Click here to Skip to main content
Click here to Skip to main content

Tagged as


, 15 Mar 2014 CPOL
Rate this:
Please Sign up or sign in to vote.
New SAX parsing model comes to .NET!

SequelMax is an improved SAX model where the programmer registers a reading delegate for the XML element of interest. SequelMax.NET engine is ported from the C++ library; The C++ SequelMax is in turn ported and modified from the Portable Elmax DOM engine. Practically, SequelMax.NET uses the same engine. This parsing engine, instead of creating and populating a internal DOM tree, invokes the registered delegates during parsing. A Javascript edition, SequelMax.js, is in the cards.

This is the XML we are going to use for our article example. Notice the last employee does not have a comment.

<?xml version="1.0" encoding="UTF-8"?>
    <Employee EmployeeID="1286" SupervisorID="666">
        <Name>Amanda Dion</Name>
        <!--Hardworking employee!-->
    <Employee EmployeeID="1287" SupervisorID="666">
        <Name>John Smith</Name>
        <!--Hardly working employee!-->
    <Employee EmployeeID="1288" SupervisorID="666">
        <Name>Sheldon Cohn</Name>

We use the Employee class to hold the data from the XML.

class Employee 
    public int EmployeeID;
    public int SupervisorID;
    public string Name;
    public string Gender;
    public double Salary;
    public string Comment;

The parsing code to read the employee XML is listed below. To read each element, a delegate has to be registered. A anonymous lambda can be used for delegate. The element path and delegate is stored in a dictionary in the Document class. The parsing engine invokes the delegate whenever the element path is matched. To do the matching, the current element path is generated from a LIFO stack which pushes the element name. After processing, the name is popped. The Open method opens and parses the XML. It is required to set up all the delegates before the Open call.

static bool ReadDoc(string file, List<Employee> list)
    SequelMaxNet.Document doc = new SequelMaxNet.Document();

    doc.RegisterStartElementDelegate("Employees|Employee", (elem) =>
        Employee emp = new Employee();
        emp.EmployeeID = elem.Attr("EmployeeID").GetInt32(0);
        emp.SupervisorID = elem.Attr("SupervisorID").GetInt32(0);
    doc.RegisterEndElementDelegate("Employees|Employee|Name", (text) =>
        list[list.Count - 1].Name = text;
    doc.RegisterEndElementDelegate("Employees|Employee|Gender", (text) =>
        list[list.Count - 1].Gender = text;
    doc.RegisterEndElementDelegate("Employees|Employee|Salary", (text) =>
        Double.TryParse(text, out list[list.Count - 1].Salary);
    doc.RegisterCommentDelegate("Employees|Employee", (text) =>
        list[list.Count - 1].Comment = text;

    return doc.Open(file);

The concise code to display the data on the console.

static void DisplayDoc(List<Employee> list)
    for (int i = 0; i < list.Count; ++i)
        Console.WriteLine("Name: {0}", list[i].Name);
        Console.WriteLine("EmployeeID: {0}", list[i].EmployeeID);
        Console.WriteLine("SupervisorID: {0}", list[i].SupervisorID);
        Console.WriteLine("Gender: {0}", list[i].Gender);
        Console.WriteLine("Salary: {0}", list[i].Salary);

        if (string.IsNullOrEmpty(list[i].Comment) == false)
            Console.WriteLine("Comment: {0}", list[i].Comment);


The console output is below. Notice again the last employee does not have a comment.

Name: Amanda Dion
EmployeeID: 1286
SupervisorID: 666
Gender: Female
Salary: 2200
Comment: Hardworking employee!

Name: John Smith
EmployeeID: 1287
SupervisorID: 666
Gender: Male
Salary: 3200
Comment: Hardly working employee!

Name: Sheldon Cohn
EmployeeID: 1288
SupervisorID: 666
Gender: Male
Salary: 5600

Please download the source code at SequelMax.NET Google Code. Currently, I have problems uploading the source code to the CodeProject. Sorry for the inconvenience.


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


About the Author

Shao Voon Wong
Software Developer
Singapore Singapore
No Biography provided

Comments and Discussions

QuestionHigh Usage? PinmemberSleety8-Apr-14 17:10 
AnswerRe: High Usage? PinprofessionalWong Shao Voon10-Apr-14 21:32 
GeneralRe: High Usage? PinmemberIgDev16-Apr-14 4:01 
GeneralRe: High Usage? PinprofessionalWong Shao Voon16-Apr-14 4:51 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

| Advertise | Privacy | Terms of Use | Mobile
Web04 | 2.8.141216.1 | Last Updated 15 Mar 2014
Article Copyright 2014 by Shao Voon Wong
Everything else Copyright © CodeProject, 1999-2014
Layout: fixed | fluid