Support alternative HTTP methods

README.md

@@ -47,6 +47,7 @@ Note that in the following example the CSRF element is marked with the `data-csr
 - `csrf` is the [CSRF][] token for the posted form. It's available in the request body as a `authenticity_token` form parameter.
   - You can also supply the CSRF token via a child element. See [usage](#Usage) example.
 - `required` is a boolean attribute that requires the validation to succeed before the surrounding form may be submitted.
+- `http-method` defaults to `POST` where data is submitted as a POST with form data. You can set `GET` and the HTTP method used will be a get with url encoded params instead.
 
 ## Events
 

custom-elements.json

@@ -56,16 +56,8 @@
           },
           "members": [
             {
-              "kind": "method",
+              "kind": "field",
               "name": "setValidity",
-              "parameters": [
-                {
-                  "name": "message",
-                  "type": {
-                    "text": "string"
-                  }
-                }
-              ],
               "inheritedFrom": {
                 "name": "AutoCheckValidationEvent",
                 "module": "src/auto-check-element.ts"
@@ -92,16 +84,8 @@
           },
           "members": [
             {
-              "kind": "method",
+              "kind": "field",
               "name": "setValidity",
-              "parameters": [
-                {
-                  "name": "message",
-                  "type": {
-                    "text": "string"
-                  }
-                }
-              ],
               "inheritedFrom": {
                 "name": "AutoCheckValidationEvent",
                 "module": "src/auto-check-element.ts"
@@ -206,6 +190,14 @@
               "type": {
                 "text": "string"
               }
+            },
+            {
+              "kind": "field",
+              "name": "httpMethod",
+              "type": {
+                "text": "string"
+              },
+              "readonly": true
             }
           ],
           "attributes": [

src/auto-check-element.ts

@@ -12,6 +12,11 @@ type State = {
   controller: Controller | null
 }
 
+enum AllowedHttpMethods {
+  GET = 'GET',
+  POST = 'POST',
+}
+
 const states = new WeakMap<AutoCheckElement, State>()
 
 class AutoCheckEvent extends Event {
@@ -176,6 +181,10 @@ export class AutoCheckElement extends HTMLElement {
   set csrfField(value: string) {
     this.setAttribute('csrf-field', value)
   }
+
+  get httpMethod(): string {
+    return AllowedHttpMethods[this.getAttribute('http-method') as keyof typeof AllowedHttpMethods] || 'POST'
+  }
 }
 
 function setLoadingState(event: Event) {
@@ -187,10 +196,11 @@ function setLoadingState(event: Event) {
 
   const src = autoCheckElement.src
   const csrf = autoCheckElement.csrf
+  const httpMethod = autoCheckElement.httpMethod
   const state = states.get(autoCheckElement)
 
   // If some attributes are missing we want to exit early and make sure that the element is valid.
-  if (!src || !csrf || !state) {
+  if (!src || (httpMethod === 'POST' && !csrf) || !state) {
     return
   }
 
@@ -214,6 +224,9 @@ function makeAbortController() {
 }
 
 async function fetchWithNetworkEvents(el: Element, url: string, options: RequestInit): Promise<Response> {
+  if (options.method === 'GET') {
+    delete options.body
+  }
   try {
     const response = await fetch(url, options)
     el.dispatchEvent(new Event('load'))
@@ -238,9 +251,10 @@ async function check(autoCheckElement: AutoCheckElement) {
   const src = autoCheckElement.src
   const csrf = autoCheckElement.csrf
   const state = states.get(autoCheckElement)
+  const httpMethod = autoCheckElement.httpMethod
 
   // If some attributes are missing we want to exit early and make sure that the element is valid.
-  if (!src || !csrf || !state) {
+  if (!src || (httpMethod === 'POST' && !csrf) || !state) {
     if (autoCheckElement.required) {
       input.setCustomValidity('')
     }
@@ -255,8 +269,13 @@ async function check(autoCheckElement: AutoCheckElement) {
   }
 
   const body = new FormData()
-  body.append(csrfField, csrf)
-  body.append('value', input.value)
+  const url = new URL(src, window.location.origin)
+  if (httpMethod === 'POST') {
+    body.append(csrfField, csrf)
+    body.append('value', input.value)
+  } else {
+    url.search = new URLSearchParams({value: input.value}).toString()
+  }
 
   input.dispatchEvent(new AutoCheckSendEvent(body))
 
@@ -269,10 +288,10 @@ async function check(autoCheckElement: AutoCheckElement) {
   state.controller = makeAbortController()
 
   try {
-    const response = await fetchWithNetworkEvents(autoCheckElement, src, {
+    const response = await fetchWithNetworkEvents(autoCheckElement, url.toString(), {
       credentials: 'same-origin',
       signal: state.controller.signal,
-      method: 'POST',
+      method: httpMethod,
       body,
     })
     if (response.ok) {

test/auto-check.js

@@ -114,6 +114,35 @@ describe('auto-check element', function () {
     })
   })
 
+  describe('using HTTP GET', function () {
+    let checker
+    let input
+
+    beforeEach(function () {
+      const container = document.createElement('div')
+      container.innerHTML = `
+        <auto-check src="/success" http-method="GET" required>
+          <input>
+        </auto-check>`
+      document.body.append(container)
+
+      checker = document.querySelector('auto-check')
+      input = checker.querySelector('input')
+    })
+
+    afterEach(function () {
+      document.body.innerHTML = ''
+      checker = null
+      input = null
+    })
+
+    it('validates input with successful server response with GET', async function () {
+      triggerInput(input, 'hub')
+      await once(input, 'auto-check-complete')
+      assert.isTrue(input.checkValidity())
+    })
+  })
+
   describe('network lifecycle events', function () {
     let checker
     let input

web-test-runner.config.js

@@ -19,7 +19,7 @@ export default {
   middleware: [
     async ({request, response}, next) => {
       const {method, path} = request
-      if (method === 'POST') {
+      if (method === 'POST' || method === 'GET') {
         if (path.startsWith('/fail')) {
           response.status = 422
           // eslint-disable-next-line i18n-text/no-en