smallwiki April 2007

smallwiki@list.inf.unibe.ch

24 participants
30 discussions

by Lukas Renggli

Hi Martial, > As a newbie in Magritte, I don't understand well how the new widgets > work in Pier. For my personal web site I'm programming in Pier, I > created a PRBoxWidget instance to encapsulate other widgets. widgets are essentially just Seaside components, but instead of #renderContentOn: you override #renderWidgetOn:. They also provide a settings command so that administrators can configure them from the web. It is also possible to plug in any Seaside component, e.g. the Sushi Store, but these are not configurable from the web. > In my case, I like to have two instances of my site main class in > my disptacher: > one for admin displaying everything and one for everybody with only a > PRSearchWidget and a PRTree (no commands, no views); each one pointing > to the same kernel. So until you don't know the url to access to the > admin path you don't see the 'login' link. > > I did this using: > > PRBoxWidget subclass: #MyNavigationWidget > instanceVariableNames: 'adminPool userPool' ...etc > > MyNavigationWidget>>#renderContentOn: > self adminConfigFlag ifTrue: > [adminPool do: [:ea | html render: ea] separatedBy: [html > break]] > ifFalse: > [userPool... > > > with adminConfigFlag being a simple boolean in the associated > WAConfiguration.. > > MyNavigationWidget>>#initialize > super initialize. > adminPool := Array with: PRTreeWidget new with: PRCommandsWidget > new with: PRViewsWidget. > userPool := Array with: PRTreeWidget new with: PRSearchWidget > > Not a beautiful OO way to do things but it worked. But now I am a bit > lost. If you understand what I mean (and you have time), I'll be glad > you shortly explain where to look for to change this in the new way > because now it doesn't work. The new way? I guess I didn't change anything special there, just the way components get initialized using Magritte? If this breaks something this was not intentional. Maybe you need to reset the settings of the widgets. > It's maybe a easy task to do but I don't know how to rethink my > interface. Did my latest changes break something in particular? Do you have a stack trace? What is the particular problem? > PS: great change in visitParagraph: . It's cool. I did those kinds of > modification in order to avoid a <div class='paragraph'> in the > start of > the default page (as I need to manage two absolute divs). Your way > is better. Thanks. I wanted to blog about that. This is absolutely needed to create sophisticated CSS layouts ... Cheers, Lukas -- Lukas Renggli http://www.lukas-renggli.ch

17 years, 8 months

Inquiry: Widgets

by Lukas Renggli

Hi, I would like to ask a question to the Pier users before doing a change to the Pier widgets: Currently every widget has its own hardcoded <div class="[custom_classes]" id="[custom_id]"> around itself and it also emits a <h1>. I am currently building some new sites and these <div> and <h1> tags rather hurt than help. I wonder if we shouldn't get rid of those <div> and <h1> altogether? I guess this is sort of a relict from SmallWiki where there were no environments. Nowadays designers can add <div> (or other tags) around a widget within the environment if necessary. There is no need to write Smalltalk for that anymore. Does that make sense? Lukas -- Lukas Renggli http://www.lukas-renggli.ch

17 years, 8 months

MAAdaptiveModel

by Chad Nantais

I am creating a model class that only has a few core attributes and will allow the user to create descriptions through a description editor. Is subclassing MAAdaptiveModel a smart alternative to using customDescription on the class side (as seen in Exercise 18 in magritte-solutions.pdf)? Thanks, Chad

17 years, 8 months

Pier Unix style security: how do I let users login 'on the fly'?

by Matthias Berth

Hello, I want to let users click on a URL, like mysite.com/seaside/pier/welcome/do_something?param1=xyz where viewing do_something needs a login and a parameter. If they are not logged in yet, I want them to login, using the PULogin command, and then do_something should be executed (without needing another click . What I do now is: mysite.com/seaside/pier/welcome?command=DoSomethingCommand&param1=xyz By changing the start: method I can let the command (my own PRCommand subclass DoSomethingCommand) capture the parameter param1 in an instance variable. I know that I can check context isLoggedIn inside DoSomethingCommand>>doValidate. But how do I transfer control to the PULogin command to give the user a login page, and then get back to do the rest of the validation for my command? Any pointers will be greatly appreciated :-) Matthias

17 years, 8 months

Magma-Pier documentation

by Keith Hodges

Magma-Pier documentation --------------------------------------------- Magma provides a virtually transparent persistency mechanism, in which the application, in this case Pier, need hardly be aware of the fact that not all of the objects which it uses are kept in memory all of the time. As far as Pier is concerned Magma will stub out objects in memory, and load them in, a process termed reifying, or reification, as needed, entirely transparently. Pier provides very controlled access to its model, including awareness of persistency issues, so it makes sense to make use of this in the Pier-Magma integration. However, Pier will have to curb its tendency to traverse its entire model for some of its operations (e.g. page removal) in order to play sensibly and scalably in a Pier-Magma installation. The Database Structure =============== The root of the Magma database is an instance of PRMagmaRepository. This is a minimal root object designed with the intention of being able to merge with root objects from other projects. For example GJallar will have a root object of its own. To adopt or merge with Pier's requirements, all that is needed is for their root object to have an accessor #pier, onto a standard Dictionary. PRMagmaRepository is a subclass of PRObject, and so has properties by default, if you can think of a reason or need to use them they are there but they are not currently used. When running Seaside-Magma-Pier, the aforementioned Dictionary in the root of the database is directly available from the Seaside session via the convenience method #pierPersistencies. (in the latest version, previously it was just #pier) "session pierPersistencies", yields a dictionary of, PRMagmaPersistency instances, keyed by PRKernel name, so to obtain the PRKernel instance of your choice: (session pierPersistencies at: 'MyPier') kernel This does the job fairly logically. ReadStrategies in Magma-Seaside ===================== The root object of the repository also provides the Magma read strategy for the repository via #buildReadStrategyOn: . A ReadStrategy tells Magma how many objects to load in simultaneously. For example, in Pier we tell Magma to reify all of the objects in a PRDocument structure in one database access/hit, since we will need them all to display or process the page. For more details about the Pier read strategy see below. This functionality, whereby the root object supplies the database read-strategy, is provided in WAReadStrategyDefault as a standard way of providing a read strategy for seaside applications in the package Magma-Seaside. There is an alternative WAMagmaReadStrategyWithLogging which provides some logging features, and this can be selected in the application configuration by over-riding the 'read strategy' setting. Logging is invaluable in fine-tuning Magma read strategies. Magma and Seaside Sessions ================== Since Pier manages its own model locking, it is perfectly ok to share a single Magma session between all seaside sessions. This functionality is provided by WAMagmaSharedSession. Other Seaside applications (Gjallar again!) have more complex arrangements using session-pools, but the basic WAMagmaSharedSession provided in the Magma-Seaside package is fine for Pier. When running using WAMagmaSharedSession a single Magma session is opened for each application (#obtainMagmaSession), and is available from the seaside session via #magmaSession. The root of the database from the magmaSession obtained via #root. The Pier-Magma package defines the convenience method #pierPersistencies as already mentioned. Pier-Magma Integration =============== The model locking performed by Pier is handled by the persistency scheme, PRPersistency and its subclasses. The default #execute: method is: PRPersistency-i-#execute: aCommand self mutex critical: [ self apply: aCommand ]. The change required to support Magma is minimal: PRMagmaPersistency-i-#execute: aCommand self mutex critical: [ self session commit: [ self apply: aCommand ] ] Thats it! What is In memory vs What is in the DB ========================= When using PRMagmaPersistency, the master list of PRKernel instances, kept in PRKernel-instances, contains a 'stub'. This is an instance of PRKernel, having #persistency as an instance of PRMagmaPersistency (also a stub), but no data, i.e. #root is nil. Whenever Pier wishes to obtain the real object, which is in the database, it calls, #realize on the stub, which calls #realizeKernel on its (stub) PRMagmaPersistency, returning the real PRKernel object, with a non-nil root, from the database. The real PRKernel object, also has a real #persistency, which is what is used to perform commands and logging etc. [The model locking mutex which is used at present is the one in the persisted PRMagmaPersistency, if this causes problems, then it will be possible to use the mutex in the memory resident (stub) PRMagmaPersistency instead]. Behind The Scenes - Saving The Model ======================== Before persisting some objects, Magma calls #maPreserialize. [ I am warned that this approach may be deprecated in the future! -- kph ]. This is used: 1) to remove the mutex from PRPersistency (Disabled at present. The mutex used to be in PRKernel and was lazily initialized, so removing it before persisting was fine, it would just be reinstated when next used. If it becomes necessary to re-enable this, then we will have to see about asking Lukas to lazily initialize the mutex once more) 2) To remove any decorations of PRChildren if they are empty. The current model implementation should not be creating empty PRChildren decorations anyway, but this is just in case. 3) Context's are tidied up before they are persisted. Properties are removed, and commands are copied, and command's answers are copied. This is to support logging. Behind the scenes - loading the model ======================== This is the read strategy that Magma-Pier uses at present: strategy minimumDepth: 0; "forVariableNamed: 'pier' onAny: PRMagmaRepository readToDepth: 2 ;" forVariableNamed: 'kernel' onAny: PRPersistency readToDepth: 1; onAny: PRKernel readToDepth: 1 ; forVariableNamed: 'decorations' onAny: PRDecorated readToDepth: 1; forVariableNamed: 'title' onAny: PRStructure readToDepth: 1; forVariableNamed: 'children' onAny: PRChildren readToDepth: (self readPathSkeletonInOneHit ifTrue: [ 1 ] ifFalse: [ 0 ]); onAny: PRDocumentItem readToDepth: 1; "reads all page items in one hit" onAny: PRComponent readToDepth: 1; yourself. If the flag #readPathSkeletonInOneHit is set, Magma, realizes all of the tree of objects necessary to resolve a url-path, in one database access cycle/hit. Depending upon other settings, this data may remain in memory. Otherwise, resolving a url-path occurs one level at a time. As you would expect the items required to display a page, are loaded in one hit. The ideal situation would be to have a path lookup cache which can perform the path look-up in one hit, and possibly obtain the whole page data in the same hit. This should be relatively straight forward, using an indexed MagmaCollection. Logging ===== The logging implementation used in PRImagePersistency has changed since the Pier-Magma integration was written, and so it follows the previous implementation. It stores a snapshot of the original data-structure, together with a collection of the context/commands that are applied to it. (it probably isnt working as intended at the moment, review required) ====== feedback comments to keith_hodges(a)yahoo.co.uk

17 years, 8 months

Pier-Magma

by Keith Hodges

The Second Chapter ============= Configuring Pier to work with Magma Step 1. Add WAMagmaConfiguration to your pier app - In /seaside/config application, click on the 'configure' link next to your pier application. - From the drop down menu named 'Add Ancestor', select 'WAMagmaConfiguration' and click the 'Add' button. - (optional step) to be tidy, click the '(remove)' link next to 'WARenderLoopConfiguration', since WAMagmaConfiguration includes this anyway. Step 2. Set the session class to 'WAMagmaSharedSession' - In the general config section, in the line entitled 'Session Class' click the 'overide' link. - From the drop down menu which appears next to 'Session Class' select 'WAMagmaSharedSession'. Step 3. (optionally) Set the location of the magma repository. - The default is set to use a directory named 'magma' in the image default directory. - overriding this setting to choose an alternative directory, or a remote magma server. Step 4. Save Changes and Close. - click the 'Save' button at the bottom of the configuration page. - click the 'Close' button to return to the dispatcher editor. Notice the appearance of a link next to the 'pier' application, 'magma'! Step 5. Create the magma repository for pier. Enter the control panel for magma using the 'magma' link next to your pier app. The top panel should report an error, (i.e. there is no database yet) * Repository path setting: *magma * Error: /media/hda1/squeak/pr_gsoc/magma/objects not found.* At present this magma control panel is application agnostic, it doesnt know anything about pier, hence you have to explicitly choose what class of root object the database should be created with. (Some magma-seaside users e.g. Gjallar, just have the app initialize the database automatically when it is not found) - To create a repository for pier in the directory specified, choose the class of the desired repository, in this case a 'PRMagmaRepository', click the 'create' button. On returning you will see something like this. *Repository Path Setting: *magma (delete) <http://localhost:8080/seaside/config?_k=NWNtlOJe&_s=lklgPNPlHkbrjqJQ&2> *Persisted Objects Count: *569 *Session Id: *2 *Cached Object Count: *670 *ReadStrategy: *a WAMagmaReadStrategyDefault *Root Object: *a PRMagmaRepository (explore) <http://localhost:8080/seaside/config?_k=NWNtlOJe&_s=lklgPNPlHkbrjqJQ&3> The 'delete' link will delete the repository and start again. The 'explore' link, is similar to the seaside 'debug' link, it opens an explorer in squeak on the root db object. Step 6. Returning to the seaside/config app, click the 'pier' link to obtain the pier persistency manager. There you will find a ui for changing which kernel is served* and its persistency scheme. *the 'serve all kernels' option needs the class PRMainAllKernels which is not loaded Switching from PRNullPersistency to PRMagmaPersistency is all that is required. Then click the 'migrate' button, and later 'commit' the change.

17 years, 8 months

Pier and Magma

by Alexander Lazarevic'

Hi, I've played with pier using the image from [1] mentioned today in [2]. This does contain magritte, pier and magma. It seems Pier does not use magma by default. Is there some description of how to make pier use magma for persistence? Alex [1]http://squeak.warwick.st/auto-build/output/make/391/LATEST/SMP/ [2]http://lists.squeakfoundation.org/pipermail/seaside/2007-April/011685.html

17 years, 8 months

Magma-Pier

by Keith Hodges

Greetings! My error was in attempting to run pier with magritte still 30 versions behind. Now that I have tested it with an up-to-date magritte, the seaside-magma-pier instructions that I have previously posted to the smallwiki mailing list should now work. In summary: 1) Load seaside and pier as usual, update to at least Seaside 2.7a1-kph.214 because that has a small fix in it. 2) Load the latest Magma from squeaksource project, MagmaTester, package MagmaServerLoader. 3) Load Pier-Magma, and Pier-PersistencyManager packages Everything has a UI from there. Configure your app to have WAMagmaConfiguration, and WAMagmaSharedSession. Use the 'magma' dispatcher editor plugin link to initialize the database, and the 'pier' dispatcher editor plugin link to switch your pier kernel between persistency schemes. (i.e. to turn PRMagmaPersistency on/off). best regards Keith

17 years, 8 months

Magma-Pier

by Keith Hodges

I am sending detailed instructions to the list for building and configuring a seaside magma pier image. There is just one slight snag, I haven't got it working with the latest pier yet. When I do I will also provide a preloaded image. regards Keith ======== The first chapter! Preparing a Seaside-Magma-Pier image from scratch. Their follows an Installer script that you can use to build an image or compare with your current image to see if it contains the required components. (this should potentially work in 3.7, 3.8, 3.9, 3.9 KernelImage or 3.10): ----------- Obtain latest Installer-Core from http://www.squeaksource.com/Installer ----------- "Image building script (execute in a workspace):" squeakmap := Installer websqueakmap. squeaksource := Installer squeaksource. lukas := Installer repository: 'http://mc.lukas-renggli.ch/'. "install some pre-requisites" squeakmap install: 'DynamicBindings'. squeakmap install: 'KomServices'. squeakmap install: 'KomHttpServer'. xmlparser := squeaksource project: 'XMLSupport'. xmlparser install: 'XML-Parser-mir.9'. seaside := squeaksource project: 'Seaside'. seaside answer: '*administrator*' with: 'seaside'; answer: '*config*' with: 'seaside'; answer: '*password*' with: 'admin'. "install latest seaside and scriptaculous" seaside install: 'Seaside2.7a1-kph.214'; install: 'Scriptaculous'. "install latest magma" magma := squeaksource project: 'MagmaTester'. magma install: 'MagmaServerLoader'; install: 'Magma seaside'; install: 'Magma sunit'. magma install: 'Seaside-Examples-Store-Magma'. "install latest magritte and pier" lukas answer: 'Would you like*' with: true; answer: '*name of your Pier kernel*' with: 'Pier 1.0.5 SMP'; answer: '*entry point*' with: 'pier'; answer: '*pplication*' with: true. lukas project: 'magritte'; install: 'Magritte-All'. lukas project: 'pier'; install: 'Pier-All'; install: 'Pier-Magma'; install: 'Pier-PersistencyManager'. "optional" "lukas install: 'Pier-Security'. "

17 years, 8 months

latest Pier and Seaside 2.8

by Brad Fuller

I noticed that newer Pier and Magritte-Seaside commits in MC have a few comments about being "for very latest Seaside." I assume that this means Seaside 2.8. First, it would be nice if the exact version was stated in the comments so we could tell what "very latest" means :-). Second: are these _only_ for Seaside 2.8, or will they work in 2.7? If not, it would be best if these could be labeled to reflect their exclusivity. ( I didn't see that this has been discussed before.) brad -- brad fuller http://www.Sonaural.com/ +1 (408) 799-6124

17 years, 8 months

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smallwiki April 2007