Add a class to parse answer json.

components/omnibox/suggestion_answer.h

Index: components/omnibox/suggestion_answer.h
diff --git a/components/omnibox/suggestion_answer.h b/components/omnibox/suggestion_answer.h
new file mode 100644
index 0000000000000000000000000000000000000000..2df06705839c09a2deac55fea2ee66781438dd88
--- /dev/null
+++ b/components/omnibox/suggestion_answer.h
@@ -0,0 +1,133 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_OMNIBOX_SUGGESTION_ANSWER_H_
+#define COMPONENTS_OMNIBOX_SUGGESTION_ANSWER_H_
+
+#include <string>
+#include <vector>
+
+#include "url/gurl.h"
+
+namespace base {
+class DictionaryValue;
+}
+
+// Structured representation of the JSON payload of a suggestion with an answer.
+// An answer has exactly two image lines, so called because they are a
+// combination of text and an optional image URL.  Each image line has 1 or more
+// text fields, each of which is required to contain a string and an integer
+// type.  The text fields are contained in a non-empty vector and two optional
+// named properties, referred to as "additional text" and "status text".
+//
+// When represented in the UI, these elements should be styled and laid out
+// according to the specification at http://goto.google.com/ais_api.

[groby-ooo-7-16, 2014/10/23 00:46:20]

We probably shouldn't have that URL here.

[Justin Donnelly, 2014/10/23 17:59:37]

Doesn't seem like this is a thing that's enforced:

https://code.google.com/p/chromium/codesearch#search/&q=http://go/&sq=package...

Wouldn't it better to make the info easily accessible to Google developers than
to leave it out just to avoid a possibly annoying broken link for non-Google
developers?  I'm genuinely asking and am open to persuasion here.

[groby-ooo-7-16, 2014/10/23 21:59:54]

You're right, it's not enforced. I'm probably overly paranoid.

+class SuggestionAnswer {
+ public:
+  class TextField {
+   public:
+    // Construct an empty, invalid field.
+    TextField();
+    ~TextField();
+
+    static bool ParseTextField(
+        const base::DictionaryValue* field_json, TextField* text_field);
+
+    bool operator==(const TextField& field) const;
+    bool operator!=(const TextField& field) const;
+
+    bool is_valid() const { return !text_.empty() && type_ >= 0; }
+
+    const std::string& text() const { return text_; }
+    int type() const { return type_; }
+
+    // Remove all data. After this call, the field will be invalid.
+    void Clear();
+
+   private:
+    std::string text_;
+    int type_;
+  };
+
+  typedef std::vector<TextField> TextFields;
+
+  class ImageLine {
+   public:
+    // Construct an empty, invalid line.
+    ImageLine();
+    ~ImageLine();
+
+    static bool ParseImageLine(
+        const base::DictionaryValue* line_json, ImageLine* image_line);
+
+    bool operator==(const ImageLine& line) const;
+    bool operator!=(const ImageLine& line) const;
+
+    // A line is only valid if the JSON representation was successfully parsed
+    // and all expected constraints were met (primarily, that there was at least
+    // one text field in the repeated text field property).
+    bool is_valid() const { return is_valid_; }
+
+    const std::vector<TextField>& text_fields() const { return text_fields_; }
+
+    bool has_additional_text() const { return additional_text_.is_valid(); }
+    const TextField& additional_text() const { return additional_text_; }
+
+    bool has_status_text() const { return status_text_.is_valid(); }
+    const TextField& status_text() const { return status_text_; }
+
+    bool has_image_url() const { return image_url_.is_valid(); }
+    const GURL& image_url() const { return image_url_; }
+
+    // Remove all data. After this call, the line will be invalid.
+    void Clear();
+
+   private:
+    TextFields text_fields_;
+    TextField additional_text_;
+    TextField status_text_;
+    GURL image_url_;
+    bool is_valid_;
+  };
+
+  // Construct an empty, invalid answer.
+  SuggestionAnswer();
+  ~SuggestionAnswer();
+
+  static bool ParseAnswer(
+        const std::string& answer_json, SuggestionAnswer* answer);
+  static bool ParseAnswer(
+        const base::DictionaryValue* answer_json, SuggestionAnswer* answer);
+
+  bool operator==(const SuggestionAnswer& answer) const;
+  bool operator!=(const SuggestionAnswer& answer) const;
+
+  // An answer is valid only if both a type has been set and the JSON
+  // representation was successfully parsed and all expected constraints were
+  // met (primarily that there were exactly two properly formed image lines).
+  bool is_valid() const {
+    return type_ >= 0 && first_line_.is_valid() && second_line_.is_valid();
+  }
+
+  const ImageLine& first_line() const { return first_line_; }
+  const ImageLine& second_line() const { return second_line_; }
+  int type() const { return type_; }
+
+  // Specify the type of this answer.  The string will be interpreted as a
+  // base10 integer.  If it can't be parsed as such, the type will be set to -1.
+  // Valid types must be non-negatiave and are defined in
+  // google3/logs/gws/config/visual_element_configuration.

[groby-ooo-7-16, 2014/10/23 00:46:19]

Probably also not :)

[Justin Donnelly, 2014/10/23 17:59:37]

Ditto

[groby-ooo-7-16, 2014/10/23 21:59:54]

Usually only referring to base or third_party. I'd really rather not... If you
want a link, make it a go one?

[Justin Donnelly, 2014/10/24 14:58:08]

Switched to a go link.  We should talk more offline if you're still concerned
about it.  My feeling is that omitting a useful link like this won't make the
fact that these codes are publicly undocumented go away, it'll just make it
harder for anyone to figure out where they come from.

+  void SetType(const std::string& type);
+  void SetType(const base::string16& type);
+
+  // Remove all data. After this call, the answer will be invalid.
+  void Clear();
+
+ private:
+  ImageLine first_line_;
+  ImageLine second_line_;
+  int type_;
+};
+
+#endif  // COMPONENTS_OMNIBOX_SUGGESTION_ANSWER_H_