salix/client/core/src/components/model-proxy/model-proxy.js

import ngModule from '../../module';
import EventEmitter from '../../lib/event-emitter';

/**
 * A filtrable model.
 *
 * @property {Function} filter The filter function
 */
export class Filtrable {
    applyFilter(userFilter, userParams) {}
    addFilter(userFilter, userParams) {}
    removeFilter() {}
}

/**
 * A sortable model.
 *
 * @property {String|Array<String>|Function} order The sort specification
 */
export class Sortable {
}

/**
 * Paginable model.
 *
 * @property {Number} limit The page size
 */
export class Paginable {
    get isLoading() {}
    get moreRows() {}
    loadMore() {}
}

/**
 * A data model.
 *
 * @event dataChange Emitted when data property changes
 */
export class DataModel extends EventEmitter {
    get data() {}
    refresh() {}
    clear() {}
}

ngModule.component('vnDataModel', {
    controller: DataModel,
    bindings: {
        data: '=?',
        autoLoad: '<?',
        autoSync: '<?',
        order: '@?',
        limit: '<?'
    }
});

/**
 * A data model that monitorizes changes to the data.
 *
 * @event dataChange Emitted when data property changes
 */
export default class ModelProxy extends DataModel {
    constructor() {
        super();
        this.resetChanges();
    }

    get orgData() {
        return this._orgData;
    }

    set orgData(value) {
        this._orgData = value;

        if (value) {
            this.proxiedData = new Array(value.length);

            for (let i = 0; i < value.length; i++)
                this.proxiedData[i] = this.createRow(Object.assign({}, value[i]), i);
        } else
            this.proxiedData = null;

        this.data = null;
        this.resetChanges();
    }

    get data() {
        return this._data;
    }

    set data(value) {
        this._data = value;
        this.emit('dataChange');
    }

    remove(index) {
        let [item] = this.data.splice(index, 1);

        let proxiedIndex = this.proxiedData.indexOf(item);
        this.proxiedData.splice(proxiedIndex, 1);

        if (!item.$isNew)
            this.removed.push(item);

        this.isChanged = true;
        this.emit('rowRemove', index);
    }

    insert(data) {
        data = Object.assign(data || {}, this.link);
        let newRow = this.createRow(data, null);
        newRow.$isNew = true;
        let index = this.proxiedData.push(newRow) - 1;

        if (this.data)
            this.data.push(newRow);

        this.isChanged = true;
        this.emit('rowInsert', index);
        return index;
    }

    createRow(obj, index) {
        let proxy = new Proxy(obj, {
            set: (obj, prop, value) => {
                if (prop.charAt(0) !== '$' && value !== obj[prop] && !obj.$isNew) {
                    if (!obj.$oldData)
                        obj.$oldData = {};
                    if (!obj.$oldData[prop])
                        obj.$oldData[prop] = value;
                    this.isChanged = true;
                }
                return Reflect.set(obj, prop, value);
            }
        });
        Object.assign(proxy, {
            $orgIndex: index,
            $oldData: null,
            $isNew: false
        });
        return proxy;
    }

    resetChanges() {
        this.removed = [];
        this.isChanged = false;

        let data = this.proxiedData;
        if (data)
            for (let row of data)
                row.$oldData = null;
    }

    applyChanges() {
        let data = this.proxiedData;
        let orgData = this.orgData;
        if (!data) return;

        for (let row of this.removed) {
            if (row.$isNew) {
                let data = {};
                for (let prop in row)
                    if (prop.charAt(0) !== '$')
                        data[prop] = row[prop];
                row.$orgIndex = orgData.push(data) - 1;
                row.$isNew = false;
            } else if (row.$oldData)
                for (let prop in row.$oldData)
                    orgData[row.$orgIndex][prop] = row[prop];
        }

        let removed = this.removed;

        if (removed) {
            removed = removed.sort((a, b) => b.$orgIndex - a.$orgIndex);

            for (let row of this.removed)
                orgData.splice(row.$orgIndex, 1);
        }

        this.resetChanges();
    }

    undoChanges() {
        let data = this.proxiedData;
        if (!data) return;

        for (let i = 0; i < data.length; i++) {
            let row = data[i];

            if (row.$oldData)
                Object.assign(row, row.$oldData);
            if (row.$isNew)
                data.splice(i--, 1);
        }

        let removed = this.removed;

        if (removed) {
            removed = removed.sort((a, b) => a.$orgIndex - b.$orgIndex);

            for (let row of this.removed)
                data.splice(row.$orgIndex, 0, row);
        }

        this.resetChanges();
    }
}

ngModule.component('vnModelProxy', {
    controller: ModelProxy,
    bindings: {
        orgData: '<?',
        data: '=?'
    }
});