fix(pat inject): Fix issue with submit buttons which are added later.

Fix an issue with submit buttons which were added after initialization
of pat-inject which did not send their value (e.g. via a pat-inject call).

Ref: scrum-1670

src/pat/inject/index.html

@@ -425,20 +425,52 @@ <h3>Inject and fix URLs of options</h3>
           </div>
         </section>
 
-        <div id="inject-demo__content-wrapper" style="display: none">
-          <section id="inject-demo__content">Liked</section>
-        </div>
+        <template id="inject-demo__like--anchor">
+          <a
+              type="button"
+              class="pat-inject"
+              href="./#inject-demo__dislike--anchor"
+              data-pat-inject="target: self::element"
+          >Like</a>
+        </template>
+
+        <template id="inject-demo__dislike--anchor">
+          <a
+              type="button"
+              class="pat-inject"
+              href="./#inject-demo__like--anchor"
+              data-pat-inject="target: self::element"
+          >Dislike</a>
+        </template>
+
+        <template id="inject-demo__like--button">
+          <button
+              type="submit"
+              name="like_button"
+              value="like"
+              formaction="./#inject-demo__dislike--button"
+              class="pat-inject"
+              data-pat-inject="target: self::element">Like</button>
+        </template>
+
+        <template id="inject-demo__dislike--button">
+          <button
+              type="submit"
+              name="like_button"
+              value="dislike"
+              formaction="./#inject-demo__like--button"
+              class="pat-inject"
+              data-pat-inject="target: self::element">Dislike</button>
+        </template>
 
         <section>
           <h3>Can replace itself</h3>
           <a
               type="button"
               class="pat-inject"
-              href="./#inject-demo__content"
+              href="./#inject-demo__dislike--anchor"
               data-pat-inject="target: self::element"
-          >
-            Like
-          </a>
+          >Like</a>
         </section>
 
         <section>
@@ -451,7 +483,9 @@ <h3>Can replace itself when a button in a form</h3>
               data-pat-inject="target: inject-demo__content-wrapper::element">
             <button
                 type="submit"
-                formaction="./#inject-demo__content"
+                name="like_button"
+                value="like"
+                formaction="./#inject-demo__dislike--button"
                 class="pat-inject"
                 data-pat-inject="target: self::element">Like</button>
           </form>

src/pat/inject/inject.js

@@ -105,6 +105,22 @@ const inject = {
                     });
                     // setup event handlers
                     if ($el[0]?.tagName === "FORM") {
+                        events.add_event_listener(
+                            $el[0],
+                            "click",
+                            "pat-inject--form-submit-click",
+                            (e) => {
+                                if (
+                                    e.target.matches(
+                                        "[type=submit], button:not([type=button]), [type=image]"
+                                    )
+                                ) {
+                                    // make sure the submitting button is sent
+                                    // with the form
+                                    ajax.onClickSubmit(e);
+                                }
+                            }
+                        );
                         events.add_event_listener(
                             $el[0],
                             "submit",
@@ -113,20 +129,6 @@ const inject = {
                                 this.onTrigger(e);
                             }
                         );
-                        for (const button of $el[0].querySelectorAll(
-                            "[type=submit], button:not([type=button]), [type=image]"
-                        )) {
-                            events.add_event_listener(
-                                button,
-                                "click",
-                                "pat-inject--form-submit-click",
-                                (e) => {
-                                    // make sure the submitting button is sent
-                                    // with the form
-                                    ajax.onClickSubmit(e);
-                                }
-                            );
-                        }
                     } else if ($el.is(".pat-subform")) {
                         log.debug("Initializing subform with injection");
                     } else {

src/pat/inject/inject.test.js

@@ -1044,24 +1044,27 @@ describe("pat-inject", function () {
                 });
 
                 it("9.2.5.2 - use an image submit with a formaction value as action URL", async function () {
-                    var $submit1 = $(
-                            '<input type="submit" name="submit" value="default" />'
-                        ),
-                        $submit2 = $(
-                            '<input type="image" name="submit" value="special" formaction="other.html" />'
-                        );
+                    const $submit = $(`
+                        <input
+                            type="image"
+                            name="submit"
+                            value="special"
+                            formaction="other.html" />
+                    `);
 
-                    $form.append($submit1).append($submit2);
+                    $form.append($submit);
 
                     pattern.init($form);
                     await utils.timeout(1); // wait a tick for async to settle.
 
                     // Work around jsDOM not submitting with image buttons.
-                    $submit2[0].addEventListener("click", () => {
-                        $submit2[0].form.dispatchEvent(events.submit_event());
+                    $submit[0].addEventListener("click", async () => {
+                        await utils.timeout(1); // wait a tick for click event reaching form before submitting.
+                        $submit[0].form.dispatchEvent(events.submit_event());
                     });
 
-                    $submit2[0].click();
+                    $submit[0].click();
+                    await utils.timeout(1); // wait a tick for click handler
 
                     var ajaxargs = $.ajax.mock.calls[$.ajax.mock.calls.length - 1][0];
                     expect($.ajax).toHaveBeenCalled();
@@ -1378,6 +1381,29 @@ describe("pat-inject", function () {
                     expect(pattern.onTrigger).toHaveBeenCalledTimes(1);
                 });
             });
+
+            it("9.2.7 - Sends submit button form values even if submit button is added after initialization.", async function () {
+                document.body.innerHTML = `
+                    <form class="pat-inject" action="test.cgi">
+                    </form>
+                `;
+
+                const pat_ajax = (await import("../ajax/ajax.js")).default;
+                jest.spyOn(pat_ajax, "onClickSubmit");
+                jest.spyOn(pattern, "onTrigger");
+
+                const form = document.querySelector("form");
+
+                pattern.init($(form));
+                await utils.timeout(1); // wait a tick for async to settle.
+
+                form.innerHTML = `<button type="submit"/>`;
+                const button = form.querySelector("button");
+                button.click();
+
+                expect(pat_ajax.onClickSubmit).toHaveBeenCalledTimes(1);
+                expect(pattern.onTrigger).toHaveBeenCalledTimes(1);
+            });
         });
     });