Add the latest version of WebVella.DocumentTemplates NUGET package to your project
This is the piece of text that the library will look for in order it to be replaced. If result can be generated for the tag it will be replaced with it, if not (eg. wrong column name) the tag will be replaced with an empty string. The usual format of the tag is as follows:
// should match of the column name in the DataTable.
// Case sensitivity depends on the DataTable settings (insensitive by default).
{{column_name}}
//square brackets are used for providing row index
{{column_name[0]}}
//brackets are used to provide parameter and parameter values
{{column_name(S=",")}}
//multiple parameters can be provided
{{column_name(S=",",F=H)}}
//functional tags start with '='
{{=sum(A2)}}
//when spreadsheet function is expected to follow tags start with '=='
{{==sum(A2)}}
The template (a.k.a. the template processor) inherits the WvTemplateBase class. It defines the characteristics of the provided template and provides ready result when its 'Process' method is used. Currently available templates are: WvSpreadsheetFileTemplate, WvEmailTemplate, WvTextFileTemplate, WvTextTemplate, WvHtmlTemplate and the WvWordFileTemplate as a next objective. More details can be reviewed in the relevant pages of this site, but in general this is what a template class looks like:
public class WvSpreadsheetFileTemplate : WvTemplateBase
{
// template objects reflect the media that is being processed
// and they can be different for each template
public XLWorkbook? Template { get; set; }
public WvSpreadsheetFileTemplateProcessResult Process(DataTable? dataSource,
CultureInfo? culture = null)
{
//calling the processor for result generation
}
}
public abstract class WvTemplateBase
{
public List<string> GroupDataByColumns { get; set; } = new List<string>();
}
The use process is pretty straight forward. You need to follow these steps:
Each processing operation have result that can include one or more result items. This usually happens when the data is group in more then one groups by the GroupDataByColumns property. In this way as an example, you can generate multiple emails by grouping the data by recipient.
using System.Data;
using WebVella.DocumentTemplates.Engines.Text;
namespace WebVella.DocumentTemplates.Examples;
internal class Program
{
static void Main(string[] args)
{
//1. Get the DataTable
DataTable dt = new DataTable();
dt.Columns.Add("email", typeof(string));
var row = dt.NewRow();
row["email"] = $"john@domain.com";
dt.Rows.Add(row);
var row2 = dt.NewRow();
row2["email"] = $"peter@domain.com";
dt.Rows.Add(row2);
//2. Setup the template
WvTextTemplate template = new()
{
GroupDataByColumns = new List<string>(),
Template = "{{email(S=\",\")}}"
};
//3. Execute and get the results
WvTextTemplateProcessResult result = template.Process(dt);
Console.WriteLine(result.ResultItems.Count);
//Output: 1
Console.WriteLine(result.ResultItems[0]);
//Output: john@domain.com,peter@domain.com
}
}
Now lets see the same example if we group the data by email
using System.Data;
using WebVella.DocumentTemplates.Engines.Text;
namespace WebVella.DocumentTemplates.Examples;
internal class Program
{
static void Main(string[] args)
{
//1. Get the DataTable
DataTable dt = new DataTable();
dt.Columns.Add("email", typeof(string));
var row = dt.NewRow();
row["email"] = $"john@domain.com";
dt.Rows.Add(row);
var row2 = dt.NewRow();
row2["email"] = $"john@domain.com";
dt.Rows.Add(row2);
var row3 = dt.NewRow();
row3["email"] = $"peter@domain.com";
dt.Rows.Add(row3);
//2. Setup the template
WvTextTemplate template = new()
{
//NOTE: we provide grouping column this time
GroupDataByColumns = new List<string>() { "email" },
Template = "{{email(S=\",\")}}"
};
//3. Execute and get the results
WvTextTemplateProcessResult result = template.Process(dt);
Console.WriteLine(result.ResultItems.Count);
//Output: 2
Console.WriteLine(result.ResultItems[0]);
//Output: john@domain.com,john@domain.com
Console.WriteLine(result.ResultItems[1]);
//Output: peter@domain.com
}
}