diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..22b280e
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,17 @@
+# editorconfig.org
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+indent_size = 2
+indent_style = space
+trim_trailing_whitespace = true
+
+[*.md]
+trim_trailing_whitespace = false
+
+[*.{json,php,xml,xml.dist}]
+indent_size = 4
diff --git a/Function.HTML-Build-Attributes.php b/Function.HTML-Build-Attributes.php
index 5fd54fa..bcc615c 100644
--- a/Function.HTML-Build-Attributes.php
+++ b/Function.HTML-Build-Attributes.php
@@ -1,68 +1,83 @@
 <?php
 
 if (!function_exists('html_build_attributes')) {
-	/**
-	 * Generate a string of HTML attributes
-	 *
-	 * @param   array          $attr      Associative array of attribute names and values.
-	 * @param   callable|null  $callback  Callback function to escape values for HTML attributes.
-	 *                                    Defaults to `htmlspecialchars()`.
-	 * @return  string  Returns a string of HTML attributes.
-	 */
-	function html_build_attributes(array $attr, callable $callback = null)
-	{
-		if (!count($attr)) {
-			return '';
-		}
+    /**
+     * Generate a string of HTML attributes
+     *
+     * @param  array|object  $attr     Associative array or object of attribute names and values.
+     * @param  callable|null $callback Callback function to escape values for HTML attributes.
+     *                                 Defaults to `htmlspecialchars()`.
+     * @return string Returns a string of HTML attributes
+     *     or a empty string if $attr is invalid or empty.
+     */
+    function html_build_attributes($attr, callable $callback = null)
+    {
+        if (is_object($attr) && !($attr instanceof \Traversable)) {
+            $attr = get_object_vars($attr);
+        }
 
-		$html = array_map(
-			function ($val, $key) use ($callback) {
-				if (is_bool($val)) {
-					return ($val ? $key : '');
-				} elseif (isset($val)) {
-					if ($val instanceof Closure) {
-						$val = $val();
-					} elseif ($val instanceof JsonSerializable) {
-						$val = json_encode(
-							$val->jsonSerialize(),
-							(JSON_UNESCAPED_SLASHES|JSON_UNESCAPED_UNICODE)
-						);
-					} elseif (is_callable([ $val, 'toArray' ])) {
-						$val = $val->toArray();
-					} elseif (is_callable([ $val, '__toString' ])) {
-						$val = strval($val);
-					}
+        if (!is_array($attr) || !count($attr)) {
+            return '';
+        }
 
-					if (is_array($val)) {
-						if (function_exists('is_blank')) {
-							$filter = function ($var) {
-								return !is_blank($var);
-							};
-						} else {
-							$filter = function ($var) {
-								return !empty($var) || is_numeric($var);
-							};
-						}
-						$val = implode(' ', array_filter($val, $filter));
-					}
+        $html = [];
+        foreach ($attr as $key => $val) {
+            if (is_null($val)) {
+                continue;
+            }
 
-					if (is_callable($callback)) {
-						$val = call_user_func($callback, $val);
-					} elseif (function_exists('esc_attr')) {
-						$val = esc_attr($val);
-					} else {
-						$val = htmlspecialchars($val, ENT_QUOTES);
-					}
+            if (is_string($key)) {
+                $key = trim($key);
 
-					if (is_string($val)) {
-						return sprintf('%1$s="%2$s"', $key, $val);
-					}
-				}
-			},
-			$attr,
-			array_keys($attr)
-		);
+                if (strlen($key) === 0) {
+                    continue;
+                }
+            }
 
-		return implode(' ', $html);
-	}
+            if (is_object($val)) {
+                if ($val instanceof Closure) {
+                    $val = $val();
+                } elseif ($val instanceof JsonSerializable) {
+                    $val = json_encode($val, (JSON_UNESCAPED_SLASHES|JSON_UNESCAPED_UNICODE));
+                } elseif (is_callable([ $val, 'toArray' ])) {
+                    $val = $val->toArray();
+                } elseif (is_callable([ $val, '__toString' ])) {
+                    $val = strval($val);
+                }
+            }
+
+            if (is_bool($val)) {
+                $html[] = ($val ? $key : '');
+                continue;
+            }
+
+            if (is_array($val)) {
+                if (function_exists('is_blank')) {
+                    $filter = function ($var) {
+                        return !is_blank($var);
+                    };
+                } else {
+                    $filter = function ($var) {
+                        return !empty($var) || is_numeric($var);
+                    };
+                }
+                $val = implode(' ', array_filter($val, $filter));
+            }
+
+            if (is_callable($callback)) {
+                $val = $callback($val);
+            } elseif (function_exists('esc_attr')) {
+                $val = esc_attr($val);
+            } else {
+                $val = htmlspecialchars($val, ENT_QUOTES);
+            }
+
+            if (is_string($val) || is_numeric($val)) {
+                $html[] = sprintf('%1$s="%2$s"', $key, $val);
+                continue;
+            }
+        }
+
+        return implode(' ', $html);
+    }
 }
diff --git a/README.md b/README.md
index 597e48a..2288d31 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # html_build_attributes
 
-(PHP 5 >= 5.4)  
+(PHP 5 >= 5.4, PHP 7, PHP 8)  
 `html_build_attributes` — Generate a string of HTML attributes.
 
 ## Description
@@ -13,17 +13,33 @@ Generate a string of HTML attributes from the associative array provided.
 
 ## Parameters
 
-- `attr` — Associative array, or object containing properties, representing attribute names and values.  
-  If `attr` is an object, then only public properties will be incorporated into the result.  
-  If a value is an array, its values will be concatenated and delimited with a space.  
-	Values that cannot be converted into strings will be ignored. If the value is Stringable, Arrayble, or a `Closure`, attempts will be made to parse as a string. 
-- `callback` — Callback function for escaping the values for the HTML attributes.  
-  If no sanitizer is provided, [`htmlspecialchars()`](http://php.net/htmlspecialchars) is used;  
-  If using WordPress, the [`esc_attr()`](https://developer.wordpress.org/reference/functions/esc_attr/) function is used.
+- `attr` — Associative array, or object containing properties, representing
+  attribute names and values.
+  
+  If `attr` is a non-iterable object, then only accessible non-static properties
+  will be incorporated into the result.
+  
+  If a value of `attr` is an array, its values will be concatenated and
+  delimited with a space.
+  
+  If a value of `attr` is a boolean, the value's key will be rendered without
+  a value.
+
+  If the value is Stringable, Arrayble, or a [`Closure`][class.closure],
+  attempts will be made to parse as a string.
+  
+	Values that cannot be converted into strings will be ignored.
+  
+- `callback` — Callback function for escaping the values for the HTML attributes.
+  
+  If no sanitizer is provided, [`htmlspecialchars()`][function.htmlspecialchars]
+  is used;
+  
+  If using WordPress, the [`esc_attr()`][wp.esc_attr] function is used.
 
 ## Return Values
 
-Returns a string of HTML attributes.
+Returns a string of HTML attributes or a empty string if `attr` is invalid or empty.
 
 ## Installation
 
@@ -35,4 +51,10 @@ $ composer require mcaskill/php-html-build-attributes
 
 ### Without Composer
 
-Why are you not using [composer](http://getcomposer.org/)? Download `Function.HTML-Build-Attributes.php` from the gist and save the file into your project path somewhere.
\ No newline at end of file
+Why are you not using [composer](http://getcomposer.org/)?
+Download `Function.HTML-Build-Attributes.php` from the gist and save the file
+into your project path somewhere.
+
+[class.closure]:             https://php.net/class.closure
+[function.htmlspecialchars]: https://php.net/function.htmlspecialchars
+[wp.esc_attr]:               https://developer.wordpress.org/reference/functions/esc_attr/
diff --git a/composer.json b/composer.json
index 9236e54..3dfb32f 100644
--- a/composer.json
+++ b/composer.json
@@ -1,23 +1,27 @@
 {
-  "name": "mcaskill/php-html-build-attributes",
-  "version": "1.0.0",
-  "description": "Generate a string of HTML attributes.",
-  "license": "MIT",
-  "authors": [
-    {
-      "name": "Chauncey McAskill",
-      "email": "chauncey@mcaskill.ca",
-      "homepage": "https://github.com/mcaskill"
+    "name": "mcaskill/php-html-build-attributes",
+    "description": "Generate a string of HTML attributes.",
+    "license": "MIT",
+    "authors": [
+        {
+            "name": "Chauncey McAskill",
+            "email": "chauncey@mcaskill.ca",
+            "homepage": "https://github.com/mcaskill"
+        }
+    ],
+    "keywords": [
+        "function",
+        "wordpress"
+    ],
+    "extra": {
+        "branch-alias": {
+            "dev-master": "1.x-dev"
+        }
+    },
+    "require": {
+        "php": ">=5.4.0"
+    },
+    "autoload": {
+        "files": [ "Function.HTML-Build-Attributes.php" ]
     }
-  ],
-  "keywords": [
-    "function",
-    "wordpress"
-  ],
-  "require": {
-    "php": ">=5.4.0"
-  },
-  "autoload": {
-    "files": [ "Function.HTML-Build-Attributes.php" ]
-  }
-}
\ No newline at end of file
+}