com.extjs.gxt.ui.client.data.JsonReader.java Source code

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Here is the source code for com.extjs.gxt.ui.client.data.JsonReader.java

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/*
 * Sencha GXT 2.3.1 - Sencha for GWT
 * Copyright(c) 2007-2013, Sencha, Inc.
 * licensing@sencha.com
 * 
 * http://www.sencha.com/products/gxt/license/
 */
package com.extjs.gxt.ui.client.data;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.i18n.client.DateTimeFormat;
import com.google.gwt.json.client.JSONArray;
import com.google.gwt.json.client.JSONObject;
import com.google.gwt.json.client.JSONParser;
import com.google.gwt.json.client.JSONValue;

/**
 * A <code>DataReader</code> implementation that reads JSON data using a
 * <code>ModelType</code> definition and produces a set of
 * <code>ModelData</code> instances.
 * 
 * <p />
 * Subclasses can override {@link #createReturnData(Object, List, int)} to
 * control what object is returned by the reader. Subclass may override
 * {@link #newModelInstance()} to return any model data subclass.
 * 
 * @param <D> the <code>ListLoadResult</code> type being returned by the reader
 */
@SuppressWarnings("deprecation")
public class JsonReader<D> implements DataReader<D> {

    private ModelType modelType;

    /**
     * Creates a new JSON reader.
     * 
     * @param modelType the model type definition
     */
    public JsonReader(ModelType modelType) {
        this.modelType = modelType;
    }

    @SuppressWarnings({ "unchecked", "rawtypes" })
    public D read(Object loadConfig, Object data) {
        JSONObject jsonRoot = null;
        if (data instanceof JavaScriptObject) {
            jsonRoot = new JSONObject((JavaScriptObject) data);
        } else {
            jsonRoot = (JSONObject) JSONParser.parse((String) data);
        }
        JSONArray root = (JSONArray) jsonRoot.get(modelType.getRoot());
        int size = root.size();
        ArrayList<ModelData> models = new ArrayList<ModelData>();
        for (int i = 0; i < size; i++) {
            JSONObject obj = (JSONObject) root.get(i);
            ModelData model = newModelInstance();
            for (int j = 0; j < modelType.getFieldCount(); j++) {
                DataField field = modelType.getField(j);
                String name = field.getName();
                Class type = field.getType();
                String map = field.getMap() != null ? field.getMap() : field.getName();
                JSONValue value = obj.get(map);

                if (value == null)
                    continue;
                if (value.isArray() != null) {
                    // nothing
                } else if (value.isBoolean() != null) {
                    model.set(name, value.isBoolean().booleanValue());
                } else if (value.isNumber() != null) {
                    if (type != null) {
                        Double d = value.isNumber().doubleValue();
                        if (type.equals(Integer.class)) {
                            model.set(name, d.intValue());
                        } else if (type.equals(Long.class)) {
                            model.set(name, d.longValue());
                        } else if (type.equals(Float.class)) {
                            model.set(name, d.floatValue());
                        } else {
                            model.set(name, d);
                        }
                    } else {
                        model.set(name, value.isNumber().doubleValue());
                    }
                } else if (value.isObject() != null) {
                    // nothing
                } else if (value.isString() != null) {
                    String s = value.isString().stringValue();
                    if (type != null) {
                        if (type.equals(Date.class)) {
                            if ("timestamp".equals(field.getFormat())) {
                                Date d = new Date(Long.parseLong(s) * 1000);
                                model.set(name, d);
                            } else {
                                DateTimeFormat format = DateTimeFormat.getFormat(field.getFormat());
                                Date d = format.parse(s);
                                model.set(name, d);
                            }
                        }
                    } else {
                        model.set(name, s);
                    }
                } else if (value.isNull() != null) {
                    model.set(name, null);
                }
            }
            models.add(model);
        }
        int totalCount = models.size();
        if (modelType.getTotalName() != null) {
            totalCount = getTotalCount(jsonRoot);
        }
        return (D) createReturnData(loadConfig, models, totalCount);
    }

    /**
     * Responsible for the object being returned by the reader.
     * 
     * @param loadConfig the load config
     * @param records the list of models
     * @param totalCount the total count
     * @return the data to be returned by the reader
     */
    @SuppressWarnings("unchecked")
    protected Object createReturnData(Object loadConfig, List<ModelData> records, int totalCount) {
        return (D) records;
    }

    protected int getTotalCount(JSONObject root) {
        if (modelType.getTotalName() != null) {
            JSONValue v = root.get(modelType.getTotalName());
            if (v != null) {
                if (v.isNumber() != null) {
                    return (int) v.isNumber().doubleValue();
                } else if (v.isString() != null) {
                    return Integer.parseInt(v.isString().stringValue());
                }
            }
        }
        return -1;
    }

    /**
     * Returns the new model instances. Subclasses may override to provide an
     * model data subclass.
     * 
     * @return the new model data instance
     */
    protected ModelData newModelInstance() {
        return new BaseModelData();
    }
}