This section has been added to reflect changes in XFRX ver. 11.3. If you are using previous XFRX versions, please see Using XFCont class paragraph below in this chapter.
There are several ways how you can setup the XFRX previewer. You can either use the already prepared standalone previewing component or start with the basic classes of the previewer component to add the previewing capabilities to your own forms.
The following subchapters describe using three classes implemented in XFRXLIB.VCX which you can use as a starting point to implement the XFRX previewer in your application:
| frmMPPreviewer | cntXFRXMultiPage | XFCont |
Implemented as a form (the easiest setup) | Yes | No | No |
Implemented as a container (can be embedded into existing forms) | No | Yes | Yes |
supports multi-tab interface | Yes | Yes | No |
supports embedded toolbar | Yes | Yes | No |
- XFCont is the basic XFRX previewer class. It is implemented as a container object and supports searching, hyperlinks, bookmarks, printing and exporting.
- cntXFRXMultiPage class extends the XFCont class functionality with multi-tab interface – it can display multiple previewer tabs in a page frame class. It also supports a (fake) embedded toolbar, which is a toolbar-like control at the top of the container, which is very useful if the previewer form is not inside the main VFP screen.
- frmMPPreviewer is a form class that implements cntXFRXMultiPage and serves as a “proxy” to the cntXFRXMultiPage class features. If all you need is a full screen report previewer, this one is the easiest to setup.
Default settings
A new objects-type property has been added to the XFCont, cntXFRXMultipage and frmMPPreviewer classes:
Name | Description | XFRX version |
---|---|---|
cImageFolder | Folder with images for XFRX preview. | 16.1.4 |
oDisplayDefaults | Display default options. | |
oPrinterOptions | Print default options. | 17.0.0 |
oExportOptions | Export default options. | 17.0.0 |
oEmailOptions | E-mail default options. | 17.0.0 |
Object oDisplayDefaults has the following properties:
Name | Type | Description | XFRX version |
---|---|---|---|
StartingPage | integer | The 1st page to show in the previewer. Default value is 1. | |
DefaultOutputFileName | string | The default output file name when exporting from the previewer. | |
PagesPerSheet | string | Encoded pages per sheet layout value. Default value: 1x1. Allowed values: 1x1, 2x1, 2x2, 3x1, 3x2, 4x2. | |
ZoomFactor | integer | the zoom factor. default value = 100. -1 = fit to width, -2 = fit page. The zoom factor will be used only of PagesPerSheet is 1x1, otherwise it defaults to -2. | |
FindColor | integer | background color of searched text | 17.0.0 |
Example:
m.loPreview = CREATEOBJECT("frmMPPreviewer") m.loPreview.oDisplayDefaults.StartingPage = 2 m.loPreview.oDisplayDefaults.DefaultOutputFileName = "invoice15_09" m.loPreview.oDisplayDefaults.ZoomFactor = -1 m.loPreview.oDisplayDefaults.PagesPerSheet = "1x1" m.loPreview.PreviewXFF(loXFF) m.loPreview.show(1)
Common methods and properties
Even though you can use different classes to provide the previewing capabilities in your application, all classes share most of the properties and methods you can use to control and customize them.
Controlling multi-tab preview features
The properties and methods described in this paragraph are implemented in cntXFRXMultiPage and frmMPPreviewer classes. The multi-tab features are not implemented in XFCont class.
Property / Method | Usage |
lShowTabForOneReport (property) | Possible values:
|
PreviewXFF (method) | Syntax: PreviewXFF(toXFF, tcCaption, tnPageNo) Call this method to preview the XFF file in the previewer. You can call this method multiple times, which would either add new reports as new pages or replace existing pages, depending on parameters. Parameters: toXFF The reference of a XFF file that is going to be previewed tcCaption (optional) The caption of the page with this report if previewing multiple reports. tnPageNo(optional) The page on which the XFF file is going to be previewed. If this parameter is empty or greater than the number of existing pages, a new page is added. If a page with this number already exists, it will be replaced. |
RemovePage (method) | Syntax: RemovePage(tnPageNo) Removes a page from the previewer. Parameters: tnPageNo (optional) The number of the page to remove. If the parameter is empty or the number is greater than the number of existing pages, the last one is removed. |
Registering an extension handler
The extension handler allows for extending the functionality of the basic classes without need of creating subclasses. All you need is to create a custom class, which implements certain methods. The custom class is registered with the XFRX previewer class (using SetExtensionHandler method) and the previewer calls the extension methods on appropriate events.
Currently supported event methods are:
Method | Usage | Comment |
---|---|---|
KeyPress | This method is called from KeyPress() method od xfcont class. Parameters: toXFF – the handler of the XFF file that is being previewed nKeyCode – Contains a number that identifies the key pressed nShiftAltCtrl - Sets a particular bit if a modifier key is held down while pressing the key specified by nKeyCode
|
USE invoices ORDER customer LOCAL m.loSession, m.lnRetval, m.loXFF, m.loPreview, m.loScripts m.loSession=EVALUATE([xfrx("XFRX#LISTENER")]) m.lnRetVal = m.loSession.SetParams("",,,,,,"XFF") && no name = just in memory IF m.lnRetVal = 0 REPORT FORM invoices OBJECT m.loSession m.loXFF = m.loSession.oxfDocument * * initialize the previewer * SET CLASSLIB TO xfrxlib ADDITIVE m.loPreview = CREATEOBJECT("frmMPPreviewer") m.loPreview.setExtensionHandler(CREATEOBJECT("MyExtensionHandler")) m.loPreview.windowType = 0 m.loPreview.iBook = 0 m.loPreview.PreviewXFF(loXFF) m.loPreview.show(1) ENDIF DEFINE CLASS MyExtensionHandler AS Custom PROCEDURE Export LPARAMETERS m.toXFF IF USED("_xfExportTypes") USE IN _xfExportTypes ENDIF * * define my export options list * CREATE CURSOR _xfExportTypes (name C(50), extension C(4), targetCode C(10)) INSERT INTO _xfExportTypes VALUES ("HTML", "html", "HTML") INSERT INTO _xfExportTypes VALUES ("PDF", "pdf", "PDF") INSERT INTO _xfExportTypes VALUES ("Excel", "xls", "XLS") ENDPROC PROCEDURE ExportOptions LPARAMETERS m.toXFF, m.toOptions IF m.toOptions.cTarget = "XLS" * * my own code to handle output to Excel * =MESSAGEBOX("exporting to "+m.toOptions.cOutputFile) RETURN .F. && suppress the default behavior ELSE RETURN .T. && continue with the default behavior ENDIF ENDPROC ENDDEFINE
SET PATH TO xfrxlib SET CLASSLIB TO xfrxlib LOCAL m.loPreview, m.loSession, m.loExtensionHandler m.loExtensionHandler = CREATEOBJECT("myExtensionHandler") m.loPreview = CREATEOBJECT("frmMPPreviewer") m.loSession=EVALUATE([xfrx("XFRX#LISTENER")]) * * create a memory XFF file * m.lnRetVal = m.loSession.SetParams(,,,,,,"XFF") IF m.lnRetVal = 0 SELECT * ; FROM customers INNER JOIN orders ON customers.customerid = orders.customerid ; INNER JOIN orderdetails ON orders.orderid = orderdetails.orderid ; ORDER BY customers.companyname, customers.customerID, orders.orderID ; INTO CURSOR custlist REPORT FORM custlist OBJECT loSession ENDIF * * assign the extension handler * m.loPreview.setExtensionHandler(loExtensionHandler) * * preview the report * m.loPreview.previewXFF(m.loSession.oxfdocument) m.loPreview.show(1) DEFINE CLASS myExtensionHandler AS CUSTOM PROCEDURE Print LPARAMETERS m.toXFF RETURN .t. && continue with the default behavior ENDPROC PROCEDURE Export LPARAMETERS m.toXFF * * now you can process the XFF file * RETURN .F. && override the default behavior ENDPROC ENDDEFINE
USE demoreps\invoices ORDER customer LOCAL m.loSession, m.lnRetval, m.loXFF, m.loPreview, m.loScripts m.loSession=EVALUATE([xfrx("XFRX#LISTENER")]) m.lnRetVal = m.loSession.SetParams(,,,,,,"XFF") && no name = just in memory IF m.lnRetVal = 0 REPORT FORM demoreps\invoices object m.loSession * * the XFRX#DRAW object reference is stored in oxfDocument property * m.loXFF = m.loSession.oxfDocument * * initialize the previewer * SET PATH TO xfrxlib SET CLASSLIB TO xfrxlib ADDITIVE m.loPreview = CREATEOBJECT("frmMPPreviewer") * * setup the extension handler * m.loPreview.oExtensionHandler = CREATEOBJECT("SampleExtensionHandler") m.loPreview.windowtype = 1 m.loPreview.iTool = 2 && embedded toolbar m.loPreview.PreviewXFF(m.loXFF) m.loPreview.show(1) ENDIF DEFINE CLASS SampleExtensionHandler as Custom PROCEDURE BeforeExport LPARAMETERS m.toSession, m.toExportParameters m.toSession.setAuthor("Martin") && set the document author property IF m.toExportParameters.cTarget = "XLS" && (XLS or XLSPLAIN) m.toSession.SetOtherParams("DISPLAY_GRID_LINES",.F.) && do not display gridlines in excel ENDIF ENDPROC PROCEDURE AfterExport LPARAMETERS m.toSession, m.toOptions IF m.toOptions.cTarget = "XLS" *COPY FILE (m.toOptions.coutputfile) TO ([anybackupfolder]\[anyfile.xls]) ENDIF ENDPROC ENDDEFINE
USE demoreps\invoices ORDER customer LOCAL m.loSession, m.lnRetval, m.loXFF, m.loPreview, m.loScripts m.loSession=EVALUATE([xfrx("XFRX#LISTENER")]) m.lnRetVal = m.loSession.SetParams(,,,,,,"XFF") && no name = just in memory IF m.lnRetVal = 0 REPORT FORM demoreps\invoices OBJECT m.loSession * * the XFRX#DRAW object reference is stored in oxfDocument property * m.loXFF = m.loSession.oxfDocument * * initialize the previewer * SET PATH TO xfrxlib SET CLASSLIB TO xfrxlib ADDITIVE m.loPreview = CREATEOBJECT("frmMPPreviewer") * * setup the extension handler * m.loPreview.oExtensionHandler = CREATEOBJECT("SampleExtensionHandler") m.loPreview.windowtype = 1 m.loPreview.iTool = 2 && embedded toolbar m.loPreview.PreviewXFF(loXFF) m.loPreview.show(1) ENDIF DEFINE CLASS SampleExtensionHandler AS CUSTOM PROCEDURE KeyPress(m.loXFCont, m.nKeyCode, m.nShiftAltCtrl) * hotkey for print P (112-p, 80-P) IF INLIST(m.nKeyCode, 112, 80) m.loXFCont.Print() ENDIF ENDPROC ENDDEFINE
Showing / hiding bookmarks
The bookmark panel behavior is controlled by the iBook property:
Property | Usage |
iBook | Controls if the bookmark should be displayed in the previewer. The allowed values are:
|
Showing / hiding previewer toolbars
There are two toolbars in the previewer control – one is placed at the bottom of the control, the other one is available as a floating toolbar panel, which by default docks at the top of the main window, or, alternatively, as an “embedded toolbar”. All three classes implement iTool and ShowStatus properties that control visibility of the toolbars:
Property | Usage | XFRX version |
classMainToolbar | The class name of the toolbar. The default value is “xfrxToolbar”. You can create a child of the default xfrxToolbar class (defined in xfrxlib.vcx) and use this property to instruct the previewer to use your class rather than the default one. This property works for the “real” toolbar – if iTool property is 0 or 1. if iTool is set to 2, cmdEmbeddedToolbar container class is used as the “embedded” toolbar. | |
ClassMainStatusBar | The class name of the status bar or embdded toolbar. The default value is “cntembeddedtoolbar”. You can create a child of the default cntembeddedtoolbarr class (defined in xfrxlib.vcx) and use this property to instruct the previewer to use your class rather than the default one. | 17.3 |
iTool | Controls the visibility of the toolbar at the top. The allowed values are:
| |
ShowStatus | Controls the visibility of the toolbar at the status bar of the previewer container. The allowed values are:
|
Displaying progress bar
Property | Usage |
oprogress | The object instance of XFRX progress bar |
USE demoreps\invoices ORDER customer LOCAL m.loSession, m.lnRetval, m.loXFF, m.loPreview, m.loScripts m.loSession=EVALUATE([xfrx("XFRX#LISTENER")]) m.lnRetVal = m.loSession.SetParams(,,,,,,"XFF") && no name = just in memory IF m.lnRetVal = 0 REPORT FORM demoreps\invoices OBJECT m.loSession * * the XFRX#DRAW object reference is stored in oxfDocument property * m.loXFF = m.loSession.oxfDocument * * initialize the previewer * SET PATH TO xfrxlib SET CLASSLIB TO xfrxlib ADDITIVE m.loPreview = CREATEOBJECT("frmMPPreviewer") * * setup the extension handler * m.loPreview.oExtensionHandler = CREATEOBJECT("SampleExtensionHandler") m.loPreview.oprogress=createobject("progress") m.loPreview.PreviewXFF(loXFF) m.loPreview.show(1) ENDIF DEFINE CLASS progress AS CUSTOM PROCEURE updateProgress LPARAM m.ta,m.tb, m.tc WAIT WINDOW NOWAIT "Page #: "+ALLT(STR(m.tb))+" Report #: "+ALLT(STR(m.ta))+" ("+ALLT(STR(m.tc))+"%)" ENDPROC ENDDEF
Using frmMPPreviewer class
This class serves as a standalone (fullscreen) previewer window. All you need to do to make it work is to pass it a reference to the XFF file to preview, using the previewXFF method, as described in Controlling multi-tab preview features paragraph above. (If you are not sure how to create a XFF file reference, please read chapters 17.0: Initializing the XFRX#DRAW class instance and 16.3: Creating temporary XFF files). Here is a very simple “Hello World” example:
LOCAL m.loPreview SET CLASSLIB TO XFRXLIB.VCX ADDITIVE m.loPreview = CREATEOBJECT("frmMPPreviewer") && create the previewer object m.loPreview.previewXFF(m.loXFF) && loXFF is XFF file reference m.loPreview.show(1) && show the form as modal
Make sure to set all properties (like iTool, ShowStatus, etc.) before you call PreviewXFF(…) otherwise they won’t be used.
Using cntXFRXMultiPage class
- Add an instance of cntXFRXMultiPage class (of XFRXLIB.VCX) into your form. Adjust the size of the cntXFRXMultiPage class object container as you need. The previewer, including the status bar, icons and scroll bars will be displayed in the container. If you resize the container in runtime, its content is automatically adjusted.
When the form is about to be released, the cntXFRXMultiPage class instance needs to do some cleanup. To enable that please call the class instance’s clearLink() method from form’s destroy method:
PROCEDURE Destroy Thisform.cntXFRX.clearLink() ENDPROC
When running the form, make sure the XFRXLIB.VCX class library is referenced in SET CLASSLIB command:
SET CLASSLIB TO XFRXLIB.VCX ADDITIVE
- Call the PreviewXFF method to preview a XFF file, as described in Controlling multi-tab preview features paragraph above.
- By default, cntXFRXMultiPage is using an instance of the XFCont class for each page. Should you like to make it use a different class (eg. a subclass of XFCont) put the class name to the ClassPreviewPage property of the cntXFRXMultiPage instance.
Using XFCont class
Add an instance of XFCONT class (of XFRXLIB.VCX) into your form. Adjust the size of the XFCONT class container as you need. The previewer, including the status bar, icons and scroll bars will be displayed in the container. If you resize the container in runtime, its content is automatically adjusted.
When the form is about to be released, the XFCONT class instance needs to do some cleanup. To enable that please call the XFCont class instance’s clearLink() method from form’s destroy method:
PROCEDURE
PROCEDURE Destroy Thisform.cntXFRX.clearLink() ENDPROC
When running the form, make sure the XFRXLIB.VCX class library is referenced in SET CLASSLIB command:
SET CLASSLIB TO XFRXLIB.VCX ADDITIVE
VFP 8.0 approach
In VFP 8.0, there are two options how to preview report in the previewer. The options differ in the calling mechanism, although internally they both work exactly the same.
Generating the “CNT” output type
The approach is using the standard syntax of calling XFRX, without explicitly using the XFRX#DRAW class (although it is used in the background). You cannot open an existing XFF file with this approach – you always need to run a report that will be previewed.
Do not send anything as the output file name
Use “CNT” as the output type parameter in the SetParams method call
Call Reset method of the previewer container class
Call SetOtherParams method of the XFRXSession class instance with the reference of XFCont instance as a parameter
Example:
LOCAL m.loSession, m.lnRetval loSession= xfrx("XFRX#INIT") m.lnRetVal = m.loSession.SetParams(,,,,,,"CNT") IF m.lnRetVal = 0 * * we are assuming the XFCont container is * available as thisform.cntXFRX * Thisform.cntXFRX.reset() m.loSession.setotherparams(Thisform.cntXFRX) m.loSession.ProcessReport("report") m.loSession.finalize() ENDIF
Using the XFRX#DRAW class
The advantage of this method is that you can preview an existing XFF file – the XFF file is opened and “converted” to “CNT” output type via the TransformReport method:
Example:
LOCAL m.loSession m.loSession= xfrx("XFRX#INIT") Thisform.oReport = xfrx("XFRX#DRAW") IF Thisform.oReport.openDocument("file.xff") Thisform.cntXFRX.reset() m.lnRetVal = m.loSession.SetParams(,,,,,,"CNT") IF m.lnRetVal = 0 m.loSession.setOtherParams(Thisform.cntXFRX) m.loSession.TransformReport(Thisform.oReport) ENDIF ENDIF
VFP 9.0 Approach
In VFP 9.0 the logic is the same, just the syntax is a little bit different – the reference to the XFCont object is copied to XFRXPreviewer property of the XFRXListener class instance and then previewReport method with the XFRX#DRAW reference as parameter is called:
LOCAL m.loSession m.loSession= xfrx("XFRX#LISTENER") Thisform.oReport = xfrx("XFRX#DRAW") IF Thisform.oReport.openDocument("file.xff") Thisform.cntXFRX.reset() m.loSession.XFRXPreviewer = Thisform.cntXFRX m.loSession.previewReport(Thisform.oReport) ENDIF
Hyperlink decoration
A new property has been added to the XFCont, cntXFRXMultipage and frmMPPreviewer classes: UnderlineHyperlinksOnPrint. You can use the following values:
0 - no decoration for hyperlinks
1 - display "normal" hyperlinks in blue, but do not decorate custom event hyperlinks (green)
2 - (default value) decorate both blue and green hyperlinks
To support this in the print output, the PrintDocument method of the XFRX#DRAW class has a new parameter, tnUnderlineHyperlinksOnPrint, with the same values and logic.
Custom buttons
This feature is implemented using the extension handler mechanism: A new method is now supported - ToolbarOnInit, which is invoked at the time the toolbar is initialized. In this method the extension handler can add new buttons to the previewer and their click events can be bound with other methods in the extension handler. A new property is now supported, too - oPreviewContainer. If it is available, the previewer will automatically fill it with the XFCont object reference for easier access to the previewer properties in the custom buttons click event methods.
Example:
USE demoreps\sales LOCAL m.loSession, m.lnRetval, m.loXFF, m.loPreview, m.loScripts m.loSession=EVALUATE([xfrx("XFRX#LISTENER")]) m.lnRetVal = m.loSession.SetParams(,,,,,,"XFF") && no name = just in memory IF m.lnRetVal = 0 REPORT FORM demoreps\sales OBJECT m.loSession * * the XFRX#DRAW object reference is stored in oxfDocument property * m.loXFF = m.loSession.oxfDocument * * initialize the previewer * SET PATH TO xfrxlib SET CLASSLIB TO xfrxlib ADDITIVE m.loPreview = CREATEOBJECT("frmMPPreviewer") * * setup the extension handler * m.loPreview.oExtensionHandler = CREATEOBJECT("SampleExtensionHandler") m.loPreview.windowtype = 1 m.loPreview.iTool = 2 && embedded toolbar *m.loPreview.iTool = 1 && standard toolbar m.loPreview.PreviewXFF(m.loXFF) m.loPreview.show(1) ENDIF DEFINE CLASS SampleExtensionHandler AS CUSTOM oPreviewContainer = .NULL. PROCEDURE ToolbarOnInit LPARAMETERS m.toToolbar LOCAL m.button IF m.toToolbar.AddObject("mybutton", "commandbutton") BINDEVENT(m.toToolbar.mybutton, "click" , This, "ButtonClicked") m.toToolbar.mybutton.tabindex = 1 m.toToolbar.mybutton.Visible = .t. IF UPPER(m.totoolbar.BaseClass)!="TOOLBAR" m.toToolbar.mybutton.left = m.toToolbar.cmdQuit.left m.toToolbar.cmdQuit.left = m.toToolbar.mybutton.left + m.toToolbar.mybutton.width ENDIF ENDIF ENDPROC PROCEDURE ButtonClicked LOCAL m.lcString m.lcString = "This.oPreviewContainer.Name: "+This.oPreviewContainer.Name+CHR(13) m.lcString = m.lcString + "current page: "+TRANSFORM(This.oPreviewContainer.nPageNo)+CHR(13) m.lcString = m.lcString + "XFRX#DRAW Object: "+This.oPreviewContainer.oXFRXWriter.Name+CHR(13) m.lcString = m.lcString + "Page count: "+TRANSFORM(This.oPreviewContainer.oXFRXWriter.PageCount)+CHR(13) WAIT WINDOW m.lcString *This.oPreviewContainer.oXFRXWriter.PrintDocument(...) *This.oPreviewContainer.oXFRXWriter.SavePicture(...) ENDPROC ENDDEFINE