class Poco::Util::ConfigurationView

Overview

This configuration implements a “view” into a sub-hierarchy of another configuration. More…

#include <ConfigurationView.h>

class ConfigurationView: public Poco::Util::AbstractConfiguration
{
public:
    // construction

    ConfigurationView(
        const std::string& prefix,
        AbstractConfiguration* pConfig
        );

protected:
    // methods

    virtual
    bool
    getRaw(
        const std::string& key,
        std::string& value
        ) const;

    virtual
    void
    setRaw(
        const std::string& key,
        const std::string& value
        );

    virtual
    void
    enumerate(
        const std::string& key,
        Keys& range
        ) const;

    virtual
    void
    removeRaw(const std::string& key);

    std::string
    translateKey(const std::string& key) const;
};

Inherited Members

public:
    // typedefs

    typedef std::vector<std::string> Keys;

    // classes

    class KeyValue;

    // fields

    Poco::BasicEvent<KeyValue> propertyChanging;
    Poco::BasicEvent<const KeyValue> propertyChanged;
    Poco::BasicEvent<const std::string> propertyRemoving;
    Poco::BasicEvent<const std::string> propertyRemoved;

    // methods

    void
    duplicate() const;

    void
    release() const;

    int
    referenceCount() const;

    bool
    hasProperty(const std::string& key) const;

    bool
    hasOption(const std::string& key) const;

    bool
    has(const std::string& key) const;

    std::string
    getString(const std::string& key) const;

    std::string
    getString(
        const std::string& key,
        const std::string& defaultValue
        ) const;

    std::string
    getRawString(const std::string& key) const;

    std::string
    getRawString(
        const std::string& key,
        const std::string& defaultValue
        ) const;

    int
    getInt(const std::string& key) const;

    unsigned int
    getUInt(const std::string& key) const;

    int
    getInt(
        const std::string& key,
        int defaultValue
        ) const;

    unsigned int
    getUInt(
        const std::string& key,
        unsigned int defaultValue
        ) const;

    double
    getDouble(const std::string& key) const;

    double
    getDouble(
        const std::string& key,
        double defaultValue
        ) const;

    bool
    getBool(const std::string& key) const;

    bool
    getBool(
        const std::string& key,
        bool defaultValue
        ) const;

    virtual
    void
    setString(
        const std::string& key,
        const std::string& value
        );

    virtual
    void
    setInt(
        const std::string& key,
        int value
        );

    virtual
    void
    setUInt(
        const std::string& key,
        unsigned int value
        );

    virtual
    void
    setDouble(
        const std::string& key,
        double value
        );

    virtual
    void
    setBool(
        const std::string& key,
        bool value
        );

    void
    keys(Keys& range) const;

    void
    keys(
        const std::string& key,
        Keys& range
        ) const;

    const AbstractConfiguration*
    createView(const std::string& prefix) const;

    AbstractConfiguration*
    createView(const std::string& prefix);

    std::string
    expand(const std::string& value) const;

    void
    remove(const std::string& key);

    void
    enableEvents(bool enable = true);

    bool
    eventsEnabled() const;

protected:
    // methods

    virtual
    bool
    getRaw(
        const std::string& key,
        std::string& value
        ) const = 0;

    virtual
    void
    setRaw(
        const std::string& key,
        const std::string& value
        ) = 0;

    virtual
    void
    enumerate(
        const std::string& key,
        Keys& range
        ) const = 0;

    virtual
    void
    removeRaw(const std::string& key);

    void
    setRawWithEvent(
        const std::string& key,
        std::string value
        );

    static
    int
    parseInt(const std::string& value);

    static
    unsigned
    parseUInt(const std::string& value);

    static
    bool
    parseBool(const std::string& value);

Detailed Documentation

This configuration implements a “view” into a sub-hierarchy of another configuration.

For example, given a configuration with the following properties:

config.value1
config.value2
config.sub.value1
config.sub.value2

and a ConfigurationView with the prefix “config”, then the above properties will be available via the view as

value1
value2
sub.value1
sub.value2

A ConfigurationView is most useful in combination with a LayeredConfiguration.

If a property is not found in the view, it is searched in the original configuration. Given the above example configuration, the property named “config.value1” will still be found in the view.

The main reason for this is that placeholder expansion (${property}) still works as expected given a ConfigurationView.

Construction

ConfigurationView(
    const std::string& prefix,
    AbstractConfiguration* pConfig
    )

Creates the ConfigurationView.

The ConfigurationView does not take ownership of the passed configuration.

Methods

virtual
bool
getRaw(
    const std::string& key,
    std::string& value
    ) const

If the property with the given key exists, stores the property’s value in value and returns true.

Otherwise, returns false.

Must be overridden by subclasses.

virtual
void
setRaw(
    const std::string& key,
    const std::string& value
    )

Sets the property with the given key to the given value.

An already existing value for the key is overwritten.

Must be overridden by subclasses.

virtual
void
enumerate(
    const std::string& key,
    Keys& range
    ) const

Returns in range the names of all subkeys under the given key.

If an empty key is passed, all root level keys are returned.

virtual
void
removeRaw(const std::string& key)

Removes the property with the given key.

Does nothing if the key does not exist.

Should be overridden by subclasses; the default implementation throws a Poco::NotImplementedException.