Added clear function to config writer.

module/VuFind/src/VuFind/Config/Writer.php

@@ -84,7 +84,7 @@ class Writer
      *
      * @param string $section Section to change/add
      * @param string $setting Setting within section to change/add
-     * @param string $value   Value to set
+     * @param string $value   Value to set (or null to unset)
      *
      * @return void
      */
@@ -109,20 +109,26 @@ class Writer
             if (preg_match('/^\[(.+)\]$/', trim($content), $matches)) {
                 // If we just left the target section and didn't find the
                 // desired setting, we should write it to the end.
-                if ($currentSection == $section && !$settingSet) {
+                if ($currentSection == $section && !$settingSet
+                    && $value !== null
+                ) {
                     $line = $setting . ' = "' . $value . '"' . "\n\n" . $line;
                     $settingSet = true;
                 }
                 $currentSection = $matches[1];
             } else if (strstr($content, '=')) {
                 $contentParts = explode('=', $content, 2);
-                $key = reset($contentParts);
-                if ($currentSection == $section && trim($key) == $setting) {
-                    $line = $setting . ' = "' . $value . '"';
+                $key = trim($contentParts[0]);
+                if ($currentSection == $section && $key == $setting) {
+                    $settingSet = true;
+                    if ($value === null) {
+                        continue;
+                    } else {
+                        $line = $setting . ' = "' . $value . '"';
+                    }
                     if (!empty($comment)) {
                         $line .= ' ;' . $comment;
                     }
-                    $settingSet = true;
                 }
             }
 
@@ -131,7 +137,7 @@ class Writer
         }
 
         // Did we loop through everything without finding a place to put the setting?
-        if (!$settingSet) {
+        if (!$settingSet && $value !== null) {
             // We never found the target section?
             if ($currentSection != $section) {
                 $this->content .= '[' . $section . "]\n";
@@ -140,6 +146,19 @@ class Writer
         }
     }
 
+    /**
+     * Remove a setting (convenience wrapper around set to null).
+     *
+     * @param string $section Section to change/add
+     * @param string $setting Setting within section to change/add
+     *
+     * @return void
+     */
+    public function clear($section, $setting)
+    {
+        $this->set($section, $setting, null);
+    }
+
     /**
      * Get the modified file's contents as a string.
      *

module/VuFind/tests/unit-tests/src/VuFindTest/Config/WriterTest.php

@@ -224,4 +224,19 @@ class WriterTest extends \VuFindTest\Unit\TestCase
         $expected = "[general]\nfoo              = \"bar\"\nfoofoofoofoofoofo = \"baz\"\n";
         $this->assertEquals($expected, $test->getContent());
     }
+
+    /**
+     * Test clearing values.
+     *
+     * @return void
+     */
+    public function testClear()
+    {
+        $cfg = "[a]\nb[]=1\nb[]=2\n[b]\nc=3\n";
+        $test = new Writer('fake.ini', $cfg);
+        $test->clear('a', 'b[]');   // clear array
+        $test->clear('b', 'c');     // clear single value
+        $test->clear('z', 'z');     // clear value that does not exist
+        $this->assertEquals("[a]\n[b]", trim($test->getContent()));
+    }
 }
\ No newline at end of file