firebase:: database:: MutableData
#include <mutable_data.h>
Instances of this class encapsulate the data and priority at a location.
Summary
It is used in transactions, and it is intended to be inspected and then updated to the desired data at that location.
Constructors and Destructors |
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MutableData(const MutableData & rhs)
Copy constructor.
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~MutableData()
Destructor.
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Public functions |
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Child(const char *path)
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Used to obtain a MutableData instance that encapsulates the data and priority at the given relative path.
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Child(const std::string & path)
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Used to obtain a MutableData instance that encapsulates the data and priority at the given relative path.
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HasChild(const char *path) const
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bool
Does this MutableData have data at a particular location?
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HasChild(const std::string & path)
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bool
Does this MutableData have data at a particular location?
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children()
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std::vector< MutableData >
Get all the immediate children of this location.
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children_count()
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size_t
Get the number of children of this location.
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key() const
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const char *
Get the key name of the source location of this data.
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key_string() const
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std::string
Get the key name of the source location of this data.
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operator=(const MutableData & rhs)
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Deprecated.
MutableData is not supposed to be assigned. Copy assignment operator. |
priority()
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Get the priority of the data contained at this snapshot.
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set_priority(const Variant & priority)
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void
Sets the priority of this field, which controls its sort order relative to its siblings.
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set_value(const Variant & value)
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void
Sets the data at this location to the given value.
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value() const
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Get the value of the data contained at this location.
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Public functions
Child
MutableData Child( const char *path )
Used to obtain a MutableData instance that encapsulates the data and priority at the given relative path.
Note that changes made to a child MutableData instance will be visible to the parent and vice versa.
Details | |||
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Parameters |
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Returns |
MutableData for the Child relative to this location. The memory will be freed when the Transaction is finished.
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Child
MutableData Child( const std::string & path )
Used to obtain a MutableData instance that encapsulates the data and priority at the given relative path.
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Parameters |
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Returns |
MutableData for the Child relative to this location. The memory will be freed when the Transaction is finished.
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HasChild
bool HasChild( const char *path ) const
Does this MutableData have data at a particular location?
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Parameters |
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Returns |
True if there is data at the specified location, false if not.
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HasChild
bool HasChild( const std::string & path )
Does this MutableData have data at a particular location?
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Parameters |
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Returns |
True if there is data at the specified location, false if not.
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MutableData
MutableData( const MutableData & rhs )
Copy constructor.
This only makes a shallow copy and copies of MutableData will share the same internal data. I.e. changes to one copy will appear in the other. The main reason the copy constructor is provided is to allow the Child method to return a MutableData by value.
children
std::vector< MutableData > children()
Get all the immediate children of this location.
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Returns |
The immediate children of this location.
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children_count
size_t children_count()
Get the number of children of this location.
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Returns |
The number of immediate children of this location.
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key
const char * key() const
Get the key name of the source location of this data.
Note:The returned pointer is only guaranteed to be valid during the transaction.
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Returns |
Key name of the source location of this data.
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key_string
std::string key_string() const
Get the key name of the source location of this data.
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Returns |
Key name of the source location of this data.
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operator=
MutableData & operator=( const MutableData & rhs )
Copy assignment operator.
Deprecated. MutableData is not supposed to be assigned.
priority
Variant priority()
Get the priority of the data contained at this snapshot.
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Returns |
The value of this location's Priority relative to its siblings.
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set_priority
void set_priority( const Variant & priority )
Sets the priority of this field, which controls its sort order relative to its siblings.
See also:firebase::database::DatabaseReference::SetPriority() for information on how Priority affects the ordering of a node's children.
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Parameters |
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set_value
void set_value( const Variant & value )
Sets the data at this location to the given value.
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Parameters |
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value
Variant value() const
Get the value of the data contained at this location.
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Returns |
The value of the data contained at this location.
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~MutableData
~MutableData()
Destructor.