=head1 NAME Jifty::Manual::Glossary - The Jifty dictionary =head1 GLOSSARY We use words. This is what they mean. =over 4 =item action An B is a specifically designed RPC call that can do something to the system, with any number of declared Ls. At runtime, an action can take Ls, which it Ls, Ls, and then uses to do something useful. Each action has a L. See L and L. =item active For an L to run, it needs to be B. Most of the time, all actions submitted are active, but it is possible to specify only a specific action as active; any non-active actions are ignored. See L. =item AJAX An acronym standing for B. Though technically incorrect, it is the buzzword that describes doing asynchronous requests to the server while the user waits. This can lead to very "dynamic" pages, as the browser does not need to refresh the entire page to update a small section of the screen. In Jifty, the sections of the screen are called Ls. See L. =item argument An B is a user-supplied input to fill in a L in an L. See L. =item canonicalize To turn an L into a more standard form. For instance, a canonicalizer could translate a user-typed date into a date object or a SQL-formatted date string. See L. =item collection A B is a class representing all or a subset of the records stored in the database regarding a particular L. See L. =item constructor A property of a L; the action B have an argument value for this parameter in order to be constructed. This is different from L, in that the user can leave mandatory fields empty. For instance, the C of a L is a constructor. See L. =item continuation A concept stolen from Lisp, Scheme, Smalltalk, and Perl 6. The continuation of any particular piece of code is the deferred operations that care about the return value at that point. In the context of Jifty, a continuation is a deferred L that may pull Ls and the like from the Ls of the current request. Continuations can be arbitrarily nested, so they are often useful to keep track of tangents that the user went on. See L. =item database version The B is the L last installed or updated in the application's database. In general, the database version will always match the schema version. The exception is when Jifty is updated to a new schema version, your application updates to a new schema version, or a plugin updates to a new schema version. When this happens, you must L your database so that the database versions and schema versions match before running your application. =item form field A widget which the browser renders. These are generally useful to ask the user for a value for an L to an L. See L. =item fragment A section of HTML (at present, a Mason component) contained in a L. Fragments are a kind of standalone Mason component which the browser can request individually. Because of this, they can only take strings and scalars as arguments, not references or objects! =item element A Mason component used by one or more other pages, which is not a whole page of itself. As opposed to L C are strictly internal, and never visible to the outside world by themselves. Elements typically live under a path beginning with or containing '/_elements'. This, and the whole idea of an element is strictly convention, but Jifty contains elements for things like page headers, menus, and showing keybindings out of the box to make your life easier. =item mandatory A property of a L; the user must enter a value for the action to validate. This is the simplest level of L. =item model Jifty uses L to store its data (though might use other storage tools at some later time). The B defines the L and provides a package for creating, reading, updating, and deleting records stored in the database. The model is generally a subclass of L. Access multiple items from a model is performed through a L. =item moniker Every instance of a L has a B. Monikers serve as identifiers for actions, to associate arguments with actions and to access specific actions "by name". Monikers need not be globally unique, but they must be unique within a single request. Monikers have no semantic meaning. See L A moniker is an arbitrary-length nonempty string containing no semicolons. It may not begin with a digit. =item parameter A B is a named parameter to an L. Jifty generally renders these on the screen as Ls. See L and L. =item region An area of the page which JavaScript can replace. The content in the region is a L. Think of the region as the box and the fragment as the content in the box. See L. =item request A single query which lists Ls to run, together with a page or list of Ls to return. This most often comes from the browser as query parameters, but may come from other sources as a L or L POST request. The answer to a request is a L. See L. =item response The answer to a L, it contains a L for every action that ran. See L. =item result The answer to a L, it contains information about if the action was a success or failure, and further detail about why or how. It can also contain arbitrary "content". See L. =item return After performing a L a user may perform a L to invoke the L created by the original tangent. =item schema The B for a L represents the structure of the data stored in an individual item in that model's L. See L. =item schema version The B is a number in L object used to determine which L your application code is expecting to use. There are three places where the schema version is important: =over =item 1. I. The Jifty application stores some details in the database. =item 2. I. Your application keeps a database version recorded in the configuration. See L. =item 3. I. Each plugin has a version associated with it affecting whatever Cs it uses. =back If any of these versions differs from their respective Ls, then you need to run the L to L to the latest schema version. Contrast with L. =item sticky A property of Ls. If a field is "sticky," values that the user entered appear there again when the page is rendered again, avoiding making the user type them again. Most Ls have form fields which are sticky on failure, so the user can update the information and try again. =item tangent A tangent is a link or redirect that causes Jifty to save the current state into a L for a later L. This operation is handy for situations when you want to jump to another page or form, but return to this page when the user is done with the "tangent" page. Because of the use of continuations, this can be especially handy because a user could go on multiple tangents and eventually return to the start. =item upgrade Generally, your Jifty application will change over time. Most of these changes will be simple changes to behavior or appearance. When changes are made to the L structure of your database, you may need to perform an B. An B is the process by which you rename columns, initialize data, or otherwise update information that needs to be updated when a change to the database needs to be made. See L, L, and L. =item validate To check that the provided value of an L is a possible value for it to have. See L. =back =cut