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. |