Implement Web scraping "HTML + XPath" (#4220)

* More PHP type hints for Fever
Follow-up of https://github.com/FreshRSS/FreshRSS/pull/4201
Related to https://github.com/FreshRSS/FreshRSS/issues/4200

* Detail

* Draft

* Progress

* More draft

* Fix thumbnail PHP type hint
https://github.com/FreshRSS/FreshRSS/issues/4215

* More types

* A bit more

* Refactor FreshRSS_Entry::fromArray

* Progress

* Starts to work

* Categories

* Fonctional

* Layout update

* Fix relative URLs

* Cache system

* Forgotten files

* Remove a debug line

* Automatic form validation of XPath expressions

* data-leave-validation

* Fix reload action

* Simpler examples

* Fix column type for PostgreSQL

* Enforce HTTP encoding

* Readme

* Fix get full content

* target="_blank"

* gitignore

* htmlspecialchars_utf8

* Implement HTML <base>
And fix/revert `xml:base` support in SimplePie https://github.com/simplepie/simplepie/commit/e49c578817aa504d8d05cd7f33857aeda9d41908

* SimplePie upstream PR merged
https://github.com/simplepie/simplepie/pull/723

1 files changed, 45 insertions, 0 deletions

diff --git a/p/scripts/extra.js b/p/scripts/extra.js
index 00a460917..505b05110 100644
--- a/p/scripts/extra.js
+++ b/p/scripts/extra.js
@@ -213,6 +213,49 @@ function init_configuration_alert() {
 	};
 }
 
+/**
+ * Allow a <select class="select-show"> to hide/show elements defined by <option data-show="elem-id"></option>
+ */
+function init_select_show() {
+	const listener = (select) => {
+		const options = select.querySelectorAll('option[data-show]');
+		for (const option of options) {
+			const elem = document.getElementById(option.dataset.show);
+			if (elem) {
+				elem.style.display = option.selected ? 'block' : 'none';
+			}
+		}
+	};
+
+	const selects = document.querySelectorAll('select.select-show');
+	for (const select of selects) {
+		select.addEventListener('change', (e) => listener(e.target));
+		listener(select);
+	}
+}
+
+/**
+ * Automatically validate XPath textarea fields
+ */
+function init_valid_xpath() {
+	const listener = (textarea) => {
+		const evaluator = new XPathEvaluator();
+		try {
+			if (textarea.value === '' || evaluator.createExpression(textarea.value) != null) {
+				textarea.setCustomValidity('');
+			}
+		} catch (ex) {
+			textarea.setCustomValidity(ex);
+		}
+	};
+
+	const textareas = document.querySelectorAll('textarea.valid-xpath');
+	for (const textarea of textareas) {
+		textarea.addEventListener('change', (e) => listener(e.target));
+		listener(textarea);
+	}
+}
+
 function init_extra() {
 	if (!window.context) {
 		if (window.console) {
@@ -227,6 +270,8 @@ function init_extra() {
 	init_slider_observers();
 	init_configuration_alert();
 	fix_popup_preview_selector();
+	init_select_show();
+	init_valid_xpath();
 }
 
 if (document.readyState && document.readyState !== 'loading') {