From 06c28d54a9edae013dbc673a517f9fc924fbbc50 Mon Sep 17 00:00:00 2001
From: Dave Tapley <dave@jefuller.com>
Date: Thu, 11 Feb 2021 16:49:32 -0700
Subject: [PATCH] Disregard stale DynamicMapLayer updates

Alleviates (1) by not updating layer
with image for a set of params which have changed
while request was in flight.

(1) https://github.com/Esri/esri-leaflet/issues/749
---
 src/Layers/DynamicMapLayer.js | 2 ++
 src/Layers/RasterLayer.js     | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/Layers/DynamicMapLayer.js b/src/Layers/DynamicMapLayer.js
index 128af59c6..053f9fb25 100644
--- a/src/Layers/DynamicMapLayer.js
+++ b/src/Layers/DynamicMapLayer.js
@@ -173,6 +173,8 @@ export var DynamicMapLayer = RasterLayer.extend({
   _requestExport: function (params, bounds) {
     if (this.options.f === 'json') {
       this.service.request('export', params, function (error, response) {
+        if(this.latestRequestParams !== params) { return; }
+
         if (error) { return; } // we really can't do anything here but authenticate or requesterror will fire
 
         if (this.options.token && response.href) {
diff --git a/src/Layers/RasterLayer.js b/src/Layers/RasterLayer.js
index cb1aa7d00..c1de453ef 100644
--- a/src/Layers/RasterLayer.js
+++ b/src/Layers/RasterLayer.js
@@ -295,7 +295,7 @@ export var RasterLayer = Layer.extend({
 
     var params = this._buildExportParams();
     Util.extend(params, this.options.requestParams);
-
+    this.latestRequestParams = params
     if (params) {
       this._requestExport(params, bounds);