The HTML Report Engine

INTRODUCTION

The HTML Report Engine is a .NET class library which helps in generating well formatted HTMLreports. It can take any DataSet as its report source. Reports can have sectional data contents and bar charts.

BACKGROUND

Crystal Reports is a reporting tool that comes along with VS.NET, but designing and deploying a Crystal Reports report in your application is a bit complex. Though this HTML report engine utility has only limited number of features, it can produce awesome reports with no complex designing and coding work involved.

USING THE CODE

It’s a generic reporting utility which takes as a report source, a DataSet containing at least oneDataTable. The class library contains three main classes:

• Field
• Section
• Report

The Field class contains report field information like report column name, column header, background color, and so on.

The Section class holds information about a section like ‘group by’ column name, title prefix, background color, charting information, and so on.

The Report class contains all the methods and properties required to render an HTML report. In this class, a few CSS (Cascaded Style Sheet) classes are used to format the report content. The following code sample explains how to use this utility in your application:

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//Include the namespace
using HTMLReportEngine;

//Create report object and set properties.
Report report = new Report();
report.ReportTitle = "Issue Report";
//Create a DataSet ds and fill it before using this code.
report.ReportSource = ds;

//Create Section
Section release = new Section("Release","Release: ");

//Create SubSection
Section project = new Section("Project","ProjectID: ");

//Add the sections to the report
release.SubSection = project;
report.Sections.Add(release);

//Add report fields to the report object.
report.ReportFields.Add(new Field("TicketNo", "Ticket", 50, ALIGN.RIGHT));
report.ReportFields.Add(new Field("CreatedBy", "CreatedBy", 150));
report.ReportFields.Add(new Field("AssignedTo", "AssignedTo"));
report.ReportFields.Add(new Field("Release", "Release", 200));
report.ReportFields.Add(new Field("Project", "Project", 150, ALIGN.RIGHT));

//Generate and save the report
report.SaveReport(@"C:\Data\Report.htm");

CLASS PROPERTIES AND METHODS

Field
Property	Type	Description
FieldName	String	A column name in the DataSet.
HeaderName	String	String to be displayed as column header.
Width	Int	Width of the column in pixels.
Alignment	ALIGN	Text alignment of the field. Default is ALIGN.LEFT.
BackColor	Color	Column background color.
HeaderBackColor	Color	Column header background color.
isTotalField	bool	If true, the field is included for total. Default is false.
Field()	Constructor	There are eight overloaded constructors available.
Section
Property	Type	Description
GroupBy	String	Column name on which group by is to be applied.
TitlePrefix	String	Prefix text for section header.
BackColor	Color	Section header background color.
GradientBackground	bool	true – to display gradient color; false – to display plain background color. Default is false.
IncludeTotal	bool	Display/hide Total row.
SubSection	Section	Subsection of type Section.
IncludeChart	bool	Display/hide chart.
ChartTitle	String	Chart title text.
ChartShowAtBottom	bool	true - show chart at bottom (after data rows); false – show chart at top. Default is false.
ChartChangeOnField	String	Chart Y-axis field, usually text field.
ChartValueField	String	Chart X-axis field, must be a numeric field. Default is record count.
ChartShowBorder	bool	Enable/disable chart border.
ChartLabelHeader	String	Chart label column header text. Default is ‘Label’.
ChartPercentageHeader	String	Chart percentage column header text. Default is ‘Percentage’.
ChartValueHeader	String	Chart value column header text. Default is ‘Value’.
Section()	Constructor	There are three overloaded constructors available.
Report
Property	Type	Description
ReportTitle	String	Report title text.
ReportSource	DataSet	Report source is a DataSet. The DataSet must contain at least one DataTable with data.
Sections	ArrayList	Collection of report sections. Each element is of type Section.
ReportFields	ArrayList	Collection of report fields. Each element is of type Field.
ReportFont	String	Report font as string.
TotalFields	ArrayList	Collection of column names to be listed in Total row. Each element is of type string.
IncludeTotal	bool	Display/hide Total row.
IncludeChart	bool	Display/hide chart.
ChartTitle	String	Chart title text.
ChartShowAtBottom	bool	true - show chart at bottom (after data rows); false – show chart at top. Default is false.
ChartChangeOnField	String	Chart Y-axis field, usually text field.
ChartValueField	String	Chart X-axis field, must be a numeric field. Default is record count.
ChartShowBorder	bool	Enable/disable chart border.
ChartLabelHeader	String	Chart label column header text. Default is ‘Label’.
ChartPercentageHeader	String	Chart percentage column header text. Default is ‘Percentage’.
ChartValueHeader	String	Chart value column header text. Default is ‘Value’.
GenerateReport()	Method	Generates the HTML report and returns it as aStringBuilder object.
SaveReport(stringfileName)	Method	Generates the HTML report and saves it to disk with the given file name.

FORMATTING THE REPORT

Including totals

This report engine supports multiple SUM fields for a report. And the SUM can be displayed on demand in any of the sections added to the report. The SUM field must be of type numeric. The following code explains how to add SUM fields:

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//Add Total fields
report.TotalFields.Add("Project");
report.TotalFields.Add("ProgressedHours");

//Set IncludeTotal property of the sections to true
project.IncludeTotal = true;
release.IncludeTotal = true;

Adding charts

This engine can produce bar charts. The developer has to provide only the ChangeOnField andValueField as input. If the developer has not given any ValueField, the record count will be taken as the Value. Changing the ChartShowAtBottom property would let your charts come either at the top or the bottom of the section.

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//Set Chart properties
release.ChartChangeOnField = "Severity";
release.ChartValueField = "ProgressedHours";

release.ChartTitle = "Severity-Wise report";
release.ChartLabelHeader = "Severity Type";
release.ChartValueHeader = "Hours";
release.ChartPercentageHeader = "Progress";

Aligning fields

Field texts can be aligned to Left, Right, or Center. By default, the text alignment is set to Left.

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//Set field Alignment
Field field1 = new Field();
field1.Alignment = ALIGN.RIGHT;

Specifying colors

The developers are allowed to change the background colors of section headers, column headers, and column data. Section headers can have gradient backgrounds by setting the GradientBackgroundproperty to true.

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//Specifying Colors
//Main Section header color
release.BackColor = Color.WhiteSmoke;
release.GradientBackground = true;

//Sub Section header color
project.BackColor = Color.GhostWhite;
project.GradientBackground = true;

//Field Colors
field1.HeaderBackColor = Color.LightSlateGray;
field1.BackColor = Color.Gainsboro;
field2.HeaderBackColor = Color.LightSlateGray;
field2.BackColor = Color.White;
field3.HeaderBackColor = Color.LightSlateGray;
field3.BackColor = Color.Gainsboro;

POINTS OF INTEREST

It is recommended that you specify the column width for all report fields except one. That one may be a variable text field. The field without column width will automatically fit into the remaining space available in the table.

There is a simple way to export data to MS Excel. You can open the generated HTML file in Internet Explorer, right click on the report, and select 'Export to Excel'. Done!