''
'' This code is part of Document Solutions for Word demos.
'' Copyright (c) MESCIUS inc. All rights reserved.
''
Imports System.IO
Imports System.Globalization
Imports GrapeCity.Documents.Word

'' This example shows how to deal with the 'data source not found' error.
Public Class DataTplFixDataMemberNotFound
    '' Code demonstrating the problem:
    Private Function Problem() As GcWordDocument
        Using oceans = File.OpenRead(Path.Combine("Resources", "data", "oceans.json"))
            Dim 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
        End Using
    End Function

    '' Code demonstrating the fix:
    Private Function Fix() As GcWordDocument
        Using oceans = File.OpenRead(Path.Combine("Resources", "data", "oceans.json"))
            Dim doc = New GcWordDocument()
            doc.DataTemplate.DataSources.Add("ds", oceans)
            '' Correct: use the correct data member name:
            doc.Body.Paragraphs.Add("{{ds.name}}")
            doc.DataTemplate.Process(CultureInfo.GetCultureInfo("en-US"))
            Return doc
        End Using
    End Function

    Function CreateDocx() As GcWordDocument
        Dim doc As GcWordDocument
        Try
            '' This fails:
            doc = Problem()
        Catch ex As Exception
            '' 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. " +
                $"The fix is to ensure that data member names used in the template match names of data members in the data source.",
                doc.Styles(BuiltInStyleId.BlockText),
                InsertLocation.Start)
        End Try
        Return doc
    End Function
End Class