From f6550518dc241da56b853c16a02b7cce3587e8e5 Mon Sep 17 00:00:00 2001
From: Samuel Marks <samuelmarks@gmail.com>
Date: Tue, 8 Dec 2015 23:49:29 +1100
Subject: [PATCH] Begun tv4.async vanilla implementation

---
 tv4.async-vanilla.js | 45 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 tv4.async-vanilla.js

diff --git a/tv4.async-vanilla.js b/tv4.async-vanilla.js
new file mode 100644
index 0000000..115ebed
--- /dev/null
+++ b/tv4.async-vanilla.js
@@ -0,0 +1,45 @@
+// Provides support for asynchronous validation (fetching schemas)
+// Callback is optional third argument to tv4.validate() - if not present, synchronous operation
+//     callback(result, error);
+if (typeof tv4.asyncValidate === 'undefined') {
+    tv4.syncValidate = tv4.validate;
+    tv4.validate = function (data, schema, callback, checkRecursive, banUnknownProperties) {
+        if (typeof callback === 'undefined')
+            return this.syncValidate(data, schema, checkRecursive, banUnknownProperties);
+        else
+            return this.asyncValidate(data, schema, callback, checkRecursive, banUnknownProperties);
+    };
+    tv4.asyncValidate = function (data, schema, callback, checkRecursive, banUnknownProperties) {
+        var result = tv4.validate(data, schema, checkRecursive, banUnknownProperties);
+        if (!tv4.missing.length)
+            return callback(result, tv4.error);
+
+        // Make a request for each missing schema
+        var missingSchemas = function() {
+            tv4.missing.map(function (schemaUri) {
+                var request = new XMLHttpRequest();
+                request.open('GET', schemaUri, true);
+
+                request.onload = function() {
+                    if (request.status >= 200 && request.status < 400)
+                        tv4.addSchema(schemaUri, JSON.parse(request.responseText));
+                    else {
+                        // If there's an error, just use an empty schema
+                        tv4.addSchema(schemaUri, {});
+                    }
+                };
+
+                request.onerror = function() {
+                    tv4.addSchema(schemaUri, {});
+                };
+
+                request.send();
+            })
+        };
+        // When all requests done, try again
+        //missingSchemas();
+        $.when.apply($, missingSchemas).done(function () {
+            var result = tv4.asyncValidate(data, schema, callback, checkRecursive, banUnknownProperties);
+        });
+    };
+}