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    operationkit
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    0.2.3 • Public • Published

    operationkit

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    Inspired by Operation and OperationQueue classes from Apple's Foundation framework for macOS, iOS, watchOS, and tvOS.

    Universal package for the browser and node.js

    Installation

    with node:

    npm install operationkit
    

    with yarn:

    yarn add operationkit
    

    with cdn:

    <script src="https://unpkg.com/operationkit/dist/operationkit.min.js"></script>
    
    // then
    window.operationkit
    

    npm bundle size

    Documentation

    Go to documentation

    Classes

    Use

    const {
        Operation,
        OpreationQueue,
        BlockOperation,
        GroupOperation,
        OperationEvent,
        QueueEvent,
        QueuePriority 
    = require('operationkit');

    Operation

    An abstract class that represents a single task.

    const operation = new Operation();
     
    const result = await operation.start();

    Add dependencies

    The operation will execute only when all dependencies are resolved.

    operation1.dependencies = [operation2];
    operation1.start()

    Console:

    // operation2 started
    // operation2 done
    // operation1 started
    // operation1 done
    

    Extend the Operation class for complex tasks

    class ValidateTokenOperation extends Operation {
        
        /**
         * Method to implement to run custom task
         * @override
         * @returns {Promise} 
         */
        async run() {
            let token = localStorage.getItem('token');
            if (!token) {
                const response = await axios('<refresh_token_api>');
                token = reponse.data;
                localStorage.setItem('token', token);
            }
            return token;
        }
        
    }

    The run function must always return a promise.

    run() {
        return new Promise((resolve, reject) => {
            const response = await axios.get('<some_api>');
            resolve(response.data);
        })
    }

    or simply use async keyword when overriding the function.

    async run() {
        const response = await axios.get('<some_api>');
        return response.data
    }

    Example

    class DownloadDataOperation extends Operation {
     
        /**
         * @override
         */
        async run() {
            try {
                const response = await axios.get('<some_api>');
                return response.data;
            } catch (e) {
                this.cancel();
            }
        }
    }

    TO NOTE: you must always return the result from the async function or Promise.resolve. You will have access to the result from the the result property or from resolving your promise.

    const downloadOperation = new DownloadDataOperation();
     
    // result is returned from your promise here
    const data = await new DownloadDataOperation();
     
    // and the same result is available from
    downloadOperation.result;

    Create a collection of complex operations that represents your application

    const validateToken = new ValidateTokenOperation();
    const getUsersApi = new GetUsersApi();
     
    getUsersApi.dependencies = [validateToken];
    getUsersApi.completionCallback = operation => {
        // operation.result;
    };
     
    getUsersApi.start()
        .then(result => { ... })
        .catch(e => { ... });

    Or set the dependency directly in the subclass:

    class GetUsersApi extends Operation {
        constructor() {
            this.dependencies = [new ValidateTokenOperation()];
        }
    }

    Operation Events

    • OperationEvent.START Operation has started to run the task
    • OperationEvent.READY Operation is ready to be executed
    • OperationEvent.DONE Operation is finished running the task
    • OperationEvent.CANCEL Operation was cancelled
    • OperationEvent.ERROR An error occured while running the task
    apiOperation.on(OperationEvent.START, (operation) => {
        console.log(operation);
    })

    OperationQueue

    A queue orchestrates the execution of operations. An operation queue executes its queued Operation objects based on their priority and readiness*.

    const operationQueue = new OperationQueue();
     
    const operation1 = new ApiOperation();
     
    const operation2 = new ApiOperation();
     
    operationQueue.addOperations([operation1, operation2]);

    Utilizing OperationQueue's maximum concurrent operations

    operationQueue.maximumConcurrentOperations = 2;

    Console:

    // operation1 started
    // operation2 started
    // operation1 done
    // operation2 done
    

    Queue Priority

    Specify the relative ordering of operations that are waiting to be started in an operation queue.

    QueuePriority.veryHigh
    QueuePriority.high
    QueuePriority.normal
    QueuePriority.low
    QueuePriority.veryLow

    These constants let you prioritize the order in which operations execute:

    const getCacheData = new GetCacheDataOperation();
    getCacheData.queuePriority = QueuePriority.high;
     
    const downloaHighRestImage = new DownloaHighRestImageOperation();
    getCacheData.queuePriority = QueuePriority.normal;
     
    operationQueue.addOperations([getCacheData, downloaHighRestImage]);

    Console:

    // getCacheData started
    // getCacheData done
    // downloaHighRestImage started
    // downloaHighRestImage done
    

    Inserting operations in a queue to control flow

    const blockOperation6 = new BlockOperation(6, async () => {
        const response = await axios.get('https://samples.openweathermap.org/data/2.5/weather?lat=35&lon=139&appid=b6907d289e10d714a6e88b30761fae22');
        const data = response.data;
        return data;
    });
     
    const operation = new DownloadDataOperation(1);
    const operation2 = new DownloadDataOperation(2);
    const operation3 = new DownloadDataOperation(3);
    const operation4 = new TimeOutOperation(4, 2000);
    const operation5 = new TimeOutOperation(5, 1000);
    const operation7 = new TimeOutOperation(7, 8000);
    const operation8 = new TimeOutOperation(8, 1500);
     
    operation.dependencies = [operation2, operation7];
    operation2.dependencies = [operation4, operation8];
    operation3.dependencies = [operation, operation5, operation2];
    operation4.dependencies = [operation5, blockOperation6];
    operation5.dependencies = [blockOperation6];
    operation8.dependencies = [operation7];
     
    const operationQueue = new OperationQueue();
    operationQueue.maximumConcurrentOperations = 10;
     
    operationQueue.completionCallback = () => {
        console.log('queue done');
    };
     
    operationQueue.addOperations([operation3]);
        

    OperationQueue Events

    • OperationEvent.DONE OperationQueue has finished running all operations
    • OperationEvent.PAUSED OperationQueue has paused
    • OperationEvent.RESUMED OperationQueue has resumed
    queue.on(OperationEvent.PAUSED, (operationQueue) => {
        console.log(operationQueue);
    })

    BlockOperation

    A helper class that accepts a function which will be exexuted as the operation's task.

    const operation = new BlockOperation(async (op) => {
        const data = await api.get();
        ...
        return data;
    });
     
    const result = await operation.start()
    console.log(result) // 'my operation result'

    You have acces to the operation in the function:

    const operation = new BlockOperation(async (op) => {
        console.log(op === operation);
    });

    GroupOperation

    Group multiple operations and return the result of each operation when they are all resolved.

    const groupOperation = new GroupOperation();
     
    groupOperation.addOperation(new GetUsersApi());
    groupOperation.addOperation(new GetPostsApi());
     
    const [users, posts] = await groupOperation.start();

    QueuePriorities are also considered when using GroupOperation.

    Run tests

    npm run test

    Run coverage

    npm run test-coverage

    Run new build

    npm run build

    Run generate documentation

    npm run docs

    Keywords

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    Install

    npm i operationkit

    DownloadsWeekly Downloads

    3

    Version

    0.2.3

    License

    ISC

    Unpacked Size

    234 kB

    Total Files

    67

    Last publish

    Collaborators

    • ohdannyboy