GstUriHandler

## GstUriHandler GstUriHandler — Interface to ease URI handling in plugins. |

## Synopsis

    #include <gst/gst.h>

                        GstURIHandler;
    struct              GstURIHandlerInterface;
    enum                GstURIType;
    enum                GstURIError;
    GQuark              gst_uri_error_quark                 (void);
    #define             GST_URI_TYPE_IS_VALID               (type)
    gboolean            gst_uri_protocol_is_valid           (const gchar *protocol);
    gboolean            gst_uri_protocol_is_supported       (const GstURIType type,
                                                             const gchar *protocol);
    gboolean            gst_uri_is_valid                    (const gchar *uri);
    gboolean            gst_uri_has_protocol                (const gchar *uri,
                                                             const gchar *protocol);
    gchar *             gst_uri_get_protocol                (const gchar *uri);
    gchar *             gst_uri_get_location                (const gchar *uri);
    gchar *             gst_uri_construct                   (const gchar *protocol,
                                                             const gchar *location);
    gchar *             gst_filename_to_uri                 (const gchar *filename,
                                                             GError **error);
    GstElement *        gst_element_make_from_uri           (const GstURIType type,
                                                             const gchar *uri,
                                                             const gchar *elementname,
                                                             GError **error);
    GstURIType          gst_uri_handler_get_uri_type        (GstURIHandler *handler);
    const gchar * const * gst_uri_handler_get_protocols     (GstURIHandler *handler);
    gchar *             gst_uri_handler_get_uri             (GstURIHandler *handler);
    gboolean            gst_uri_handler_set_uri             (GstURIHandler *handler,
                                                             const gchar *uri,
                                                             GError **error);

## Object Hierarchy

      GInterface
       +----GstURIHandler

## Description

The URIHandler is an interface that is implemented by Source and Sink GstElement to simplify then handling of URI.

An application can use the following functions to quickly get an element that handles the given URI for reading or writing (`gst_element_make_from_uri()`).

Source and Sink plugins should implement this interface when possible.

Last reviewed on 2005-11-09 (0.9.4)

## Details

### GstURIHandler

    typedef struct _GstURIHandler GstURIHandler;

Opaque GstURIHandler structure.

### struct GstURIHandlerInterface

    struct GstURIHandlerInterface {
      GTypeInterface parent;

      /* vtable */
      /* querying capabilities */
      GstURIType             (* get_type)           (GType type);
      const gchar * const *  (* get_protocols)      (GType type);

      /* using the interface */
      gchar *                (* get_uri)            (GstURIHandler * handler);
      gboolean               (* set_uri)            (GstURIHandler * handler,
                                                     const gchar   * uri,
                                                     GError       ** error);
    };

Any GstElement using this interface should implement these methods.

GTypeInterface `parent`; | The parent interface type
`get_type` () | Method to tell whether the element handles source or sink URI.
`get_protocols` () | Method to return the list of protocols handled by the element.
`get_uri` () | Method to return the URI currently handled by the element.
`set_uri` () | Method to set a new URI.

### enum GstURIType

    typedef enum {
      GST_URI_UNKNOWN,
      GST_URI_SINK,
      GST_URI_SRC
    } GstURIType;

The different types of URI direction.

`GST_URI_UNKNOWN` | The URI direction is unknown
`GST_URI_SINK` | The URI is a consumer.
`GST_URI_SRC` | The URI is a producer.

### enum GstURIError

    typedef enum {
      GST_URI_ERROR_UNSUPPORTED_PROTOCOL,
      GST_URI_ERROR_BAD_URI,
      GST_URI_ERROR_BAD_STATE,
      GST_URI_ERROR_BAD_REFERENCE
    } GstURIError;

Different URI-related errors that can occur.

`GST_URI_ERROR_UNSUPPORTED_PROTOCOL` | The protocol is not supported
`GST_URI_ERROR_BAD_URI` | There was a problem with the URI
`GST_URI_ERROR_BAD_STATE` | Could not set or change the URI because the URI handler was in a state where that is not possible or not permitted
`GST_URI_ERROR_BAD_REFERENCE` | There was a problem with the entity that the URI references

### gst_uri_error_quark ()

    GQuark              gst_uri_error_quark                 (void);

### GST_URI_TYPE_IS_VALID()

    #define GST_URI_TYPE_IS_VALID(type) ((type) == GST_URI_SRC || (type) == GST_URI_SINK)

Tests if the type direction is valid.

`type` : | A GstURIType

### gst_uri_protocol_is_valid ()

    gboolean            gst_uri_protocol_is_valid           (const gchar *protocol);

Tests if the given string is a valid protocol identifier. Protocols must consist of alphanumeric characters, '+', '-' and '.' and must start with a alphabetic character. See RFC 3986 Section 3.1.

`protocol` : | A string
Returns : | TRUE if the string is a valid protocol identifier, FALSE otherwise.

### gst_uri_protocol_is_supported ()

    gboolean            gst_uri_protocol_is_supported       (const GstURIType type,
                                                             const gchar *protocol);

Checks if an element exists that supports the given URI protocol. Note that a positive return value does not imply that a subsequent call to `gst_element_make_from_uri()` is guaranteed to work.

`type` : | Whether to check for a source or a sink
`protocol` : | Protocol that should be checked for (e.g. "http" or "smb")
Returns : | TRUE

### gst_uri_is_valid ()

    gboolean            gst_uri_is_valid                    (const gchar *uri);

Tests if the given string is a valid URI identifier. URIs start with a valid scheme followed by ":" and maybe a string identifying the location.

`uri` : | A URI string
Returns : | TRUE if the string is a valid URI

### gst_uri_has_protocol ()

    gboolean            gst_uri_has_protocol                (const gchar *uri,
                                                             const gchar *protocol);

Checks if the protocol of a given valid URI matches `protocol`.

`uri` : | a URI string
`protocol` : | a protocol string (e.g. "http")
Returns : | `TRUE` if the protocol matches.

### gst_uri_get_protocol ()

    gchar *             gst_uri_get_protocol                (const gchar *uri);

Extracts the protocol out of a given valid URI. The returned string must be freed using `g_free()`.

`uri` : | A URI string
Returns : | The protocol for this URI.

### gst_uri_get_location ()

    gchar *             gst_uri_get_location                (const gchar *uri);

Extracts the location out of a given valid URI, ie. the protocol and "://" are stripped from the URI, which means that the location returned includes the hostname if one is specified. The returned string must be freed using `g_free()`.

Free-function: g_free

`uri` : | A URI string
Returns : | the location for this URI. Returns NULL if the URI isn't valid. If the URI does not contain a location, an empty string is returned. [transfer full]

### gst_uri_construct ()

    gchar *             gst_uri_construct                   (const gchar *protocol,
                                                             const gchar *location);

Constructs a URI for a given valid protocol and location.

Free-function: g_free

`protocol` : | Protocol for URI
`location` : | Location for URI. [transfer none]
Returns : | a new string for this URI. Returns NULL if the given URI protocol is not valid, or the given location is NULL. [transfer full]

### gst_filename_to_uri ()

    gchar *             gst_filename_to_uri                 (const gchar *filename,
                                                             GError **error);

Similar to `g_filename_to_uri()`, but attempts to handle relative file paths as well. Before converting `filename` into an URI, it will be prefixed by the current working directory if it is a relative path, and then the path will be canonicalised so that it doesn't contain any './' or '../' segments.

On Windows filename should be in UTF-8 encoding.

`filename` : | absolute or relative file name path
`error` : | pointer to error, or NULL

### gst_element_make_from_uri ()

    GstElement *        gst_element_make_from_uri           (const GstURIType type,
                                                             const gchar *uri,
                                                             const gchar *elementname,
                                                             GError **error);

Creates an element for handling the given URI.

`type` : | Whether to create a source or a sink
`uri` : | URI to create an element for
`elementname` : | Name of created element, can be NULL. [allow-none]
`error` : | address where to store error information, or NULL. [allow-none]
Returns : | a new element or NULL if none could be created. [transfer full]

### gst_uri_handler_get_uri_type ()

    GstURIType          gst_uri_handler_get_uri_type        (GstURIHandler *handler);

Gets the type of the given URI handler

`handler` : | A GstURIHandler.
Returns : | the GstURIType of the URI handler. Returns GST_URI_UNKNOWN if the `handler` isn't implemented correctly.

### gst_uri_handler_get_protocols ()

    const gchar * const * gst_uri_handler_get_protocols     (GstURIHandler *handler);

Gets the list of protocols supported by `handler`. This list may not be modified.

`handler` : | A GstURIHandler.
Returns : | the supported protocols. Returns NULL if the `handler` isn't implemented properly, or the `handler` doesn't support any protocols. [transfer none][element-type utf8]

### gst_uri_handler_get_uri ()

    gchar *             gst_uri_handler_get_uri             (GstURIHandler *handler);

Gets the currently handled URI.

`handler` : | A GstURIHandler
Returns : | the URI currently handled by the `handler`. Returns NULL if there are no URI currently handled. The returned string must be freed with `g_free()` when no longer needed. [transfer full]

### gst_uri_handler_set_uri ()

    gboolean            gst_uri_handler_set_uri             (GstURIHandler *handler,
                                                             const gchar *uri,
                                                             GError **error);

Tries to set the URI of the given handler.

`handler` : | A GstURIHandler
`uri` : | URI to set
`error` : | address where to store a GError in case of an error, or NULL. [allow-none]
Returns : | TRUE if the URI was set successfully, else FALSE.