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 <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(

[Sam McNally, 2017/01/09 03:15:21]

Make this a function in the anonymous namespace.

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

Done.

+    const std::string& url_template,

[Sam McNally, 2017/01/09 03:15:21]

StringPiece

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

Done.

+    std::vector<base::StringPiece>& split_template) {

[Sam McNally, 2017/01/09 03:15:21]

Use pointers for out parameters.

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

Done.

+  // 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.
+  std::vector<int> delimeter_indices;

[Sam McNally, 2017/01/09 03:15:21]

std::vector<size_t> delimiter_indices;

[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() &&

[Sam McNally, 2017/01/09 03:15:21]

How about url_template.substr(i, 2) == "%{"?

[constantina, 2017/01/09 23:51:03]

Done.

+        url_template[i + 1] == '{') {
+      // Error: Saw two opens in a row; previous wasn't closed.
+      if (last_saw_open) {
+        return true;

[Sam McNally, 2017/01/09 03:15:21]

When returning a bool, true usually means success.

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

Swapped true and false.

+      }
+      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 (!isdigit(url_template[i]) && !isalpha(url_template[i]) &&
+          url_template[i] != '_' && url_template[i] != '_') {

[Sam McNally, 2017/01/09 03:15:21]

We really like underscores?

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

Fixed. We also love hyphens.

+        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(

[Sam McNally, 2017/01/09 03:15:21]

(assuming |url_template| is a StringPiece)

push_back(url_template.substr(start_index_to_copy, delimeter_indices[i] -
start_index_to_copy))

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

Done.

+        base::StringPiece(&url_template[0] + start_index_to_copy,
+                          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|.

[Sam McNally, 2017/01/09 03:15:21]

I wonder if it might be simpler to store a before and after position for each
delimiter instead.

[Matt Giuca, 2017/01/09 04:50:14]

What do you mean exactly? Like separate index vars for the open and close?

Connie and I just had a chat about reworking this algorithm. I suggested
something a bit along these lines (separate code for finding the end delimiter
to the start) but nothing we thought of significantly improved the complexity
and I think I'm happy to leave it as-is.

If you disagree, can you be more specific about what you want?

[constantina, 2017/01/09 23:51:03]

As discussed in person, we will store the StringPieces, and do the replacements,
in the first for loop simultaneously, instead of storing indices. Will do this
in the next patch.

+  for (size_t i = 1; i < split_template.size(); i += 2) {
+    base::StringPiece placeholder = split_template[i];

[Sam McNally, 2017/01/09 03:15:21]

base::StringPiece&

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

Done.

+    split_template[i] =

[Sam McNally, 2017/01/09 03:15:21]

placeholder = placeholder.substr(2, placeholder.size() - 3)

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

Done.

+        base::StringPiece(placeholder.data() + 2, placeholder.size() - 3);
+  }
+  return 0;

[Sam McNally, 2017/01/09 03:15:21]

Don't implicitly convert to bool.

[constantina, 2017/01/09 23:51:03]

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;

[Sam McNally, 2017/01/09 03:15:21]

Be consistent with whether single line ifs have braces.

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

Done.

+
+  std::string empty_string = "";

[Sam McNally, 2017/01/09 03:15:21]

Remove.

[constantina, 2017/01/09 23:51:03]

Done.

+  // 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 =

[Sam McNally, 2017/01/09 03:15:21]

auto

[constantina, 2017/01/09 23:51:03]

Done.

+        placeholder_to_data.find(placeholder);
+    if (it != placeholder_to_data.end()) {
+      split_template[i] = base::StringPiece(it->second);

[Sam McNally, 2017/01/09 03:15:21]

You shouldn't need an explicit cast here.

[constantina, 2017/01/09 23:51:03]

Done.

+    } else {
+      split_template[i] = empty_string;

[Sam McNally, 2017/01/09 03:15:21]

.clear();

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

Done.

+    }
+  }
+
+  // Precalculate size of |url_filled_template|.
+  url_template_filled->clear();
+  int filled_size = 0;

[Sam McNally, 2017/01/09 03:15:21]

size_t

[constantina, 2017/01/09 23:51:03]

Done.

+  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) {

[Sam McNally, 2017/01/09 03:15:21]

const auto& piece

[constantina, 2017/01/09 23:51:03]

Done.

+    *url_template_filled += piece.as_string();

[Sam McNally, 2017/01/09 03:15:21]

piece.AppendToString(url_template_filled);

as_string() creates a copy.

[constantina, 2017/01/09 23:51:03]

Done.

+  }
+  return 0;
+}
+
+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);

[Sam McNally, 2017/01/09 03:15:21]

We should probably return an error if !target_url.is_valid().

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

Done.

+  OpenTargetURL(target_url);
+
+  callback.Run(base::Optional<std::string>());
 }