ActiveReports 8 > ActiveReports User Guide > Samples and Walkthroughs > Walkthroughs > Section Report Walkthroughs > Export > Custom HTML Outputter |
You can create a custom HTML outputter for your ActiveReports ASP.NET Web Application.
Note: You cannot create a custom HTML outputter for a page report because the html rendering extension does not support the custom output formatter. |
This walkthrough is split up into the following activities:
To create a public class for the HTML outputter
C# code. |
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public class MyCustomHtmlOutputter: IOutputHtml |
The following example shows what the complete code for the method looks like.
To write the code in Visual Basic.NET
Visual Basic.NET code. Paste JUST ABOVE the class. |
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Imports System Imports System.IO Imports System.Web Imports System.Text Imports GrapeCity.ActiveReports Imports GrapeCity.ActiveReports.Export.Html |
Visual Basic.NET code. Paste INSIDE the class. |
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Implements IOutputHtml 'The http context of the request. Private context As System.Web.HttpContext = Nothing 'The directory in which to save filename--this ensures that the filename 'is unique. Private dirToSave As System.IO.DirectoryInfo = Nothing Public mainPage As String = "" Public Sub New(ByVal context As System.Web.HttpContext) If context Is Nothing Then Throw New ArgumentNullException("context") End If Me.context = context Dim dirName As String = context.Server.MapPath("ReportOutput") Me.dirToSave = New DirectoryInfo(dirName) End Sub #Region "Implementation of IOutputHtml" Public Function OutputHtmlData(ByVal info As HtmlOutputInfoArgs) As String Implements IOutputHtml.OutputHtmlData Dim temp As String = "" Select Case info.OutputKind Case HtmlOutputKind.BookmarksHtml Case HtmlOutputKind.FramesetHtml temp = Me.GenUniqueFileNameWithExtension(".html") Dim fs As New FileStream(temp, FileMode.CreateNew) Me.WriteStreamToStream(info.OutputStream, fs) fs.Close() Return temp Case HtmlOutputKind.HtmlPage 'Store the name of the main page so we can redirect the 'browser to it Me.mainPage = Me.GenUniqueFileNameWithExtension(".html") Dim fs As New FileStream(Me.mainPage, FileMode.CreateNew) Me.WriteStreamToStream(info.OutputStream, fs) fs.Close() Return Me.mainPage Case HtmlOutputKind.ImageJpg 'Create a file with a .jpg extension: temp = Me.GenUniqueFileNameWithExtension(".jpg") Dim fs As New FileStream(temp, FileMode.CreateNew) fs = File.Create(temp) Me.WriteStreamToStream(info.OutputStream, fs) fs.Close() Return temp Case HtmlOutputKind.ImagePng 'Create a file with a .png extension: temp = Me.GenUniqueFileNameWithExtension(".png") Dim fs As New FileStream(temp, FileMode.CreateNew) Me.WriteStreamToStream(info.OutputStream, fs) fs.Close() Return temp Case Else 'Default to html: temp = Me.GenUniqueFileNameWithExtension(".html") Dim fs As New FileStream(temp, FileMode.CreateNew) Me.WriteStreamToStream(info.OutputStream, fs) fs.Close() Return temp End Select End Function Public Sub Finish() Implements IOutputHtml.Finish End Sub #End Region Private Sub WriteStreamToStream(ByVal sourceStream As Stream, ByVal targetStream As Stream) 'Find the size of the source stream: Dim size As Integer = CType(sourceStream.Length, Integer) 'Create a buffer that same size Dim buffer(size) As Byte 'Move the source stream to the beginning sourceStream.Seek(0, SeekOrigin.Begin) 'Copy the sourceStream into our buffer sourceStream.Read(buffer, 0, size) 'Write out the buffer to the target stream targetStream.Write(buffer, 0, size) End Sub Private Function GenUniqueFileNameWithExtension(ByVal extensionWithDot As String) As String Dim r As New System.Random() Dim unique As Boolean = False Dim filePath As String = "" Dim iRandom As Integer = 0 'Generate a random name until it's unique While Not unique iRandom = r.Next() 'Build the full filename Dim sb = New StringBuilder() sb.Append(Me.dirToSave.FullName) sb.Append(Path.DirectorySeparatorChar) sb.Append(iRandom.ToString()) sb.Append(extensionWithDot) filePath = sb.ToString() If File.Exists(filePath) = False Then unique = True Else unique = False End If End While Return filePath End Function End Class |
To write the code in C#
C# code. Paste JUST ABOVE the class. |
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using System; using System.IO; using System.Web; using System.Text; using GrapeCity.ActiveReports; using GrapeCity.ActiveReports.Export.Html; |
C# code. Paste INSIDE the class. |
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//The http context of the request private System.Web.HttpContext context = null; //The directory in which to save filename--this ensures that the filename //is unique. private System.IO.DirectoryInfo dirToSave = null; public string mainPage = ""; public MyCustomHtmlOutputter(System.Web.HttpContext context) { if(context == null) { throw new ArgumentNullException("context"); } this.context = context; string dirName = context.Server.MapPath("ReportOutput"); this.dirToSave = new DirectoryInfo(dirName); } #region Implementation of IOutputHtml public string OutputHtmlData(HtmlOutputInfoArgs info) { string temp = ""; switch(info.OutputKind) { case HtmlOutputKind.BookmarksHtml: case HtmlOutputKind.FramesetHtml: { temp = this.GenUniqueFileNameWithExtension(".html"); FileStream fs = File.Create(temp); this.WriteStreamToStream(info.OutputStream, fs); fs.Close(); return temp; } case HtmlOutputKind.HtmlPage: { //Store the name of the main page so we can //redirect the browser to it this.mainPage = this.GenUniqueFileNameWithExtension(".html"); FileStream fs = File.Create(this.mainPage); this.WriteStreamToStream(info.OutputStream, fs); fs.Close(); return this.mainPage; } case HtmlOutputKind.ImageJpg: { // Create a file with a .jpg extension: temp = this.GenUniqueFileNameWithExtension(".jpg"); FileStream fs = File.Create(temp); this.WriteStreamToStream(info.OutputStream, fs); fs.Close(); return temp; } case HtmlOutputKind.ImagePng: { //Create a file with a .png extension: temp = this.GenUniqueFileNameWithExtension(".png"); FileStream fs = File.Create(temp); this.WriteStreamToStream(info.OutputStream, fs); fs.Close(); return temp; } default: { //Default to html: temp = this.GenUniqueFileNameWithExtension(".html"); FileStream fs = File.Create(temp); this.WriteStreamToStream(info.OutputStream, fs); fs.Close(); return temp; } } } public void Finish() { } #endregion private void WriteStreamToStream(Stream sourceStream, Stream targetStream) { //Find the size of the source stream int size = (int)sourceStream.Length; //Create a buffer that same size byte[] buffer = new byte[size]; //Move the source stream to the beginning sourceStream.Seek(0, SeekOrigin.Begin); //Copy the sourceStream into our buffer sourceStream.Read(buffer, 0, size); //Write out the buffer to the target stream targetStream.Write(buffer, 0, size); } private string GenUniqueFileNameWithExtension(string extensionWithDot) { System.Random r = new Random(); bool unique = false; string filePath = ""; int iRandom = 0; //Generate a random name until it's unique while(!unique) { iRandom = r.Next(); //Buld the full filename System.Text.StringBuilder sb = new System.Text.StringBuilder(); sb.Append(this.dirToSave.FullName); sb.Append(Path.DirectorySeparatorChar); sb.Append(iRandom.ToString()); sb.Append(extensionWithDot); filePath = sb.ToString(); unique = !File.Exists(filePath); } return filePath; } |
To add code to the Web Form to export to HTML
The following example shows what the code for the method looks like.
To write the code in Visual Basic.NET
Visual Basic.NET code. Paste INSIDE the Page Load event. |
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Dim rpt As New rptCustHTML() 'Buffer this page's output until the report output is ready. 'Clear any part of this page that might have already been buffered for output. 'Clear any headers that might have already been buffered (such as the content type 'Tell the browser and the "network" that the resulting data of this page should be 'Tell the browser this is an Html document so it will use an appropriate viewer. 'Create the Html export object Dim outputter As New MyCustomHtmlOutputter(Me.Context) |
To write the code in C#
C# code. Paste INSIDE the Page Load event. |
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rptCustHTML rpt = new rptCustHTML(); try { rpt.Run(false); } catch (Exception eRunReport) { //If the report fails to run, report the error to the user Response.Clear(); Response.Write("<h1>Error running report:</h1>"); Response.Write(eRunReport.ToString()); return; } //Buffer this page's output until the report output is ready. Response.Buffer = true; //Clear any part of this page that might have already been buffered for output. Response.ClearContent(); //Clear any headers that might have already been buffered (such as the content //type for an HTML page) Response.ClearHeaders(); //Tell the browser and the "network" that the resulting data of this page should //be cached since this could be a dynamic report that changes upon each request. Response.Cache.SetCacheability(HttpCacheability.NoCache); //Tell the browser this is an Html document so it will use an appropriate viewer. Response.ContentType = "text/html"; //Create the HTML export object GrapeCity.ActiveReports.Export.Html.Section.HtmlExport htmlExport1 = new GrapeCity.ActiveReports.Export.Html.Section.HtmlExport(); //Export the report to HTML in this session's webcache MyCustomHtmlOutputter outputter = new MyCustomHtmlOutputter(this.Context); this.htmlExport1.Export(rpt.Document, outputter, ""); Response.Redirect("ReportOutput" + "/" + System.IO.Path.GetFileName(outputter.mainPage)); |
To add a folder to the project for report output