PHP programming

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Blocksare the brains behind magento's templating scheme.Blocks for anested set of objects that coordinate the modelswith the templatefiles. Each block controls one template file: a simple html and phpmixed file with a .phtml extension.




Allblocks extend the base class Mage_Core_Block_Template, which inturn,extends Mage_Core-Block_Abstract. The chiefmethod of a blockis its toHtml() method.This method translates the block's templatefile into html using the renderView()method.




The roleof a resource in magento is to manage databaseconnnections.Resources are defined under the globla xml tagof anyconfig.xml file.




Magentowidgets are magento extensions with a predefined set ofconfiguration options.


And database change you make should bescripted; this includes schema and data changes.Magentowill get acollection of all the setup resource and their corresponding moduleversion numbers from the config,xml files.


Magento will then go to the core_resourcetable and get a collection of all the setup resourceand theirversion numbers stored in the table.


If the setup resource does not exist inthe core_resource table, it will run an installscript.
If the resource version in the databaseis less than the one in the config.xml files. Itwill run one tomant update scripts.If the resource version in the database isgreater than the one In the config.xml file, it will ruan arollback script.


A node is an abstract object that maycontain data and may have relationship to othernodes.


variable_get() function is a wrapperfunction for reading the global $conf variable.Joomlaoperatedsdirectly with the PHP language and the joomla application itself isa framework of php classes. By addressing some of the joomlaobjects such as Jdocument and JdocumentHTML in your templates code,you can render output of modules and components, as wellasretrieve information about the current executionenvironment.




The function you used in the basictemplate called the include method of the jdoc object.TheJdocument class is the class that you will spend most of your timecalling.There is one primary function or method within jdoc that isused within a template:include.


Patterns that are classified ascreational related to the mechanisms of the creation ofobjects.


All APIs need to accept request.Typically, with a RESTful API, you will have a well-definedURLscheme.


Dijit, the widget system built on Dojo,can do the heavy lifting for you. A widget, alsocalled a Dijitcomponent, Is a user interface control build from html andjavascript. You create one by adding a simple dojoType = attributeto an html tag.




Dojo's remote scripting facilities enablea client-side script to communicate with a serverwithout a pagereload.dojo.data is an api specification like jdbc or odbc. Adojo.data driver implements this specification and responds torequests from your data-enabled widgets or javascriptcode.


Every object in javascript contains areference to another object termedd its prototype.Sincetheprototype is another object itself,it also contains a reference toits prototype.This forms a chain of objects. The chain terminateswith the prototype for the build-in Objecttype.




When dojo.connect is used to connect ahandler to a trigger function, then handler is automaticallyinvokedafter the trigger function completes and is passed the samearguments that were provided to the triggerfunction.






In thepublish-subscribe pattern, serveral functions register theirinterest in a topic. The function dojo.query takesa css selectorand returns an array of nodes that match the selector. The array ofnodes is returned in a Dojo NodeListobject.




Event injavascript or dojo based applications are essential to makingapplications work.Connecting an event handlerto an element or anobject is one of the most common things you will do when developingapplications using dojo. The dojo.io package provides portable codefor xmlhttp and other, more complicated, transportmechanism.




You canalso link from a view to another view ,using the link_tomethod,which creates hyperlinks.