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Maximizing Efficiency: Streamline Your Workflows with an XML Converter Online

In today’s fast-paced digital age, businesses need to find ways to maximize efficiency and streamline their workflows. One tool that can greatly assist in achieving this goal is an XML converter online. This powerful tool allows you to seamlessly convert XML files into various formats, saving you time and effort. In this article, we will explore how an XML converter online can revolutionize your document management processes.

What is an XML Converter Online?

An XML converter online is a web-based tool that enables the conversion of XML files into different formats such as HTML, PDF, CSV, and more. It simplifies the process of handling and manipulating XML data by providing a user-friendly interface that allows for quick and accurate conversions.

Simplify Data Management

One of the key benefits of using an XML converter online is simplifying data management. XML files are widely used for storing structured data, but they can be complex to work with directly. With an XML converter online, you can easily convert these files into more accessible formats like CSV or Excel spreadsheets.

By converting your XML files into a format that is easier to manage, you can streamline your data processing workflows. This means less time spent manually extracting information from complex XML structures and more time focusing on analyzing and utilizing the data.

Enhance Collaboration

Another advantage of using an XML converter online is enhancing collaboration within your team or with external stakeholders. When working with large datasets stored in XML format, it can be difficult for multiple people to access and interpret the information effectively.

By converting your XML files into a more universally compatible format such as PDF or HTML, you can ensure that everyone involved in the project can easily view and understand the data. This promotes better collaboration among team members and eliminates any compatibility issues that may arise when sharing complex XML files.

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Introduction

Currently there is a set of units that provides support for XML on Free Pascal. These units are called "XMLRead", "XMLWrite" and "DOM" and they are part of the Free Component Library (FCL) from the Free Pascal Compiler. The FCL is already on the default search path for the compiler on Lazarus, so you only need to add the units to your uses clause in order to get XML support. The FCL is not documented currently (October / 2005), so this short tutorial aims at introducing XML access using those units.

The XML DOM (Document Object Model) is a set of standardized objects that provide a similar interface for using XML on different languages and systems. The standard only specifies the methods, properties and other interface parts of the object, leaving the implementation free for different languages. The FCL currently fully supports the XML DOM 2.0 and a subset of XML DOM 3.0 listed here .

Usage Examples

Below there is a list of XML data manipulation examples with growing complexity.

Units in the uses clause

FPC comes with XML units that supports UTF8 and UTF16. They may not have the latest updates, so there is as well a version of those units (prefixed with "laz2_") in the Lazarus package LazUtils. The units are compatible and one can change from to the other just by changing the uses clause.

The units for using the FPC XML support which uses strings encoded in the system encoding are:

• XMLStreaming

The units for using the Lazarus XML support which has full UTF-8 Unicode support are:

• laz2_XMLRead
• laz2_XMLWrite
• laz2_XMLCfg
• laz2_XMLUtils
• laz_XMLStreaming.

Not all of them are needed in every example, though. You will need DOM as it defines several types including TXMLDocument.

Reading a text node

For Delphi Programmers:

Note that when working with TXMLDocument, the text within a Node is considered a separate TEXT Node. As a result, you must access a node's text value as a separate node. Alternatively, the TextContent property may be used to retrieve content of all text nodes beneath the given one, concatenated together.

The ReadXMLFile procedure always creates a new TXMLDocument , so you don't have to create it beforehand. However, be sure to destroy the document by calling Free when you are done.

For instance, consider the following XML:

The following code example shows both the correct and the incorrect ways of getting the value of the text node (add the units laz2_XMLRead and laz2_DOM to the used units list):

Note that ReadXMLFile(...) ignores all leading whitespace characters when parsing a document. The section whitespace characters describes how to keep them.

Printing the names of nodes and attributes

If you want to navigate the DOM tree: when you need to access nodes in sequence, it is best to use FirstChild and NextSibling properties (to iterate forward), or LastChild and PreviousSibling (to iterate backward).

For random access it is possible to use ChildNodes or GetElementsByTagName methods, but these will create a TDOMNodeList object which eventually must be freed. This differs from other DOM implementations like MSXML, because the FCL implementation is object-based, not interface-based.

The following example shows how to print the names of nodes to a TMemo placed on a form.

Below is the XML file called 'test.xml':

And here the Pascal code to execute the task:

This will print:

Populating a TreeView with XML

One common use of XML files is to parse them and show their contents in a tree like format. You can find the TTreeView component on the "Common Controls" tab on Lazarus.

The function below will take a XML document previously loaded from a file or generated on code, and will populate a TreeView with it´s contents. The caption of each node will be the content of the first attribute of each node.

Another example that displays the complete XML structure including all attribute values (note: the long line referencing TreeView has been split so it will word wrap for this wiki; when writing it in code you do not have to break the line unless you like the formatting) :

Modifying a XML document

The first thing to remember is that TDOMDocument is the "handle" to the DOM. You can get an instance of this class by creating one or by loading a XML document.

Nodes on the other hand cannot be created like a normal object. You *must* use the methods provided by TDOMDocument to create them, and later use other methods to put them in the correct place in the tree. This is because nodes must be "owned" by a specific document in DOM.

Below are some common methods from TDOMDocument:

CreateElement creates a new element.

CreateTextNode creates a text node.

CreateAttribute creates an attribute node.

CreateCDATASection creates a CDATA section: regular XML markup characters such as <> are not interpreted within the CDATA section. See Wikipedia article on CDATA

A more convenient method to manipulate attributes is to use TDOMElement.SetAttribute method, which is also represented as the default property of TDOMElement :

And here an example method that will locate the selected item on a TTreeView and then insert a child node to the XML document it represents. The TreeView must be previously filled with the contents of an XML file using the XML2Tree function .

Create a TXMLDocument from a string

Given an XML document in string variable MyXmlString , the following code will create it's DOM:

Validating a document

Since March 2007, DTD validation facility has been added to the FCL XML parser. Validation is checking that logical structure of the document conforms to the predefined rules, called Document Type Definition (DTD).

Here is an example of XML document with a DTD:

This DTD specifies that 'root' element must have one or more 'child' elements, and that 'child' elements may have only character data inside. If parser detects any violations from these rules, it will report them.

Loading such document is slightly more complicated. Let's assume we have XML data in a TStream object:

Whitespace characters

If you want to preserve leading whitespace characters in node texts, the above method is the way to load your XML document. Leading whitespace characters are ignored by default. That is the reason why the ReadXML(...) function never returns any leading whitespace characters in node texts. Before calling Parser.Parse(Src, TheDoc) insert the line

This will force the parser to return all whitespace characters including all the newline characters that exist in an XML document to make it more readable!

The following code is similar to the ReadXMLFile() procedure, but preserves leading whitespace:

Note that the xml document Doc is an out parameter created by the local Parser . It is the user's responsibility to free the Doc himself when it is no longer needed.

Streamed reading

DOM-based processing requires the entire document loaded into memory. This may be not desirable, or not possible if document is huge. FCL provides functionality to read XML data one node at a time, using TXMLReader class and its descendants. This is similar to SAX, but works without callbacks. TXMLReader closely resembles .NET XmlReader class. A basic example follows:

Generating a XML file

Below is the complete code to write a XML file. (This was taken from a tutorial in the DeveLazarus blog) Please, remember to include the DOM and XMLWrite units in your uses clause.

The result will be the XML file below:

An example where you don't need to reference an item by index.

Generated XML:

Starting from FPC version 2.4, the XML reader is able to process data in any encoding by using external decoders. See XML_Decoders for more details.

According to the XML standard, the encoding attribute in the first line of the XML is optional in case the actual encoding is UTF-8 ( without BOM - Byte Order Marker) or UTF-16 (UTF-16 BOM).

TXMLDocument has an encoding property since FPC 2.4. It is ignored as WriteXMLFile always uses UTF-8.

• FPC 2.4 doesn´t generate an encoding attribute in the first line of the XML file
• FPC 2.6.0 and later explicitly write an UTF8 encoding attribute, as this is needed for some programs that cannot handle the XML without it.
• XML Decoders
• Using INI Files
• Internet Tools , for XPath 2 / XQuery processing

External Links

• W3Schools Xml Tutorial
• Thomas Zastrow article Alternate link FPC and XML

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The W3C XML Schema 1.0 Recommendation defines an XML schema language. Its salient characteristics are:

• Unlike the DTD language defined in XML 1.0 (and in ISO 8879,
• It defines a set of simple types or datatypes for use in attribute
• It also provides a notion of complex types (for use with
• It distinguishes systematically between the generic identifiers
• It allows for explicit relations between types. New
• It defines explicitly what information generated as a by-product
• It provides for wildcards in content models, which can match
• Instead of treating validity of documents as a simple all-or-nothing

Note: 'XML Schema' is the name of the language defined by the W3C Rec. 'XML schema' is a common noun in English denoting a schema (in whatever formalism) for an XML vocabulary. To avoid confusion between the two, some people prefer to use the names 'XSD' or 'WXS' (W3C XML Schema) for the language defined in the Rec. or to use the full name 'W3C XML Schema' whenever confusion might otherwise arise.

What follows is a sketch of a possible skeleton set of topics related to XML Schema, to help encourage the development of a useful wiki on the subject.

All of these pages need to be drafted. You can help!

XML Schema software

Different kinds of software may be 'schema-aware'. It would be useful to have separate wiki pages with discussions of each type and pointers to specific software of the type.

Among the most obvious class of schema-aware software are:

• schema-based validators
• schema-aware XML editors and editing tools
• data binding tools (for marshalling and de-marshalling
• form generators
• schema-writing and maintenance tools
• schema conversion tools
• tools for exploring or displaying information about schemas
• schema analyzers
• schema-aware XSLT and XQuery engines
• general toolkits

For more detail, see the page on XML Schema software .

Interoperability issues

Any schema-aware software is likely to be aimed at a particular application type or application domain; language features that don't match up neatly with the assumptions of the particular domain may be omitted or neglected. Among the features which are either unsupported or supported less conveniently than other features are:

• mixed content : since most object-oriented languages lack
• recursive elements : many users report that their tools
• choices : these pose a problem for many data-binding tools;
• substitution groups : data binding tools often provide
• UPA ( unique particle attribution constraint ): some tools

Schema technical issues

Perhaps some of these should be discussed in this page; others should probably be in separate pages.

• Co-occurrence constraints
• schema vs schema document
• assembling a schema
• schemas and object-orientation
• schemas and the relational model
• schemas and Web Services
• XML Schema 1.0 and document-oriented vocabularies
• sources of variation among schema processors
• the 'unique particle attribution' (UPA) constraint :
• the 'element declarations consistent' (EDC) constraint
• versioning schema-defined languages
• versioning XML Schema itself

Other schema languages

Other languages that may be used to constrain data in XML or other forms:

• SQL Schemas

Some languages appear to be of mostly historical interest now (some of these may belong in the list above, if they are still actively used and developed)

• XML Data and XML Data Reduced (XDR)
• SOX (Schema for Object-0riented XML)
• DCD (Document Content Description for XML)
• DDML (Document Definition Markup Language)
• http://www.w3.org/XML/Schema
• http://en.wikipedia.org/wiki/XML_Schema
• XML Schema Part 0 : Primer
• XML Schema Part 1 : Structures
• XML Schema Part 2 : Datatypes

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