JsonTableDataSource.cs

using FastReport.Utils;
using FastReport.Utils.Json;
using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;

namespace FastReport.Data.JsonConnection
{
    /// <summary>
    /// JsonTableDataSource present a json array object
    /// </summary>
    public class JsonTableDataSource : TableDataSource
    {
        #region Private Fields

        private JsonArray _json;
        private bool updateSchema;
        private bool simpleStructure;
        private string tableData;

        #endregion Private Fields

        #region Public Properties

        /// <summary>
        /// Gets or sets value for force update schema on init schema
        /// </summary>
        [Browsable(false)]
        public bool UpdateSchema
        {
            get
            {
                return updateSchema;
            }
            set
            {
                updateSchema = value;
            }
        }
        /// <summary>
        /// Get or sets simplify mode for array types
        /// </summary>
        [Browsable(false)]
        public bool SimpleStructure
        {
            get
            {
                return simpleStructure;
            }

            set
            {
                simpleStructure = value;
            }
        }

        /// <inheritdoc />
        [Browsable(false)]
        public override string TableData
        {
            get
            {
                if (String.IsNullOrEmpty(tableData))
                {
                    tableData = Json.ToString();
                }
                return tableData;
            }

            set
            {
                tableData = value;
            }
        }

        #endregion Public Properties

        #region Internal Properties

        internal JsonArray Json
        {
            get
            {
                if (_json == null)
                {
                    if (StoreData && !String.IsNullOrEmpty(tableData))
                    {
                        _json = JsonBase.FromString(tableData) as JsonArray;
                    }
                    else
                    {
                        _json = GetJson(Parent, this) as JsonArray;
                    }
                    if (_json == null)
                        _json = new JsonArray();
                }
                return _json;
            }
            set
            {
                _json = value;
            }
        }

        #endregion Internal Properties

        #region Private Properties

        private int CurrentIndex
        {
            get
            {
                if (currentRow is int)
                    return (int)currentRow;
                if (CurrentRowNo < Rows.Count)
                {
                    object result = Rows[CurrentRowNo];
                    if (result is int)
                        return (int)result;
                }
                return CurrentRowNo;
            }
        }

        #endregion Private Properties

        #region Public Constructors

        /// <inheritdoc/>
        public JsonTableDataSource()
        {
            DataType = typeof(JsonArray);
        }

        #endregion Public Constructors

        #region Public Methods

        /// <inheritdoc/>
        public override void InitializeComponent()
        {
            base.InitializeComponent();
            Json = null;
        }

        /// <inheritdoc/>
        public override void InitSchema()
        {
            if (Columns.Count == 0 || UpdateSchema && !StoreData)
            {

                if (Connection is JsonDataSourceConnection)
                {
                    JsonDataSourceConnection con = Connection as JsonDataSourceConnection;

                    InitSchema(this, con.JsonSchema, con.SimpleStructure);
                }
            }
            UpdateSchema = false;
        }

        /// <inheritdoc/>
        public override void LoadData(ArrayList rows)
        {
            Json = null;
            // JSON is calculated property, no problem with null
            if (rows != null && Json != null)
            {
                rows.Clear();
                int count = Json.Count;
                for (int i = 0; i < count; i++)
                {
                    rows.Add(i);
                }
            }
        }

        #endregion Public Methods

        #region Internal Methods

        internal static object GetJsonBaseByColumn(Base parentColumn, Column column)
        {
            if (parentColumn is JsonTableDataSource)
            {
                JsonTableDataSource jsonTableDataSource = parentColumn as JsonTableDataSource;
                if (jsonTableDataSource.SimpleStructure)
                {
                    if (!String.IsNullOrEmpty(column.PropName))
                    {
                        if((parentColumn as JsonTableDataSource).RowCount == 0) {
                            return null;
                        }

                        var obj = (parentColumn as JsonTableDataSource).Json[(parentColumn as JsonTableDataSource).CurrentIndex];

                        return (obj as JsonBase)[column.PropName];
                    }
                }
                else
                {
                    switch (column.PropName)
                    {
                        case "item":
                            return (parentColumn as JsonTableDataSource).Json[(parentColumn as JsonTableDataSource).CurrentIndex];
                    }
                    JsonTableDataSource source = column as JsonTableDataSource;
                    return source.Json;
                }
            }
            if (parentColumn is Column && !String.IsNullOrEmpty(column.PropName))
            {
                object json = GetJsonBaseByColumn(parentColumn.Parent, parentColumn as Column);
                if (json is JsonBase)
                {
                    return (json as JsonBase)[column.PropName];
                }
            }

            return null;
        }

        internal static object GetValueByColumn(Base parentColumn, Column column)
        {
            if (parentColumn is JsonTableDataSource)
            {
                switch (column.PropName)
                {
                    case "index":
                        return (parentColumn as JsonTableDataSource).CurrentIndex;

                    case "array":
                        return (parentColumn as JsonTableDataSource).Json;
                }
            }

            object json = GetJsonBaseByColumn(parentColumn, column);

            return json;
        }

        internal static void InitSchema(Column table, JsonSchema schema, bool simpleStructure)
        {
            List<Column> saveColumns = new List<Column>();
            switch (schema.Type)
            {
                case "object":
                    foreach (KeyValuePair<string, JsonSchema> kv in schema.Properties)
                    {
                        if (kv.Value.Type == "object")
                        {
                            Column c = new Column();
                            c.Name = kv.Key;
                            c.Alias = kv.Key;
                            c.PropName = kv.Key;
                            c.DataType = kv.Value.DataType;
                            c = UpdateColumn(table, c, saveColumns);
                            InitSchema(c, kv.Value, simpleStructure);
                        }
                        else if (kv.Value.Type == "array")
                        {
                            Column c = new JsonTableDataSource();
                            c.Name = kv.Key;
                            c.Alias = kv.Key;
                            c.PropName = kv.Key;
                            c.DataType = kv.Value.DataType;
                            c = UpdateColumn(table, c, saveColumns);

                            InitSchema(c, kv.Value, simpleStructure);

                        }
                        else
                        {
                            Column c = new Column();
                            c.Name = kv.Key;
                            c.Alias = kv.Key;
                            c.PropName = kv.Key;
                            c.DataType = kv.Value.DataType;
                            c.SetBindableControlType(c.DataType);
                            UpdateColumn(table, c, saveColumns);
                        }
                    }
                    break;

                case "array":
                    JsonSchema items = schema.Items;

                    bool simpleArray = false;

                    if (table is JsonTableDataSource)
                    {
                        JsonTableDataSource jsonTableDataSource = table as JsonTableDataSource;
                        simpleArray = jsonTableDataSource.SimpleStructure =
                            simpleStructure & items.Type == "object";
                    }

                    if (simpleArray)
                    {
                        // remake schema in simplify mode
                        InitSchema(table, items, simpleStructure);
                        // and return, no need to clear column data
                        // in this case this method has no control to columns
                        return;
                    }


                    {
                        Column c = new Column();
                        c.Name = "index";
                        c.Alias = "index";
                        c.PropName = "index";
                        c.DataType = typeof(int);
                        UpdateColumn(table, c, saveColumns);
                    }



                    {
                        Column c;
                        bool iSchema = false;

                        if (items.Type == "object")
                        {
                            c = new Column();
                            iSchema = true;

                        }
                        else if (items.Type == "array")
                        {
                            c = new JsonTableDataSource();
                            iSchema = true;
                        }
                        else
                        {
                            c = new Column();
                        }

                        c.Name = "item";
                        c.Alias = "item";
                        c.PropName = "item";
                        c.DataType = items.DataType;
                        c = UpdateColumn(table, c, saveColumns);

                        if (iSchema)
                            InitSchema(c, items, simpleStructure);
                    }

                    {
                        Column c = new Column();
                        c.Name = "array";
                        c.Alias = "array";
                        c.PropName = "array";
                        c.DataType = typeof(JsonBase);
                        UpdateColumn(table, c, saveColumns);
                    }

                    break;
            }

            for (int i = 0; i < table.Columns.Count; i++)
            {
                if (!(table.Columns[i].Calculated || saveColumns.Contains(table.Columns[i])))
                {
                    table.Columns.RemoveAt(i);
                    i--;
                }
            }
        }

        internal object GetJson(Base parentColumn, Column column)
        {
            if (parentColumn is IJsonProviderSourceConnection)
            {
                return (parentColumn as IJsonProviderSourceConnection).GetJson(this);
            }

            if (parentColumn is JsonTableDataSource)
            {

                JsonTableDataSource source = parentColumn as JsonTableDataSource;

                if (source.SimpleStructure)
                {
                    object parentJson = source.Json[source.CurrentIndex];
                    if (parentJson is JsonBase && !String.IsNullOrEmpty(column.PropName))
                    {
                        return (parentJson as JsonBase)[column.PropName];
                    }
                }
                else
                {
                    return source.Json[source.CurrentIndex] as object;
                }
            }
            else if (parentColumn is Column)
            {
                object parentJson = GetJson(parentColumn.Parent, parentColumn as Column);
                if (parentJson is JsonBase && !String.IsNullOrEmpty(column.PropName))
                {
                    return (parentJson as JsonBase)[column.PropName];
                }
            }
            return null;
        }

        #endregion Internal Methods

        #region Protected Methods

        /// <inheritdoc/>
        protected override object GetValue(Column column)
        {
            return GetValueByColumn(column.Parent, column);
        }

        /// <inheritdoc/>
        protected override object GetValue(string alias)
        {
            // TODO TEST
            Column column = this;
            string[] colAliases = alias.Split('.');

            foreach (string colAlias in colAliases)
            {
                column = column.Columns.FindByAlias(colAlias);
                if (column == null)
                    return null;
            }

            return GetValueByColumn(column.Parent, column);
        }

        #endregion Protected Methods

        #region Private Methods

        private static Column UpdateColumn(Column table, Column c, List<Column> list)
        {
            foreach (Column child in table.Columns)
            {
                if (child.PropName == c.PropName)
                {
                    child.DataType = c.DataType;
                    list.Add(child);
                    return child;
                }
            }
            table.AddChild(c);
            list.Add(c);
            return c;
        }

        #endregion Private Methods


        ///  <inheritdoc/>
        public override void Serialize(FRWriter writer)
        {
            base.Serialize(writer);

            if (SimpleStructure)
            {
                writer.WriteBool("SimpleStructure", SimpleStructure);
            }
        }
    }
}