@ohos.data.uniformTypeDescriptor (Uniform Data Definition and Description)

The uniformTypeDescriptor module abstracts and defines OpenHarmony uniform data types.

NOTE

The initial APIs of this module are supported since API version 10. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import uniformTypeDescriptor from '@ohos.data.uniformTypeDescriptor';

UniformDataType

Enumerates OpenHarmony uniform data types. Some data types are related. For example, the JPEG type belongs to the IMAGE type.

System capability: SystemCapability.DistributedDataManager.UDMF.Core

TypeDescriptor¹¹⁺

Provides attributes and APIs for describing a uniform data type and its relationship with other uniform data types.

System capability: SystemCapability.DistributedDataManager.UDMF.Core

belongsTo¹¹⁺

belongsTo(type: string): boolean

Checks whether this data type belongs to the specified uniform data type.

System capability: SystemCapability.DistributedDataManager.UDMF.Core

Parameters

Return value

Example

import uniformTypeDescriptor from '@ohos.data.uniformTypeDescriptor';
import { BusinessError } from '@ohos.base';

try{
    let typeObj : uniformTypeDescriptor.TypeDescriptor = uniformTypeDescriptor.getTypeDescriptor('general.type-script');
    let ret = typeObj.belongsTo('general.plain-text');
    if(ret) {
        console.info('type general.type-script belongs to type general.plain-text');
    }
} catch(e) {
    let error: BusinessError = e as BusinessError;
    console.error(`belongsTo throws an exception. code is ${error.code}, message is ${error.message} `);
}

isLowerLevelType¹¹⁺

isLowerLevelType(type: string): boolean

Checks whether this data type is a lower-level type of the specified uniform data type. 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.

System capability: SystemCapability.DistributedDataManager.UDMF.Core

Parameters

Return value

Example

import uniformTypeDescriptor from '@ohos.data.uniformTypeDescriptor';
import { BusinessError } from '@ohos.base';

try{
    let typeObj : uniformTypeDescriptor.TypeDescriptor = uniformTypeDescriptor.getTypeDescriptor('general.type-script');
    let ret = typeObj.isLowerLevelType('general.plain-text');
    if(ret) {
        console.info('type general.type-script is lower level type of type general.plain-text');
    }
} catch(e) {
    let error: BusinessError = e as BusinessError;
    console.error(`isLowerLevelType throws an exception. code is ${error.code}, message is ${error.message} `);
}

isHigherLevelType¹¹⁺

isHigherLevelType(type: string): boolean

Checks whether this data type is a higher-level type of the specified uniform data type. 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.

System capability: SystemCapability.DistributedDataManager.UDMF.Core

Parameters

Return value

Example

import uniformTypeDescriptor from '@ohos.data.uniformTypeDescriptor';
import { BusinessError } from '@ohos.base';

try{
    let typeObj : uniformTypeDescriptor.TypeDescriptor = uniformTypeDescriptor.getTypeDescriptor('general.plain-text');
    let ret = typeObj.isHigherLevelType('general.type-script');
    if(ret) {
        console.info('type general.plain-text is higher level type of type general.type-script');
    }
} catch(e) {
    let error: BusinessError = e as BusinessError;
    console.error(`isHigherLevelType throws an exception. code is ${error.code}, message is ${error.message} `);
}

equals¹¹⁺

equals(typeDescriptor: TypeDescriptor): boolean

Checks whether this data type is the same as the specified uniform data type. That is, compares typeIds of two TypeDescriptor objects.

System capability: SystemCapability.DistributedDataManager.UDMF.Core

Parameters

Return value

Example

import uniformTypeDescriptor from '@ohos.data.uniformTypeDescriptor';
import { BusinessError } from '@ohos.base';

try{
    let typeA : uniformTypeDescriptor.TypeDescriptor = uniformTypeDescriptor.getTypeDescriptor('general.type-script');
    let typeB : uniformTypeDescriptor.TypeDescriptor = uniformTypeDescriptor.getTypeDescriptor('general.python-script');
    if(!typeA.equals(typeB)) {
      console.info('typeA is not equal to typeB');
    }
} catch(e) {
    let error: BusinessError = e as BusinessError;
    console.error(`throws an exception. code is ${error.code}, message is ${error.message} `);
}

uniformTypeDescriptor.getTypeDescriptor¹¹⁺

getTypeDescriptor(typeId: string): TypeDescriptor

Obtains the TypeDescriptor object based on the uniform data type ID.

System capability: SystemCapability.DistributedDataManager.UDMF.Core

Parameters

Return value

Example

import uniformTypeDescriptor from '@ohos.data.uniformTypeDescriptor';
import { BusinessError } from '@ohos.base';

try {
    let typeObj : uniformTypeDescriptor.TypeDescriptor = uniformTypeDescriptor.getTypeDescriptor('com.adobe.photoshop-image');
    if (typeObj) {
        let typeId = typeObj.typeId;
        let belongingToTypes = typeObj.belongingToTypes;
        let description = typeObj.description;
        let referenceURL = typeObj.referenceURL;
        let iconFile = typeObj.iconFile;
        console.info(`typeId: ${typeId}, belongingToTypes: ${belongingToTypes}, description: ${description}, referenceURL: ${referenceURL}, iconFile: ${iconFile}`);
    } else {
        console.info('type com.adobe.photoshop-image does not exist');
    }
} catch(e) {
    let error: BusinessError = e as BusinessError;
    console.error(`getTypeDescriptor throws an exception. code is ${error.code}, message is ${error.message} `);
}

uniformTypeDescriptor.getUniformDataTypeByFilenameExtension¹¹⁺

getUniformDataTypeByFilenameExtension(filenameExtension: string, belongsTo?: string): string

Obtains the uniform data type ID based on the given file name extension and data type.

System capability: SystemCapability.DistributedDataManager.UDMF.Core

Parameters

Return value

Example

import uniformTypeDescriptor from '@ohos.data.uniformTypeDescriptor';
import { BusinessError } from '@ohos.base';

try {
    let typeId = uniformTypeDescriptor.getUniformDataTypeByFilenameExtension('.ts', 'general.plain-text');
    if(typeId) {
        console.info('typeId is general.type-script');
    }
} catch(e) {
    let error: BusinessError = e as BusinessError;
    console.error(`getUniformDataTypeByFilenameExtension throws an exception. code is ${error.code}, message is ${error.message} `);
}

uniformTypeDescriptor.getUniformDataTypeByMIMEType¹¹⁺

getUniformDataTypeByMIMEType(mimeType: string, belongsTo?: string): string

Obtains the uniform data type ID based on the given MIME type and data type.

System capability: SystemCapability.DistributedDataManager.UDMF.Core

Parameters

Return value

Example

import uniformTypeDescriptor from '@ohos.data.uniformTypeDescriptor';
import { BusinessError } from '@ohos.base';

try {
    let typeId = uniformTypeDescriptor.getUniformDataTypeByMIMEType('image/jpeg', 'general.image');
    if(typeId) {
        console.info('typeId is general.jpeg');
    }
} catch(e) {
    let error: BusinessError = e as BusinessError;
    console.error(`getUniformDataTypeByMIMEType throws an exception. code is ${error.code}, message is ${error.message} `);
}