Add passthru to AphrontRequest

Summary:
For transaction interfaces, I want to prompt the user when they take an action that has no effect, e.g.:

  Action Has No Effect

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We already do this for Differential, but it's all hard-coded. T912 is an open task for fixing this for Maniphest.

To do this in a general way, I want to embed the entire request in the dialog as hidden inputs, then add a "__continue__" key and resubmit the form. The endpoint will read this key the second time through and apply what effects it can (e.g., just post a comment).

This adds a mechanism for getting all the request data, minus "magic" like __dialog__ and __csrf__. We need to jump through some hoops because of how PHP encodes arrays.

Test Plan: Ran unit tests, built "no effect" dialogs on top of this.

Reviewers: btrahan, vrana

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T912, T2104

Differential Revision: https://secure.phabricator.com/D4158

src/aphront/AphrontRequest.php

@@ -17,6 +17,7 @@ final class AphrontRequest {
   const TYPE_FORM = '__form__';
   const TYPE_CONDUIT = '__conduit__';
   const TYPE_WORKFLOW = '__wflow__';
+  const TYPE_CONTINUE = '__continue__';
 
   private $host;
   private $path;
@@ -334,4 +335,58 @@ final class AphrontRequest {
     return true;
   }
 
+  public function isContinueRequest() {
+    return $this->isFormPost() && $this->getStr('__continue__');
+  }
+
+  /**
+   * Get application request parameters in a flattened form suitable for
+   * inclusion in an HTTP request, excluding parameters with special meanings.
+   * This is primarily useful if you want to ask the user for more input and
+   * then resubmit their request.
+   *
+   * @return  dict<string, string>  Original request parameters.
+   */
+  public function getPassthroughRequestParameters() {
+    $data = self::flattenData($this->getRequestData());
+
+    // Remove magic parameters like __dialog__ and __ajax__.
+    foreach ($data as $key => $value) {
+      if (strncmp($key, '__', 2)) {
+        unset($data[$key]);
+      }
+    }
+
+    return $data;
+  }
+
+
+  /**
+   * Flatten an array of key-value pairs (possibly including arrays as values)
+   * into a list of key-value pairs suitable for submitting via HTTP request
+   * (with arrays flattened).
+   *
+   * @param   dict<string, wild>    Data to flatten.
+   * @return  dict<string, string>  Flat data suitable for inclusion in an HTTP
+   *                                request.
+   */
+  public static function flattenData(array $data) {
+    $result = array();
+    foreach ($data as $key => $value) {
+      if (is_array($value)) {
+        foreach (self::flattenData($value) as $fkey => $fvalue) {
+          $fkey = '['.preg_replace('/(?=\[)|$/', ']', $fkey, $limit = 1);
+          $result[$key.$fkey] = $fvalue;
+        }
+      } else {
+        $result[$key] = (string)$value;
+      }
+    }
+
+    ksort($result);
+
+    return $result;
+  }
+
+
 }

src/aphront/__tests__/AphrontRequestTestCase.php

@@ -79,4 +79,56 @@ final class AphrontRequestTestCase extends PhabricatorTestCase {
     }
   }
 
+  public function testFlattenRequestData() {
+    $test_cases = array(
+      array(
+        'a' => 'a',
+        'b' => '1',
+        'c' => '',
+      ),
+      array(
+        'a' => 'a',
+        'b' => '1',
+        'c' => '',
+      ),
+
+      array(
+        'x' => array(
+          0 => 'a',
+          1 => 'b',
+          2 => 'c',
+        ),
+      ),
+      array(
+        'x[0]' => 'a',
+        'x[1]' => 'b',
+        'x[2]' => 'c',
+      ),
+
+      array(
+        'x' => array(
+          'y' => array(
+            'z' => array(
+              40 => 'A',
+              50 => 'B',
+              'C' => 60,
+            ),
+          ),
+        ),
+      ),
+      array(
+        'x[y][z][40]' => 'A',
+        'x[y][z][50]' => 'B',
+        'x[y][z][C]'  => '60',
+      ),
+    );
+
+    for ($ii = 0; $ii < count($test_cases); $ii += 2) {
+      $input  = $test_cases[$ii];
+      $expect = $test_cases[$ii + 1];
+
+      $this->assertEqual($expect, AphrontRequest::flattenData($input));
+    }
+  }
+
 }