Using Nematrian Web Functions in more sophisticated programming environments such as Visual Studio

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As explained in Web Services Introductory Pages, the Nematrian website provides a wide range of web services that users can access directly via the Internet. To do this, the user needs to include calls to the relevant web services within some suitable software container, e.g. in programs written in VBA code within Excel (or another Microsoft Office application), see here, directly in a web page in HTML and Javascript or in software written using Visual Basic or C++ code, see below.

In what follows we assume that users are trying to access Nematrian web functions using via Visual Basic within Visual Studio although many other Software Development Kits (SDK) operate in a relatively similar fashion.

We suggest that you first try accessing Nematrian web services by inserting into your browser the following URL: http://www.nematrian.com/WebServices.asmx

If this comes up with a long list of functions then you should be able to access Nematrian's web service functions using this URL or equivalent URL's for other Nematrian public servers. Almost all of the web services accessible via this .asmx page require you to have a live Nematrian site Session ID, with the exception of 'Complex Sum'.

Almost all Nematrian web service functions return back answers using a bespoke structure that includes an error flag, an indication of the amount of credit deducted from your Session Id when you ran the function and the result of running the function (if the error flag was not triggered). This is to make the functions as versatile as possible. The elements in each structure are called .ErrFlag, .Debit and .Answer respectively. .ErrFlag is a String variable and .Debit is a Double variable. The structure taken by .Answer varies according to the purpose of the function and can be found from the relevant function description page.

To access the software within your code you first need to add a reference to the relevant software (e.g. by using the Add a web reference command in the "Website" drop-down menu). The dialogue box opened via this Visual Studio menu command allows you to browse for the URL for the web service you are attempting to access. To avoid excessive usage of a single URL, the Nematrian web site may distribute its delivery of web services across several parallel web sites (i.e. several URLs). Where practical, it will endeavour to assign you the same URL whenever you log in (to avoid you needing to recompile your code to refer to a new reference URL). The dialogue box allows you to name the Nematrian web service anything you like; it is assumed below that you have called it mnWebService.

Software along the lines of the following will then, for example, call the Nematrian Sudoku Solver (it is assumed here that you are using Visual Basic as the programming language within Visual Studio):

Option Explicit On
Imports System.Web.Services.Protocols

Private Function
SudokuSolve( _
ByVal SessionID As String, _
ByVal SudokuType As String, _
ByVal BaseStartingData() As Byte, _
ByVal IterationLimit As Integer) As mnWebService.mnSudokuSolution

Dim ws As New mnWebService.WebServices
SudokuSolve = ws.SudokuSolve(SessionID, SudokuType, BaseStartingData, IterationLimit)
End Function

The input parameters for this function (and the corresponding web service) are:



Description of Variable



User's SessionID as obtained by logging into the Nematrian website



Type of Sudoku puzzle being solved, "Standard", "Samurai", "Killer" or "General"



Unidimensional byte array that contains the base starting data



a large number (e.g. 100000) limiting no of iterations Solver will execute

The output of this function has the following structure

Structure mnSudokuSolution
Dim ErrFlag As String
Dim Xcoord() As Byte
Dim Ycoord() As Byte
Dim SolutionValue() As Byte
Dim TimeTaken As Double
Dim NoTimesAccessed As Integer
End Structure

So, for example, we can tell whether the Sudoku puzzle has a (unique) solution by using code such as:

Dim SudokuSoln As mnWebService.mnSudokuSolution
Dim ErrFlag As String
SudokuSoln = SudokuSolve(SessionID, SudokuType, BaseStartingData, IterationLimit)
If SudokuSoln.ErrFlag<>"" Then
End If





Users should not insert software generated by the website into their own programs or spreadsheets unless they understand what it does and are sure that it will not damage or corrupt any of their existing work.


The Nematrian website takes no responsibility for losses arising from use of code sourced from this page or from its web service example code generator facility.


Please bear in mind that it is possible that hackers may tamper with the Nematrian website and introduce malicious code in the hope that you will run this code assuming that it will work as you expect. If you have any doubts about whether the code you see on this page may be malicious then please refer to an expert.


Use of the Nematrian website, including its web services, is subject to the terms of the Nematrian License Agreement. By making use of the site, including its web services functionality, you agree to be bound by this Agreement.


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