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• What does your Lisp workflow look like?

  - by Duncan Bayne

  I'm learning Lisp at the moment, coming from a language progression that is Locomotive BASIC - Z80 Assembler - Pascal - C - Perl - C# - Ruby. My approach is to simultaneously: write a simple web-scraper using SBCL, QuickLisp, closure-html, and drakma watch the SICP lectures I think this is working well; I'm developing good 'Lisp goggles', in that I can now read Lisp reasonably easily. I'm also getting a feel for how the Lisp ecosystem works, e.g. Quicklisp for dependencies. What I'm really missing, though, is a sense of how a seasoned Lisper actually works. When I'm coding for .NET, I have Visual Studio set up with ReSharper and VisualSVN. I write tests, I implement, I refactor, I commit. Then when I'm done enough of that to complete a story, I write some AUATs. Then I kick off a Release build on TeamCity to push the new functionality out to the customer for testing & hopefully approval. If it's an app that needs an installer, I use either WiX or InnoSetup, obviously building the installer through the CI system. So, my question is: as an experienced Lisper, what does your workflow look like? Do you work mostly in the REPL, or in the editor? How do you do unit tests? Continuous integration? Packaging & deployment? When you sit down at your desk, steaming mug of coffee to one side and a framed photo of John McCarthy to the other, what is it that you do? Currently, I feel like I am getting to grips with Lisp coding, but not Lisp development ...

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• NetBeans 6.9 Released

  - by Duncan Mills

  Great news, the first NetBeans release that has been conducted fully under the stewardship of Oracle has now been released. NetBeans IDE 6.9 introduces the JavaFX Composer, a visual layout tool for building JavaFX GUI applications, similar to the Swing GUI builder for Java SE applications. With the JavaFX Composer, developers can quickly build, visually edit, and debug Rich Internet Applications (RIA) and bind components to various data sources, including Web services. The NetBeans 6.9 release also features OSGi interoperability for NetBeans Platform applications and support for developing OSGi bundles with Maven. With support for OSGi and Swing standards, the NetBeans Platform now supports the standard UI toolkit and the standard module system, providing a unique combination of standards for modular, rich-client development. Additional noteworthy features in this release include support for JavaFX SDK 1.3, PHP Zend framework, and Ruby on Rails 3.0; as well as improvements to the Java Editor, Java Debugger, issue tracking, and more. Head over to NetBeans.org for more details and of course downloads!

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• Centered Content using panelGridLayout

  - by Duncan Mills

  A classic layout conundrum,  which I think pretty much every ADF developer may have faced at some time or other, is that of truly centered (centred) layout. Typically this requirement comes up in relation to say displaying a login type screen or similar. Superficially the  problem seems easy, but as my buddy Eduardo explained when discussing this subject a couple of years ago it's actually a little more complex than you might have thought. If fact, even the "solution" provided in that posting is not perfect and suffers from a several issues (not Eduardo's fault, just limitations of panelStretch!) The top, bottom, end and start facets all need something in them The percentages you apply to the topHeight, startWidth etc. are calculated as part of the whole width.  This means that you have to guestimate the correct percentage based on your typical screen size and the sizing of the centered content. So, at best, you will in fact only get approximate centering, and the more you tune that centering for a particular browser size the more it will fail if the user resizes. You can't attach styles to the panelStretchLayout facets so to provide things like background color or fixed sizing you need to embed another container that you can apply styles to, typically a panelgroupLayout   For reference here's the code to print a simple 100px x 100px red centered square  using the panelStretchLayout solution, approximately tuned to a 1980 x 1080 maximized browser (IDs omitted for brevity): <af:panelStretchLayout startWidth="45%" endWidth="45%"                        topHeight="45%"  bottomHeight="45%" >   <f:facet name="center">     <af:panelGroupLayout inlineStyle="height:100px;width:100px;background-color:red;"                          layout="vertical"/>   </f:facet>   <f:facet name="top">     <af:spacer height="1" width="1"/>   </f:facet>   <f:facet name="bottom">     <af:spacer height="1" width="1"/>   </f:facet>   <f:facet name="start">     <af:spacer height="1" width="1"/>   </f:facet>   <f:facet name="end">     <af:spacer height="1" width="1"/>    </f:facet> </af:panelStretchLayout>  And so to panelGridLayout  So here's the  good news, panelGridLayout makes this really easy and it works without the caveats above.  The key point is that percentages used in the grid definition are evaluated after the fixed sizes are taken into account, so rather than having to guestimate what percentage will "more, or less", center the content you can just say "allocate half of what's left" to the flexible content and you're done. Here's the same example using panelGridLayout: <af:panelGridLayout> <af:gridRow height="50%"/> <af:gridRow height="100px"> <af:gridCell width="50%" /> <af:gridCell width="100px" halign="stretch" valign="stretch"  inlineStyle="background-color:red;"> <af:spacer width="1" height="1"/> </af:gridCell> <af:gridCell width="50%" /> </af:gridRow> <af:gridRow height="50%"/> </af:panelGridLayout>  So you can see that the amount of markup is somewhat smaller (as is, I should mention, the generated DOM structure in the browser), mainly because we don't need to introduce artificial components to ensure that facets are actually observed in the final result.  But the key thing here is that the centering is no longer approximate and it will work as expected as the user resizes the browser screen.  By far this is a more satisfactory solution and although it's only a simple example, it will hopefully open your eyes to the potential of panelGridLayout as your number one, go-to layout container. Just a reminder though, right now, panelGridLayout is only available in 11.1.2.2 and above.

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• PanelGridLayout - A Layout Revolution

  - by Duncan Mills

  With the most recent 11.1.2 patchset (11.1.2.3) there has been a lot of excitement around ADF Essentials (and rightly so), however, in all the fuss I didn't want an even more significant change to get missed - yes you read that correctly, a more significant change! I'm talking about the new panelGridLayout component, I can confidently say that this one of the most revolutionary components that we've introduced in 11g, even though it sounds rather boring. To be totally accurate, panelGrid was introduced in 11.1.2.2 but without any presence in the component palette or other design time support, so it was largely missed unless you read the release notes. However in this latest patchset it's finally front and center. Its time to explore - we (really) need to talk about layout.  Let's face it,with ADF Faces rich client, layout is a rather arcane pursuit, once you are a layout master, all bow before you, but it's more of an art than a science, and it is often, in fact, way too difficult to achieve what should (apparently) be a pretty simple. Here's a great example, it's a homework assignment I set for folks I'm teaching this stuff to:  The requirements for this layout are: The header is 80px high, the footer is 30px. These are both fixed.  The first section of the header containing the logo is 180px wide The logo is centered within the top left hand corner of the header  The title text is start aligned in the center zone of the header and will wrap if the browser window is narrowed. It should be aligned in the center of the vertical space  The about link is anchored to the right hand side of the browser with a 20px gap and again is center aligned vertically. It will move as the browser window is reduced in width. The footer has a right aligned copyright statement, again middle aligned within a 30px high footer region and with a 20px buffer to the right hand edge. It will move as the browser window is reduced in width. All remaining space is given to a central zone, which, in this case contains a panelSplitter. Expect that at some point in time you'll need a separate messages line in the center of the footer.  In the homework assigment I set I also stipulate that no inlineStyles can be used to control alignment or margins and no use of other taglibs (e.g. JSF HTML or Trinidad HTML). So, if we take this purist approach, that basic page layout (in my stock solution) requires 3 panelStretchLayouts, 5 panelGroupLayouts and 4 spacers - not including the spacer I use for the logo and the contents of the central zone splitter - phew! The point is that even a seemingly simple layout needs a bit of thinking about, particulatly when you consider strechting and browser re-size behavior. In fact, this little sample actually teaches you much of what you need to know to become vaguely competant at layouts in the framework. The underlying result of "the way things are" is that most of us reach for panelStretchLayout before even finishing the first sip of coffee as we embark on a new page design. In fact most pages you will see in any moderately complex ADF page will basically be nested panelStretchLayouts and panelGroupLayouts, sometimes many, many levels deep. So this is a problem, we've known this for some time and now we have a good solution. (I should point out that the oft-used Trinidad trh tags are not a particularly good solution as you're tie-ing yourself to an HTML table based layout in that case with a host of attendent issues in resize and bi-di behavior, but I digress.) So, tadaaa, I give to you panelGridLayout. PanelGrid, as the name suggests takes a grid like (dare I say slightly gridbag-like) approach to layout, dividing your layout into rows and colums with margins, sizing, stretch behaviour, colspans and rowspans all rolled in, all without the use of inlineStyle. As such, it provides for a much more powerful and consise way of defining a layout such as the one above that is actually simpler and much more logical to design. The basic building blocks are the panelGridLayout itself, gridRow and gridCell. Your content sits inside the cells inside the rows, all helpfully allowing both streching, valign and halign definitions without the need to nest further panelGroupLayouts. So much simpler!  If I break down the homework example above my nested comglomorate of 12 containers and spacers can be condensed down into a single panelGrid with 3 rows and 5 cell definitions (39 lines of source reduced to 24 in the case of the sample). What's more, the actual runtime representation in the browser DOM is much, much simpler, and clean, with basically one DIV per cell (Note that just because the panelGridLayout semantics looks like an HTML table does not mean that it's rendered that way!) . Another hidden benefit is the runtime cost. Because we can use a single layout to achieve much more complex geometries the client side layout code inside the browser is having to work a lot less. This will be a real benefit if your application needs to run on lower powered clients such as netbooks or tablets. So, it's time, if you're on 11.1.2.2 or above, to smile warmly at your panelStretchLayouts, wrap the blanket around it's knees and wheel it off to the Sunset Retirement Home for a well deserved rest. There's a new kid on the block and it wants to be your friend. 

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• Making Those PanelBoxes Behave

  - by Duncan Mills

  I have a little problem to solve earlier this week - misbehaving <af:panelBox> components... What do I mean by that? Well here's the scenario, I have a page fragment containing a set of panelBoxes arranged vertically. As it happens, they are stamped out in a loop but that does not really matter. What I want to be able to do is to provide the user with a simple UI to close and open all of the panelBoxes in concert. This could also apply to showDetailHeader and similar items with a disclosed attrubute, but in this case it's good old panelBoxes.  Ok, so the basic solution to this should be self evident. I can set up a suitable scoped managed bean that the panelBoxes all refer to for their disclosed attribute state. Then the open all / close commandButtons in the UI can simply set the state of that bean for all the panelBoxes to pick up via EL on their disclosed attribute. Sound OK? Well that works basically without a hitch, but turns out that there is a slight problem and this is where the framework is attempting to be a little too helpful. The issue is that is the user manually discloses or hides a panelBox then that will override the value that the EL is setting. So for example. I start the page with all panelBoxes collapsed, all set by the EL state I'm storing on the session I manually disclose panelBox no 1. I press the Expand All button - all works as you would hope and all the panelBoxes are now disclosed, including of course panelBox 1 which I just expanded manually. Finally I press the Collapse All button and everything collapses except that first panelBox that I manually disclosed.  The problem is that the component remembers this manual disclosure and that overrides the value provided by the expression. If I change the viewId (navigate away and back) then the panelBox will start to behave again, until of course I touch it again! Now, the more astute amoungst you would think (as I did) Ah, sound like the MDS personalizaton stuff is getting in the way and the solution should simply be to set the dontPersist attribute to disclosed | ALL. Alas this does not fix the issue.  After a little noodling on the best way to approach this I came up with a solution that works well, although if you think of an alternative way do let me know. The principle is simple. In the disclosureListener for the panelBox I take a note of the clientID of the panelBox component that has been touched by the user along with the state. This all gets stored in a Map of Booleans in ViewScope which is keyed by clientID and stores the current disclosed state in the Boolean value.  The listener looks like this (it's held in a request scope backing bean for the page): public void handlePBDisclosureEvent(DisclosureEvent disclosureEvent) { String clientId = disclosureEvent.getComponent().getClientId(FacesContext.getCurrentInstance()); boolean state = disclosureEvent.isExpanded(); pbState.addTouchedPanelBox(clientId, state); } The pbState variable referenced here is a reference to the bean which will hold the state of the panelBoxes that lives in viewScope (recall that everything is re-set when the viewid is changed so keeping this in viewScope is just fine and cleans things up automatically). The addTouchedPanelBox() method looks like this: public void addTouchedPanelBox(String clientId, boolean state) { //create the cache if needed this is just a Map<String,Boolean> if (_touchedPanelBoxState == null) { _touchedPanelBoxState = new HashMap<String, Boolean>(); } // Simply put / replace _touchedPanelBoxState.put(clientId, state); } So that's the first part, we now have a record of every panelBox that the user has touched. So what do we do when the Collapse All or Expand All buttons are pressed? Here we do some JavaScript magic. Basically for each clientID that we have stored away, we issue a client side disclosure event from JavaScript - just as if the user had gone back and changed it manually. So here's the Collapse All button action: public String CloseAllAction() { submitDiscloseOverride(pbState.getTouchedClientIds(true), false); _uiManager.closeAllBoxes(); return null; }  The _uiManager.closeAllBoxes() method is just manipulating the master-state that all of the panelBoxes are bound to using EL. The interesting bit though is the line:  submitDiscloseOverride(pbState.getTouchedClientIds(true), false); To break that down, the first part is a call to that viewScoped state holder to ask for a list of clientIDs that need to be "tweaked": public String getTouchedClientIds(boolean targetState) { StringBuilder sb = new StringBuilder(); if (_touchedPanelBoxState != null && _touchedPanelBoxState.size() > 0) { for (Map.Entry<String, Boolean> entry : _touchedPanelBoxState.entrySet()) { if (entry.getValue() == targetState) { if (sb.length() > 0) { sb.append(','); } sb.append(entry.getKey()); } } } return sb.toString(); } You'll notice that this method only processes those panelBoxes that will be in the wrong state and returns those as a comma separated list. This is then processed by the submitDiscloseOverride() method: private void submitDiscloseOverride(String clientIdList, boolean targetDisclosureState) { if (clientIdList != null && clientIdList.length() > 0) { FacesContext fctx = FacesContext.getCurrentInstance(); StringBuilder script = new StringBuilder(); script.append("overrideDiscloseHandler('"); script.append(clientIdList); script.append("',"); script.append(targetDisclosureState); script.append(");"); Service.getRenderKitService(fctx, ExtendedRenderKitService.class).addScript(fctx, script.toString()); } } This method constructs a JavaScript command to call a routine called overrideDiscloseHandler() in a script attached to the page (using the standard <af:resource> tag). That method parses out the list of clientIDs and sends the correct message to each one: function overrideDiscloseHandler(clientIdList, newState) { AdfLogger.LOGGER.logMessage(AdfLogger.INFO, "Disclosure Hander newState " + newState + " Called with: " + clientIdList); //Parse out the list of clientIds var clientIdArray = clientIdList.split(','); for (var i = 0; i < clientIdArray.length; i++){ var panelBox = flipPanel = AdfPage.PAGE.findComponentByAbsoluteId(clientIdArray[i]); if (panelBox.getComponentType() == "oracle.adf.RichPanelBox"){ panelBox.broadcast(new AdfDisclosureEvent(panelBox, newState)); } }  }  So there you go. You can see how, with a few tweaks the same code could be used for other components with disclosure that might suffer from the same problem, although I'd point out that the behavior I'm working around here us usually desirable. You can download the running example (11.1.2.2) from here. 

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• Application Scope v's Static - Not Quite the same

  - by Duncan Mills

  An interesting question came up today which, innocent as it sounded, needed a second or two to consider. What's the difference between storing say a Map of reference information as a Static as opposed to storing the same map as an application scoped variable in JSF?  From the perspective of the web application itself there seems to be no functional difference, in both cases, the information is confined to the current JVM and potentially visible to your app code (note that Application Scope is not magically propagated across a cluster, you would need a separate instance on each VM). To my mind the primary consideration here is a matter of leakage. A static will be (potentially) visible to everything running within the same VM (OK this depends on which class-loader was used but let's keep this simple), and this includes your model code and indeed other web applications running in the same container. An Application Scoped object, in JSF terms, is much more ring-fenced and is only visible to the Web app itself, not other web apps running on the same server and not directly to the business model layer if that is running in the same VM. So given that I'm a big fan of coding applications to say what I mean, then using Application Scope appeals because it explicitly states how I expect the data to be used and a provides a more explicit statement about visibility and indeed dependency as I'd generally explicitly inject it where it is needed.  Alternative viewpoints / thoughts are, as ever, welcomed...

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• C programming in 2011

  - by Duncan Bayne

  Many moons ago I cut C code for a living, primarily while maintaining a POP3 server that supported a wide range of OSs (Linux, *BSD, HPUX, VMS ...). I'm planning to polish the rust off my C skills and learn a bit about language implementation by coding a simple FORTH in C. But I'm wondering how (or whether?) have things changed in the C world since 2000. When I think C, I think ... comp.lang.c ANSI C wherever possible (but C89 as C99 isn't that widely supported) gcc -Wall -ansi -pedantic in lieu of static analysis tools Emacs Ctags Autoconf + make (and see point 2 for VMS, HP-UX etc. goodness) Can anyone who's been writing in C for the past eleven years let me know what (if anything ;-) ) has changed over the years? (In other news, holy crap, I've been doing this for more than a decade).

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• New Sample Demonstrating the Traversing of Tree Bindings

  - by Duncan Mills

  A technique that I seem to use a fair amount, particularly in the construction of dynamic UIs is the use of a ADF Tree Binding to encode a multi-level master-detail relationship which is then expressed in the UI in some kind of looping form – usually a series of nested af:iterators, rather than the conventional tree or treetable. This technique exploits two features of the treebinding. First the fact that an treebinding can return both a collectionModel as well as a treeModel, this collectionModel can be used directly by an iterator. Secondly that the “rows” returned by the collectionModel themselves contain an attribute called .children. This attribute in turn gives access to a collection of all the children of that node which can also be iterated over. Putting this together you can represent the data encoded into a tree binding in all sorts of ways. As an example I’ve put together a very simple sample based on the HT schema and uploaded it to the ADF Sample project. It produces this UI: The important code is shown here for a Region -> Country -> Location Hierachy: <af:iterator id="i1" value="#{bindings.AllRegions.collectionModel}" var="rgn"> <af:showDetailHeader text="#{rgn.RegionName}" disclosed="true" id="sdh1"> <af:iterator id="i2" value="#{rgn.children}" var="cnty">     <af:showDetailHeader text="#{cnty.CountryName}" disclosed="true" id="sdh2">       <af:iterator id="i3" value="#{cnty.children}" var="loc">         <af:panelList id="pl1">         <af:outputText value="#{loc.City}" id="ot3"/>           </af:panelList>         </af:iterator>       </af:showDetailHeader>     </af:iterator>   </af:showDetailHeader> </af:iterator>  You can download the entire sample from here:

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• Towards Ultra-Reusability for ADF - Adaptive Bindings

  - by Duncan Mills

  The task flow mechanism embodies one of the key value propositions of the ADF Framework, it's primary contribution being the componentization of your applications and implicitly the introduction of a re-use culture, particularly in large applications. However, what if we could do more? How could we make task flows even more re-usable than they are today? Well one great technique is to take advantage of a feature that is already present in the framework, a feature which I will call, for want of a better name, "adaptive bindings". What's an adaptive binding? well consider a simple use case.  I have several screens within my application which display tabular data which are all essentially identical, the only difference is that they happen to be based on different data collections (View Objects, Bean collections, whatever) , and have a different set of columns. Apart from that, however, they happen to be identical; same toolbar, same key functions and so on. So wouldn't it be nice if I could have a single parametrized task flow to represent that type of UI and reuse it? Hold on you say, great idea, however, to do that we'd run into problems. Each different collection that I want to display needs different entries in the pageDef file and: I want to continue to use the ADF Bindings mechanism rather than dropping back to passing the whole collection into the taskflow   If I do use bindings, there is no way I want to have to declare iterators and tree bindings for every possible collection that I might want the flow to handle  Ah, joy! I reply, no need to panic, you can just use adaptive bindings. Defining an Adaptive Binding  It's easiest to explain with a simple before and after use case.  Here's a basic pageDef definition for our familiar Departments table.  <executables> <iterator Binds="DepartmentsView1" DataControl="HRAppModuleDataControl" RangeSize="25"             id="DepartmentsView1Iterator"/> </executables> <bindings> <tree IterBinding="DepartmentsView1Iterator" id="DepartmentsView1">   <nodeDefinition DefName="oracle.demo.model.vo.DepartmentsView" Name="DepartmentsView10">     <AttrNames>       <Item Value="DepartmentId"/>         <Item Value="DepartmentName"/>         <Item Value="ManagerId"/>         <Item Value="LocationId"/>       </AttrNames>     </nodeDefinition> </tree> </bindings>  Here's the adaptive version: <executables> <iterator Binds="${pageFlowScope.voName}" DataControl="HRAppModuleDataControl" RangeSize="25"             id="TableSourceIterator"/> </executables> <bindings> <tree IterBinding="TableSourceIterator" id="GenericView"> <nodeDefinition Name="GenericViewNode"/> </tree> </bindings>  You'll notice three changes here.   Most importantly, you'll see that the hard-coded View Object name  that formally populated the iterator Binds attribute is gone and has been replaced by an expression (${pageFlowScope.voName}). This of course, is key, you can see that we can pass a parameter to the task flow, telling it exactly what VO to instantiate to populate this table! I've changed the IDs of the iterator and the tree binding, simply to reflect that they are now re-usable The tree binding itself has simplified and the node definition is now empty.  Now what this effectively means is that the #{node} map exposed through the tree binding will expose every attribute of the underlying iterator's collection - neat! (kudos to Eugene Fedorenko at this point who reminded me that this was even possible in his excellent "deep dive" session at OpenWorld  this year) Using the adaptive binding in the UI Now we have a parametrized  binding we have to make changes in the UI as well, first of all to reflect the new ID that we've assigned to the binding (of course) but also to change the column list from being a fixed known list to being a generic metadata driven set: <af:table value="#{bindings.GenericView.collectionModel}" rows="#{bindings.GenericView.rangeSize}"         fetchSize="#{bindings.GenericView.rangeSize}"           emptyText="#{bindings.GenericView.viewable ? 'No data to display.' : 'Access Denied.'}"           var="row" rowBandingInterval="0"           selectedRowKeys="#{bindings.GenericView.collectionModel.selectedRow}"           selectionListener="#{bindings.GenericView.collectionModel.makeCurrent}"           rowSelection="single" id="t1"> <af:forEach items="#{bindings.GenericView.attributeDefs}" var="def">   <af:column headerText="#{bindings.GenericView.labels[def.name]}" sortable="true"            sortProperty="#{def.name}" id="c1">     <af:outputText value="#{row[def.name]}" id="ot1"/>     </af:column>   </af:forEach> </af:table> Of course you are not constrained to a simple read only table here.  It's a normal tree binding and iterator that you are using behind the scenes so you can do all the usual things, but you can see the value of using ADFBC as the back end model as you have the rich pantheon of UI hints to use to derive things like labels (and validators and converters...)  One Final Twist  To finish on a high note I wanted to point out that you can take this even further and achieve the ultra-reusability I promised. Here's the new version of the pageDef iterator, see if you can notice the subtle change? <iterator Binds="{pageFlowScope.voName}"  DataControl="${pageFlowScope.dataControlName}" RangeSize="25"           id="TableSourceIterator"/>  Yes, as well as parametrizing the collection (VO) name, we can also parametrize the name of the data control. So your task flow can graduate from being re-usable within an application to being truly generic. So if you have some really common patterns within your app you can wrap them up and reuse then across multiple developments without having to dictate data control names, or connection names. This also demonstrates the importance of interacting with data only via the binding layer APIs. If you keep any code in the task flow generic in that way you can deal with data from multiple types of data controls, not just one flavour. Enjoy!

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• Supporting and testing multiple versions of a software library in a Maven project

  - by Duncan Jones

  My company has several versions of its software in use by our customers at any one time. My job is to write bespoke Java software for the customers based on the version of software they happen to be running. I've created a Java library that performs many of the tasks I regularly require in a normal project. This is a Maven project that I deploy to our local Artifactory and pull down into other Maven projects when required. I can't decide the best way to support the range of software versions used by our customers. Typically, we have about three versions in use at any one time. They are normally backwards compatible with one another, but that cannot be guaranteed. I have considered the following options for managing this issue: Separate editions for each library version I make a separate release of my library for each version of my company software. Using some Maven cunningness I could automatically produce a tested version linked to each of the then-current company software versions. This is feasible, but not without its technical challenges. The advantage is that this would be fairly automatic and my unit tests have definitely executed against the correct software version. However, I would have to keep updating the versions supported and may end up maintaining a large collection of libraries. One supported version, but others tested I support the oldest software version and make a release against that. I then perform tests with the newer software versions to ensure it still works. I could try and make this testing automatic by having some non-deployed Maven projects that import the software library, the associated test JAR and override the company software version used. If those projects build, then the library is compatible. I could ensure these meta-projects are included in our CI server builds. I welcome comments on which approach is better or a suggestion for a different approach entirely. I'm leaning towards the second option.

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• What makes Erlang suitable for cloud applications?

  - by Duncan

  We are starting a new project and implementing on our corporations's instantiation of an openstack cloud (see http://www.openstack.org/). The project is security tooling for our corporation. We currently run many hundreds of dedicated servers for security tools and are moving them to our corporations instantiation of openstack. Other projects in my company currently use erlang in several distributed server applications, and other Q/A point out erlang is used in several popular cloud services. I am trying to convince others to consider where it might be applicable on our project. What are erlang's strengths for cloud programming? Where are areas it is particularly appropriate to use erlang?

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• Controlling the Sizing of the af:messages Dialog

  - by Duncan Mills

  Over the last day or so a small change in behaviour between 11.1.2.n releases of ADF and earlier versions has come to my attention. This has concerned the default sizing of the dialog that the framework automatically generates to handle the display of JSF messages being handled by the <af:messages> component. Unlike a normal popup, you don't have a physical <af:dialog> or <af:window> to set the sizing on in your page definition, so you're at the mercy of what the framework provides. In this case the framework now defines a fixed 250x250 pixel content area dialog for these messages, which can look a bit weird if the message is either very short, or very long. Unfortunately this is not something that you can control through the skin, instead you have to be a little more creative. Here's the solution I've come up with.  Unfortunately, I've not found a supportable way to reset the dialog so as to say  just size yourself based on your contents, it is actually possible to do this by tweaking the correct DOM objects, but I wanted to start with a mostly supportable solution that only uses the best practice of working through the ADF client side APIs. The Technique The basic approach I've taken is really very simple.  The af:messages dialog is just a normal richDialog object, it just happens to be one that is pre-defined for you with a particular known name "msgDlg" (which hopefully won't change). Knowing this, you can call the accepted APIs to control the content width and height of that dialog, as our meerkat friends would say, "simples" 1 The JavaScript For this example I've defined three JavaScript functions.   The first does all the hard work and is designed to be called from server side Java or from a page load event to set the default. The second is a utility function used by the first to validate the values you're about to use for height and width. The final function is one that can be called from the page load event to set an initial default sizing if that's all you need to do. Function resizeDefaultMessageDialog() /**  * Function that actually resets the default message dialog sizing.  * Note that the width and height supplied define the content area  * So the actual physical dialog size will be larger to account for  * the chrome containing the header / footer etc.  * @param docId Faces component id of the document  * @param contentWidth - new content width you need  * @param contentHeight - new content height  */ function resizeDefaultMessageDialog(docId, contentWidth, contentHeight) {   // Warning this value may change from release to release   var defMDName = "::msgDlg";   //Find the default messages dialog   msgDialogComponent = AdfPage.PAGE.findComponentByAbsoluteId(docId + defMDName); // In your version add a check here to ensure we've found the right object!   // Check the new width is supplied and is a positive number, if so apply it.   if (dimensionIsValid(contentWidth)){       msgDialogComponent.setContentWidth(contentWidth);   }   // Check the new height is supplied and is a positive number, if so apply it.   if (dimensionIsValid(contentHeight)){       msgDialogComponent.setContentHeight(contentHeight);   } }  Function dimensionIsValid()  /**  * Simple function to check that sensible numeric values are   * being proposed for a dimension  * @param sampleDimension   * @return booolean  */ function dimensionIsValid(sampleDimension){     return (!isNaN(sampleDimension) && sampleDimension > 0); } Function  initializeDefaultMessageDialogSize() /**  * This function will re-define the default sizing applied by the framework   * in 11.1.2.n versions  * It is designed to be called with the document onLoad event  */ function initializeDefaultMessageDialogSize(loadEvent){   //get the configuration information   var documentId = loadEvent.getSource().getProperty('documentId');   var newWidth = loadEvent.getSource().getProperty('defaultMessageDialogContentWidth');   var newHeight = loadEvent.getSource().getProperty('defaultMessageDialogContentHeight');   resizeDefaultMessageDialog(documentId, newWidth, newHeight); } Wiring in the Functions As usual, the first thing we need to do when using JavaScript with ADF is to define an af:resource  in the document metaContainer facet <af:document>   ....     <f:facet name="metaContainer">     <af:resource type="javascript" source="/resources/js/hackMessagedDialog.js"/>    </f:facet> </af:document> This makes the script functions available to call.  Next if you want to use the option of defining an initial default size for the dialog you use a combination of <af:clientListener> and <af:clientAttribute> tags like this. <af:document title="MyApp" id="doc1">   <af:clientListener method="initializeDefaultMessageDialogSize" type="load"/>   <af:clientAttribute name="documentId" value="doc1"/>   <af:clientAttribute name="defaultMessageDialogContentWidth" value="400"/>   <af:clientAttribute name="defaultMessageDialogContentHeight" value="150"/>  ...   Just in Time Dialog Sizing  So  what happens if you have a variety of messages that you might add and in some cases you need a small dialog and an other cases a large one? Well in that case you can re-size these dialogs just before you submit the message. Here's some example Java code: FacesContext ctx = FacesContext.getCurrentInstance();          //reset the default dialog size for this message ExtendedRenderKitService service =              Service.getRenderKitService(ctx, ExtendedRenderKitService.class); service.addScript(ctx, "resizeDefaultMessageDialog('doc1',100,50);");          FacesMessage msg = new FacesMessage("Short message"); msg.setSeverity(FacesMessage.SEVERITY_ERROR); ctx.addMessage(null, msg);  So there you have it. This technique should, at least, allow you to control the dialog sizing just enough to stop really objectionable whitespace or scrollbars. 1 Don't worry if you don't get the reference, lest's just say my kids watch too many adverts.

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• ADF - Now with Robots!

  - by Duncan Mills

  I mentioned this briefly in a tweet the other day, just before the full rush of OOW really kicked off, so I though it was worth re-visiting. Check out this video, and then read on: So why so interesting? Well - you probably guessed from the title, ADF is involved. Indeed this is as about as far from the traditional ADF data entry application as you can get. Instead of a database at the back-end there's basically a robot. That's right, this remarkable tape drive is controlled through an ADF using all your usual friends of ADF Faces, Controller and Binding (but no ADFBC for obvious reasons). ADF is used both on the touch screen you see on the front of the device in the video, and also for the remote management console which provides a visual representation of the slots and drives. The latter uses ADF's Active Data Framework to provide a real-time view of what's going on the rack. . What's even more interesting (for the techno-geeks) is the fact that all of this is running out of flash storage on a ridiculously small form factor with tiny processor - I probably shouldn't reveal the actual specs but take my word for it, don't complain about the capabilities of your laptop ever again! This is a project that I've been personally involved in and I'm pumped to see such a good result and,  I have to say, those hardware guys are great to work with (and have way better toys on their desks than we do). More info in the SL150 (should you feel the urge to own one) is here. 

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• Selective Suppression of Log Messages

  - by Duncan Mills

  Those of you who regularly read this blog will probably have noticed that I have a strange predilection for logging related topics, so why break this habit I ask?  Anyway here's an issue which came up recently that I thought was a good one to mention in a brief post.  The scenario really applies to production applications where you are seeing entries in the log files which are harmless, you know why they are there and are happy to ignore them, but at the same time you either can't or don't want to risk changing the deployed code to "fix" it to remove the underlying cause. (I'm not judging here). The good news is that the logging mechanism provides a filtering capability which can be applied to a particular logger to selectively "let a message through" or suppress it. This is the technique outlined below. First Create Your Filter  You create a logging filter by implementing the java.util.logging.Filter interface. This is a very simple interface and basically defines one method isLoggable() which simply has to return a boolean value. A return of false will suppress that particular log message and not pass it onto the handler. The method is passed the log record of type java.util.logging.LogRecord which provides you with access to everything you need to decide if you want to let this log message pass through or not, for example  getLoggerName(), getMessage() and so on. So an example implementation might look like this if we wanted to filter out all the log messages that start with the string "DEBUG" when the logging level is not set to FINEST:  public class MyLoggingFilter implements Filter {     public boolean isLoggable(LogRecord record) {         if ( !record.getLevel().equals(Level.FINEST) && record.getMessage().startsWith("DEBUG")){          return false;            }         return true;     } } Deploying   This code needs to be put into a JAR and added to your WebLogic classpath.  It's too late to load it as part of an application, so instead you need to put the JAR file into the WebLogic classpath using a mechanism such as the PRE_CLASSPATH setting in your domain setDomainEnv script. Then restart WLS of course. Using The final piece if to actually assign the filter.  The simplest way to do this is to add the filter attribute to the logger definition in the logging.xml file. For example, you may choose to define a logger for a specific class that is raising these messages and only apply the filter in that case.  <logger name="some.vendor.adf.ClassICantChange"         filter="oracle.demo.MyLoggingFilter"/> You can also apply the filter using WLST if you want a more script-y solution.

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• Adaptive Connections For ADFBC

  - by Duncan Mills

  Some time ago I wrote an article on Adaptive Bindings showing how the pageDef for a an ADF UI does not have to be wedded to a fixed data control or collection / View Object. This article has proved pretty popular, so as a follow up I wanted to cover another "Adaptive" feature of your ADF applications, the ability to make multiple different connections from an Application Module, at runtime. Now, I'm sure you'll be aware that if you define your application to use a data-source rather than a hard-coded JDBC connection string, then you have the ability to change the target of that data-source after deployment to point to a different database. So that's great, but the reality of that is that this single connection is effectively fixed within the application right?  Well no, this it turns out is a common misconception. To be clear, yes a single instance of an ADF Application Module is associated with a single connection but there is nothing to stop you from creating multiple instances of the same Application Module within the application, all pointing at different connections.  If fact this has been possible for a long time using a custom extension point with code that which extends oracle.jbo.http.HttpSessionCookieFactory. This approach, however, involves writing code and no-one likes to write any more code than they need to, so, is there an easier way? Yes indeed.  It is in fact  a little publicized feature that's available in all versions of 11g, the ELEnvInfoProvider. What Does it Do?  The ELEnvInfoProvider  is  a pre-existing class (the full path is  oracle.jbo.client.ELEnvInfoProvider) which you can plug into your ApplicationModule configuration using the jbo.envinfoprovider property. Visuallty you can set this in the editor, or you can also set it directly in the bc4j.xcfg (see below for an example) . Once you have plugged in this envinfoprovider, here's the fun bit, rather than defining the hard-coded name of a datasource instead you can plug in a EL expression for the connection to use.  So what's the benefit of that? Well it allows you to defer the selection of a connection until the point in time that you instantiate the AM. To define the expression itself you'll need to do a couple of things: First of all you'll need a managed bean of some sort – e.g. a sessionScoped bean defined in your ViewController project. This will need a getter method that returns the name of the connection. Now this connection itself needs to be defined in your Application Server, and can be managed through Enterprise Manager, WLST or through MBeans. (You may need to read the documentation [http://docs.oracle.com/cd/E28280_01/web.1111/b31974/deployment_topics.htm#CHDJGBDD] here on how to configure connections at runtime if you're not familiar with this)   The EL expression (e.g. ${connectionManager.connection} is then defined in the configuration by editing the bc4j.xcfg file (there is a hyperlink directly to this file on the configuration editing screen in the Application Module editor). You simply replace the hardcoded JDBCName value with the expression.  So your cfg file would end up looking something like this (notice the reference to the ELEnvInfoProvider that I talked about earlier) <BC4JConfig version="11.1" xmlns="http://xmlns.oracle.com/bc4j/configuration">   <AppModuleConfigBag ApplicationName="oracle.demo.model.TargetAppModule">   <AppModuleConfig DeployPlatform="LOCAL"  JDBCName="${connectionManager.connection}" jbo.project="oracle.demo.model.Model" name="TargetAppModuleLocal" ApplicationName="oracle.demo.model.TargetAppModule"> <AM-Pooling jbo.doconnectionpooling="true"/> <Database jbo.locking.mode="optimistic">       <Security AppModuleJndiName="oracle.demo.model.TargetAppModule"/>    <Custom jbo.envinfoprovider="oracle.jbo.client.ELEnvInfoProvider"/> </AppModuleConfig> </AppModuleConfigBag> </BC4JConfig> Still Don't Quite Get It? So far you might be thinking, well that's fine but what difference does it make if the connection is resolved "just in time" rather than up front and changed as required through Enterprise Manager? Well a trivial example would be where you have a single application deployed to your application server, but for different users you want to connect to different databases. Because, the evaluation of the connection is deferred until you first reference the AM you have a decision point that can take the user identity into account. However, think about it for a second.  Under what circumstances does a new AM get instantiated? Well at the first reference of the AM within the application yes, but also whenever a Task Flow is entered -  if the data control scope for the Task Flow is ISOLATED.  So the reality is, that on a single screen you can embed multiple Task Flows, all of which are pointing at different database connections concurrently. Hopefully you'll find this feature useful, let me know... 

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• ADF Logging In Deployed Apps

  - by Duncan Mills

  Harking back to my series on using the ADF logger and the related  ADF Insider Video, I've had a couple of queries this week about using the logger from Enterprise Manager (EM). I've alluded in those previous materials to how EM can be used but it's evident that folks need a little help.  So in this article, I'll quickly look at how you can switch logging on from the EM console for an application and how you can view the output.  Before we start I'm assuming that you have EM up and running, in my case I have a small test install of Fusion Middleware Patchset 5 with an ADF application deployed to a managed server. Step 1 - Select your Application In the EM navigator select the app you're interested in: At this point you can actually bring up the context ( right mouse click) menu to jump to the logging, but let's do it another way.  Step 2 - Open the Application Deployment Menu At the top of the screen, underneath the application name, you'll find a drop down menu which will take you to the options to view log messages and configure logging, thus: Step 3 - Set your Logging Levels  Just like the log configuration within JDeveloper, we can set up transient or permanent (not recommended!) loggers here. In this case I've filtered the class list down to just oracle.demo, and set the log level to config. You can now go away and do stuff in the app to generate log entries. Step 4 - View the Output  Again from the Application Deployment menu we can jump to the log viewer screen and, as I have here, start to filter down the logging output to the stuff you're interested in.  In this case I've filtered by module name. You'll notice here that you can again look at related log messages. Importantly, you'll also see the name of the log file that holds this message, so it you'd rather analyse the log in more detail offline, through the ODL log analyser in JDeveloper, then you can see which log to download.

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• How to access WCF RIA service from Windows Service?

  - by Duncan Bayne

  I have a functioning SL4 application; inside the ClientBin directory I have an .svc file that describes my service: <% @ServiceHost Service="MyApp.Services.MyServiceFactory="System.ServiceModel.DomainServices.Hosting.DomainServiceHostFactory" %> When I browse to http://localhost:52878/ClientBin/MyApp-Services-MyService.svc I see the following: "You have created a service. To test this service, you will need to create a client and use it to call the service. You can do this using the svcutil.exe tool from the command line with the following syntax: svcutil.exe http://localhost:52878/ClientBin/MyApp-Services-MyService.svc?wsdl" I want to access that service from a Windows Service application. My understanding is that I need to enable SOAP end-points in order to make this happen. So, I add the following to my web.config file: <domainServices> <endpoints> <add name="soap" type="System.ServiceModel.DomainServices.Hosting.SoapXmlEndpointFactory, System.ServiceModel.DomainServices.Hosting, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> </endpoints> </domainServices> Firstly, Intellisense complains about the presence of the tag, saying "The element system.ServiceModel has invalid child element domainServices." Secondly, the aforementioned Silverlight application stops working, presumably because this change breaks the underlying web services. Thirdly, it appears that the System.ServiceModel.DomainServices.Hosting assembly doesn't actually contain the SoapXmlEndpointFactory type; if I try to browse to the service after adding the above to web.config I see: "Could not load type 'System.ServiceModel.DomainServices.Hosting.SoapXmlEndpointFactory' from assembly 'System.ServiceModel.DomainServices.Hosting, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'." If I inspect the assembly using Reflector, I see that it contains the DomainServiceEndpointFactory and PoxBinaryEndpointFactory types, but no SoapXmlEndpointFactory. Could someone please let me know what I'm doing wrong? I can't believe that it should be this hard to simply consume a WCF RIA service in something other than a Silverlight application! Yours, Duncan Bayne

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• Using NSNumberFormatter to get a decimal value from an international currency string

  - by Duncan A

  It seems that the NSNumberFormatter can't parse Euro (and probably other) currency strings into a numerical type. Can someone please prove me wrong. I'm attempting to use the following to get a numeric amount from a currency string: NSNumberFormatter *currencyFormatter = [[[NSNumberFormatter alloc] init] autorelease]; [currencyFormatter setNumberStyle:NSNumberFormatterCurrencyStyle]; NSNumber *currencyNumber = [currencyFormatter numberFromString:currencyString]; This works fine for UK and US currency amounts. It even deals with $ and £ and thousands separators with no problems. However, when I use it with euro currency amounts (with the Region Format set to France or Germany in the settings app) it returns an empty string. All of the following strings fail: 12,34 € 12,34 12.345,67 € 12.345,67 It's worth noting that these strings match exactly what comes out of the NSNumberFormatter's stringFromNumber method when using the corresponding locale. Setting the Region Format to France in the settings app, then setting currencyNumber to 12.34 in the following code, results in currencyString being set to '12,34 €' : NSNumberFormatter *currencyFormatter = [[[NSNumberFormatter alloc] init] autorelease]; [currencyFormatter setNumberStyle:NSNumberFormatterCurrencyStyle]; NSString *currencyString = [currencyFormatter stringFromNumber:currencyNumber]; It would obviously be fairly easy to hack around this problem specifically for the Euro but I'm hoping to sell this app in as many countries as possible and I'm thinking that a similar situation is bound to occur with other locales. Does anyone have an answer? TIA, Duncan

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• VPython in Eclipse - thinks it has the wrong architecture type.

  - by Duncan Tait

  Evening, So I've recently installed VPython on my MacBook (OS X, Snow Leopard) - and it works absolutely fine in IDLE and from the command line (interactive mode). However, eclipse has issues. Firstly it couldn't find it (which is a bit of an issue actually with all these 'easy install' python modules - when they don't tell you where they actually install to!) but I searched it out in the depths of Library\Frameworks... and added that to the System PYTHONPATH listbox in Eclipse. Now it can find it, but it says the following: Traceback (most recent call last): File "/Users/duncantait/dev/workspace/Network_Simulation/src/Basic/Net_Sim1.py", line 15, in <module> import visual File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/visual/__init__.py", line 59, in <module> import cvisual ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/visual/cvisual.so, 2): no suitable image found. Did find: /Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/visual/cvisual.so: mach-o, but wrong architecture I am guessing that VPython might not be built for a 64-bit architecture (Intel), but the fact remains that it works in both IDLE and command prompt... So there must be a way to configure Eclipse to run it right? (Wishful thinking). Thanks for any help! Duncan

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• Exception calling remote SOAP call from thread

  - by Duncan

  This is an extension / next step of this question I asked a few minutes ago. I've a Delphi application with a main form and a thread. Every X seconds the thread makes a web services request for a remote object. It then posts back to the main form which handles updating the UI with the new information. I was previously using a TTimer object in my thread, and when the TTimer callback function ran, it ran in the context of the main thread (but the remote web services request did work). This rather defeated the purpose of the separate thread, and so I now have a simple loop and sleep routine in my thread's Execute function. The problem is, an exception is thrown when returning from GetIMySOAPService(). procedure TPollingThread.Execute; var SystemStatus : TCWRSystemStatus; begin while not Terminated do begin sleep(5000); try SystemStatus := GetIMySOAPService().GetSystemStatus; PostMessage( ParentHandle, Integer(apiSystemStatus), Integer(SystemStatus), 0 ); SystemStatus.DataContext := nil; LParam(SystemStatus) := 0; except end; end; end; Can anyone advise as to why this exception is being thrown when calling this function from the thread? I'm sure I'm overlooking something fundamental and simple. Thanks, Duncan

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• JDeveloper and ADF at UKOUG

  - by Grant Ronald

  This year, Oracle ADF and JDeveloper has a big showing at the UKOUG (about 22 hours worth!!)- Europe's largest Oracle User Group.  There are three days packed with awesome ADF content delivered by some of the leading lights in ADF Developement including Duncan Mills, Frank Nimphius, Shay Shmeltzer, Susan Duncan, Lucas Jellema, Steven Davelaar, Sten Vesterli (and I'll be there as well!). Please make sure you refer to the official agenda for timings but an outline is here (if you think there are any sessions I have missed let me know and I will add them) Monday 10:00 - 10:45 - Deepdive into logical and physical data modeling with JDeveloper 10:00 - 12:15 - Debugging ADF Applications 12:15 - 13:15 - Learn ADF Task Flows in 60 Minutes 14:30 - 15:15 - ADF's Hidden Gem - the Groovy scripting language in Oracle ADF 15:25 - 16:10 - ADF Patterns for Forms Conversions 16:35 - 17:35 - Dummies Guide to Oracle ADF 16:35 - 17:35 - ADF Security Overview - Strategies and Best Practices 17:45 - 18:30 - A Methodology for Enterprise Applications with Oracle ADF Tuesday 09:00 - 10:00 - Real World Performance Tuning for Oracle ADF 11:15 - 12:15 - Keynote: Modern Development, Mobility and Rich Internet Applications 11:15 - 12:15 - Migration to Fusion Middleware 11g: Real world cases of Forms, ADF and Identity Management upgrades 14:40 - 15:20 - What's new in JDeveloper 11gR2 14:40 - 15:20 - Development Tools Roundtable 15:35 - 16:20 - ALM in Jdeveloper is exciting! 16:40 - 17:40 - Moving Oracle Forms to Oracle ADF: Case Studies Wednesday 09:00 - 10:00 - Building a Multi-Tasking ADF Application with Dynamic Regions and Dynamic Tabs 10:10 - 10:55 - Building Highly Reusable ADF Taskflows 12:30 - 13:30 - Design Patterns, Customization and Extensibility of Fusion Applications 14:25 - 15:10 - Continuous Integration with Hudson: What a year! 14:00 - 17:00 - Wednesday Wizardry with Fusion Middleware - Live application development demonstration with ADF, SOA Suite 15:20 - 16:05 - Adding Mobile and Web 2.0 UIs to Existing Applications - The Fusion Way  16:15 - 17:00 - Leveraging ADF for Building Complex Custom Applications

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• Creating Shared Wifi Connection on Windows 7 WITHOUT wep/wpa security?

  - by Duncan

  Ok, for some reason I just can't figure this out on Windows 7. Never had an issue with it on Windows XP, never tried in Vista. I realize that I need to create an Ad-Hoc setup which I can do. However I can't get it to share the wireless signal on my laptop. Even if I go into the adapter settings. I need (well, want) to connect my old Psion netBook to my home network and due to the wireless card, I can't have any form of security. Thanks in advance!

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• Automated software installation for MS Windows?

  - by Duncan Bayne

  I am currently setting up a Windows development environment (the whole Visual Studio 2010 stack plus plugins on top of Windows 7). This has got me wondering whether there's a Windows equivalent to what I do for dev environment setup in Ubuntu. It takes literally hours to get a dev environment set up in Windows, involving a lot of manual intervention. On Ubuntu, I have two shell scripts - one I run as root which configures the system using apt-get (amongst other things), one I run as me which configures my user account. Those scripts live in my private Subversion repository. To set up a dev environment from scratch requires five commands: sudo apt-get install -y subversion svn co http://svn.XXXX.XXX/personal/ cd personal sudo ./ubuntu_setup_root.sh ./ubuntu_setup_user.sh The only human intervention required is to pick a root password for MySQL. So it takes only a few minutes of human attention to go from a vanilla Ubuntu installation to a full development environment with the latest builds of everything, perfectly tailored down to shortcut keys and wallpaper. Is there an equivalent process for Windows? In an ideal world it'd be something trivially scriptable using C# Script or Powershell, which could live in source control & make use of a repository of ISOs downloaded from MSDN ...

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• SMTP host name vs. domain in "From:" address vis-a-vis Email Deliverability

  - by Jared Duncan

  I'm trying to implement (or make sure that I'm correctly following) email sending best practices to improve deliverability, but the role of the smtp server's host name vs the domain name of the From: email address seems to be unclear, even after reading dozens of people's articles/input. Specifically, I understand that to satisfy the reverse DNS check, there must be a PTR record for the IP address of the sending machine that yields a domain name that matches the host name of the sending machine / SMTP server. Some say it needs to match the one given by the "hostname" command, most say it's the one provided with the HELO / EHLO statement, and this guy even says they MUST be the same (according to / enforced by what, I don't know; that's only a minor point of confusion, anyhow). First, what I can't find anywhere is whether or not the domain name of the From: email address needs to match the domain name of the SMTP server. So in my case, I have a VPS with linode. It primarily hosts a particular domain of mine, example.com, but I also sometimes do work on other projects: foo.com and bar.com. So what I'm wondering is if I can just leave the default linode PTR record (which resolves to abc.def.linode.com), make sure that abc.def.linode.com is what my mail server (qmail) is configured to say at HELO, and then proceed to use it to send out emails for example.com, foo.com, et al. If so, then I am confused by the advice given here, specifically (in a listing of bad case scenarios): No SPF record for the domain being used in the HELO command Why would THAT domain need an SPF record? And if it does, which domain should it provide whitelisting for: the HELO domain, or the domain of the From: email address (envelope sender)? Also, which domain would need to accept mail sent to [email protected]? If the domains must be the same, that would seem rather limiting to me, because then for every domain you wanted to send email from, you'd have to get another IP address for it. It would also compromise or ruin one's ability to do non-email sending things (e.g. wget) relatively anonymously. However, the upside--if this is the case--is that it would make for a far less confusing setup. I'm currently using the linode.com SMTP+PTR domain and example.com From: address combination without much of any deliverability issue, but my volume is very low and I'd like to know if someone out there has experience with larger volumes and has specifically tested the difference and/or has inside knowledge and/or has an authoritative answer (and source) for this particular question. I'm happy to clarify anything, let me know. Thanks in advance.

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• Severe mysqldump performance degradation using Centos Linux, 8GB PAE and MySQL 5.0.77

  - by Duncan Harris

  We use MySQL 5.0.77 on CentOS 5.5 on VMWare: Linux dev.ic.soschildrensvillages.org.uk 2.6.18-194.11.4.el5PAE #1 SMP Tue Sep 21 05:48:23 EDT 2010 i686 i686 i386 GNU/Linux We have recently upgraded from 4GB RAM to 8GB. When we did this the time of our mysqldump overnight backup jumped from under 10 minutes to over 2 hours. It also caused unresponsiveness on our plone based web site due to database load. The dump is using the optimized mysqldump format and is spooled directly through a socket to another server. Any ideas on what we could do to fix gratefully appreciated. Would a MySQL upgrade help? Anything we can do to MySQL config? Anything we can do to Linux config? Or do we have to add another server or go to 64-bit? We ran a previous (non-virtual) server on 6GB PAE and didn't notice a similar issue. This was on same MySQL version, but Centos 4.4. Server config file: [mysqld] port=3307 socket=/tmp/mysql_live.sock wait_timeout=31536000 interactive_timeout=31536000 datadir=/var/mysql/live/data user=mysql max_connections = 200 max_allowed_packet = 64M table_cache = 2048 binlog_cache_size = 128K max_heap_table_size = 32M sort_buffer_size = 2M join_buffer_size = 2M lower_case_table_names = 1 innodb_data_file_path = ibdata1:10M:autoextend innodb_buffer_pool_size=1G innodb_log_file_size=300M innodb_log_buffer_size=8M innodb_flush_log_at_trx_commit=1 innodb_file_per_table [mysqldump] # Do not buffer the whole result set in memory before writing it to # file. Required for dumping very large tables quick max_allowed_packet = 64M [mysqld_safe] # Increase the amount of open files allowed per process. Warning: Make # sure you have set the global system limit high enough! The high value # is required for a large number of opened tables open-files-limit = 8192 Server variables: mysql> show variables; +---------------------------------+------------------------------------------------------------------+ | Variable_name | Value | +---------------------------------+------------------------------------------------------------------+ | auto_increment_increment | 1 | | auto_increment_offset | 1 | | automatic_sp_privileges | ON | | back_log | 50 | | basedir | /usr/local/mysql-5.0.77-linux-i686-glibc23/ | | binlog_cache_size | 131072 | | bulk_insert_buffer_size | 8388608 | | character_set_client | latin1 | | character_set_connection | latin1 | | character_set_database | latin1 | | character_set_filesystem | binary | | character_set_results | latin1 | | character_set_server | latin1 | | character_set_system | utf8 | | character_sets_dir | /usr/local/mysql-5.0.77-linux-i686-glibc23/share/mysql/charsets/ | | collation_connection | latin1_swedish_ci | | collation_database | latin1_swedish_ci | | collation_server | latin1_swedish_ci | | completion_type | 0 | | concurrent_insert | 1 | | connect_timeout | 10 | | datadir | /var/mysql/live/data/ | | date_format | %Y-%m-%d | | datetime_format | %Y-%m-%d %H:%i:%s | | default_week_format | 0 | | delay_key_write | ON | | delayed_insert_limit | 100 | | delayed_insert_timeout | 300 | | delayed_queue_size | 1000 | | div_precision_increment | 4 | | keep_files_on_create | OFF | | engine_condition_pushdown | OFF | | expire_logs_days | 0 | | flush | OFF | | flush_time | 0 | | ft_boolean_syntax | + -><()~*:""&| | | ft_max_word_len | 84 | | ft_min_word_len | 4 | | ft_query_expansion_limit | 20 | | ft_stopword_file | (built-in) | | group_concat_max_len | 1024 | | have_archive | YES | | have_bdb | NO | | have_blackhole_engine | YES | | have_compress | YES | | have_crypt | YES | | have_csv | YES | | have_dynamic_loading | YES | | have_example_engine | NO | | have_federated_engine | YES | | have_geometry | YES | | have_innodb | YES | | have_isam | NO | | have_merge_engine | YES | | have_ndbcluster | DISABLED | | have_openssl | DISABLED | | have_ssl | DISABLED | | have_query_cache | YES | | have_raid | NO | | have_rtree_keys | YES | | have_symlink | YES | | hostname | app.ic.soschildrensvillages.org.uk | | init_connect | | | init_file | | | init_slave | | | innodb_additional_mem_pool_size | 1048576 | | innodb_autoextend_increment | 8 | | innodb_buffer_pool_awe_mem_mb | 0 | | innodb_buffer_pool_size | 1073741824 | | innodb_checksums | ON | | innodb_commit_concurrency | 0 | | innodb_concurrency_tickets | 500 | | innodb_data_file_path | ibdata1:10M:autoextend | | innodb_data_home_dir | | | innodb_adaptive_hash_index | ON | | innodb_doublewrite | ON | | innodb_fast_shutdown | 1 | | innodb_file_io_threads | 4 | | innodb_file_per_table | ON | | innodb_flush_log_at_trx_commit | 1 | | innodb_flush_method | | | innodb_force_recovery | 0 | | innodb_lock_wait_timeout | 50 | | innodb_locks_unsafe_for_binlog | OFF | | innodb_log_arch_dir | | | innodb_log_archive | OFF | | innodb_log_buffer_size | 8388608 | | innodb_log_file_size | 314572800 | | innodb_log_files_in_group | 2 | | innodb_log_group_home_dir | ./ | | innodb_max_dirty_pages_pct | 90 | | innodb_max_purge_lag | 0 | | innodb_mirrored_log_groups | 1 | | innodb_open_files | 300 | | innodb_rollback_on_timeout | OFF | | innodb_support_xa | ON | | innodb_sync_spin_loops | 20 | | innodb_table_locks | ON | | innodb_thread_concurrency | 8 | | innodb_thread_sleep_delay | 10000 | | interactive_timeout | 31536000 | | join_buffer_size | 2097152 | | key_buffer_size | 8384512 | | key_cache_age_threshold | 300 | | key_cache_block_size | 1024 | | key_cache_division_limit | 100 | | language | /usr/local/mysql-5.0.77-linux-i686-glibc23/share/mysql/english/ | | large_files_support | ON | | large_page_size | 0 | | large_pages | OFF | | lc_time_names | en_US | | license | GPL | | local_infile | ON | | locked_in_memory | OFF | | log | OFF | | log_bin | OFF | | log_bin_trust_function_creators | OFF | | log_error | | | log_queries_not_using_indexes | OFF | | log_slave_updates | OFF | | log_slow_queries | OFF | | log_warnings | 1 | | long_query_time | 10 | | low_priority_updates | OFF | | lower_case_file_system | OFF | | lower_case_table_names | 1 | | max_allowed_packet | 67108864 | | max_binlog_cache_size | 4294963200 | | max_binlog_size | 1073741824 | | max_connect_errors | 10 | | max_connections | 200 | | max_delayed_threads | 20 | | max_error_count | 64 | | max_heap_table_size | 33554432 | | max_insert_delayed_threads | 20 | | max_join_size | 18446744073709551615 | | max_length_for_sort_data | 1024 | | max_prepared_stmt_count | 16382 | | max_relay_log_size | 0 | | max_seeks_for_key | 4294967295 | | max_sort_length | 1024 | | max_sp_recursion_depth | 0 | | max_tmp_tables | 32 | | max_user_connections | 0 | | max_write_lock_count | 4294967295 | | multi_range_count | 256 | | myisam_data_pointer_size | 6 | | myisam_max_sort_file_size | 2146435072 | | myisam_recover_options | OFF | | myisam_repair_threads | 1 | | myisam_sort_buffer_size | 8388608 | | myisam_stats_method | nulls_unequal | | ndb_autoincrement_prefetch_sz | 1 | | ndb_force_send | ON | | ndb_use_exact_count | ON | | ndb_use_transactions | ON | | ndb_cache_check_time | 0 | | ndb_connectstring | | | net_buffer_length | 16384 | | net_read_timeout | 30 | | net_retry_count | 10 | | net_write_timeout | 60 | | new | OFF | | old_passwords | OFF | | open_files_limit | 8192 | | optimizer_prune_level | 1 | | optimizer_search_depth | 62 | | pid_file | /var/mysql/live/mysqld.pid | | plugin_dir | | | port | 3307 | | preload_buffer_size | 32768 | | profiling | OFF | | profiling_history_size | 15 | | protocol_version | 10 | | query_alloc_block_size | 8192 | | query_cache_limit | 1048576 | | query_cache_min_res_unit | 4096 | | query_cache_size | 0 | | query_cache_type | ON | | query_cache_wlock_invalidate | OFF | | query_prealloc_size | 8192 | | range_alloc_block_size | 4096 | | read_buffer_size | 131072 | | read_only | OFF | | read_rnd_buffer_size | 262144 | | relay_log | | | relay_log_index | | | relay_log_info_file | relay-log.info | | relay_log_purge | ON | | relay_log_space_limit | 0 | | rpl_recovery_rank | 0 | | secure_auth | OFF | | secure_file_priv | | | server_id | 0 | | skip_external_locking | ON | | skip_networking | OFF | | skip_show_database | OFF | | slave_compressed_protocol | OFF | | slave_load_tmpdir | /tmp/ | | slave_net_timeout | 3600 | | slave_skip_errors | OFF | | slave_transaction_retries | 10 | | slow_launch_time | 2 | | socket | /tmp/mysql_live.sock | | sort_buffer_size | 2097152 | | sql_big_selects | ON | | sql_mode | | | sql_notes | ON | | sql_warnings | OFF | | ssl_ca | | | ssl_capath | | | ssl_cert | | | ssl_cipher | | | ssl_key | | | storage_engine | MyISAM | | sync_binlog | 0 | | sync_frm | ON | | system_time_zone | GMT | | table_cache | 2048 | | table_lock_wait_timeout | 50 | | table_type | MyISAM | | thread_cache_size | 0 | | thread_stack | 196608 | | time_format | %H:%i:%s | | time_zone | SYSTEM | | timed_mutexes | OFF | | tmp_table_size | 33554432 | | tmpdir | /tmp/ | | transaction_alloc_block_size | 8192 | | transaction_prealloc_size | 4096 | | tx_isolation | REPEATABLE-READ | | updatable_views_with_limit | YES | | version | 5.0.77 | | version_comment | MySQL Community Server (GPL) | | version_compile_machine | i686 | | version_compile_os | pc-linux-gnu | | wait_timeout | 31536000 | +---------------------------------+------------------------------------------------------------------+ 237 rows in set (0.00 sec)

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