Add a runnable and useful exampe

README.md

@@ -72,45 +72,72 @@ add_subdirectory(path-to-this-project json-schema-validator)
 See also `app/json-schema-validate.cpp`.
 
 ```C++
+#include <iostream>
+
 #include "json-schema.hpp"
 
 using nlohmann::json;
 using nlohmann::json_uri;
 using nlohmann::json_schema_draft4::json_validator;
 
-static void loader(const json_uri &uri, json &schema)
+// The schema is defined based upon a string literal
+static json person_schema = R"(
 {
-    // get the schema from uri and feed it into schema
+    "$schema": "http://json-schema.org/draft-04/schema#",
-    // if not possible, otherwise, throw an excpetion
+    "title": "A person",
+    "properties": {
+        "name": {
+            "description": "Name",
+            "type": "string"
+        },
+        "age": {
+            "description": "Age of the person",
+            "type": "number",
+            "minimum": 2,
+            "maximum": 200
+        }
+    },
+    "required": [
+                 "name",
+                 "age"
+                 ],
+    "type": "object"
 }
 
-int main(void)
+)"_json;
-{
-    json schema;
 
+// The people are defined with brace initialization
+static json bad_person = {{"age", 42}};
+static json good_person = {{"name", "Albert"}, {"age", 42}};
+
+int main(){
+    
     /* json-parse the schema */
-
+    
-    json_validator validator(loader); // create validator with a loader-callback
+    json_validator validator; // create validator
-
+    
     try {
-        validator.set_root_schema(schema); // insert root-schema
+        validator.set_root_schema(person_schema); // insert root-schema
     } catch (const std::exception &e) {
-        std::cerr << "Validation failed, here is why: " << e.what() << "\n";
+        std::cerr << "Validation of schema failed, here is why: " << e.what() << "\n";
         return EXIT_FAILURE;
     }
-
+    
-    json document;
+    /* json-parse the people */
-
+    
-    /* json-parse the document */
+    for (auto &person : {bad_person, good_person})
-
+    {
-    try {
+        std::cout << "About to validate this person:\n" << std::setw(2) << person << std::endl;
-        validator.validate(document); // validate the document
+        try {
-    } catch (const std::exception &e) {
+            validator.validate(person); // validate the document
-        std::cerr << "Validation failed, here is why: " << e.what() << "\n";
+            std::cout << "Validation succeeded\n";
-        return EXIT_FAILURE;
+        } catch (const std::exception &e) {
+            std::cerr << "Validation failed, here is why: " << e.what() << "\n";
+        }
     }
     return EXIT_SUCCESS;
 }
+
 ```
 
 # Compliance