utd.h

Overview

Defines APIs and structs related to the Uniform Type Descriptors (UTDs).

File to include: <database/udmf/utd.h>

Library: libudmf.so

System capability: SystemCapability.DistributedDataManager.UDMF.Core

Since: 12

Related module: UDMF

Summary

Structs

Name	typedef Keyword	Description
OH_Utd	OH_Utd	Defines a struct for a UTD.

Functions

Name	Description
OH_Utd* OH_Utd_Create(const char* typeId)	Creates an OH_Utd instance and a pointer to it.
void OH_Utd_Destroy(OH_Utd* pThis)	Destroys an OH_Utd instance.
const char* OH_Utd_GetTypeId(OH_Utd* pThis)	Obtains the type ID from an OH_Utd instance.
const char* OH_Utd_GetDescription(OH_Utd* pThis)	Obtains the description from an OH_Utd instance.
const char* OH_Utd_GetReferenceUrl(OH_Utd* pThis)	Obtains the URL from an OH_Utd instance.
const char* OH_Utd_GetIconFile(OH_Utd* pThis)	Obtains the path of the default icon file from an OH_Utd instance.
const char** OH_Utd_GetBelongingToTypes(OH_Utd* pThis, unsigned int* count)	Obtains the relationships between the data from an OH_Utd instance.
const char** OH_Utd_GetFilenameExtensions(OH_Utd* pThis, unsigned int* count)	Obtains the file name extensions associated with an OH_Utd instance.
const char** OH_Utd_GetMimeTypes(OH_Utd* pThis, unsigned int* count)	Obtains the MIME types associated with an OH_Utd instance.
const char** OH_Utd_GetTypesByFilenameExtension(const char* extension, unsigned int* count)	Obtains the uniform data types based on the file name extensions.
const char** OH_Utd_GetTypesByMimeType(const char* mimeType, unsigned int* count)	Obtains the uniform data types based on the MIME types.
bool OH_Utd_BelongsTo(const char* srcTypeId, const char* destTypeId)	Checks whether a UTD belongs to the target UTD.
bool OH_Utd_IsLower(const char* srcTypeId, const char* destTypeId)	Checks whether a UTD is a lower-level type of the target UTD. For example, TYPE_SCRIPT is a lower-level type of SOURCE_CODE, and TYPE_SCRIPT and SOURCE_CODE are lower-level types of PLAIN_TEXT.
bool OH_Utd_IsHigher(const char* srcTypeId, const char* destTypeId)	Checks whether a UTD is a higher-level type of the target UTD. For example, SOURCE_CODE is a higher-level type of TYPE_SCRIPT, and PLAIN_TEXT is a higher-level type of SOURCE_CODE and TYPE_SCRIPT.
bool OH_Utd_Equals(OH_Utd* utd1, OH_Utd* utd2)	Checks whether two UTDs are the same.
void OH_Utd_DestroyStringList(const char** list, unsigned int count)	Destroys a UTD list.

Function Description

OH_Utd_Create()

OH_Utd* OH_Utd_Create(const char* typeId)

Description

Creates an OH_Utd instance and a pointer to it.

Since: 12

Parameters

Name	Description
const char* typeId	Pointer to the type ID of the instance to create.

Returns

Type	Description
OH_Utd*	Returns a pointer to the OH_Utd instance created if the operation is successful; returns nullptr otherwise. If this pointer is no longer required, use OH_Utd_Destroy to destroy it. Otherwise, memory leaks may occur.

OH_Utd_Destroy()

void OH_Utd_Destroy(OH_Utd* pThis)

Description

Destroys an OH_Utd instance.

Since: 12

Parameters

Name	Description
OH_Utd* pThis	Pointer to the OH_Utd instance.

OH_Utd_GetTypeId()

const char* OH_Utd_GetTypeId(OH_Utd* pThis)

Description

Obtains the type ID from an OH_Utd instance.

Since: 12

Parameters

Name	Description
OH_Utd* pThis	Pointer to the OH_Utd instance.

Returns

Type	Description
const char*	Returns a pointer to the type ID obtained if the operation is successful; returns nullptr otherwise.

OH_Utd_GetDescription()

const char* OH_Utd_GetDescription(OH_Utd* pThis)

Description

Obtains the description from an OH_Utd instance.

Since: 12

Parameters

Name	Description
OH_Utd* pThis	Pointer to the OH_Utd instance.

Returns

Type	Description
const char*	Returns a pointer to the description obtained if the operation is successful; returns nullptr otherwise.

OH_Utd_GetReferenceUrl()

const char* OH_Utd_GetReferenceUrl(OH_Utd* pThis)

Description

Obtains the URL from an OH_Utd instance.

Since: 12

Parameters

Name	Description
OH_Utd* pThis	Pointer to the OH_Utd instance.

Returns

Type	Description
const char*	Returns a pointer to the URL obtained if the operation is successful; returns nullptr otherwise.

OH_Utd_GetIconFile()

const char* OH_Utd_GetIconFile(OH_Utd* pThis)

Description

Obtains the path of the default icon file from an OH_Utd instance.

Since: 12

Parameters

Name	Description
OH_Utd* pThis	Pointer to the OH_Utd instance.

Returns

Type	Description
const char*	Returns a pointer to the path of the default icon file obtained if the operation is successful; returns nullptr otherwise.

OH_Utd_GetBelongingToTypes()

const char** OH_Utd_GetBelongingToTypes(OH_Utd* pThis, unsigned int* count)

Description

Obtains the relationships between the data from an OH_Utd instance.

Since: 12

Parameters

Name	Description
OH_Utd* pThis	Pointer to the OH_Utd instance.
unsigned int* count	Pointer to the number of data types obtained.

Returns

Type	Description
const char**	Returns a pointer to the relationship information obtained if the operation is successful; returns nullptr otherwise.

OH_Utd_GetFilenameExtensions()

const char** OH_Utd_GetFilenameExtensions(OH_Utd* pThis, unsigned int* count)

Description

Obtains the file name extensions associated with an OH_Utd instance.

Since: 12

Parameters

Name	Description
OH_Utd* pThis	Pointer to the OH_Utd instance.
unsigned int* count	Pointer to the number of file name extensions obtained.

Returns

Type	Description
const char**	Returns a pointer to the file name extensions obtained if the operation is successful; returns nullptr otherwise.

OH_Utd_GetMimeTypes()

const char** OH_Utd_GetMimeTypes(OH_Utd* pThis, unsigned int* count)

Description

Obtains the MIME types associated with an OH_Utd instance.

Since: 12

Parameters

Name	Description
OH_Utd* pThis	Pointer to the OH_Utd instance.
unsigned int* count	Pointer to the number of MIME types obtained.

Returns

Type	Description
const char**	Returns a pointer to the MIME types obtained if the operation is successful; returns nullptr otherwise.

OH_Utd_GetTypesByFilenameExtension()

const char** OH_Utd_GetTypesByFilenameExtension(const char* extension, unsigned int* count)

Description

Obtains the UTDs based on the file name extensions.

Since: 12

Parameters

Name	Description
const char* extension	Pointer to the file name extensions.
unsigned int* count	Pointer to the number of data types obtained.

Returns

Type	Description
const char**	Returns a pointer to the UTDs obtained. If it is no longer required, use OH_Utd_DestroyStringList to destroy it. Otherwise, memory leakage occurs.

OH_Utd_GetTypesByMimeType()

const char** OH_Utd_GetTypesByMimeType(const char* mimeType, unsigned int* count)

Description

Obtains the UTDs based on the MIME types.

Since: 12

Parameters

Name	Description
const char* mimeType	Pointer to the MIME types.
unsigned int* count	Pointer to the number of data types obtained.

Returns

Type	Description
const char**	Returns a double pointer to the UTDs obtained. If it is no longer required, use OH_Utd_DestroyStringList to destroy it. Otherwise, memory leakage occurs.

OH_Utd_BelongsTo()

bool OH_Utd_BelongsTo(const char* srcTypeId, const char* destTypeId)

Description

Checks whether a UTD belongs to the target UTD.

Since: 12

Parameters

Name	Description
const char* srcTypeId	Pointer to the UTD to check.
const char* destTypeId	Pointer to the target UTD.

Returns

Type	Description
bool	Returns true if the UTD belongs to the target UTD; returns false otherwise.

OH_Utd_IsLower()

bool OH_Utd_IsLower(const char* srcTypeId, const char* destTypeId)

Description

Checks whether a UTD is a lower-level type of the target UTD. For example, TYPE_SCRIPT is a lower-level type of SOURCE_CODE, and TYPE_SCRIPT and SOURCE_CODE are lower-level types of PLAIN_TEXT.

Since: 12

Parameters

Name	Description
const char* srcTypeId	Pointer to the UTD to check.
const char* destTypeId	Pointer to the target UTD.

Returns

Type	Description
bool	Returns true if the UTD is a lower-level type of the target UTD; returns false otherwise.

OH_Utd_IsHigher()

bool OH_Utd_IsHigher(const char* srcTypeId, const char* destTypeId)

Description

Checks whether a UTD is a higher-level type of the target UTD. For example, SOURCE_CODE is a higher-level type of TYPE_SCRIPT, and PLAIN_TEXT is a higher-level type of SOURCE_CODE and TYPE_SCRIPT.

Since: 12

Parameters

Name	Description
const char* srcTypeId	Pointer to the UTD to check.
const char* destTypeId	Pointer to the target UTD.

Returns

Type	Description
bool	Returns true if the UTD is a higher-level type of the target UTD; returns false otherwise.

OH_Utd_Equals()

bool OH_Utd_Equals(OH_Utd* utd1, OH_Utd* utd2)

Description

Checks whether two UTDs are the same.

Since: 12

Parameters

Name	Description
OH_Utd* utd1	Pointer to an OH_Utd instance.
OH_Utd* utd2	Pointer to another OH_Utd instance.

Returns

Type	Description
bool	Returns true if the two instances are the same; returns false otherwise.

OH_Utd_DestroyStringList()

void OH_Utd_DestroyStringList(const char** list, unsigned int count)

Description

Destroys a UTD list.

Since: 12

Parameters

Name	Description
const char** list	Double pointer to the UTD list to destroy.
unsigned int count	Length of the UTD list.

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