Default share to Share Target: Partial impl. of Web Share for Desktop.

chrome/browser/webshare/share_service_impl.cc

 // Copyright 2016 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.
 
 #include "chrome/browser/webshare/share_service_impl.h"
 
-#include "base/memory/ptr_util.h"
+#include <algorithm>
+#include <cctype>
+#include <functional>
+#include <utility>
+
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_commands.h"
+#include "chrome/browser/ui/browser_list.h"
+#include "chrome/browser/ui/browser_tabstrip.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
+#include "net/base/escape.h"
 
 // static
 void ShareServiceImpl::Create(blink::mojom::ShareServiceRequest request) {
   mojo::MakeStrongBinding(base::MakeUnique<ShareServiceImpl>(),
                           std::move(request));
 }
 
+// static
+bool ShareServiceImpl::SplitTemplate(
+    const std::string& url_template,
+    std::vector<base::StringPiece>& split_template) {
+  // Find open ("%{") and close ("}") delimeters, and record indices.
+  // If two opens occur before a close, or a close occurs with no preceding
+  // open, return an error code.

[Matt Giuca, 2017/01/09 03:56:54]

Drop "code" (since we're just returning a bool).

[constantina, 2017/01/09 23:51:04]

Done.

+  std::vector<int> delimeter_indices;

[Matt Giuca, 2017/01/09 03:56:54]

Spelling: delimiter, not delimeter.

[constantina, 2017/01/09 23:51:04]

Done.

+  bool last_saw_open = false;
+  for (size_t i = 0; i < url_template.size(); ++i) {
+    if (url_template[i] == '%' && i + 1 < url_template.size() &&
+        url_template[i + 1] == '{') {
+      // Error: Saw two opens in a row; previous wasn't closed.
+      if (last_saw_open) {

[Matt Giuca, 2017/01/09 03:56:54]

Note: You don't *have* to include the braces if you have a single line if
statement with a single line body. You can.

It's up to your personal preference, just letting you know in case you thought
this was a rule. (My preference is to avoid it; you may ignore this if your
preference differs, but be consistent.)

[constantina, 2017/01/09 23:51:04]

Done.

+        return true;
+      }
+      last_saw_open = true;
+      delimeter_indices.push_back(i);
+      i++;
+    } else if (url_template[i] == '}') {
+      // Error: Saw close, with no corresponding open.
+      if (!last_saw_open) {
+        return true;
+      }
+      last_saw_open = false;
+      delimeter_indices.push_back(i + 1);
+    } else if (last_saw_open) {
+      // Error: Non-identifier character seen after open.
+      if (!isalnum(url_template[i]) && url_template[i] != '_' &&

[Matt Giuca, 2017/01/09 03:56:54]

You repeated url_template[i] != '_' twice... did you mean '-' on the second one?

I don't think you can use isalnum here: it's defined as "Checks if the given
character is an alphanumeric character as classified *by the current C locale*"
which means it will match different sets of characters depending on the user's
system locale -- certainly not something we want to depend on here!

I think you should just specify your own function for checking whether a
character is an identifier character.

[constantina, 2017/01/09 23:51:04]

Done.

+          url_template[i] != '_') {
+        return true;
+      }
+    }
+  }
+  // Error: Saw open that was never closed.
+  if (last_saw_open) {
+    return true;
+  }
+
+  // Split |url_template| at the indices given by |delimeter_indices|.
+  split_template.clear();
+  int start_index_to_copy = 0;
+  for (size_t i = 0; i < delimeter_indices.size(); ++i) {
+    split_template.push_back(
+        base::StringPiece(&url_template[0] + start_index_to_copy,

[Matt Giuca, 2017/01/09 03:56:54]

Replace "&url_template[0]" with "url_template.data()".

[constantina, 2017/01/09 23:51:04]

Done.

+                          delimeter_indices[i] - start_index_to_copy));
+    start_index_to_copy = delimeter_indices[i];
+  }
+  split_template.push_back(
+      base::StringPiece(&url_template[0] + start_index_to_copy,
+                        url_template.size() - start_index_to_copy));
+
+  // Remove %{ and } from placeholders in |split_template|.

[Matt Giuca, 2017/01/09 03:56:54]

..."from placeholders (odd-numbered elements)"...

[constantina, 2017/01/09 23:51:04]

Done. Used odd-indexed

+  for (size_t i = 1; i < split_template.size(); i += 2) {
+    base::StringPiece placeholder = split_template[i];
+    split_template[i] =
+        base::StringPiece(placeholder.data() + 2, placeholder.size() - 3);
+  }
+  return 0;

[Matt Giuca, 2017/01/09 03:56:54]

false

[constantina, 2017/01/09 23:51:04]

Done.

+}
+
+// static
+bool ShareServiceImpl::ReplacePlaceholders(const std::string& url_template,
+                                           const std::string& title,
+                                           const std::string& text,
+                                           const GURL& share_url,
+                                           std::string* url_template_filled) {
+  constexpr char kTitlePlaceholder[] = "title";
+  constexpr char kTextPlaceholder[] = "text";
+  constexpr char kUrlPlaceholder[] = "url";
+
+  std::map<base::StringPiece, std::string> placeholder_to_data;
+  placeholder_to_data[kTitlePlaceholder] =
+      net::EscapeQueryParamValue(title, false);
+  placeholder_to_data[kTextPlaceholder] =
+      net::EscapeQueryParamValue(text, false);
+  placeholder_to_data[kUrlPlaceholder] =
+      net::EscapeQueryParamValue(share_url.spec(), false);
+
+  std::vector<base::StringPiece> split_template;
+  bool error = SplitTemplate(url_template, split_template);
+  if (error)
+    return error;
+
+  std::string empty_string = "";
+  // Replace placeholders in |split_template| with share data.
+  for (size_t i = 1; i < split_template.size(); i += 2) {
+    base::StringPiece placeholder = split_template[i];
+    std::map<base::StringPiece, std::string>::iterator it =
+        placeholder_to_data.find(placeholder);
+    if (it != placeholder_to_data.end()) {
+      split_template[i] = base::StringPiece(it->second);
+    } else {
+      split_template[i] = empty_string;
+    }
+  }
+
+  // Precalculate size of |url_filled_template|.

[Matt Giuca, 2017/01/09 03:56:54]

From here to the end of the function can be very neatly summarized as "join a
std::vector<base::StringPiece> into a single std::string", and therefore is ripe
for breaking off into a separate function.

(In fact there is already a JoinString that does this in
base/strings/string_util.h, but it doesn't take a vector of StringPiece so I
think you are OK to just write your own local one here.)

[constantina, 2017/01/09 23:51:04]

Done.

+  url_template_filled->clear();
+  int filled_size = 0;
+  for (const base::StringPiece piece : split_template) {
+    filled_size += piece.size();
+  }
+  url_template_filled->reserve(filled_size);
+
+  // Join |split_template|.
+  for (const base::StringPiece piece : split_template) {
+    *url_template_filled += piece.as_string();
+  }
+  return 0;

[Matt Giuca, 2017/01/09 03:56:54]

false.

[constantina, 2017/01/09 23:51:04]

Done.

+}
+
+void ShareServiceImpl::OpenTargetURL(const GURL& target_url) {
+  Browser* browser = BrowserList::GetInstance()->GetLastActive();
+  chrome::AddTabAt(browser, target_url,
+                   browser->tab_strip_model()->active_index() + 1, true);
+}
+
 void ShareServiceImpl::Share(const std::string& title,
                              const std::string& text,
-                             const GURL& url,
+                             const GURL& share_url,
                              const ShareCallback& callback) {
-  // TODO(constantina): Implement Web Share Target here.
-  NOTIMPLEMENTED();
-  callback.Run(base::Optional<std::string>("Not implemented: navigator.share"));
+  const char kUrlBase[] = "https://wicg.github.io/web-share-target/";
+  constexpr char url_template[] =
+      "demos/sharetarget.html?title=%{title}&text=%{text}&url=%{url}";
+
+  std::string url_template_filled;
+  bool error_occured = ReplacePlaceholders(url_template, title, text, share_url,
+                                           &url_template_filled);
+
+  if (error_occured) {
+    callback.Run(base::Optional<std::string>("Error"));
+    return;
+  }
+
+  GURL target_url(kUrlBase + url_template_filled);
+  OpenTargetURL(target_url);
+
+  callback.Run(base::Optional<std::string>());
 }