feat: support read flag value from ENV var

Author: inhere

README.md

@@ -10,9 +10,10 @@ Generic PHP command line flags parse library
 
 ## Features
 
-- Generic parse CLI options and arguments.
+- Generic CLI options and arguments parser.
 - Support set value data type(`int,string,bool,array`), will auto format input value.
 - Support set default value for option/argument.
+- Support read flag value from ENV var.
 - Support set option/argument is required.
 - Support set validator for check input value.
 - Support auto generate help message.
@@ -24,7 +25,7 @@ Generic PHP command line flags parse library
 
 **Options**:
 
-- Support long option `--long`
+- Support long option. eg: `--long` `--long value`
 - Support short option `-s -a value`, allow set multi short names.
 - Support define array option
   - eg: `--tag php --tag go` will get `tag: [php, go]`

src/AbstractFlags.php

@@ -67,6 +67,7 @@ abstract class AbstractFlags implements ParserInterface
         'showType'  => '', // use for show help
         // 'index'    => 0, // only for argument
         'required'  => false,
+        'envVar'    => '', // support read value from ENV var
         'default'   => null,
         'shorts'    => [], // only for option. ['a', 'b']
         // value validator

src/Flag/AbstractFlag.php

@@ -16,8 +16,10 @@
 use Toolkit\PFlag\Exception\FlagException;
 use Toolkit\PFlag\FlagType;
 use Toolkit\Stdlib\Obj;
+use Toolkit\Stdlib\OS;
 use function is_array;
 use function is_bool;
+use function trim;
 
 /**
  * Class Flag
@@ -55,6 +57,13 @@ abstract class AbstractFlag implements ArrayAccess, FlagInterface
      */
     protected $showType = '';
 
+    /**
+     * ENV var name. support read value from ENV var
+     *
+     * @var string
+     */
+    protected $envVar = '';
+
     /**
      * The default value
      *
@@ -155,6 +164,11 @@ public function init(): void
             $this->default = FlagType::fmtBasicTypeValue($this->type, $this->default);
             $this->value   = $this->default;
         }
+
+        // support set value from ENV.
+        if ($this->envVar && ($envVal = OS::getEnvVal($this->envVar))) {
+            $this->value = FlagType::fmtBasicTypeValue($this->type, $envVal);
+        }
     }
 
     /**
@@ -303,6 +317,7 @@ public function toArray(): array
             'desc'     => $this->desc,
             'type'     => $this->type,
             'default'  => $this->default,
+            'envVar'   => $this->envVar,
             'required' => $this->required,
             'isArray'  => $this->isArray(),
             'showType' => $this->getShowType(),
@@ -364,4 +379,20 @@ public function setValidator(?callable $validator): void
     {
         $this->validator = $validator;
     }
+
+    /**
+     * @return string
+     */
+    public function getEnvVar(): string
+    {
+        return $this->envVar;
+    }
+
+    /**
+     * @param string $envVar
+     */
+    public function setEnvVar(string $envVar): void
+    {
+        $this->envVar = trim($envVar);
+    }
 }

src/SFlags.php

@@ -9,9 +9,9 @@
 
 namespace Toolkit\PFlag;
 
-use Closure;
 use Toolkit\Cli\Helper\FlagHelper;
 use Toolkit\PFlag\Exception\FlagException;
+use Toolkit\Stdlib\OS;
 use function array_slice;
 use function current;
 use function explode;
@@ -577,16 +577,22 @@ protected function parseOptRules(array $rules): void
 
             // has default value
             if (isset($define['default'])) {
+                if ($define['required']) {
+                    throw new FlagException("cannot set a default value, if flag is required. flag: $name");
+                }
+
                 $default = FlagType::fmtBasicTypeValue($type, $define['default']);
 
                 // save as value.
                 $this->opts[$name] = $define['default'] = $default;
+            }
 
-                if ($define['required']) {
-                    throw new FlagException("cannot set a default value, if flag is required. flag: $name");
-                }
+            // support read value from ENV var
+            if ($define['envVar'] && ($envVal = OS::getEnvVal($define['envVar']))) {
+                $this->opts[$name] = FlagType::fmtBasicTypeValue($type, $envVal);
             }
 
+            // has shorts
             if ($define['shorts']) {
                 foreach ($define['shorts'] as $short) {
                     $this->setAlias($name, $short, true);