us to keep querying in a single line without breaking the chain. Otherwise, we would have to use if-else statements and add more lines.
const posts = await Post
.when( getUserId(), ( query, userId ) =>
query.where( "author_id", userId )
)
.all();
function getUserId()
{
if( something )
{
return 481516;
}
else
{
return null;
}
}
GET /api/v1.0/posts?filter[author_id]=eq:481516
You have to be careful with falsy values. For example, if you pass 0 as an user ID, it will be considered as false, and the constraint block won't be executed, even though it should by your perspective.
Sometimes, we might want to pass additional parameters to the query that restorm doesn't handle explicitly.
To do this, we can use the params method. It accepts an object of additional parameters. We should pass all the parameters that we want to pass to the query at once.
const params =
{
foo: "bar",
do: true,
some: [ "good", "bad", "ugly" ]
}
const posts = await Post.params( params ).get();
GET /api/v1.0/posts?foo=bar&do=true&some=good,bad,ugly
If we want to use a custom resource, we can do it by using the from method.
With this method, we can bypass the current resource defined on the model and create requests to a custom resource temporarily.
We can specify the resource name directly as a string.
const posts = await Post.from( "timeline" ).all();
GET /api/v1.0/timeline
All the items in the returned collection will be instance of Post model.
Sometimes, we might want to extend the current resource some additions. To achieve this, we can use the from method with a callback function. Restorm will pass the current resource as the first argument to the callback function. We should return calculated resource back from the callback function.
const posts = await Post
.from( resource => resource + "/most-popular-of-the-month" )
.all();
GET /api/v1.0/posts/most-popular-of-the-month?limit=10
Sometimes, we might want to build dynamic resource URIs depending on some model instances that we have already.
const post = new Post({ id: 48 });
const comment = new Comment({ id: 4815, post_id: post.id });
const reactions = await Reaction.from( post, comment, "reactions" ).all();
GET /api/v1.0/posts/48/comments/4815/reactions
In real world, reactions would belong to posts, comments, and even personal messages. Defining a static resource name in the model wouldn't work in this case. This is where the from method shines.
Restorm provides a set of methods that allow us to perform CRUD operations on RESTful resources, and we have seen above how to handle the (R)ead side by get, all, find, first methods.
So let's see how to perform (C)reate, (U)pdate and (D)elete operations.
On HTTP protocol, a resource creation should be performed by sending a POST request to the RESTful api endpoints.
We designed a few alternative ways to create resources.
First, we can create resources as model instances and send them.
const title = "Elon Musk went to the Moon instead of Mars";
const content = "Yeah! You heard right, he did just like that! Unbelievable.";
const draft = new Article({ title });
// and we can assign missed properties later to the model
draft.content = content;
const article = await draft.post();
// or
const article = await draft.save();
if( article instanceof Error )
{
console.log( "network or server errors", article );
}
The post method returns a promise that will be fulfilled with an instance of Article model or an Error if there is an issue about the network or server side. The Restorm won't throw any network or server errors. That means you can't catch them with async-await & try-catch or then-catch mechanism. Restorm will supress throwing all the HTTP errors with 400 and 500 status codes and network errors as well.
If you want to handle these kinds of errors, you can add event listeners to your queries or models, or you can handle them manually at that very moment when they are returned by the post method.
If Restorm detects issues with the usage of its methods, it will throw an error and stop your application. You shouldn't catch and handle these kind of errors manually or suppress them; you need to resolve and eliminate them.
Let's go back the examples. We could also statically use the post method.
const newArticle = await Article.post(
{
title: "Elon Musk went to the Moon instead of Mars",
content: "Yeah! You heard right, he did just like that! Unbelievable."
});
console.log( newArticle.id );
// 1
POST /api/v1.0/articles
The result should look like this:
{
"id": 1,
"title": "Elon Musk went to the Moon instead of Mars",
"content": "Yeah! You heard right, he did just like that! Unbelievable."
}
The post method is very self-explanatory, it just sends a POST request to the api endpoint but the save method has something magical behind it.
If the primary key (id in this case) is not set on the model instance like the example above, it will send a POST request, otherwise it will send a PATCH request. We will see that in the next sections.
We can update an existing resource by sending a PATCH or PUT request to api endpoints.
As you know already the PUT is used to update an existing resource as a whole. That means, missing properties should convert to null or default values on the database.
The PATCH on the other hand, is used to update only some of the properties of the resource and missing properties will be stay as they are. This is what makes PATCH lightweight compared to PUT.
Restorm smart enough to know which properties of the model you modified and that gives us an opportunity to send always a lightweight PATCH request instead of a PUT.
const article = await Article.find( 1 );
article.title = "Jeff Bezos went to the Moon instead of Mars";
await article.save();
// or more explicitly
await article.patch();
PATCH /api/v1.0/articles/1
And the resource will be like:
{
"id": 1,
"title": "Jeff Bezos went to the Moon instead of Mars",
"content": "Yeah! You heard right, he did just like that! Unbelievable."
}
The save method will send a PATCH request if the case is about updating an existing resource. However, sometimes we really want to send a PUT request. We can do that by using the put method of Restorm.
const state =
{
title: "Jeff Bezos went to the Moon instead of Mars"
}
// we can request the resource as a model from the endpoint
const article = await Article.find( 1 );
// or we can bake the model manually without `GET` request
// if we sure that the resource exists remotely
const article = new Article({ id: 1 });
// and we can send a `PUT` request for a model
await article.put( state );
// or shortly we can use static syntax
await Article.put( 1, state );
PUT /api/v1.0/articles/1
And the resource should be like:
{
"id": 1,
"title": "Jeff Bezos went to the Moon instead of Mars",
"content": null
}
Restorm provides an event management system to handle network errors, server errors and internal events.
We can bind event listeners to our queries, models or model instances. Events are kind of hooks that will be triggered when certain events happen.
Since Restorm have this mechanism, it doesn't need to throw network and server errors. Restorm only throws runtime errors. So that means network errors and 400-500 errors will be suppressed and won't stop the application. We should grab and handle them manually.
We can register our listeners with on method.
Multiple event listeners can be added for a single event. The bound event listeners will be executed in the order they were bound when the event occurs.
const post = await Post.on( "failed", gettingPostFailed ).find( 1 );
const another = await Post.find( 2 );
function gettingPostFailed( err )
{
console.log( err )
}
Note that if the on method on the models called statically just like the above, it will create a QueryBuilder instance internally, binds the event listener we passed to it and returns query builder instance.
The event listeners that bound to a QueryBuilder will be effective only for that specific query builder instance.
The first query will print the error object in the console when the api endpoint returns an 400, 500 http status code or a network error happens. But the second query won't log anything even if it has an error because it's running on a different query builder instance and we didn't bind any event listener to it.
We can easily remove the event listeners by using off method but we should extract the QueryBuilder instance when using static methods of a models.
const query = Post.on( "failed", gettingPostFailed );
const post = await query.find( 1 );
query.off( "failed", gettingPostFailed );
const anotherPost = await query.find( 2 );
Even if the second attempt has an error, it won't be logged because we unbound the event listener from it.
We can also make event listeners to execute only once by using once property while we bind the event.
const post = await query
.on( "failed", gettingPostFailed, { once: true })
.find( 1 );
// or
const post = await Post
.on( "failed", gettingPostFailed, { once: true })
.find( 1 );
As you know already, Restorm transforms remote resources into Model instances. We also can bind event listeners to any model instance.
const post = await Post.find( 1 );
// we can make changes step by step
post.title = "Lorem ipsum";
post.on( 304, postNotModified );
await post.patch();
// we can remove the event listener
post.off( 304, postNotModified );
function postNotModified( post, response, data )
{
console.log ( post );
// this word refers to QueryBuilder instance
console.log( this );
}
This time, the on method is not static. It operates on the context of the model that represents the resource and every model has its own query builder instance. It will bind the event listener we provided to the query builder that under the hood and return the model's itself, so we can chain. After that, patching happened over the same QueryBuilder instance.
We removed the event listener by using off method right after the patch request complete. But we could also use once property to make event listener to run only once. With that we couldn't need to unbind the event listener manually.
We could write same code more compactly like this:
await ( await Post.find( 1 ))
.on( 304, console.log, { once: true })
.patch({ title: "Lorem ipsum" });
That would send two requests to the server. To reduce the number of requests, we can rewrite it like this:
await Post
.on( 304, console.log, { once: true })
.patch( 1, { title: "Lorem ipsum" });
Sometimes we might want to bind event listeners for all queries to track events globally (app level).
We can define global event listeners as static methods on the models prefixed with on keyword like onFailed or onSuccess.
import { Model } from "@iceylan/restorm";
class BaseModel extends Model
{
static onFailed( err )
{
console.log( err );
// this word refers to QueryBuilder instance
console.log( this );
}
}
const post = await Post.find( 1 );
From now on, every child model of the BaseModel will inherit a listener for the failed event.
We can overwrite the event listeners in child models.
class Post extends BaseModel
{
static onFailed( err )
{
alert( err.message );
}
}
Now, all the failed queries of the Post model will be displayed in alert dialog instead of console.
If we want, we can extend parent model's event listeners instead of overwriting them.
class Post extends BaseModel
{
static onFailed( err )
{
super.onFailed( err );
alert( err.message );
}
}
Now, first, failed queries that related to the Post model will be logged to the console and then an alert dialog will be displayed.
Restorm currently doesn't support a way to explicitly removing event listeners that inherited from parent models. But at least, we can overwrite them and left it's body empty. With that way, the listener will still be there and it will be triggered but with no effect.
| Event Name | When |
|---|---|
waiting | request is initiated and waiting for the response |
success | request was successful with a status code 200-299 range |
failed | request was failed with a status code that is in the 400-599 range |
finished | request is finished, regardless of its outcome |
canceled | request is canceled by Restorm or the user before it finished |
paginated | request is finished, pagination is ready |
network-error | request failed due to a network level error |
[StatusCodes] | request is finished and the server responds with the corresponding status code. For example, if the server responds with a 404 status code, the 404 event is triggered. |
Restorm provides a structure for handling a set of model instances. We prefer to call it a collection. It extends native Array constructor. So we can say that collections a specialized type of array.
We can use all the methods that we use on arrays. But note that methods like map or filter, which return an array when used on arrays, will return a collection instead of an array since it's a collection anyway.
The all method returns a promise that will be fulfilled with a collection of model instances.
const posts = await Post.all();
Now, we have a collection that holds models baked by Restorm. Let's see what we can do with it.
We can easily grab the first item of the collection.
console.log( posts.first());
Getting the last item is easy as well as getting the first item.
console.log( posts.last());
// item or undefined
With array syntax we could use posts[ posts.length - 1 ].
We can easily check if the collection contains a specific model by using the model or its primary key.
console.log( posts.contains( post ));
// or
console.log( posts.contains( 1 ));
Of course there is no need to mention we can use native filter or find array method to do more complex analysis to check if the collection contains a specific model.
Some case we might want to take a difference between two collections. We can use the diff method to get the difference between two collections.
const items = new Collection( 1, 2, 3, 4 );
const even = new Collection( 2, 4 );
const odd = items.diff( even );
console.log( odd );
// 1, 3
Main advantage of the diff method is that it knows how to deal with models.
const posts = await Post.all();
const evenIDPosts = await Post.whereIn( "id", [ 2, 4, 6, 8 ]).all();
console.log( posts.diff( evenIDPosts ));
// [{ id: 1, ... }, { id: 3, ... }]
Two collection might contains same resources with different model instances but it didn't matter because of the diff method compares the primary keys.
Sometimes we need only a specific field from the models (or objects). We can use the pluck method to collect values of those field and get them as a brand new collection.
console.log(
posts.pluck( "title" ).last()
);
Sometimes we need to convert the collection to JSON as a whole. toJson method will do it for us.
console.log( posts.toJson());
// equivalent to
console.log( JSON.stringify( posts ));
We can easily use array methods on the collection.
For example, let's say we want to get the first 5 models from the collection. We can use slice method to achieve that.
console.log(
posts.slice( 0, 5 ).pluck( "id" )
);
// 1, 2, 3, 4, 5
As you see, slice method returns a collection.
Also, there are other array methods like sort, push, pop, shift, and unshift that mutate the array. We didn't touch that convention here. They will mutate the collection.
FAQs
Provides a robust interface for managing access to RESTful resources in JavaScript.
We found that @iceylan/restorm demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
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