Defining the need for LDAP patience in Visual C#

Maker Code 39 in Visual C# Defining the need for LDAP patience

The Achilles heal of working with Active Directory is LDAP you can t get away from it Even when working with the LINQ to Active Directory provider, you must contend with issues such as creating an LDAP URI for the connection and working with distinguished names It s in your best interest to spend time working with the various administrator tools on test machines before you begin writing Active Directory code Even small mistakes can have costly consequences on a production system The best way to approach Active Directory is to assume that you ll make a mistake Copy as much as you can directly from Active Directory as shown in the example in this chapter When you can t copy, have a friend or two verify your code Creating the right URIs and distinguished names appears simple, but it can become deceptively complex Never test a new Active Directory application or an application update on a production machine because you ll almost certainly regret doing so in the long run

13

Considering what makes a LINQ solution viable Developing a COM+ application Developing an RDF application Developing a MySQL application

he previous chapters of this book have shown you what appears to be a considerable number of LINQ solutions, but these examples only skim the surface of what LINQ can do As was shown in Table 1-1, you can find a significant number of LINQ to solutions on the Internet In fact, you saw two of these LINQ to solutions in s 11 and 12, where you discovered how to work with Office 2007 and Active Directory, respectively You can probably use LINQ in more places than anticipated or even expected This chapter examines a few more of the possibilities More important than the existing solutions are the solutions you need for your particular needs Most organizations have custom applications and may wonder whether LINQ will work for them The interesting thing about LINQ is that it s expandable without resorting to using extreme amounts of low-level code Yes, you must have good coding skills to write a provider of your own, but as the LINQ to Active Directory example in 12 shows, you can write a provider using standard C# programming techniques This chapter also explores some of the issues you must consider before you attempt to write a provider of your own

Given the right provider, you can use LINQ to technology to connect to just about anything Many developers will likely create their own provider using the techniques shown with the LINQ to Active Directory example in 12

Microsoft even provides instructions for creating your own LINQ to provider at http://msdn2microsoftcom/en-us/library/bb546158aspx The Microsoft example is complete, but it s also a typical Microsoft example in that it s so complex that only a developer with a lot of experience will understand it This is the example to use, though, if you need a high-performance, fully functional provider that does everything Fortunately, you don t have to rely on this one complex example as your own solution Microsoft provides a considerable number of examples at http://msdn2microsoft com/en-us/library/bb397965aspx (Visual Basic developers will want to look at the examples at http://msdn2microsoftcom/en-us/ library/bb397978aspx) A simpler solution than starting from scratch for creating providers is to rely on a kit that automates some of the coding requirements For example, the LINQExtender kit, at http://wwwcodeplexcom/LinqExtender, can help you create a new provider in a relatively short time (Make sure you get the latest version of the LINQExtender kit to ensure you get good results) However, using a kit can have the downside of performance penalties because you re adding yet another processing level to the resulting application Most users won t even notice the difference, though, and the time saved by developers using LINQ is a big benefit To see how someone else has faired using the LINQExtender kit, check out the LINQ to Flickr solution at http://www codeplexcom/LINQFlickr The article at http://dotnetslackers com/articles/csharp/CreatingCustomLINQProviderUsingLinq Extenderaspx provides complete details on using LINQExtender to build a solution of your own The question remains of whether your application will work properly with LINQ Although LINQ doesn t have many requirements and you can overcome many of them through data conversion or careful programming, an application does need to meet some criteria to work well with LINQ The following list provides an overview of these basic requirements: Structured: A structure lets you interact with the data in an orderly manner It doesn t matter whether the data is in a hierarchical format, such as XML, or in a tabular format, such as SQL Server In fact, the data need not even appear in a single file you could process the data from a group of files on a hard drive if desired However, in all these cases, the data has an identifiable structure Many binary files, such as those used to store graphics, have an identifiable structure, so you aren t even limited to data that appears in human readable form Repetitious: A single instance of a data element doesn t require a query because you already know what that single instance entails To use LINQ successfully, you must be able to define a sequence of repeated data elements Not every data element need contain every property (such as