packages (or their equivalents on your operating system):
$ sudo apt-get install curl git make unzip apache2 \
- pandoc yui-compressor libbsd-resource-perl
+ pandoc libbsd-resource-perl
You also need Node.js, but unfortunately the `node-js` package is not
available for Debian wheezy. You can either get it from
+Event passing
+-------------
+
+The primary method of communication between components of the widget
+set -- specifically, between teams and their widgets -- is event
+passing. Widgets subscribe to named events; when something relevant
+happens (such as the reception of a message from metasearch
+middleware), the event is published, along with the relevant data. All
+widgets that susbcribed to the event are then notified, and can take
+appropriate action.
+
+Different kinds of events have different data associated with
+them. This data is passed when the event is published, and so is made
+available to the subscribing code.
+
+The possible events, and their associated data, are described
+[below](#events).
+
+
Defining new types of widget
----------------------------
* You can add functionality to a widget by subscribing it to an
event's queue using `this.team.queue("EVENT").subscribe`. The
argument is a function which is called whenever the event is
- published. The arguments to the event-callback function are
- different for different events.
+ published.
* As with so much JavaScript programming, the value of the special
variable `this` is lost inside the `subscribe` callback function,
except where overrides are passed in. If defaults are also
provided, then these are used when the parent widget provides
no values. Both the `overrides` and `defaults` arguments are
- hashes: the latter is optional.
-
- See for example the `Credo` widget defined in the example
- area's `mkws-widget-credo.js` file. This uses several
- invocations of `subwidget` to create a complex compound widget
- with numerous text, facet and image panes. FIXME: rename this
- widget and everything related to it.
+ hashes: the latter is optional. This can be used to assemble
+ compound widgets containing several subwidgets.
In addition to these properties and methods of the bare widget object,
some kinds of specific widget add other properties of their own. For
-example, the `Builder` widget uses a `callback` property as the
+example, the `builder` widget uses a `callback` property as the
function that it use to publish the widget definition that it
constructs. This defaults to the builtin function `alert`, but can be
-overridden by derived widgets such as `ConsoleBuilder`.
+overridden by derived widgets such as `console-builder`.
Team methods
* `String team.currentRecordData()`
These are all simple accessor functions that provide the ability to
-read properties of the team.
+read properties of the team. `submitted` is initially false, then
+becomes true when the first search is submitted (manually or
+automatically).
* `Array team.filters()` --
Another accessor function, providing access to the array of
prevailing filters (which narrow the search results by means
of Pazpar2 filters and limits). This is really too complicated
an object for the widgets to be given access to, but it's
- convenient to do it this way. If you must insist on using
+ convenient to do it this way. If you have a reason for using
this, see the `Navi` widget, which is the only place it's used.
* `Bool team.targetFiltered(targetId)` --
and there is probably no reason for you to use it.
* `Hash team.config()` --
- Access to the team's configuration settings. There is almost
- certainly no reason to use this: the settings that haven't
+ Access to the team's configuration settings. There is
+ rarely a need to use this: the settings that haven't
been overridden are accessible via `this.config`.
* `Void team.set_sortOrder(string)`, `Void team.set_perpage(number)` --
- "Setter" functions for the team's sortOrder and perpage
+ "Setter" functions for the team's `sortOrder` and `perpage`
functions. Unlikely to be needed outside of the `Sort` and
`Perpage` widgets.
* `Queue team.queue(eventName)` --
Returns the queue associated with the named event: this can be
- used to subscribe to the event (or more rarely to publish it).
+ used to subscribe to the event (or more rarely to publish
+ it). See [the section on events, below](#events).
* `Void team.newSearch(query, sortOrder, maxrecs, perpage, limit, targets, targetfilter)` --
Starts a new search with the specified parameters. All but the
query may be omitted, in which case the prevailing defaults
- are used.
+ are used. The meanings of the parameters are those of the
+ same-named [configuration
+ settings](mkws-manual.html#configuration-settings) described in
+ the user's manual.
* `Void team.reShow()` --
Using the existing search, re-shows the result records after a
and returns it in a form that can be invoked as a function,
passed a data-set.
-Some of these methods either (A) are really too low-level and should
-not be exposed, or (B) should be widget-level methods. The present
-infelicities reflect the fact that some code that rightly belongs in
-widgets is still in the team. When we finish migrating it, the widget
-API should get simpler.
+Some of these methods are arguably too low-level and should not be
+exposed; others should probably be widget-level methods. The present
+infelicities should be fixed in future releases, but backwards
+compatibility with the present API will be maintained for at least one
+complete major-release cycle.
Events
------
-FIXME: list of events that can be usefully subscribed to.
-
+The following events are generated by the widget-set code:
+
+* `authenticated` (authName, realm) --
+ When authentication is completed successfully, this event is
+ published to _all_ teams. Two parameters are passed: the
+ human-readable name of the library that has been authenticated
+ onto, and the correponding machine-readable library ID.
+
+* `ready` --
+ Published to _all_ teams when they are ready to search. No
+ parameters are passed. This event is used to implement
+ automatic searching, and should probably not be used by
+ application code.
+
+* `stat` (data) --
+ Published to a team when a `stat` response is reveived from
+ Pazpar2. The data from the response is passed as a parameter.
+
+* `firstrecords` (hitcount) --
+ Published to a team when the first set of records is found by
+ a search. The number of records found (so far) is passed as
+ the parameter.
+
+* `complete` (hitcount) --
+ Published to a team when a search is complete, and no more
+ records will be found (i.e. all targets have either responded
+ or failed with an error). The final number of records found is
+ passed as the parameter.
+
+* `targets` (data) --
+ Published to a team when a `bytarget` response is reveived from
+ Pazpar2. The data from the response is passed as a parameter.
+
+* `facets` (data) --
+ Published to a team when a `term` response is reveived from
+ Pazpar2. The data from the response is passed as a parameter.
+
+* `pager` (data) --
+ Published to a team when a `show` response is reveived from
+ Pazpar2. The data from the response is passed as a
+ parameter. This event is used to update the pager, showing how
+ many records have been found, which page is being displayed,
+ etc.
+
+* `records` (data) --
+ Also published to a team when a `show` response is reveived
+ from Pazpar2. The data from the response is passed as a
+ parameter. This event is used to update the displayed records.
+
+* `record` (data) --
+ Published to a team when a `record` response is reveived from
+ Pazpar2 (i.e. the full data for a single record). The data
+ from the response is passed as a parameter.
+
+* `navi` --
+ Published to a team when a new search is about to be
+ submitted. This is a signal that the navigation area, showing
+ which filters are in effect, should be updated. No parameter
+ is passed: the event handler should consult `team.filters` to
+ see what the prevailing set is.
+
+* `log` (teamName, timestamp, message) --
+ Published to a team when a message is about to be logged to
+ the console for debugging. Three arguments are passed: the
+ name of the team that generated the log message, a timestamp
+ string, and the message itself. Note that this event is _not_
+ published when the widget-set core code generates a log
+ message -- only when a team or a widget does.
- - -
projects / mkws-moved-to-github.git / blobdiff