Added JS injector for ArcGIS

javascript-injectors/README.md

@@ -228,9 +228,16 @@ $ screenly asset inject-js "$ASSET_ID" "$JAVASCRIPT_URL"
 * Download [zabbix-login-via-credentials.js](https://github.com/Screenly/Playground/tree/master/javascript-injectors/examples/zabbix-login-via-credentials.js) and modify it with your credentials.
 * Run `screenly asset inject-js "$ASSET_ID" /path/to/script.js` to add the JavaScript
 
-## Sign in to Dynatrace via credentials
+## Sign in to Dynatrace via credentials arcgis-logo.svg
 
 <img src="../images/dynatrace-logo.svg" alt="Dynatrace logo" width="150"/>
 
 * Download [dynatrace-login-via-credentials.js](https://github.com/Screenly/Playground/tree/master/javascript-injectors/examples/dynatrace-login-via-credentials.js) and modify it with your credentials.
 * Run `screenly asset inject-js "$ASSET_ID" /path/to/script.js` to add the JavaScript
+
+## Sign in to ArcGIS via credentials
+
+<img src="../images/arcgis-logo.svg" alt="ArcGIS logo" width="150"/>
+
+* Download [arcgis-signin-via-credentials.js](https://github.com/Screenly/Playground/tree/master/javascript-injectors/examples/arcgis-signin-via-credentials.js) and modify it with your credentials.
+* Run `screenly asset inject-js "$ASSET_ID" /path/to/script.js` to add the JavaScript

javascript-injectors/examples/arcgis-signin-via-credentials.js

@@ -0,0 +1,31 @@
+(function () {
+  const username = '<USERNAME>'
+  const password = '<PASSWORD>'
+
+  const authLocation = '/portal/sharing/rest/oauth2/authorize'
+
+  function setValue (selector, value) {
+    const element = document.querySelector(selector)
+    element.value = value
+    element.dispatchEvent(new Event('change'))
+  }
+
+  function submitForm () {
+    document.querySelector('button[id="signIn"]').click()
+  }
+
+  function login () {
+    try {
+      setValue('input[name="username"]', username)
+      setValue('input[name="password"]', password)
+      submitForm()
+    } catch (error) {
+      console.warn(error)
+      setTimeout(login, 3000)
+    }
+  }
+
+  if (window.location.pathname === authLocation) {
+    login()
+  }
+})()