@geoext/geoext/src/data/model/Layer.js

GeoExt is Open Source and enables building desktop-like GIS applications through the web. It is a JavaScript framework that combines the GIS functionality of OpenLayers with the user interface savvy of the ExtJS library provided by Sencha.

/* Copyright (c) 2015-present The Open Source Geospatial Foundation
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
/**
 * The layer model class used by the stores.
 *
 * @class GeoExt.data.model.Layer
 */
Ext.define('GeoExt.data.model.Layer', {
  extend: 'GeoExt.data.model.Base',
  mixins: ['GeoExt.mixin.SymbolCheck'],

  // <debug>
  symbols: ['ol.layer.Group', 'ol.layer.Base', 'ol.layer.Base#get'],
  // </debug>

  /**
   * The layer property that will be used to label the model in views.
   *
   * @cfg {string}
   */
  textProperty: 'name',

  /**
   * The layer property that will be used to describe the model in views.
   *
   * @cfg {string}
   */
  descriptionProperty: 'description',

  /**
   * The text label that will be shown in model views representing unnamed
   * layers.
   *
   * @cfg {string}
   */
  unnamedLayerText: 'Unnamed Layer',

  /**
   * The text label that will be shown in model views representing unnamed
   * group layers.
   *
   * @cfg {string}
   */
  unnamedGroupLayerText: 'Unnamed Group Layer',

  /**
   * This property specifies which properties are synchronized between
   * the store record and the ol layer object.
   *
   * By default this only the property `'title'`.
   *
   * @cfg {Array<string>}
   */
  synchronizedProperties: ['title'],

  fields: [
    {
      name: 'isLayerGroup',
      type: 'boolean',
      persist: false,
      convert: function (v, record) {
        const layer = record.getOlLayer();
        if (layer) {
          return layer instanceof ol.layer.Group;
        }
        return undefined;
      },
    },
    {
      name: 'text',
      type: 'string',
      persist: false,
      convert: function (v, record) {
        let name = v;
        let defaultName;
        let textProp;

        if (!name) {
          textProp = record.textProperty;
          defaultName = record.get('isLayerGroup')
            ? record.unnamedGroupLayerText
            : record.unnamedLayerText;
          name = record.getOlLayerProp(textProp, defaultName);
        }

        return name;
      },
    },
    {
      name: 'opacity',
      type: 'number',
      persist: false,
      convert: function (v, record) {
        return record.getOlLayerProp('opacity');
      },
    },
    {
      name: 'minResolution',
      type: 'number',
      persist: false,
      convert: function (v, record) {
        return record.getOlLayerProp('minResolution');
      },
    },
    {
      name: 'maxResolution',
      type: 'number',
      persist: false,
      convert: function (v, record) {
        return record.getOlLayerProp('maxResolution');
      },
    },
    {
      name: 'qtip',
      type: 'string',
      persist: false,
      convert: function (v, record) {
        return record.getOlLayerProp(record.descriptionProperty, '');
      },
    },
    {
      name: 'qtitle',
      type: 'string',
      persist: false,
      convert: function (v, record) {
        return record.get('text');
      },
    },
  ],

  proxy: {
    type: 'memory',
    reader: {
      type: 'json',
    },
  },

  /**
   * Returns the `ol.layer.Base` object used in this model instance.
   *
   * @return {ol.layer.Base} The `ol.layer.Base` object.
   */
  getOlLayer: function () {
    if (this.data instanceof ol.layer.Base) {
      return this.data;
    }
  },

  /**
   * Returns a property value of the `ol.layer.Base` object used in this model
   * instance. If the property is null, the optional default value will  be
   * returned.
   *
   * @param  {string} prop         The property key.
   * @param  {Object} defaultValue The optional default value.
   * @return {Object}              The returned property.
   */
  getOlLayerProp: function (prop, defaultValue) {
    const layer = this.getOlLayer();
    const value = layer ? layer.get(prop) : undefined;
    return value !== undefined ? value : defaultValue;
  },
});