DataTplAggregates.cs
//
// 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 GrapeCity.Documents.Word;
using DocumentFormat.OpenXml.Wordprocessing;
using System.Globalization;

namespace DsWordWeb.Demos
{
    // This example demonstrates the available aggregate functions that can be used with the 'calc'
    // report templates feature for data aggregation.
    // Unlike other report templates constructs, aggregates do not cause repetition of content
    // in the generated document. Instead, they aggregate data and insert the single resulting
    // value into the document.
    // Aggregate functions' arguments can be expressions involving data, other functions and constants.
    public class DataTplAggregates
    {
        public GcWordDocument CreateDocx()
        {
            // Generate a simple data source with random numeric data:
            var values = new List<decimal>();
            var rnd = Util.NewRandom();
            var count = rnd.Next(10, 20);
            for (int i = 0; i < count; ++i)
                values.Add(new decimal(Math.Round((double)rnd.Next(0, 1000000) / rnd.Next(1, 100), 2)));

            var doc = new GcWordDocument();
            doc.Body.Sections.First.PageSetup.Margin.Top = 36;
            doc.Body.Sections.First.PageSetup.Margin.Bottom = 36;
            doc.Body.Sections.First.PageSetup.Margin.Left = 36;
            doc.Body.Sections.First.PageSetup.Margin.Right = 36;

            // Add the data source:
            doc.DataTemplate.DataSources.Add("ds", values);

            // Styles and templates to show results:
            var numberedListTemplate = doc.ListTemplates.Add(BuiltInListTemplateId.NumberDefault, "numberedListTemplate");
            var bulletListTemplate = doc.ListTemplates.Add(BuiltInListTemplateId.BulletDefault, "bulletListTemplate");
            var exStyle = doc.Styles[BuiltInStyleId.Heading3];
            var resStyle = doc.Styles[BuiltInStyleId.Strong];

            // Print data to be summarized:
            var paras = doc.Body.Paragraphs;
            paras.Add("Data values to aggregate:", doc.Styles[BuiltInStyleId.Heading2]);
            var p = paras.Add("{{#ds}}{{ds.value}}{{/ds}}", doc.Styles[BuiltInStyleId.ListParagraph]);
            p.ListFormat.Template = numberedListTemplate;

            // Print the results:
            paras.Add("Simple aggregates:", doc.Styles[BuiltInStyleId.Heading2]);
            add("{{ calc Average(ds.value) }}");
            add("{{ calc Count(ds.value) }}");
            add("{{ calc First(ds.value) }}");
            add("{{ calc Last(ds.value) }}");
            add("{{ calc Max(ds.value) }}");
            add("{{ calc Min(ds.value) }}");
            add("{{ calc Sum(ds.value) }}");

            paras.Add("Aggregates on expressions:", doc.Styles[BuiltInStyleId.Heading2]);
            add("{{ calc Sum(ds.value / Count(ds.value)) }}");
            add("{{ calc Average(Pow(ds.value, 2)) }}");
            add("{{ calc Average(Sqrt(ds.value)) }}");
            add("{{ calc Sum(Iif(ds.value > 50, ds.value, 0)) }}");

            // Process the templates:
            doc.DataTemplate.Process(CultureInfo.GetCultureInfo("en-US"));

            // Add a short note describing the demo at the top of the document:
            paras.Insert(
                "This example demonstrates the available aggregate functions that can be used with the 'calc' " +
                "report templates feature for data aggregation. " +
                "Unlike other report templates constructs, aggregates do not cause repetition of content " +
                "in the generated document. Instead, they aggregate data and insert the (single) resulting " +
                "value into the document. " +
                "For example, to insert the sum of a field's values in all records of a data source, " +
                "the template '{{calc Sum(ds.value)}}' can be used. " +
                "Aggregate functions' arguments can be expressions involving data, other functions and constants. " +
                "The data source used in this demo is a list of random decimal values. " +
                "Please see this example's source code for full details.",
                InsertLocation.Start);
            paras.Insert("Report templates: calc aggregate functions", doc.Styles[BuiltInStyleId.Heading1], InsertLocation.Start);

            // Done:
            return doc;

            void add(string expr)
            {
                // \x200B is a zero-width space used to prevent template expansion:
                paras.Add(expr.Insert(1, "​​​\x200B") + " :  ", exStyle).ListFormat.Template = bulletListTemplate;
                paras.Last.GetRange().Runs.Add(expr, resStyle);
            }
        }
    }
}