Alpatch

Alpatch is an Alpine.js plugin for making HTTP requests to patch application state and the DOM, similar to htmx and datastar.

Features

• 5 magic methods $get, $post, $put, $patch and $delete
• 1 directive x-alpatch
• DOM morphing with @alpinejs/morph
• Backend agnostic -- Use any server side language and templating engine
• 2.77 KB bundle size (minified + gziped)

Installation

Install via npm

npm install alpatch

Then register the plugin

import Alpine from 'alpinejs';
import Alpatch from 'alpatch';

Alpine.plugin(Alpatch);

Alpine.start();

Or use a CDN

<script defer src="https://cdn.jsdelivr.net/npm/alpatch@latest"></script>

Note: If you want to use DOM morphing you have to include the @alpinejs/morph plugin

How it works

1. Issue a request, using one of the 5 magics or the x-alpatch directive
2. Alpatch collects all values of the current scope / values of the selected form
3. Alpatch encodes those values (application/json or application/x-www-form-urlencoded) and sends a HTTP request to your backend
4. Your backend responds with an Alpatch Response
5. Alpatch receives the response and updates state, DOM and history accordingly

Usage

Fetch html from the server

<div x-data>
    <button @click="$get('/message')">Click Me!</button>
    <div id="message"></div>
</div>

Server Response

{
    "elements": {
        "selector": "#message",
        "html": "<p>Hello World!</p>"
    }
}

New DOM

<div x-data>
    <button @click="$get('/message')">Click Me!</button>
    <div id="message"><p>Hello World!</p></div>
</div>

---

Patch state

<div x-data="{ number: 0 }">
    <button @click="$get('/number')">Generate Number</button>
    <div x-text="number"></div>
</div>

Server Response

{
    "scope": {
        "number": 1234
    }
}

New DOM

<!-- Current state: { number: 1 }-->
<div x-data="{ number: 0 }">
    <button @click="$get('/number')">Generate Number</button>
    <div x-text="number">1</div>
</div>

---

Using forms

<form @submit.prevent="$post('/signin', { contentType: 'form' })">
    <input name="name" placeholder="Enter your name...">
    <button role="submit">Submit</button>
</form>

---

Using the x-alpatch directive

<div x-data>
    <button x-alpatch:post="/example">Do something</button>
</div>

Alpatch Response Protocol

{
    // Alpatch protocol identifier (required)
    "protocol": "alpatch",
    // Contains navigation info
    "navigation": {
        // The URL (required). Uses the history API to set URL.
        "url": "/example",
        // When set to true, all the patches will be ignored
        // and window.location.href is set to "url"
        "redirect": false,
        // Wherher history.replaceState() should be used instead of
        // history.pushState()
        "replace": false,
        // Sets the document title
        "title": "Page Name"
    },
    // Array of element-patches
    "elements": [
        {
            // Uses document.querySelector() to find the target.
            // Each element-patch has to contain either "selector" or "ref" 
            "selector": "#some-id",
            // Uses the $refs magic to find the target.
            "ref": "refName",
            // The html (required)
            "html": "<h1>Heading</h1>",
            // One of those options (replace is default):
            // morph, replace, replaceInner, append, prepend, before, after
            "strategy": "replace"
        }
    ],
    // State-patches will be morphed into their relative x-data stacks
    // or into the closest x-data scope in case no fitting value is found.
    "scope": {
        "value": "foobar"
    },
    // State-patches to global stores.
    // Each value will be morphed into the respective store of the corresponding Alpine store. 
    "store": {
        "user": {
            "userId": "user123"
        }
    }
}

Note: There are no server side SDKs yet. You have to create the alpatch response by yourself.

API Reference

Request magics

// Method can be get, post, put, patch and delete
function $get(
    // URL of the request (required)
    url, 

    // Options (optional)
    {
        // === Source options ===
        
        // "json" or "form"
        contentType = 'json',
        // Used when contentType is "form". Defaults to the element, the magic is called from.
        formEl,
        // Custom payload for "json" contentType
        payload,
        // How the json payload should be constructed. Either "auto" or "morph".
        // "auto" will use the payload if available. If not it will use the current scope.
        // "morph" will compine the current scope and the provided payload.
        payloadSource,

        // === Request options ===
        
        // Custom headers
        headers = {},
        requestAbort = 'auto',
        timeoutDuration = 15_000,
        maxRetries = 5,
        // Increses the retryInterval on each miss.
        retryMultiplier = 2,
        retryInterval = 2000,
        maxRetryInterval = 20_000,
        // Whether or not the request should be abortet on window / app / tab change
        // Default is false except for GET
        abortOnVisibilityChange,

        // === Patch options ===

        // Whether or not redirects and history changes should be executed
        autoNavigate = true,
        // Whether or not element patches should be applied
        autoPatchElements = true,
        // Whether or not scope or store patches should be merged
        autoPatchState = true,
    }
): Promise<any> // Returns a promise with the Alpatch response object

Directive

x-alpatch:get.input="https://example.com"
           |    |              |
       method  event          url

• Default method is "get".
• Default event is "submit" for <form>s, "change" for <input>, <textarea> and <select> elements, and "click" for everything else.
• If the attribute value is left out, x-alpatch uses the href attribute.

Roadmap

• testing
• more consistent code

Development

# Install dependencies
npm install

# Build
npm run build

# Build with watch mode
npm run dev

Contributing

Contributions are welcome! Please open an issue or submit a pull request.

License

MIT