[FIX] website, website_blog, website_sale: stay on the backend view

Since [the merge of the frontend into the backend] and more precisely
since [this commit], clicks on some elements makes the user switch from
the backend view to the frontend view.

Steps to reproduce (just an example):
- Go to /blog from the backend (/@/blog)
- Click on a tag (eg: adventure)

=> users are redirected to the frontend view, we do not want that. This
commit makes the user stay in the backend. For some scenarios (like the
one above), we create a fake form and submit it. The forms have a target
attribute that specifies where the form response should be displayed.
This commit set back the default value for the target attribute when a
user clicks on a blog tag, a course tag, the pager, ... so that the
response is displayed in the current context (the iframe when the user
is in the backend).

Note that [this commit] introduced the target attribute change to fix
two issues:
1. The opening of the payment gateways in the iframe.
2. The create page from a 404 page in the backend.

After [this other commit] has been merged, to prevent the first issue so
here we just remove the target attribute change except for the case of
the second issue.

[the merge of the frontend into the backend]: https://github.com/odoo/odoo/commit/31cc10b91dc7762e23b4bde9b945be0c4ce3fe3b
[this commit]: https://github.com/odoo/odoo/commit/2d44f2792dec0b2f205475a22dbedc97e9c54a64
[this other commit]: https://github.com/odoo/odoo/commit/3a32b9e1efa6277b345dc9239334680651690df7

task-3054970

closes odoo/odoo#114056

Signed-off-by: Romain Derie (rde) <rde@odoo.com>

addons/website/static/src/js/utils.js

@@ -284,8 +284,9 @@ function sendRequest(route, params) {
     let form = document.createElement('form');
     form.setAttribute('action', route);
     form.setAttribute('method', params.method || 'POST');
-    const isInIframe = window.frameElement && window.frameElement.classList.contains('o_iframe');
-    if (isInIframe) {
+    // This is an exception for the 404 page create page button, in backend we
+    // want to open the response in the top window not in the iframe.
+    if (params.forceTopWindow) {
         form.setAttribute('target', '_top');
     }
 

addons/website/views/website_templates.xml

@@ -2244,7 +2244,7 @@
             <div class="container">
                 <div class="alert alert-info text-center d-lg-flex justify-content-between align-items-center">
                     <p class="m-lg-0 text-info">This page does not exist, but you can create it as you are editor of this site.</p>
-                    <a role="button" class="btn btn-info js_disable_on_click post_link" t-attf-href="/website/add/#{path}?redirect=1#{from_template and '&amp;template=%s' % from_template}">Create Page</a>
+                    <a role="button" class="btn btn-info js_disable_on_click post_link" data-post_force-top-window="true" t-attf-href="/website/add/#{path}?redirect=1#{from_template and '&amp;template=%s' % from_template}">Create Page</a>
                 </div>
                 <div class="text-center text-muted p-3"><i class="fa fa-info-circle"></i> Edit the content below this line to adapt the default <strong>Page not found</strong> page.</div>
             </div>

addons/website_blog/static/tests/tours/blog_tags_tour.js

@@ -51,5 +51,16 @@ wTourUtils.registerWebsitePreviewTour('blog_tags', {
         content: "Verify tag does not appear in blog post anymore",
         trigger: "iframe #o_wblog_post_content div:has(.badge):not(:contains(testtag))",
         run: () => {}, // it's a check
+    }, {
+        content: "Go back to /blog",
+        trigger: "iframe #top_menu a[href='/blog'] span",
+    }, {
+        content: "Click on the adventure tag",
+        trigger: "iframe a[href^='/blog/tag/adventure']",
+    }, {
+        content: "Verify we are still on the backend",
+        trigger: "iframe span:contains(adventure) i.fa-tag",
+        run: () => {}, // it's a check
+
     }]
 );

addons/website_sale/static/tests/tours/website_sale_add_to_cart_snippet_tour.js

@@ -44,11 +44,11 @@ wTourUtils.registerWebsitePreviewTour('add_to_cart_snippet_tour', {
         ...wTourUtils.selectElementInWeSelectWidget('action_picker_opt', 'Buy Now'),
         ...wTourUtils.clickOnSave(),
         wTourUtils.clickOnElement('add to cart button', 'iframe .s_add_to_cart_btn'),
-        wTourUtils.assertPathName('/shop/payment', 'button[name=o_payment_submit_button]'),
+        wTourUtils.assertPathName('/@/shop/payment', 'iframe button[name=o_payment_submit_button]'),
 
-        wsTourUtils.goToCart({quantity: 4, backend: false}),
-        wsTourUtils.assertCartContains({productName: 'Acoustic Bloc Screens'}),
-        wsTourUtils.assertCartContains({productName: 'Conference Chair (Steel)'}),
-        wsTourUtils.assertCartContains({productName: 'Conference Chair (Aluminium)'}),
+        wsTourUtils.goToCart({quantity: 4, backend: true}),
+        wsTourUtils.assertCartContains({productName: 'Acoustic Bloc Screens', backend: true}),
+        wsTourUtils.assertCartContains({productName: 'Conference Chair (Steel)', backend: true}),
+        wsTourUtils.assertCartContains({productName: 'Conference Chair (Aluminium)', backend: true}),
     ],
 );