Replace jQuery ajax() with the fetch API in all of our own code.

diff --git a/www/js/remoteglot.js b/www/js/remoteglot.js
index d98c90210d7c3e216a0f4d7dad813bc45f96ffb7..7245407a491e2ac9ccae6b3aa8248315f5a5320e 100644 (file)
--- a/www/js/remoteglot.js
+++ b/www/js/remoteglot.js
@@ -193,7 +193,7 @@ var current_display_move = null;
  * The current backend request to get main analysis (not history), if any,
  * so that we can abort it.
  *
- * @type {?jqXHR}
+ * @type {?AbortController}
  * @private
  */
 var current_analysis_xhr = null;
@@ -210,7 +210,7 @@ var current_analysis_request_timer = null;
 /**
  * The current backend request to get historic data, if any.
  *
- * @type {?jqXHR}
+ * @type {?AbortController}
  * @private
  */
 var current_historic_xhr = null;
@@ -218,7 +218,7 @@ var current_historic_xhr = null;
 /**
  * The current backend request to get hash probes, if any, so that we can abort it.
  *
- * @type {?jqXHR}
+ * @type {?AbortController}
  * @private
  */
 var current_hash_xhr = null;
@@ -257,36 +257,52 @@ var get_unique = function() {
 var request_update = function() {
        current_analysis_request_timer = null;
 
-       current_analysis_xhr = $.ajax({
-               url: backend_url + "?ims=" + ims + "&unique=" + unique
-       }).done(function(data, textstatus, xhr) {
-               if (delay_ms === 0) {
-                       process_update_response(data, textstatus, xhr);
-               } else {
-                       setTimeout(function() { process_update_response(data, textstatus, xhr); }, delay_ms);
-               }
+       let handle_err = () => {
+               // Backend error or similar. Wait ten seconds, then try again.
+               current_analysis_request_timer = setTimeout(function() { request_update(); }, 10000);
+       };
+
+       current_analysis_xhr = new AbortController();
+       const signal = current_analysis_xhr.signal;
+       fetch(backend_url + "?ims=" + ims + "&unique=" + unique, { signal })
+               .then((response) => response.json().then(data => ({ok: response.ok, headers: response.headers, json: data})))  // ick
+               .then((obj) => {
+                       if (!obj.ok) {
+                               handle_err();
+                               return;
+                       }
+
+                       if (delay_ms === 0) {
+                               process_update_response(obj.json, obj.headers);
+                       } else {
+                               setTimeout(function() { process_update_response(obj.json, obj.headers); }, delay_ms);
+                       }
+
+                       // Next update.
+                       if (!backend_url.match(/history/)) {
+                               var timeout = 100;
+                               current_analysis_request_timer = setTimeout(function() { request_update(); }, timeout);
+                       }
+               })
+               .catch((err) => {
+                       if (err.name === 'AbortError') {
+                               // Aborted because we are switching backends. Abandon and don't retry,
+                               // because another one is already started for us.
+                       } else {
+                               handle_err(err);
+                       }
+               })
+               .finally(() => {
+                       // Display.
+                       document.body.style.opacity = null;
+               })
 
-               // Next update.
-               if (!backend_url.match(/history/)) {
-                       var timeout = 100;
-                       current_analysis_request_timer = setTimeout(function() { request_update(); }, timeout);
-               }
-       }).fail(function(jqXHR, textStatus, errorThrown) {
-               document.body.style.opacity = null;
-               if (textStatus === "abort") {
-                       // Aborted because we are switching backends. Abandon and don't retry,
-                       // because another one is already started for us.
-               } else {
-                       // Backend error or similar. Wait ten seconds, then try again.
-                       current_analysis_request_timer = setTimeout(function() { request_update(); }, 10000);
-               }
-       });
 }
 
-var process_update_response = function(data, textstatus, xhr) {
-       sync_server_clock(xhr.getResponseHeader('Date'));
-       ims = xhr.getResponseHeader('X-RGLM');
-       var num_viewers = xhr.getResponseHeader('X-RGNV');
+var process_update_response = function(data, headers) {
+       sync_server_clock(headers.get('Date'));
+       ims = headers.get('X-RGLM');
+       var num_viewers = headers.get('X-RGNV');
        var new_data;
        if (Array.isArray(data)) {
                new_data = JSON.parse(JSON.stringify(current_analysis_data));
@@ -295,7 +311,7 @@ var process_update_response = function(data, textstatus, xhr) {
                new_data = data;
        }
 
-       var minimum_version = xhr.getResponseHeader('X-RGMV');
+       var minimum_version = headers.get('X-RGMV');
        if (minimum_version && minimum_version > SCRIPT_VERSION) {
                // Upgrade to latest version with a force-reload.
                location.reload(true);
@@ -1724,20 +1740,31 @@ var update_historic_analysis = function() {
        var filename = "/history/move" + (current_display_move + 1) + "-" +
                hiddenboard.fen().replace(/ /g, '_').replace(/\//g, '-') + ".json";
 
-       current_historic_xhr = $.ajax({
-               url: filename
-       }).done(function(data, textstatus, xhr) {
-               displayed_analysis_data = data;
+       let handle_err = () => {
+               displayed_analysis_data = {'failed': true};
                update_board();
-       }).fail(function(jqXHR, textStatus, errorThrown) {
-               if (textStatus === "abort") {
-                       // Aborted because we are switching backends. Don't do anything;
-                       // we will already have been cleared.
-               } else {
-                       displayed_analysis_data = {'failed': true};
+       };
+
+       current_historic_xhr = new AbortController();
+       const signal = current_analysis_xhr.signal;
+       fetch(filename, { signal })
+               .then((response) => response.json().then(data => ({ok: response.ok, json: data})))  // ick
+               .then((obj) => {
+                       if (!obj.ok) {
+                               handle_err();
+                               return;
+                       }
+                       displayed_analysis_data = obj.json;
                        update_board();
-               }
-       });
+               })
+               .catch((err) => {
+                       if (err.name === 'AbortError') {
+                               // Aborted because we are switching backends. Abandon and don't retry,
+                               // because another one is already started for us.
+                       } else {
+                               handle_err();
+                       }
+               });
 }
 
 /**
@@ -1919,11 +1946,12 @@ var explore_hash = function(fen) {
                current_hash_display_timer = null;
        }
        $("#refutationlines").empty();
-       current_hash_xhr = $.ajax({
-               url: backend_hash_url + "?fen=" + fen
-       }).done(function(data, textstatus, xhr) {
-               show_explore_hash_results(data, fen);
-       });
+
+       current_hash_xhr = new AbortController();
+       const signal = current_analysis_xhr.signal;
+       fetch(backend_hash_url + "?fen=" + fen, { signal })
+               .then((response) => response.json())
+               .then((data) => { show_explore_hash_results(data, fen); });
 }
 
 /** Process the JSON response from a hash probe request.