//// This code is part of Document Solutions for Word demos.// Copyright (c) MESCIUS inc. All rights reserved.//using System;using System.IO;using System.Globalization;using GrapeCity.Documents.Word;
namespace DsWordWeb.Demos{    // This example shows how to deal with the 'data source not found' error    // by ignoring non-existent data members.    public class DataTplAltFixDataMemberNotFound    {        // Code demonstrating the problem:        GcWordDocument Problem()        {            using var oceans = File.OpenRead(Path.Combine("Resources", "data", "oceans.json"));            var doc = new GcWordDocument();            doc.DataTemplate.DataSources.Add("ds", oceans);            // Incorrect: our data source does not have a member 'wrong_name':            doc.Body.Paragraphs.Add("{{ds.wrong_name}}");            doc.DataTemplate.Process(CultureInfo.GetCultureInfo("en-US"));            return doc;        }
        // Code demonstrating the fix:        GcWordDocument Fix()        {            using var oceans = File.OpenRead(Path.Combine("Resources", "data", "oceans.json"));            var doc = new GcWordDocument();            doc.DataTemplate.DataSources.Add("ds", oceans);            // Still incorrect: our data source does not have a member 'wrong_name':            doc.Body.Paragraphs.Add("{{ds.wrong_name}}");            // An alternative fix is to specify relaxed handling of missing fields,            // this will ignore such template tags bug will not throw exceptions:            doc.DataTemplate.Options.MissingFieldsHandling = DataTemplateMissingFieldsHandling.Relaxed;            doc.DataTemplate.Process(CultureInfo.GetCultureInfo("en-US"));            return doc;        }
        public GcWordDocument CreateDocx()        {            GcWordDocument doc;            try            {                // This fails:                doc = Problem();            }            catch (Exception ex)            {                // This works:                doc = Fix();                // Insert a brief explanation of the problem and the fix into the generated document:                doc.Body.Paragraphs.Insert(                    $"The error \"{ex.Message}\" occurred because in the template a non-existing path to a data member was used. " +                    $"To avoid exceptions in such cases, DataTemplate.Options.MissingFieldsHandling property can be set to " +                    $"DataTemplateMissingFieldsHandling.Relaxed. This will cause the template engine to ignore missing fields " +                    $"without throwing exceptions.",                    doc.Styles[BuiltInStyleId.BlockText],                    InsertLocation.Start);            }            return doc;        }    }}