Version Beta www.capesoft.com

Contents

Introduction
Features [Suggested Reading]
What xFilesXML Doesn't Do [Suggested Reading]
Limitations
Future Ideas
What is XML?
xFileXML Quick Start Guide
            Loading / Importing & Parsing XML Files [Suggested Reading]
            Creating an XML File or String [Suggested Reading]
xFiles Template [Suggested Reading]
Some Practical Applications of the xFilesXML Class    [Suggested Reading]
            Loading XML Files
            Creating RSS Feed Files
            Storing Global Settings in an XML file
            Creating SOAP requests
            Using a View to create a filtered, sorted, XML file
            Storing multiple things in the same XML file
Examples
Classes

xFileXML Class - XML loading and saving the easy way.

Jump Start (great for new users and beginners) [Suggested Reading]
xFileXML Methods
xFileXML Properties

xFileLinkDLL Class - Runtime DLL Loading

xFileLinkDLL Jump Start  [Suggested Reading]
xFileLinkDLL_Methods
xFileLinkDLL Properties

FAQ
Support
Installation
Distribution
License & Copyright
Version History

Introduction

CapeSoft xFiles is a collection of classes for hand-coders.
It provides the following functionality:

• Reading and writing XML files directly to and from Groups, Queues and Files  (TPS, or any other backend). Support for writing xml from Views is also included.
• Fast reading and writing of XML files to and from Clarion data structure with no significant overhead for the XML - files are read from disk and written to disk at the speed at which a binary file can be read or written.
• Support for creating RSS feeds
• Support for creating simple SOAP server or SOAP client packets. (Not all SOAP possibilities are supported yet.)
• Automatic encoding of binary data, BLOB and MEMOs in XML. Automatic addition of CDATA tags when needed.
• XML support for nested queues and groups within queues, groups and files (Clarion 6 and above)
• XML support for fields with multiple dimension (Clarion 6 and above)
• Create XML in memory from queues, groups, views and files, or populate a queue, group or file from a string in memory that contains the XML.
• Use xFilesXML to load and save all program settings in one go using the Load and Save methods.
• xFileSettings class replaces storing settings in INI files with XML files, using Get and Put and the same syntax as is used for INI files.
• Reading and Writing binary (and text) files to and from disk. Includes dynamic memory allocation for loading any size file into memory (as a string).
• Supports automatic ZIP and UNZIP compression when reading and writing files (including XML files).
• Very high precision timers using the xFileFastTimer class. Uses 64bit precision for accurate, high resolutions timers.
• xFilesExplode supports decompressing files compressed with the proprietary Implode algorithm.

We wrote xFiles a number of years ago, and it provided fast XML functionality, which we used in a number of our products (CapeSoft Email Server and CapeSoft Mailer among others). It worked so well, that we decided others would benefit from using it too.

Note: xFiles is for hand coders. This means you will need to call the xFiles methods within your code, for example self.Load() and self.Save(). This accessory is not purely template driven and requires hand-coding to operate.

One of the best things about xFiles is that is it really, really fast (yeah, really, you will be surprised just how fast it is!). This means that it outperforms other XML toolkits (for example the Microsoft SAX toolkit).

• Writes a Queue, Group, View or File to an XML file simply by calling the self.Save() method.
• Reads an XML file into a data structure (Queue, Group or File) by calling the self.Load() method.
• Reads and Writes XML files fast and reliably.
• No knowledge of XML is required.
• The xFileXML class also allows application settings (for example global application settings stored in a global group) to be stored in XML files.
• Alternatively the xFileSetting class can be used to replace settings that you would previously have stored in INI files. This class uses XML files for ultra fast, reliable storage of settings.
• Thread safe.
• Includes a number of extra utility classes for providing high precision timers, API runtime DLL linking, and basic zip compression.
• xFiles is Clarion Source Code. This means that your application is not dependent on external DLLs or Microsoft toolkits. The xFiles classes are compiled into your application and they run on all flavors of the Windows 32-bit Operating Systems.

  

What xFilesXML Doesn't Do

• xFilesXML is very fast, however it was not built to be a generic XML parser. This means that it handles basic XML, but does not process all types of XML. It does however read every file that it creates.

Limitations

• File size must be less than 2.1 GB (2147483638 bytes).
• There is a maximum field name length for xFilesXML of 80 characters. This can be changed to any value desired.
• The maximum number of fields per File, View, Group or Queue is determined by the XF:MaxFields equate (This is 252 by default). This can be set to any value as required.
• xFiles support a small subset of compression (zip, unzip and explode). Compression support is very much Beta (feature incomplete), we would not advise using xFiles as a compression utility at this point - it compresses an XML file (or other file) into a ZIP file, and decompresses a file inside a ZIP, but it is not currently a generic ZIP or compression solution.

Future Ideas

• Complete support for compression
• xFileXML - should have option to force write all fields (even if blank)
• xFileXML - should have option to not write 0 value fields

What is XML?

XML is an acronym for EXtensible Markup Language. It is an open standard for describing data in a standard, easy to use, format. XML uses a similar tag structure as HTML, however XML tags define what elements contain, and not the format for displaying them. While HTML uses predefined tags, XML allows tags to be defined by the developer. This makes XML extremely flexible, while still being easy to use. XML is an excellent format for transferring and storing information.

XML is more Rigid than HTML, it is not tolerant of errors, XML documents need to be "well formed", which means they must comply with fairly rigid rules.

XML and HTML Tags
Following are examples of XML and HTML tags. Note that the XML statements define data content, whereas the HTML lines deal with fonts and display (boldface). XML defines "what it is," and HTML defines "how it looks."

XML

<firstName>Maria</firstName>
<lastName>Roberts</lastName>
<dateBirth>10-29-52</dateBirth>

HTML

<font size="3">Maria Roberts</font>
<b>October 29, 1952</b>

CapeSoft xFiles reads and writes basic XML, it does not currently support all possible XML, however it will read any XML files that it creates. The intent of xFiles is to be small, fast (very fast), and simple. It is not a generic XML parser and is not intended to read all possible XML documents, although we will expand the support for more complex XML in future versions.

Advantages of XML

• Robust, logically-verifiable format is based on international standards.
• The hierarchical structure is suitable for most (but not all) types of documents.
• XML Files are plain text files, unencumbered by licenses or restrictions
• Easily readable (by both human and machine).
• Also easily editable.
• Portable and compatible across multiple platforms (Windows, *nix, Mac etc.).
• It is platform-independent, thus relatively immune to changes in technology.
• It and its predecessor, SGML, have been in use for well over a decade, so there is extensive experience and software available.
  

For more information visit http://www.w3.org/XML/. XML definition and information based on content from http://www.answers.com/topic/xml.

xFileXML Quick Start Guide
Loading / Importing & Parsing XML Files

Keen to get started? Or just don't like wading through all the documentation? This section is just for you - the basics on how to get xFiles working as quickly and simply as possible.

Things you need to know to Load XML
Loading From an XML File into a Group, Queue or File
Loading From an XML String into a Group, Queue or File
Loading XML from the Web into a Clarion Structure

Things you need to know to load XML

XML Files come in all shapes and sizes, but reading them into a Clarion structure can usually be done with a single line of code. In additional the File can be either stored on disk, or already be in RAM as a string. Importing from either of these is trivial.

Creating the xml object in your procedure.

You can use the xFiles extension template to add an XFiles object to your procedure. Or you can hand-code the object declaration in the data section of your procedure. It'll look something like this;

xml    xFileXML

Matching the field names to the XML.

The secret to the simplicity of the Load is that the NAME (or External Name attribute) of the fields you are loading matches the xml tags in the xml file. For example, if you have xml that looks like this:

<xml>
    <server>www.capesoft.com</server>
    <port>80</port>
</xml>

then your group should have the same field names:

Settings    Group
Server        String(80)
Port          Long
            End

xFiles simply matches up the names and the tags, and copies the data across for you.

In some cases the xml tags have names that are not legal Clarion field names. Or you may just want to change the tag name to match your field name. In this case set the External Name to match the tag name. For example:

<xml>
    <web-server>www.capesoft.com</web-server>
    <web-port>80</web-port>
</xml>

then in your group set the external names:

Whatever    Group
Server        String(80),Name('web-server')
Port          Long,Name('web-port')
            End

XML containing multiple records

In multi-record XML xFiles needs to know the FileBoundary and the RecordBoundary. These properties tell xFiles what part of the xml file to parse, and most importantly when a record is complete. For example in the following xml

<?xml version="1.0" encoding="US-ASCII"?>
<table>
  <item>
    <name>Bruce</name>
     <age>29</age>
  </item>
  <item>
    <name>Bob</name>
     <age>40</age>
  </item>
</table>

The file boundary is <table> (since all the records fall between <table> and </table>) and the record boundary is <item> (since the data we are interested in, the name and age, falls between <item> and </item>)

We can store this file in a Queue, which would look something like this;

NamesQueue    Queue
name            String(20)
age             Long
              End

TIP: The first step is looking at the XML file in question and deciding on the most appropriate structure to load it into. A Group is best if the xml contains a "single record" and is typically used for program settings and things like that. If the structure contains a repeating structure (in other words, multiple records) then a Queue or File is more appropriate. Of course an In-Memory file can be used as a File rather than using a Queue.

TIP: Although a valid XML file always has a single FileBoundary, that wraps the XML from top to bottom, not all systems generate XML that conforms to this standard. So xFiles allows the FileBoundary to be blank. If it is blank, then xFiles parses the file as if there is no file boundary.

In the case of a Group, it is possible to set the RecordBoundary blank, and still have a valid XML file. For example;

<?xml version="1.0" encoding="US-ASCII"?>
<data>
  <server>www.capesoft.com</server>
  <port>80</port>
</data>
XML with Attributes

In this case the FileBoundary should be set to blank and the RecordBoundary should be set to data.

An alternative approach to XML, that the file you have may use, is the use of attributes. This is just another way of storing information. xFiles treats attributes on the record boundary exactly as if they were separate fields.  For example;

<record firstname="bruce" lastname="brown">
   <dob>1/1/2000</dob>
</record>

is processed as if it was

<record>
   <firstname>bruce</firstname>
   <lastname>brown</lastname>
   <dob>1/1/2000</dob>
</record>

Loading an XML File from the disk into a Clarion Structure

Once you have determined the data structure you will be using, if it is a Queue or a File, you also need to determine the File Boundary and Record Boundary. Once you know that then importing the XML file is a single line of code.

xml.Load(Structure,XmlFileName,[FileBoundary],[RecordBoundary])

The last 2 parameters are optional in the case of a Group, but it's always better to include them if you know what they are.
For example;

xml.Load(NamesQueue,'c:\temp\names.xml','table','item')
or
xml.Load(Settings,'.\settings.xml')

Loading an XML File from a string into a Clarion Structure

This is just as easy as loading it from a file. The syntax of the load method changes slightly to accommodate the name, and length, of the string instead of the file name. ie

xml.Load(Structure,String,Length,[FileBoundary],[RecordBoundary])

For example;

xml.Load(Settings,SomeString,len(clip(SomeString)))
or
xml.Load(NamesQueue,net.packet.bindata,net.packet.bindatalen,'table',item')

Tip: Because the String parameter is passed as a pointer, you can't put a constant in here, you must use a variable. In other words the following will  fail to compile;

xml.Load(Settings,'<server>www.capesoft.com</server>',100)

Loading XML from the Web into a Clarion Structure

When two programs want to communicate across the web they often pass their information formatted as XML. Web Services are nothing more than servers that answer "Questions" using XML. This XML is usually wrapped in a SOAP envelope, but not always. A SOAP envelope is nothing more than some extra XML stuff included in the packet.

In short, you do not need to be at all worried about Web Services, or SOAP. It's all just XML, and xFiles can handle it just like any other XML. However it arrives, it will be available to you as a string, and you can parse this string into a Clarion structure just as described in the section above.

Tip: Interacting with a Web Service typically consists of 2 parts. A Request, and a Response. This section deals with handling the Response. For more information on forming the Request, see the section [....]

If, for example, you have used a NetTalk WebClient object to fetch the XML from the server, then you would add a single line of code into the .PageReceived method to parse the incoming reply into a Group, Queue or File. For example, the Convert example does it with this line;

xml.load(resultGroup,self.page,len(clip(self.page)),'','ChangeLengthUnitResponse')

If that page was an RSS feed, then the following line would copy the feed into a Queue.

xml.load(RssQueue,self.page,len(clip(self.page)),'channel','item')

The Queue declaration would look something like this;

RssQueue  QUEUE,PRE(rss)
Title       STRING(255)
Link        STRING(255)
Description STRING(1024)
          END

xFileXML Quick Start Guide
Creating an XML File or String

Keen to get started? Or just don't like wading through all the documentation? This section is just for you - the basics on how to get xFiles working as quickly and simply as possible.

In the same way that you can load an XML file into a Clarion structure, you can also create XML files very quickly and easily.

Saving a Clarion Structure to an XML file on the Disk
Saving a Clarion structure to an XML string in Memory
Properties which can be set before a call to Save
Properties which can be set in SaveTweakFieldSettings
Methods which can be used during a Save

Saving a Clarion Structure to an XML file on the Disk

xml.Save(Structure,XmlFileName,[FileBoundary],[RecordBoundary])

The last 2 parameters are optional but it's always better to include them if you know what they are. Note that if you include one you will need to include both. In the case of a Group, the FileBoundary can be a blank string.
For example;

xml.Save(NamesQueue,'c:\temp\names.xml','table','item')
or
xml.Save(Settings,'.\settings.xml')

You can use a Group, Queue, View or File as the structure holding the data being saved.

the method returns 0 if successful, non-zero otherwise. If not successful the errorcode will be in the .Error property, and a description of the error will be in the .ErrorStr property.

Saving a Clarion structure to an XML string in Memory

xml.Save(Structure,XmlFileName,[FileBoundary],[RecordBoundary])

This is the same as saving the xml to a File, except that the XmlFileName parameter is not used. After the call to save, the xml data will be in the property xmlData. The length of this string is in XmlDataLen. For example;

xml.save('NamesQueue')
Blob[1 : xml.XmlDataLen] = xml.XmlData

Properties which can be set before a call to Save

There are a number of properties which you can set just before doing a save. These properties affect the way the Xml looks.

Properties which can be set in SaveTweakFieldSettings

These properties are an array, where the array index is the field number of each field in the Group, Queue, File or View record. Setting these properties allows you to modify behaviour for individual fields in the record.

Methods which can be used during a Save

These methods allow you to embed code that affects the Save as it is happening.

xFileXML Quick Start Guide

Keen to get started? Or just don't like wading through all the documentation? This section is just for you - the basics on how to get xFiles working as quickly and simply as possible. In your Clarion\3rdparty\Examples\xFiles\Jumpstart directory there is the completed jumpstart application for reference.

Create a new application and add an xFiles object to the main window. Create a new application and make the Main procedure a window. Add the xFiles Global Extension template (Global - Extensions - Insert - Activate Capesoft's xFiles) Right click on the Main procedure and Choose "extensions", then press the "insert" button. Choose "IncludexFilesObject - Use an xFiles object" from the 'Class xFiles - CapeSoft xFiles - Version x.xx" section. In the "This Object Name" field enter "xmlWriter". Click OK. Add the data to be exported Right Click on the Main procedure and choose "Data' from the popup menu. Click Insert. Name the field "dataQ" and choose "Queue" from the Data Type dropdown. Click OK. The New Field dialog comes up again - this time enter "Contact" for the Field Name. Click OK, then Cancel to return to the Local Data dialog box. Press Close to close the Local Data dialog box. Add code to populate the data Right click on the Main procedure and choose "Window". Add a button to the window with the Text "populate". Right click on the button, choose "Embeds". Insert an embed in the Accepted embed (choose "source" from the Embed Type list). Insert the following code into the embed: dataQ:Contact = 'Bob' Add(dataQ) dataQ:Contact = 'Fred' Add(dataQ) dataQ:Contact = 'Phil' Add(dataQ) dataQ:Contact = 'Sue' Add(dataQ) Click Exit and save the changes. Click Close on the Embedded Source window. Choose the XML file to export to and export the data. Right click on Main and choose "Window". In the Window editor add another button, this time with the text "Save XML". Right click on the new "Save XML" button and choose embeds. Insert a source embed in the Accepted embed for the button. Add the following source to the embed: xmlWriter.Save(dataQ, 'dataQ.xml') Click Exit and save the source. Close the Embedded Source window, then click Exit to close the Window Editor. Compile and run the application. (Make sure the project is compiled in 32 bit mode!). Press the Populate button and then the Save XML button. The "dataQ.xml" file will be create in the application directory with the contents of the queue. Loading from the XML file You can easily add a button to load from the XML file into the queue, simply add the following code to the Accepted embed of a button: xmlWriter.Load(dataQ, 'dataQ.xml')

Check out the Some Practical Applications section for other practical applications for xFiles.

xFileLinkDLL Quick Start Guide - Runtime DLL Loading

Adding runtime DLL loading to a new or existing application. Open an existing application, or create a new application and add the xFiles Global Extension template (Global - Extensions - Insert - Activate CapeSoft xFiles) Right click on the procedure that you want to load the DLL and functions in and Choose Extensions, then press the Insert button. Choose "IncludexFilesObject - Use an xFiles object" from the "Class xFiles - CapeSoft xFiles - Version x.xx" section. In the "This Object Name" field enter the name of the object, for example "dllLoader". Click OK. In order to load a function at  First you need a "function pointer". This is a long that will be used to call the function. You can add these to you global data embed, or to the module data, depending on where you want to use the function. fp_unzOpen          long, Name(unzOpen) Declare the prototype so that Clarion knows what parameters the function takes. Typically this is done inside the global map:     Module('MyRuntimeFunctions') unzOpen(*cstring ZipPathName), long, C, Raw, Dll(_fp_)     end In your code you use the xFilesLinkDLL object (the local extension adds the object for you) to load the DLL and get the function address:     ret = dllLoader.LinkDLLFunction ('zip.dll', 'unzOpen', fp_unzOpen) It is a good idea to check that the pointer is not zero once you call the LinkDLLFunction() method:     if fp_unzOpen = 0         ! Could not load Function     end You can link as many functions as you like, and the object handles loading the DLL, getting the addresses, and freeing the library once complete. Call the function just like any other function in your application: if unzOpen (filename)     Message('Sorry, there was an error opening the file') end

xFiles Templates

Generic xFiles Template (to use an xFiles object)
Export to/Import from XML Control Template

The Global xFiles Extension Template

In order to use xFiles, you need to add the Global Extension Template initially:

• Click on the Global button, and Choose "Extensions", then press the "insert" button.
  

• Choose the "ActivatexFiles - Activate Capesoft's xFiles" from the 'Class xFiles - CapeSoft xFiles - Version x.xx" section.

• Remove File Prefix from field Labels - removes the file prefix from fields labels that are entered into the XML file. Note: these settings must match on import and export (if using a different instance of this control template to do the other import/export)

• Replace colon in field name with a dot - if checked, all colons in field names are replaced with a dot in the XML tags (a colon is an invalid character in an XML tag)

• Encoding method - allows you to select whether to use iso-8859-1, utf-8 or windows-1252. The default method is iso-8859-1, but you can force it to one of the others if you prefer.

• Set Logging to - allows you to force debug logging on or off - otherwise you can use the compile time settings that are in the classes (normally off).

• Customize Header and Footer - allows you to enter a customizable Header and or Footer (for things like RSS Feeds, etc).

• Field Type Overrides - if you don't want to save MEMOs and/or BLOBs into your XML file, then you can disable this with these checkboxes.

• CDATA Saving - you can encase your data in CDATA tags - you can select which field type you would like to do this for using these checkboxes

Generic xFiles Template (to use an xFiles object)

xFiles provides a template to make it simple to add an object to a procedure. To use the template:

• Right click on the procedure you wish to add an object to and Choose "extensions", then press the "insert" button.
• Choose "IncludexFilesObject - Use an xFiles object" from the 'Class xFiles - CapeSoft xFiles - Version x.xx" section.
• In the "This Object Name" field enter "xmlWriter".

The class details tab allows properties to be added to the class and methods to be added, overloaded or customised and provides access to the method and data embeds for the object.

Export to/Import from XML Control Template

You can populate this control template onto a window, and export a file/queue/group to a file from a button on the window.

You can setup the following options in the control template:

• Local Data - the data source (typically this would be the name of the file to export - or the queue or group)

• XML File - the file to export the data to. You can use quotes or a variable name.

• Display Status - shows a message after exporting or importing the file.

• ThisWindow.Reset(1) - resets the window after loading the file, forcing your browses and fields to be refreshed.

• Remove File Prefix from field Labels - removes the file prefix from fields labels that are entered into the XML file. Note: these settings must match on import and export (if using a different instance of this control template to do the other import/export)

• Encoding method - allows you to select whether to use iso-8859-1, utf-8 or windows-1252. The default method is iso-8859-1, but you can force it to one of the others if you prefer.

• Set Logging to - allows you to force debug logging on or off - otherwise you can use the compile time settings that are in the classes (normally off).

• Customize Header and Footer - allows you to enter a customizable Header and or Footer (for things like RSS Feeds, etc).

• Field Type Overrides - if you don't want to save MEMOs and/or BLOBs into your XML file, then you can disable this with these checkboxes.

• CDATA Saving - you can encase your data in CDATA tags - you can select which field type you would like to do this for using these checkboxes

Some Practical Applications

Loading XML Files
Creating RSS Feed Files
Storing Global Settings in an XML file
Creating SOAP requests

Creating RSS Feed Files

• Create a window in your application and add the xFiles Global template (if you have not done so already) and the xFiles local extension template. You can leave the default template settings as they are.
• Your RSSFeedQueue should be of the following example structure:

  Item         QUEUE,PRE()
  Title             STRING(252)
  Description       STRING(1024)
  Link              STRING(252)
  ExtraFieldsInHere FieldTypes
               END

  Your queue must be labeled 'Item' and have the 'Title', 'Description' and 'Link' fields present. You can include additional fields for extra information as well (which will be ignored by the RSS aggregator).

• In the ThisWindow.Init() method, set the following properties:

• Add the necessary RSS feed items to the queue (you'll want to add them to the front of the queue so that newest items are at the 'top of the pile'):

Item.Title = 'My New Item'
Item.Description = 'My new RSS feed description'
Item.Link = 'www.mywebsite.com\MyNewItem.htm'
Add(Item,1)

 

• Add a button to the window (Create RSS Feed) and in the accept event save the file:

ThisXMLFile.save(RSSFeedQueue,'RSSFeedfile.xml')

This will create the file locally, and you'll need to upload it (which you will require an FTP process - ideally like NetTalk's SendFTP).

Storing Global Settings in an XML file

Many people are used to storing global settings in INI files, or perhaps a registry. There' s a much easier way using xFiles to store global settings. Because xFiles stores (and retrieves) a generic group structure, you can add variables without worrying about updating your store variable procedure. The only thing you need to be aware of is that variables stored (and retrieved) must be within a group structure. For example:

GlobalSettings       group, pre(GLOSET) ! Everything in this group will be stored in the XML settings file
WebSite                string(252)
EmailAddress           string(252)
                     end
FTPPostWindowThread  long ! Not stored in the XML settings file - we don't want this stored.

In our code, we simply call the save (and load) command for storing (and retrieving) the global settings we require preserved:

  ThisXMLFile.save(GlobalSettings,'GlobalSettingsFile.xml')

and

  ThisXMLFile.load(GlobalSettings,'GlobalSettingsFile.xml')

Creating SOAP requests

SOAP Servers are programs out on the network that you can interact with. Each program is different, but a protocol, SOAP, exists which makes it possible for different programs to communicate with each other.

SOAP packets are usually passed between programs using TCP/IP connections, and wrapped with a HTTP header. A tool like NetTalk makes this really easy to do. However inside the packet the request is formatted using XML, and thus XFiles can be very useful in this regard.

A complete description of SOAP is beyond the scope of this document, however you do not usually need to be a SOAP expert in order to make simple SOAP servers and clients.

You will find some working examples in \Clarion\3rdParty\Examples\SOAPClient. These examples use NetTalk to run, but you can convert them to use other networking tools if you wish.

A SOAP envelope is automatically wrapped around your regular XML if you set the SOAPEnvelope property to 1.

A typical SOAP request looks like this;

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Body>
<ChangeLengthUnit xmlns="http://www.webserviceX.NET/">
<LengthValue>5</LengthValue>
<FromLengthUnit>Centimeters</FromLengthUnit>
<ToLengthUnit>Inches</ToLengthUnit>
</ChangeLengthUnit>
</soap:Body>
</soap:Envelope>

However different soap servers require different specific tags. To support this xFiles allows you to set the specific text for each part of the packet. Here is the request again, but this time I've replaced the optional parts with the name of the property you can set.

<?xml version="1.0" encoding="SaveEncoding"?>
<SOAPEnvelopeBoundary SOAPEnvelopeBoundaryAttribute>
<SOAPBodyBoundary>
<_pFileBoundary p_FileBoundaryAttribute>
<_pRecordBoundary _pRecordBoundaryAttribute>
<LengthValue>5</LengthValue>
<FromLengthUnit>Centimeters</FromLengthUnit>
<ToLengthUnit>Inches</ToLengthUnit>
</_pRecordBoundary>
</_PFileBoundary>
</SOAPBodyBoundary>
</SOAPEnvelopeBoundary>

The above properties can all be set in the SaveTweakSettings method. Note that the _pFileBoundary tag is optional, and should be set to nothing if it is not required.

Other properties you need to set are .SOAPEnvelope (set to 1 to wrap the XML in a Soap Envelope) and .TagCase (usually you need to set this to XF:CaseAsIs - more on that in a moment.)

For example, the code to create the packet above looks like this

xml.SOAPEnvelope = 1
xml.SaveEncoding = 'utf-8'
Xml._pFileBoundary = ''
Xml._pRecordBoundary = 'ChangeLengthUnit'
Xml._pRecordBoundaryAttribute = 'xmlns="http://www.webserviceX.NET/"'
Xml.TagCase = XF:CaseAsIs
xml.SOAPEnvelopeBoundaryAttribute = &|
                       'xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"' & |
                       ' xmlns:xsd="http://www.w3.org/2001/XMLSchema"' &|
                       ' xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"'
xml.SOAPEnvelopeBoundary = 'soap:Envelope'
xml.SOAPBodyBoundary = 'soap:Body'

For the actual XML in the middle, a simple group is all that is required.

RequestGroup   GROUP,PRE(Request)
LengthValue      DECIMAL(9,3),NAME('LengthValue')
FromLengthUnit   STRING(32),NAME('fromLengthUnit')
ToLengthUnit     STRING(32),NAME('toLengthUnit')
               END

(Take notice of the Name attribute, more on that in a minute.)

After setting all the values in the group to their desired state, you can then create the PostString (ready for the NetTalk side of things) using 2 simple lines of code.

  xml.Save(RequestGroup)
  PostString = xml.xmldata

The call to Save converts the group into XML, and stores the result in the .XmlData property. Because the .SOAPEnvelope property (and all the other properties) have been set appropriately in SaveTweakSettings, the text that is in .XmlData is the complete SOAP request.

It is worth mentioning a slight complication alluded to earlier which needs to be taken into account. Most SOAP servers are picky, and require the tag names to be case sensitive. In other words
<LengthValue>5</LengthValue> is not the same as
<lengthvalue>5</lengthvalue> which is not the same as
<lengthValue>5</lengthValue>

The most common mistake when speaking to a SOAP server is getting these tag names not-quite-right, and hence the server returns an error. xFiles supports a variety of possible tag cases (when creating the XML) and these are set using the .TagCase property as we saw above. Possible values for .TagCase are XF:CaseLower, XF:CaseUpper, and XF:CaseAsIs.

 If your SOAP server requires upper, or lower case tags, then you don't need to worry about the External Name for each field, just set the .TagCase property to the appropriate value and continue. If however the server requires a mixed case (as this example does) then you need to set the Name for each item in your group. Be very careful with the case - in this example the LengthValue tag started with a capital letter, but the fromLengthUnit tag did not.

Using a View to create a filtered, sorted, XML file

Exporting a whole data table, including all records and all fields to an xml file is easy. Simply use the .Save method. For example

xFileXML.Save(Customers, 'customers.xml')

If however you only want to export a subset of the fields, or records, or if you want to specify the sort order for the export, then the above command is too limited. In this case what you need to do is export the xml using a VIEW as the data source, rather than a file.

The Dict example, which you'll find in the  \clarion\3rdparty\examples\xfiles\dict folder has an example of creating a view, and then using it to create the xml file.

For example

xml      xFileXml
ThisView View(Wages)
            Project(wag:Employee)
         End
  code
  xml.Save(ThisView,'employees.xml')

The important thing to remember about views is that you get to decide which fields are included, and which are excluded. In addition you decide what the FILTER and ORDER properties for the view are.

Last, but not least, it's useful to remember that all Browses and Reports in your application are based on Views. Thus it is possible to export the contents of a Browse, or Report, to XML but using this xFiles function, and making use of the views constructed for you by these templates.  

Storing multiple things in the same XML file.

Up to now all the examples have shown a single entity (Group, Queue, File or View) being stored in an XML file. However it is possible to store multiple entities in the same file.

In order to place multiple entities in the same xml file the following basic steps occur;

1. Get the class ready, by setting the Root-Node (the wrapper around the whole thing) and telling the class not to automatically close the root node.

xml.RootBoundary = 'whatever'
xml.DontCloseTags = 1

2. Save the first entity as normal

xml._pFileBoundary = 'Document'
xml.Save(ReportFormat ,Loc:XmlName)

3. Set the append flag so the following items are appended

xml.append = 1

4. Add as many entities to the file as you like, using the normal techniques. Although the boundaries do not have to be unique you may chose to make them unique so they can be loaded separately later on.

xml._pFileBoundary = 'DefnFieldsLocal'
xml.Save(rrDefnFieldsLocalView,Loc:XmlName)

xml._pFileBoundary = 'DefnFieldsGlobal'
xml.Save(rrDefnFieldsGlobalView,Loc:XmlName)

5. Finally before sending the final entity, tell the object to close the root tag.

xml.DontCloseTags = 0
xml._pFileBoundary = 'DefnBandControls'
xml.Save(rrDefnBandControlsView,Loc:XmlName)

NOTE: This approach cannot be used if a zipped xml file is being made using the built-in zipping classes.

Examples

Notes on getting started.
The examples are an excellent place to get started. The JumpStart example is a quick and easy way to see how to use xFiles with the minimum of code or effort. The xFiles Demo example is also an good place to see a few of the basic uses of xFiles, it uses the xFileXML and xFileBinary classes and demonstrates a few of the basic of using xFiles classes.

Classes

This lists the Classes provided by xFiles at this time, along with a description of the functionality provided by each class.

The methods for each class is listed below, along with a fuller explanation of what the classes do. See the Examples for more. Please note this section of the documentation is under construction and we are expanding it to include all class methods and a full description, usage information, examples etc.

xFileXML Class Methods - XML reading and writing the easy way

xFileXML.AddRecord (<any p_F1>,<any p_F2>,<any p_F3>, ...)

Adds a record to the xFilesXML record queue. The method takes up to 20 ANY parameters, which allows the addition of records to a queue where the type of a field is not known.

Parameters:

See Also:

xFileXML.Load(), xFileXML.Save()

xFileXML.Copy (*Group p_Group, byte p_Direction=0)

xFileXML.Copy (*Queue p_Queue, byte p_Direction=0)

Copies the records from the internal xFileXML group/queue property to the passed group/queue, or from the passed group/queue to the xFiles group/queue. The direction parameter specifies whether the data is copied from the parameter to the xFilesXML property or from the property to the passed variable.

Parameters:

See Also:

xFileXML.Load(), xFileXML.Save()

xFileXML.Init (*Queue p_Queue, string p_FileName)

xFileXML.Init (*Group p_Group, string p_FileName)

xFileXML.Init (*File p_File, string p_FileName)

xFileXML.Init (*View p_View, string p_FileName)

Initialises the xFileXML object to the a particular data structure and file, you can call this method at any point to change the data structure that is read from and written to, and the XML file that is used. If you are setting any of the class properties such as LoadFields and SaveFields then Init must be call after setting the class properties in order to use them.

Note: As well as passing a Queue, you can also pass a Group, File or View to the Init method to have xFiles read and write using a group, file, view or queue. (Views are Write-Only, not Read).

Note: You don't need to call Init unless you set advanced class properties like xFileXML.loadFields, xFileXML.saveFields and xFileXML.copyFields. If you set these properties to change which fields are saved then you need to use the first method above and call Init(). Otherwise you can call the Load and Save methods and pass them the queue/group/file/view and file name without calling Init().

Parameters:

Examples

 ! DATA
myQueue           queue
from                  string(80)
to                    string(80)
                  end

xmlFileName       string(260)

! CODE
    xmlFileName = 'myXmlFile.xml'
    thisFileXML.Init(myQueue, xmlFileName)

See Also:

xFileXML.Load(), xFileXML.Save()

xFileXML.Load (*Queue p_Queue, string p_fileName, <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Load (*Group p_Group, string p_fileName, <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Load (*File p_File, string p_fileName, <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Load (*Queue p_Group, *String p_XMLString, Long p_XMLStringLength, <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Load (*Group p_Group, *String p_XMLString, Long p_XMLStringLength, <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Load (*File p_File, *String p_XMLString, Long p_XMLStringLength, <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Load ()

Loads an XML file into the data structure.

The first parameter is the Clarion data structure that will receive the parsed XML. Valid structures are a Queue, File or Group.

The second parameter is the name of the file on disk, or the name of the string which is holding the XML in memory. If the XML is in a string, then an additional parameter, the length of the string, is required at this point.

Following this are 2 optional parameters that allow you to specify the File Boundary, and Record Boundary tags.

The .Load method (no parameters) ultimately loads the XML into the specified structure. It is included here for completeness but it should not usually be called directly.

Parameters

Examples

 ! DATA
myQueue           queue
from                  string(80)
to                    string(80)
                  end

xmlFileName       string(260)

  CODE
    xmlFileName = 'myXmlFile.xml'
    thisFileXML.Load(myQueue, xmlFileName)

 ! DATA
myGroup           group
from                  string(80)
to                    string(80)
                  end

xmlFileName       string(260)

  CODE
    xmlFileName = 'myXmlFile.xml'
    thisFileXML.Init(myGroup, xmlFileName)

    thisFileXML.Load()

See Also:

xFileXML.Save(), xFileXML.Init(), Loading XML Files

xFileXML.Save (*Queue p_Queue, string p_fileName, <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Save (*File p_File, string p_fileName, <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Save (*View p_View, string p_fileName, <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Save (*Group p_Group, string p_fileName, <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Save (*Queue p_Queue, <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Save (*File p_File <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Save (*View p_View <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Save (*Group p_Group <string p_FileBoundary>,<string p_RecordBoundary>)

xFileXML.Save ()

Saves a Clarion data structure into an XML file, or string.

The first parameter is the Clarion data structure that holds the data to be exported. Valid structures are a Queue, File, View or Group.

The second parameter is the name of the file on disk. If the XML is to be stored in a string, in memory, then this parameter is ignored.

Following this are 2 optional parameters that allow you to specify the File Boundary, and Record Boundary tags.

The .Save method (no parameters) ultimately saves the XML into the file or string. It is included here for completeness but it should not usually be called directly.

Parameters: