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  • Excel Pivot table: Calculated field based on only the first row of a group

    - by Meysam
    I've got the following data and pivot table: The Total column in the pivot table is the sum of the following calculated field: =start-TIME(7, 30, 0) I know that this calculation is wrong for what I want to achieve. I need to know how much delay I have had on each day to start the work. e.g. on 1-Oct-12, assuming I should have started my work at 7:30, 8:00 - 7:30 which yields 30 minutes delay, 1 hour delay for 2-Oct-12 and 50 minutes for 3-Oct-12. So my question is, how can I have a calculated field based on only the first row of each group in a pivot table?

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  • Using Table-Valued Parameters in SQL Server

    - by Jesse
    I work with stored procedures in SQL Server pretty frequently and have often found myself with a need to pass in a list of values at run-time. Quite often this list contains a set of ids on which the stored procedure needs to operate the size and contents of which are not known at design time. In the past I’ve taken the collection of ids (which are usually integers), converted them to a string representation where each value is separated by a comma and passed that string into a VARCHAR parameter of a stored procedure. The body of the stored procedure would then need to parse that string into a table variable which could be easily consumed with set-based logic within the rest of the stored procedure. This approach works pretty well but the VARCHAR variable has always felt like an un-wanted “middle man” in this scenario. Of course, I could use a BULK INSERT operation to load the list of ids into a temporary table that the stored procedure could use, but that approach seems heavy-handed in situations where the list of values is usually going to contain only a few dozen values. Fortunately SQL Server 2008 introduced the concept of table-valued parameters which effectively eliminates the need for the clumsy middle man VARCHAR parameter. Example: Customer Transaction Summary Report Let’s say we have a report that can summarize the the transactions that we’ve conducted with customers over a period of time. The report returns a pretty simple dataset containing one row per customer with some key metrics about how much business that customer has conducted over the date range for which the report is being run. Sometimes the report is run for a single customer, sometimes it’s run for all customers, and sometimes it’s run for a handful of customers (i.e. a salesman runs it for the customers that fall into his sales territory). This report can be invoked from a website on-demand, or it can be scheduled for periodic delivery to certain users via SQL Server Reporting Services. Because the report can be created from different places and the query to generate the report is complex it’s been packed into a stored procedure that accepts three parameters: @startDate – The beginning of the date range for which the report should be run. @endDate – The end of the date range for which the report should be run. @customerIds – The customer Ids for which the report should be run. Obviously, the @startDate and @endDate parameters are DATETIME variables. The @customerIds parameter, however, needs to contain a list of the identity values (primary key) from the Customers table representing the customers that were selected for this particular run of the report. In prior versions of SQL Server we might have made this parameter a VARCHAR variable, but with SQL Server 2008 we can make it into a table-valued parameter. Defining And Using The Table Type In order to use a table-valued parameter, we first need to tell SQL Server about what the table will look like. We do this by creating a user defined type. For the purposes of this stored procedure we need a very simple type to model a table variable with a single integer column. We can create a generic type called ‘IntegerListTableType’ like this: CREATE TYPE IntegerListTableType AS TABLE (Value INT NOT NULL) Once defined, we can use this new type to define the @customerIds parameter in the signature of our stored procedure. The parameter list for the stored procedure definition might look like: 1: CREATE PROCEDURE dbo.rpt_CustomerTransactionSummary 2: @starDate datetime, 3: @endDate datetime, 4: @customerIds IntegerListTableTableType READONLY   Note the ‘READONLY’ statement following the declaration of the @customerIds parameter. SQL Server requires any table-valued parameter be marked as ‘READONLY’ and no DML (INSERT/UPDATE/DELETE) statements can be performed on a table-valued parameter within the routine in which it’s used. Aside from the DML restriction, however, you can do pretty much anything with a table-valued parameter as you could with a normal TABLE variable. With the user defined type and stored procedure defined as above, we could invoke like this: 1: DECLARE @cusomterIdList IntegerListTableType 2: INSERT @customerIdList VALUES (1) 3: INSERT @customerIdList VALUES (2) 4: INSERT @customerIdList VALUES (3) 5:  6: EXEC dbo.rpt_CustomerTransationSummary 7: @startDate = '2012-05-01', 8: @endDate = '2012-06-01' 9: @customerIds = @customerIdList   Note that we can simply declare a variable of type ‘IntegerListTableType’ just like any other normal variable and insert values into it just like a TABLE variable. We could also populate the variable with a SELECT … INTO or INSERT … SELECT statement if desired. Using The Table-Valued Parameter With ADO .NET Invoking a stored procedure with a table-valued parameter from ADO .NET is as simple as building a DataTable and passing it in as the Value of a SqlParameter. Here’s some example code for how we would construct the SqlParameter for the @customerIds parameter in our stored procedure: 1: var customerIdsParameter = new SqlParameter(); 2: customerIdParameter.Direction = ParameterDirection.Input; 3: customerIdParameter.TypeName = "IntegerListTableType"; 4: customerIdParameter.Value = selectedCustomerIds.ToIntegerListDataTable("Value");   All we’re doing here is new’ing up an instance of SqlParameter, setting the pamameters direction, specifying the name of the User Defined Type that this parameter uses, and setting its value. We’re assuming here that we have an IEnumerable<int> variable called ‘selectedCustomerIds’ containing all of the customer Ids for which the report should be run. The ‘ToIntegerListDataTable’ method is an extension method of the IEnumerable<int> type that looks like this: 1: public static DataTable ToIntegerListDataTable(this IEnumerable<int> intValues, string columnName) 2: { 3: var intergerListDataTable = new DataTable(); 4: intergerListDataTable.Columns.Add(columnName); 5: foreach(var intValue in intValues) 6: { 7: var nextRow = intergerListDataTable.NewRow(); 8: nextRow[columnName] = intValue; 9: intergerListDataTable.Rows.Add(nextRow); 10: } 11:  12: return intergerListDataTable; 13: }   Since the ‘IntegerListTableType’ has a single int column called ‘Value’, we pass that in for the ‘columnName’ parameter to the extension method. The method creates a new single-columned DataTable using the provided column name then iterates over the items in the IEnumerable<int> instance adding one row for each value. We can then use this SqlParameter instance when invoking the stored procedure just like we would use any other parameter. Advanced Functionality Using passing a list of integers into a stored procedure is a very simple usage scenario for the table-valued parameters feature, but I’ve found that it covers the majority of situations where I’ve needed to pass a collection of data for use in a query at run-time. I should note that BULK INSERT feature still makes sense for passing large amounts of data to SQL Server for processing. MSDN seems to suggest that 1000 rows of data is the tipping point where the overhead of a BULK INSERT operation can pay dividends. I should also note here that table-valued parameters can be used to deal with more complex data structures than single-columned tables of integers. A User Defined Type that backs a table-valued parameter can use things like identities and computed columns. That said, using some of these more advanced features might require the use the SqlDataRecord and SqlMetaData classes instead of a simple DataTable. Erland Sommarskog has a great article on his website that describes when and how to use these classes for table-valued parameters. What About Reporting Services? Earlier in the post I referenced the fact that our example stored procedure would be called from both a web application and a SQL Server Reporting Services report. Unfortunately, using table-valued parameters from SSRS reports can be a bit tricky and warrants its own blog post which I’ll be putting together and posting sometime in the near future.

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  • Suggestions for opening the Rails toolbox to design a challenge game?

    - by keruilin
    How would you suggest designing a challenge system as part of a food-eating game so that it's automated as possible? All RoR tools, design patterns and logic are at your disposal (e.g., admin consoles, crontab, arch, etc.). Prize goes to whoever can suggest the simplest and most-automated design! Here are the requirements: User has many challenges. Badge has many challenges. (A unique badge is awarded for each challenge won.) Only one challenge can run at a time. Each challenge has a limited number of days that it runs. For example, one challenge can run 3 days, while another runs 7 days. Challenges can be seasonal. For example, "Eat 13 Pumpkins" only runs during the Fall. New challenges are added to the game on an ongoing basis. For example, a new challenge every week. Each challenge has a certain probability of being selected to run. For example, "Eat 10 Pies" challenge has 10% chance of being selected to run. As each new challenge is added to the database, I want the probabilities of running to change dynamically. I want to avoid the scenario where I'm manually updating a database field just to change the probability from 10% to 5%, for example. Challenges act like Easter eggs. Challenge icons pop-up at different places on the webpage. User is awarded a badge for successfully completing a challenge, but only when it's active. There is some wait time between each challenge. Between 1 and 7 days. Which wait time is random, but the probability of the wait time being short is high and the probability of it being a long wait time is low.

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  • What makes my code DDD (domain-driven design) qualified?

    - by oykuo
    Hi All, I'm new to DDD and am thinking about using this design technique in my project. However, what strikes me about DDD is that how basic the idea is. Unlike other design techniques such as MVC and TDD, it doesn't seems to contain any ground breaking ideas. For example, I'm sure some of you will have the same feeling that the idea of root aggregates and repositories are nothing new because when you are was writing MVC web applications you have to have one single master object (i.e. the root aggregate) that contain other minor objects (i.e. value objects and entities) in the model layer in order to send data to a strongly typed view. To me, the only new idea in DDD is probably the "Smart" entities (i.e. you are supposed to have business rules on root aggregates) Separation between value object, root aggregate and entities. Can anyone tell me if I have missed out anything here? If that's all there is to DDD, if I update one of my existing MVC application with the above 2 new ideas, can I claim it's an TDD, MVC and DDD applcation?

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  • PHP mysql multi-table search returning different table and field data row after row

    - by Kinyanjui Kamau
    Hi Guys, I am building a social networking site that is dedicated to nightclubs and night events. Among other tables, I have a users table, events table and establishments table. I am really intrigued with how Facebook in particular is able to query and return matches of not just users but also pages, ads etc row after row. Im sure most who are reading this have tried the facebook search My question is in my case, should I: Perform 3 separate LIKE %search% on each of the tables on search.php. Draw up 3 separate tables to show the results of what matches in the relevant queries which are collapsed when empty(on the same search.php) ie In search.php //query users table $query_user = "SELECT user_first_name, user_last_name, username, picture_thumb_url, avatar FROM users JOIN picture ON users.user_id = picture.user_id AND picture.avatar=1 ORDER BY users.user_id"; $result_users = mysql_query($query_user, $connections) or die(mysql_error()); $row_result_users = mysql_fetch_assoc($wid_updates); //query events table $query_event = "SELECT event_thumb_url, event_name, event_venue, event_date FROM event WHERE event_name LIKE '%".$search_value."%'"; $event = mysql_query($query_event, $connections) or die(mysql_error()); $row_event = mysql_fetch_assoc($event); $totalRows_event = mysql_num_rows($event); //query establishments table $query_establishment = "SELECT establishment_thumb_url, establishment_name, location_id, establishment_pricing FROM establishment WHERE establishment_name LIKE '%".$search_value."%'"; $establishment = mysql_query($query_establishment, $connections) or die(mysql_error()); $row_establishment = mysql_fetch_assoc($establishment); $totalRows_establishment = mysql_num_rows($establishment); My html: <table max-width="500" name="users" border="0"> <tr> <td width="50" height="50"></td> <td width="150"></td> <td width="150"></td> <td width="150"></td> </tr> </table> <table width="500" name="events" border="0"> <tr> <td width="50" height="50"><a href="#profile.php"><img src="Images/<?php echo $row_event['event_thumb_url']; ?>" border="0" height="50" width="50"/></a></td> <td width="150"><?php echo $row_event['event_name']; ?></td> <td width="150"><?php echo $row_event['event_venue']; ?></td> <td width="150"><?php echo $row_event['event_date']; ?></td> </tr> </table> <table width="500" name="establishments" border="0"> <tr> <td width="50" height="50"><a href="#profile.php"><img src="Establishment_Images/<?php echo $row_establishment['establishment_thumb_url']; ?>" border="0" height="50" width="50"/></a></td> <td width="150"><?php echo $row_establishment['establishment_name']; ?></td> <td width="150"><?php echo $row_establishment['location_id']; ?></td> <td width="150"><?php echo $row_establishment['establishment_pricing']; ?></td> </tr> </table> I haven't populated the PHP echo's for the user table. This is just to give you an idea of what I am trying to do. Any assistance?

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  • Software or Photoshop plugins for professional photo album design

    - by Iain Fraser
    I am a graphic designer (among other things) and I'm used to doing magazine advertisements, brochures, posters and that sort of thing. Recently I was approached by a photographer who wants a graphic designer to produce wedding albums for him. I have already done a couple for him but I'm finding it hard to work by just arranging my layouts in Photoshop alone. It's very time consuming, but quite repetitive - especially when you're dealing with common page layouts. I know a lot of photographers use album design software to speed up the process a bit. What's the industry standard in terms of album design software?

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  • Design Pattern Books, Papers or Resources for Non-Object Orientated Paradigms?

    - by FinnNk
    After viewing this video on InfoQ about functional design patterns I was wondering what resources are out there on design patterns for non-object orientated paradigms. There are plenty out there for the OO world (GOF, etc, etc) and for architecture (EoEAA, etc, etc) but I'm not aware of what's out there for functional, logic, or other programming paradigms. Is there anything? A comment during the video suggests possibly not - does anyone know better? (By the way, by design patterns I don't mean language features or data structures but higher level approaches to designing an application - as discussed in the linked video)

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  • Should I use the factory design pattern for every class?

    - by Frog
    I've been writing a website in PHP. As the code becomes more complex, I keep finding problems that can be solved using the factory design pattern. For example: I've a got a class Page which has subclasses HTMLPage, XMLPage, etc. Depending on some input I need to return an object of either one of these classes. I use the factory design pattern to do this. But as I encounter this problem in more classes, I keep having to change code which still initiates an object using its constructor. So now I'm wondering: is it a good idea to change all code so that it uses the factory design pattern? Or are there big drawbacks? I'm currently in a position to change this, so your answers would be really helpful.

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  • Is the structure used for these web pages a design pattern?

    - by aspdotnetuser
    I want to know if the structure for an ASP.NET website I'm working on uses a design pattern for it's web pages. If it is a design pattern, what is it called? The web pages have the following structure: UserDetails page (UserDetails.aspx) - includes UserDetailsController.ascx user control. UserDetailsController.ascx includes sub user controls like UserAccountDetails.ascx and UserLoginDetails.ascx etc Each sub user control contains a small amount of code/logic, the 'controller' user controls that host these sub user controls (i.e UserDetailsController.ascx) appear to call the business rules code and pass the data to the sub user controls. Is this a design pattern? What is it called?

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  • 3 column layout with css display table, with first row having multiple rows?

    - by Damainman
    I am working on a new website which: Has 3 columns - Each Column being a cell First column has 3 rows (Logo, Nav, icons) - Has a Div with display: table which wraps arround 3 divs with display:table-row. Other two columns only have 1 row. With the middle column being the content area. However since this is my first time using display:table, I am running into some things that aren't so clear to me. I was trying to avoid floating divs. If I need multiple rows with one cell in each row per column, do I embed each cell in a row or just create each row and not declare cells. I understand that browsers automatically create the missing elements but I want to make sure I do this properly to avoid any side effects that might occur due to the browser automatically creating the missing elements. Edit: I think my brain is just over worked, I guess I can accomplish this by just using 3 divs in the first column instead of using a nested table div with the rows. This just popped into my head.

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  • How do you enhance your websites speed without compromising the design and access?

    - by Thorn007
    How do you enhance your websites load speed without killing the design and accessibility? File compression, CDN, Gzip? What are the best tools for doing so? For example, Google has optimized their site without compromising the design. Also, many website can kill the purity of their images with compression. Is there a way, more or lest best practice, to increase speed without compromising the design and accessibility? Note: sorry for being so vague but I don't know how else to phrase this question.

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  • Where should I ask for feedbacks about web design? [closed]

    - by mariosangiorgio
    Possible Duplicate: Where can I get my website critiqued I am developing my personal website and I'd like to have feedbacks about its design. Is there any site/forum you would recommend me? I know that the best solution would be to hire a professional web designer and have him design my website, but I am also interested in understanding how to improve my design skills. Of course any recommended book, website, resource is more than welcome. I am not posting here the link to my home page because I think this Q/A site is more about web-development in general, but if you'd like to see my personal page and give some feedback I'll link it.

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  • Design of Business Layer

    - by Adil Mughal
    Hi, We are currently revamping our architecture and design of application. We have just completed design of Data Access Layer which is generic in the sense that it works using XML and reflection to persist data. Any ways now we are in the phase of designing business layer. We have read some books related to Enterprise Architecture and Design so we have found that there are few patterns that can be applied on business layer. Table Pattern and Domain Model are example of such patterns. Also we have found Domain Driven Design as well. Earlier we decided to build Entities against table objects. But we found that there is difference in Entities and Value Objects when it comes to DDD. For those of you who have gone through such design. Please guide me related to pattern, practice and sample. Thank you in advance! Also please feel free to discuss if you didn't get any point of mine.

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  • What design pattern do you use the most?

    - by spoon16
    I'm interested in understanding what design patterns people find themselves using often. Hopefully this list will help other recognize common scenarios and the associated design pattern that can be used to solve them. Please describe a common problem you find yourself solving and the design pattern(s) you use to solve it. Links to blogs or documentation describing the pattern are also appreciated. Edit: Please expand on your answers a bit, I would like this to be a useful reference for someone who wants to learn more about design patterns and is curious on what situations a specific design pattern might be used. Nobody has linked to any "more learning" resources.

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  • Documenting a policy based design

    - by academicRobot
    I'm re-working some prototype code into a policy based design in C++, and I'm wondering what the best practice is for documenting the design. My current plan is to document: Policy hierarchy Overview of each policy Description of each type/value/function in each policy I was thinking of putting this into a doxygen module, but this looks like it will be a bit awkward since formatting will have to be done by hand without code to base the doc on (that is, documenting the policies rather than the implementation of the policies). So my questions are: Are there other aspects of the design that should be documented? Are there any tricks to doing this efficiently in doxygen? Is there a tool other than doxygen thats better suited to this? What are some examples of well documented policy based design? This is my first serious attempt at policy based design. I think I have a working grasp of the principles, but whatever naivety I expose in this question is fair game for an answer too.

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  • Analysis and Design for Functional Programming

    - by edalorzo
    How do you deal with analysis and design phases when you plan to develop a system using a functional programming language like Haskell? My background is in imperative/object-oriented programming languages, and therefore, I am used to use case analysis and the use of UML to document the design of program. But the thing is that UML is inherently related to the object-oriented way of doing software. And I am intrigued about what would be the best way to develop documentation and define software designs for a system that is going to be developed using functional programming. Would you still use use case analysis or perhaps structured analysis and design instead? How do software architects define the high-level design of the system so that developers follow it? What do you show to you clients or to new developers when you are supposed to present a design of the solution? How do you document a picture of the whole thing without having first to write it all? Is there anything comparable to UML in the functional world?

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  • Java ORM related question - SQL Vs Google DB (Big Table?) GAE

    - by StackerFlow
    I was wondering about the following two options when one is not using SQL tables but ORM based DBs (Example - when you are using GAE) Would the second option be less efficient? Requirement: There is an object. The object has a collection of similar items. I need to store this object. Example, say the object is a tree and it has a collection of leaves. Option 1: Traditional SQL type structure: Table for the Tree (with TreeId as the identifier for a row in the Table.) Table for the Leaves (where each leaf has a TreeId and to show the leaves of a tree, I query all leaves where the TreeId is the Id of the tree.) Here, the Tree structure DOES NOT have a field with leaves. Option 2: ORM / GAE Tables: Using the same example above, I have an object for Tree where the object has a collection (Set/List in Java/C++) of leaves. I store and retrieve the Tree together with the leaves (as the leaves are implemented as a Set in the Tree object) My question is, will the second one be less efficient that the first option? If so, why? Are there other alternatives? Thank you!

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  • Rotate a table in word

    - by Jake Pearson
    I have a word 2007 document in portrait mode. I have a table that is too wide to fit in 8.5" but would fit in 11". Is there a way to make just one page landscape? Or alternately is there a way to rotate a table 90 degrees?

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  • Change collation of a MySQL table to utf8_general_cs

    - by jack
    I tried to change collation MySQL table to utf8_general_cs but got following error: mysql> ALTER TABLE table_name CONVERT TO CHARACTER SET utf8 COLLATE 'utf8_general_cs'; ERROR 1273 (HY000): Unknown collation: 'utf8_general_cs' I run "SHOW COLLATE" command and "utf8_general_cs" is not in the results. What can I do now?

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  • Excel, Pivot table, Relocate Filters on the worksheet

    - by Maria
    Hej, In my worksheet where i have my pivot table i have many different filters to chose between. For the view of the eye it doesnt really look nice and i want to be able to maybe split tha t long list of filters into a few shorter once. But i cant figure out how to do this. Ive seen where i can move the whole pivot table, but then its all included and as one unsplitable piece.... anyone knows if this is possible??

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  • Flow-Design Cheat Sheet &ndash; Part I, Notation

    - by Ralf Westphal
    You want to avoid the pitfalls of object oriented design? Then this is the right place to start. Use Flow-Oriented Analysis (FOA) and –Design (FOD or just FD for Flow-Design) to understand a problem domain and design a software solution. Flow-Orientation as described here is related to Flow-Based Programming, Event-Based Programming, Business Process Modelling, and even Event-Driven Architectures. But even though “thinking in flows” is not new, I found it helpful to deviate from those precursors for several reasons. Some aim at too big systems for the average programmer, some are concerned with only asynchronous processing, some are even not very much concerned with programming at all. What I was looking for was a design method to help in software projects of any size, be they large or tiny, involing synchronous or asynchronous processing, being local or distributed, running on the web or on the desktop or on a smartphone. That´s why I took ideas from all of the above sources and some additional and came up with Event-Based Components which later got repositioned and renamed to Flow-Design. In the meantime this has generated some discussion (in the German developer community) and several teams have started to work with Flow-Design. Also I´ve conducted quite some trainings using Flow-Orientation for design. The results are very promising. Developers find it much easier to design software using Flow-Orientation than OOAD-based object orientation. Since Flow-Orientation is moving fast and is not covered completely by a single source like a book, demand has increased for at least an overview of the current state of its notation. This page is trying to answer this demand by briefly introducing/describing every notational element as well as their translation into C# source code. Take this as a cheat sheet to put next to your whiteboard when designing software. However, please do not expect any explanation as to the reasons behind Flow-Design elements. Details on why Flow-Design at all and why in this specific way you´ll find in the literature covering the topic. Here´s a resource page on Flow-Design/Event-Based Components, if you´re able to read German. Notation Connected Functional Units The basic element of any FOD are functional units (FU): Think of FUs as some kind of software code block processing data. For the moment forget about classes, methods, “components”, assemblies or whatever. See a FU as an abstract piece of code. Software then consists of just collaborating FUs. I´m using circles/ellipses to draw FUs. But if you like, use rectangles. Whatever suites your whiteboard needs best.   The purpose of FUs is to process input and produce output. FUs are transformational. However, FUs are not called and do not call other FUs. There is no dependency between FUs. Data just flows into a FU (input) and out of it (output). From where and where to is of no concern to a FU.   This way FUs can be concatenated in arbitrary ways:   Each FU can accept input from many sources and produce output for many sinks:   Flows Connected FUs form a flow with a start and an end. Data is entering a flow at a source, and it´s leaving it through a sink. Think of sources and sinks as special FUs which conntect wires to the environment of a network of FUs.   Wiring Details Data is flowing into/out of FUs through wires. This is to allude to electrical engineering which since long has been working with composable parts. Wires are attached to FUs usings pins. They are the entry/exit points for the data flowing along the wires. Input-/output pins currently need not be drawn explicitly. This is to keep designing on a whiteboard simple and quick.   Data flowing is of some type, so wires have a type attached to them. And pins have names. If there is only one input pin and output pin on a FU, though, you don´t need to mention them. The default is Process for a single input pin, and Result for a single output pin. But you´re free to give even single pins different names.   There is a shortcut in use to address a certain pin on a destination FU:   The type of the wire is put in parantheses for two reasons. 1. This way a “no-type” wire can be easily denoted, 2. this is a natural way to describe tuples of data.   To describe how much data is flowing, a star can be put next to the wire type:   Nesting – Boards and Parts If more than 5 to 10 FUs need to be put in a flow a FD starts to become hard to understand. To keep diagrams clutter free they can be nested. You can turn any FU into a flow: This leads to Flow-Designs with different levels of abstraction. A in the above illustration is a high level functional unit, A.1 and A.2 are lower level functional units. One of the purposes of Flow-Design is to be able to describe systems on different levels of abstraction and thus make it easier to understand them. Humans use abstraction/decomposition to get a grip on complexity. Flow-Design strives to support this and make levels of abstraction first class citizens for programming. You can read the above illustration like this: Functional units A.1 and A.2 detail what A is supposed to do. The whole of A´s responsibility is decomposed into smaller responsibilities A.1 and A.2. FU A thus does not do anything itself anymore! All A is responsible for is actually accomplished by the collaboration between A.1 and A.2. Since A now is not doing anything anymore except containing A.1 and A.2 functional units are devided into two categories: boards and parts. Boards are just containing other functional units; their sole responsibility is to wire them up. A is a board. Boards thus depend on the functional units nested within them. This dependency is not of a functional nature, though. Boards are not dependent on services provided by nested functional units. They are just concerned with their interface to be able to plug them together. Parts are the workhorses of flows. They contain the real domain logic. They actually transform input into output. However, they do not depend on other functional units. Please note the usage of source and sink in boards. They correspond to input-pins and output-pins of the board.   Implicit Dependencies Nesting functional units leads to a dependency tree. Boards depend on nested functional units, they are the inner nodes of the tree. Parts are independent, they are the leafs: Even though dependencies are the bane of software development, Flow-Design does not usually draw these dependencies. They are implicitly created by visually nesting functional units. And they are harmless. Boards are so simple in their functionality, they are little affected by changes in functional units they are depending on. But functional units are implicitly dependent on more than nested functional units. They are also dependent on the data types of the wires attached to them: This is also natural and thus does not need to be made explicit. And it pertains mainly to parts being dependent. Since boards don´t do anything with regard to a problem domain, they don´t care much about data types. Their infrastructural purpose just needs types of input/output-pins to match.   Explicit Dependencies You could say, Flow-Orientation is about tackling complexity at its root cause: that´s dependencies. “Natural” dependencies are depicted naturally, i.e. implicitly. And whereever possible dependencies are not even created. Functional units don´t know their collaborators within a flow. This is core to Flow-Orientation. That makes for high composability of functional units. A part is as independent of other functional units as a motor is from the rest of the car. And a board is as dependend on nested functional units as a motor is on a spark plug or a crank shaft. With Flow-Design software development moves closer to how hardware is constructed. Implicit dependencies are not enough, though. Sometimes explicit dependencies make designs easier – as counterintuitive this might sound. So FD notation needs a ways to denote explicit dependencies: Data flows along wires. But data does not flow along dependency relations. Instead dependency relations represent service calls. Functional unit C is depending on/calling services on functional unit S. If you want to be more specific, name the services next to the dependency relation: Although you should try to stay clear of explicit dependencies, they are fundamentally ok. See them as a way to add another dimension to a flow. Usually the functionality of the independent FU (“Customer repository” above) is orthogonal to the domain of the flow it is referenced by. If you like emphasize this by using different shapes for dependent and independent FUs like above. Such dependencies can be used to link in resources like databases or shared in-memory state. FUs can not only produce output but also can have side effects. A common pattern for using such explizit dependencies is to hook a GUI into a flow as the source and/or the sink of data: Which can be shortened to: Treat FUs others depend on as boards (with a special non-FD API the dependent part is connected to), but do not embed them in a flow in the diagram they are depended upon.   Attributes of Functional Units Creation and usage of functional units can be modified with attributes. So far the following have shown to be helpful: Singleton: FUs are by default multitons. FUs in the same of different flows with the same name refer to the same functionality, but to different instances. Think of functional units as objects that get instanciated anew whereever they appear in a design. Sometimes though it´s helpful to reuse the same instance of a functional unit; this is always due to valuable state it holds. Signify this by annotating the FU with a “(S)”. Multiton: FUs on which others depend are singletons by default. This is, because they usually are introduced where shared state comes into play. If you want to change them to be a singletons mark them with a “(M)”. Configurable: Some parts need to be configured before the can do they work in a flow. Annotate them with a “(C)” to have them initialized before any data items to be processed by them arrive. Do not assume any order in which FUs are configured. How such configuration is happening is an implementation detail. Entry point: In each design there needs to be a single part where “it all starts”. That´s the entry point for all processing. It´s like Program.Main() in C# programs. Mark the entry point part with an “(E)”. Quite often this will be the GUI part. How the entry point is started is an implementation detail. Just consider it the first FU to start do its job.   Patterns / Standard Parts If more than a single wire is attached to an output-pin that´s called a split (or fork). The same data is flowing on all of the wires. Remember: Flow-Designs are synchronous by default. So a split does not mean data is processed in parallel afterwards. Processing still happens synchronously and thus one branch after another. Do not assume any specific order of the processing on the different branches after the split.   It is common to do a split and let only parts of the original data flow on through the branches. This effectively means a map is needed after a split. This map can be implicit or explicit.   Although FUs can have multiple input-pins it is preferrable in most cases to combine input data from different branches using an explicit join: The default output of a join is a tuple of its input values. The default behavior of a join is to output a value whenever a new input is received. However, to produce its first output a join needs an input for all its input-pins. Other join behaviors can be: reset all inputs after an output only produce output if data arrives on certain input-pins

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