//
// This code is part of Document Solutions for Word demos.
// Copyright (c) MESCIUS inc. All rights reserved.
//
using System;
using System.IO;
using System.Drawing;
using System.Collections.Generic;
using System.Linq;
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;
}
}
}