From 55f8b0dea9772b976acb81057f92313ca0949b57 Mon Sep 17 00:00:00 2001
From: Pavel Shevaev <pacha.shevaev@gmail.com>
Date: Fri, 5 May 2023 12:10:20 +0300
Subject: [PATCH] Adding initial support for null structs (but not generic
 ones)

---
 src/codegen.inc.php    | 37 +++++++++++++++++++++++++------------
 src/data_utils.inc.php | 12 ++++++------
 tpl/macro.twig         |  6 ++++++
 3 files changed, 37 insertions(+), 18 deletions(-)

diff --git a/src/codegen.inc.php b/src/codegen.inc.php
index 4cba5b0..b004f46 100644
--- a/src/codegen.inc.php
+++ b/src/codegen.inc.php
@@ -145,20 +145,25 @@ function data2value($name, \mtgType $type, $buf, $prefix = '', $tokens = array()
 
   $cond_indent = $indent."  ";
 
-  $default_value_arg = array_key_exists('default', $tokens) ? default_value($tokens['default']) : 'null';
+  $default_value_arg = array_key_exists('default', $tokens) ? ', '.default_value($tokens['default']) : '';
   if($type instanceof \mtgMetaStruct)
   {
     $default = array_key_exists('default', $tokens) ? $tokens['default'] : null;
     if($default)
     {
       $default = json_decode($default, true);
-      if(!is_array($default))
+      if(is_array($default))
+      {
+        $default = str_replace("\n", "",  var_export($default, true));
+        $default_value_arg = ", \$assoc ? $default : array_values($default)";
+      }
+      else if($default === null)
+      {
+        $default_value_arg = ", null";
+      }
+      else
         throw new Exception("Bad default struct: " . $tokens['default']);
-      $default = str_replace("\n", "",  var_export($default, true));
-      $default_value_arg = "\$assoc ? $default : array_values($default)";
     }
-    else
-      $default_value_arg = "null";
   }
 
   $str .= "\n";
@@ -166,7 +171,7 @@ function data2value($name, \mtgType $type, $buf, $prefix = '', $tokens = array()
   if($as_is)
     $tmp_val = $buf;
   else
-    $str .= $indent."{$tmp_val} = \metagen_php\array_extract_val({$buf}, \$assoc, '{$name}', {$default_value_arg});\n";
+    $str .= $indent."{$tmp_val} = \metagen_php\array_extract_val({$buf}, \$assoc, '{$name}' {$default_value_arg});\n";
 
   if($type instanceof \mtgBuiltinType)
   {
@@ -184,9 +189,13 @@ function data2value($name, \mtgType $type, $buf, $prefix = '', $tokens = array()
     }
     else
     {
-      $str .= $cond_indent."{$tmp_val} = " . apply_value_filters($name, $tokens, "{$tmp_val}"). ";\n";
-      $str .= $cond_indent."\$tmp_sub_arr__ = \metagen_php\\val_arr({$tmp_val});\n";
-      $str .= $cond_indent."{$pname} = new {$type}(\$tmp_sub_arr__, \$assoc);\n";
+      $str .= $cond_indent."if({$tmp_val} === null) {\n";
+      $str .= $cond_indent."  {$pname} = null; \n";
+      $str .= $cond_indent."} else {\n";
+      $str .= $cond_indent."  {$tmp_val} = " . apply_value_filters($name, $tokens, "{$tmp_val}"). ";\n";
+      $str .= $cond_indent."  \$tmp_sub_arr__ = \metagen_php\\val_arr({$tmp_val});\n";
+      $str .= $cond_indent."  {$pname} = new {$type}(\$tmp_sub_arr__, \$assoc);\n";
+      $str .= "}";
     }
   }
   else if($type instanceof \mtgArrType)
@@ -242,9 +251,9 @@ function value2data($name, \mtgType $type, $buf, $prefix = '', $tokens = array()
   else if($type instanceof \mtgMetaStruct)
   {
     if(array_key_exists('virtual', $tokens))
-      $str .= $indent."\metagen_php\array_set_value({$buf}, \$assoc, '$name', is_array({$pname}) ? {$pname} : {$pname}->export(\$assoc, true/*virtual*/));";
+      $str .= $indent."\metagen_php\array_set_value({$buf}, \$assoc, '$name', !is_object({$pname}) ? {$pname} : {$pname}->export(\$assoc, true/*virtual*/));";
     else
-      $str .= $indent."\metagen_php\array_set_value({$buf}, \$assoc, '$name', is_array({$pname}) ? {$pname} : {$pname}->export(\$assoc));";
+      $str .= $indent."\metagen_php\array_set_value({$buf}, \$assoc, '$name', !is_object({$pname}) ? {$pname} : {$pname}->export(\$assoc));";
   }
   else if($type instanceof \mtgMetaEnum)
   {
@@ -277,3 +286,7 @@ function value2data($name, \mtgType $type, $buf, $prefix = '', $tokens = array()
   return $str;
 }
 
+function is_null_str($default)
+{
+  return is_string($default) && json_decode($default, true) === null;
+}
diff --git a/src/data_utils.inc.php b/src/data_utils.inc.php
index ceb5062..a28a514 100644
--- a/src/data_utils.inc.php
+++ b/src/data_utils.inc.php
@@ -2,7 +2,7 @@
 namespace metagen_php;
 use Exception;
 
-function array_extract_val(&$arr, $assoc, $name, $default = null)
+function array_extract_val(&$arr, $assoc, $name)
 {
   if(!is_array($arr))
     throw new Exception("$name: Not an array");
@@ -11,17 +11,17 @@ function array_extract_val(&$arr, $assoc, $name, $default = null)
   {
     if(sizeof($arr) == 0)
     {
-      if($default !== null)
-        return $default;
+      if(func_num_args() == 4)
+        return func_get_arg(3);
       throw new Exception("$name: No next array item");
     }
     return array_shift($arr);
   }
 
-  if(!isset($arr[$name]))
+  if(!array_key_exists($name, $arr))
   {
-    if($default !== null)
-      return $default;
+    if(func_num_args() == 4)
+      return func_get_arg(3);
     throw new Exception("$name: No array item");
   }
 
diff --git a/tpl/macro.twig b/tpl/macro.twig
index 1babf4b..b444d32 100644
--- a/tpl/macro.twig
+++ b/tpl/macro.twig
@@ -191,7 +191,13 @@ array_merge(parent::CLASS_FIELDS_PROPS(),
 
 {% macro field_init_value(o, f) %}
   {%- if f.type is instanceof('\\mtgMetaStruct') ~%}
+
+    {%- if has_token(f, 'default') and token(f, 'default') == 'null' -%}
+    null
+    {%- else -%}
   new {{f.type}}()
+    {%- endif -%}
+
   {%- elseif f.type is instanceof('\\mtgMetaEnum') ~%}
     {%- if has_token(f, 'default') -%}
       {{f.type}}::{{token(f, 'default')|replace({'"' : ''})|default_value}}