components/search/search.h

// 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_SEARCH_SEARCH_H_
#define COMPONENTS_SEARCH_SEARCH_H_

#include <stdint.h>

#include <string>

#include "base/strings/string_split.h"

namespace search {

// Returns whether the Instant Extended API is enabled. This is always true on
// desktop and false on mobile.
bool IsInstantExtendedAPIEnabled();

// Returns the value to pass to the &espv CGI parameter when loading the
// embedded search page from the user's default search provider. Returns 0 if
// the Instant Extended API is not enabled.
uint64_t EmbeddedSearchPageVersion();

// Type for a collection of experiment configuration parameters.
typedef base::StringPairs FieldTrialFlags;

// Finds the active field trial group name and parses out the configuration
// flags. On success, |flags| will be filled with the field trial flags. |flags|
// must not be NULL. Returns true iff the active field trial is successfully
// parsed and not disabled.
// Note that |flags| may be successfully populated in some cases when false is
// returned - in these cases it should not be used.
// Exposed for testing only.
bool GetFieldTrialInfo(FieldTrialFlags* flags);

// Given a FieldTrialFlags object, returns the uint64_t value of the provided
// flag.
// Exposed for testing only.
uint64_t GetUInt64ValueForFlagWithDefault(const std::string& flag,
                                          uint64_t default_value,
                                          const FieldTrialFlags& flags);

// Returns a string indicating whether InstantExtended is enabled, suitable
// for adding as a query string param to the homepage or search requests.
std::string InstantExtendedEnabledParam();

// Returns a string that will cause the search results page to update
// incrementally. Currently, Instant Extended passes a different param to
// search results pages that also has this effect, so by default this function
// returns the empty string when Instant Extended is enabled. However, when
// doing instant search result prerendering, we still need to pass this param,
// as Instant Extended does not cause incremental updates by default for the
// prerender page. Callers should set |for_prerender| in this case to force
// the returned string to be non-empty.
std::string ForceInstantResultsParam(bool for_prerender);

}  // namespace search

#endif  // COMPONENTS_SEARCH_SEARCH_H_