New section on four-layer structure of the code.

[mkws-moved-to-github.git] / doc / mkws-developer.markdown

diff --git a/doc/mkws-developer.markdown b/doc/mkws-developer.markdown
index 2689eb6..9d3ac4b 100644 (file)
--- a/doc/mkws-developer.markdown
+++ b/doc/mkws-developer.markdown
@@ -1,13 +1,90 @@
 % The MasterKey Widget Set developer's guide
 % Mike Taylor
 % The MasterKey Widget Set developer's guide
 % Mike Taylor

-% 11 August 2014
+% November 2014

 
 
 
 

-Overview
+Introduction
+============
+
+This manual is for people who want to build the widget set from
+source, develop the widget set's core code, or (more likely) create
+their own widgets as extensions to the main set.
+
+Those who want to use existing widgets should read
+[The MKWS manual: embedded metasearching with the MasterKey Widget
+Set](mkws-manual.html) instead.
+
+
+Required development tools
+==========================
+
+If you are building the widget set, you will need the following Debian
+packages (or their equivalents on your operating system):
+
+       $ sudo apt-get install curl git make unzip apache2 \
+           pandoc yui-compressor 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
+wheezy-backports or download the source from
+http://nodejs.org/download/ and build it yourself. You need both Node
+itself and its package manager NPM: `make install` puts them into
+`/usr/local/bin`.
+
+
+Concepts

 ========
 
 ========
 

-Core concepts
--------------
+Code structure
+--------------
+
+The code of the widget set is in four main layers, described here from
+the bottom up:
+
+1. The core code, which manages the set of widget teams, default
+options, authentication onto the Service Proxy, and the creation of
+widgets from HTML elements.
+This code is in `mkws-core.js`
+
+2. The team code, which manages teams of widgets. This is responsible
+for the collections of widgets that make up teams, event queues, and
+handling search-and-retrieval events
+This code is in `mkws-team.js`
+
+3. The generic widget code, which handles the creation of widget
+objects, parsing configuration attributes from their HTML elements,
+and firing off automatic searches.
+
+4. The code for individual widgets, which is specific to those
+widgets. It often involves subscribing to events and responding to
+them by setting the HTML of the widget element, but need not do
+so. The code for many of the most important widgets is in
+`mkws-widget-main.js`, but certain other widgets are defined in other
+files beginning with the prefix `mkws-widget-`.
+
+In addition to this code, there are several source files containing
+support code:
+
+* `mkws-filter.js` contains support routine implementing the
+filter-set data structure, which contains information about which
+filters (e.g. by target, or by facet) are in force.
+
+* `mkws-handlebars.js` contains Handlebars helpers which can be used
+by the HTML templates.
+
+* `mkws-popup.js` defines a special widget for creating popup
+  windows. These may, but need not, contain other MKWS widgets,
+  forming a popup searching application.
+
+The final component of the source code is the set of Handlebars
+templates, in the `templates` directory, which are used to emit the
+HTML of the various widgets' contents. These are compiled into the
+file `mkws-templates.js`.
+
+
+
+Defining new types of widget
+----------------------------

 
 Development with MKWS consists primarily of defining new types of
 widgets. These can interact with the core functionality is several
 
 Development with MKWS consists primarily of defining new types of
 widgets. These can interact with the core functionality is several

@@ -134,13 +211,38 @@ be used by the derived widget.
 * `String this.value()` --
        A function returning the value of the widget's HTML element.
 
 * `String this.value()` --
        A function returning the value of the widget's HTML element.
 

-* TODO autosearch()
-
-* TODO hideWhenNarrow()
-
-* TODO subwidget()
-
-* TODO expandValue()
+* `VOID autosearch()` --
+       Registers that this kind of widget is one that requires an
+       automatic search to be run for it if an `autosearch` attribute
+       is provided on the HTML element. This is appropriate for
+       widgets such as `Records` and `Facet` that display some part
+       of a search result.
+
+* `VOID hideWhenNarrow()` --
+       Registers that this widget should hide itself when the page
+       becomes "narrow" -- that is, fewer pixels in width that the
+       threshhold value specified by the top-level configuration item
+       `responsive_design_width`. Should be used for "unimportant"
+       widgets that can be omitted from the mobile version of a site.
+
+* `expandValue()` --
+       TODO: either document this or remove it from the API.
+
+* `subwidget(type, overrides, defaults)` --
+       Returns the HTML of a subwidget of the specified type, which
+       can then be inserted into the widget using the
+       `this.node.html` function. The subwidget is given the same
+       attributes at the parent widget that invokes this 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. TODO: rename this
+       widget and everything related to it.

 
 In addition to these properties and methods of the bare widget object,
 some kinds of specific widget add other properties of their own. For
 
 In addition to these properties and methods of the bare widget object,
 some kinds of specific widget add other properties of their own. For

@@ -224,6 +326,13 @@ 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.
 
 widgets is still in the team. When we finish migrating it, the widget
 API should get simpler.
 

+
+Events
+------
+
+TODO: list of events that can be usefully subscribed to.
+
+

 - - -
 
 - - -
 

-Copyright (C) 2013-2014 by IndexData ApS, <http://www.indexdata.com>
+Copyright (C) 2013-2014 Index Data ApS. <http://indexdata.com>