1 % Embedded metasearching with the MasterKey Widget Set
9 There are lots of practical problems in building resource discovery
10 solutions. One of the biggest, and most ubiquitous is incorporating
11 metasearching functionality into existing web-sites -- for example,
12 content-management systems, library catalogues or intranets. In
13 general, even when access to core metasearching functionality is
14 provided by simple web-services such as
15 [Pazpar2](http://www.indexdata.com/pazpar2), integration work is seen
16 as a major part of most projects.
18 Index Data provides several different toolkits for communicating with
19 its metasearching middleware, trading off varying degrees of
20 flexibility against convenience:
22 * pz2.js -- a low-level JavaScript library for interrogating the
23 Service Proxy and Pazpar2. It allows the HTML/JavaScript programmer
24 to create JavaScript applications display facets, records, etc. that
25 are fetched from the metasearching middleware.
27 * masterkey-ui-core -- a higher-level, complex JavaScript library that
28 uses pz2.js to provide the pieces needed for building a
29 full-featured JavaScript application.
31 * MasterKey Demo UI -- an example of a searching application built on
32 top of masterkey-ui-core. Available as a public demo at
33 http://mk2.indexdata.com/
35 * MKDru -- a toolkit for embedding MasterKey-like searching into
38 All of these approaches require programming to a greater or lesser
39 extent. Against this backdrop, we introduced MKWS (the MasterKey
40 Widget Set) -- a set of simple, very high-level HTML+CSS+JavaScript
41 components that can be incorporated into any web-site to provide
42 MasterKey searching facilities. By placing `<div>`s with well-known
43 identifiers in any HTML page, the various components of an application
44 can be embedded: search-boxes, results areas, target information, etc.
50 The following is a complete MKWS-based searching application:
54 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
55 <title>MKWS demo client</title>
56 <script type="text/javascript" src="http://mkws.indexdata.com/mkws-complete.js"></script>
57 <link rel="stylesheet" href="http://mkws.indexdata.com/mkws.css" />
60 <div id="mkwsSearch"></div>
61 <div id="mkwsResults"></div>
65 Go ahead, try it! You don't even need a web-server. Just copy and
66 paste this HTML into a file on your computer -- `/tmp/magic.html`,
67 say -- and point your web-browser at it:
68 `file:///tmp/magic.html`. Just like that, you have working
75 If you know any HTML, the structure of the file will be familar to
76 you: the `<html>` element at the top level contains a `<head>` and a
77 `<body>`. In addition to whatever else you might want to put on your
78 page, you can add MKWS elements.
80 These fall into two categories. First, the prerequisites in the HTML
81 header, which are loaded from the tool site mkws.indexdata.com:
84 contains all the JavaScript needed by the widget-set.
87 provides the default CSS styling
89 Second, within the HTML body, `<div>` elements with special IDs that
90 begin `mkws` can be provided. These are filled in by the MKWS code,
91 and provide the components of the searching UI. The very simple
92 application above has only two such components: a search box and a
93 results area. But more are supported. The main `<div>`s are:
95 * `mkwsSearch` -- provides the search box and button.
97 * `mkwsResults` -- provides the results area, including a list of
98 brief records (which open out into full versions when clicked),
99 paging for large results sets, facets for refining a search,
100 sorting facilities, etc.
102 * `mkwsLang` -- provides links to switch between one of several
103 different UI languages. By default, English, Danish and German are
106 * `mkwsSwitch` -- provides links to switch between a view of the
107 result records and of the targets that provide them. Only
108 meaningful when `mkwsTargets` is also provided.
110 * `mkwsTargets` -- the area where per-target information will appear
111 when selected by the link in the `mkwsSwitch` area. Of interest
112 mostly for fault diagnosis rather than for end-users.
114 * `mkwsStat` --provides a status line summarising the statistics of
117 To see all of these working together, just put them all into the HTML
120 <div id="mkwsSwitch"></div>
121 <div id="mkwsLang"></div>
122 <div id="mkwsSearch"></div>
123 <div id="mkwsResults"></div>
124 <div id="mkwsTargets"></div>
125 <div id="mkwsStat"></div>
130 Many aspects of the behaviour of MKWS can be modified by setting
131 parameters into the `mkws_config` object. **This must be done *before*
132 including the MKWS JavaScript** so that when that code is executed it
133 can refer to the configuration values. So the HTML header looks like
136 <script type="text/javascript">
139 sort_default: "title",
143 <script type="text/javascript" src="http://mkws.indexdata.com/mkws-complete.js"></script>
145 This configuration sets the UI language to Danish (rather than the
146 default of English), initially sorts search results by title rather
147 than relevance (though as always this can be changed in the UI) and
148 makes the search box a bit wider than the default.
150 The full set of supported configuration items is described in the
151 reference guide below.
154 Control over HTML and CSS
155 -------------------------
157 More sophisticated applications will not simply place the `<div>`s
158 together, but position them carefully within an existing page
159 framework -- such as a Drupal template, an OPAC or a SharePoint page.
161 While it's convenient for simple applications to use a monolithic
162 `mkwsResults` area which contains record, facets, sorting options,
163 etc., customised layouts may wish to treat each of these components
164 separately. In this case, `mkwsResults` can be omitted, and the
165 following lower-level components provided instead:
167 * `mkwsTermlists` -- provides the facets
169 * `mkwsRanking` -- provides the options for how records are sorted and
170 how many are included on each page of results.
172 * `mkwsPager` -- provides the links for navigating back and forth
173 through the pages of records.
175 * `mkwsNavi` -- when a search result has been narrowed by one or more
176 facets, this area shows the names of those facets, and allows the
177 selected values to be clicked in order to remove them.
179 * `mkwsRecords` -- lists the actual result records.
181 Customisation of MKWS searching widgets can also be achieved by
182 overriding the styles set in the toolkit's CSS stylesheet. The default
183 styles can be inspected in `mkws.css` and overridden in any
184 styles that appears later in the HTML than that file. At the simplest
185 level, this might just mean changing fonts, sizes and colours, but
186 more fundamental changes are also possible.
188 To properly apply styles, it's necessary to understand how the HTML is
189 structured, e.g. which elements are nested within which
190 containers. The structures used by the widget-set are described in the
191 reference guide below.
198 ### Message of the day
200 Some applications might like to open with content in the area that
201 will subsequently be filled with result-records -- a message of the
202 day, a welcome message or a help page. This can be done by placing an
203 `mkwsMOTDContainer` division on the page next to `mkwsResults` or
204 `mkwsRecords`. The contents of this element are initially displayed,
205 but will be hidden when a search is made.
208 ### Customised display using Handlebars templates
210 Certain aspects of the widget-set's display can be customised by
211 providing Handlebars templates with well-known IDs that begin with the
212 string `mkwsTemplate`. At present, the supported templates are:
214 * `mkwsTemplateSummary` -- used for each summary record in a list of
217 * `mkwsTemplateRecord` -- used when displaying a full record.
219 For both of these the metadata record is passed in, and its fields can
220 be referenced in the template. As well as the metadata fields
221 (`md-*`), two special fields are provided to the `mkwsTemplateSummary`
222 template, for creating popup links for full records. These are `_id`,
223 which must be provided as the `id` attribute of a link tag, and
224 `_onclick`, which must be provided as the `onclick` attribute.
226 For example, an application can install a simple author+title summary
227 record in place of the usual one providing the following template:
229 <script id="mkwsTemplateSummary" type="text/x-handlebars-template">
231 <span>{{md-author}}</span>
233 <a href="#" id="{{_id}}" onclick="{{_onclick}}">
238 For details of Handlebars template syntax, see
239 [the online documentation](http://handlebarsjs.com/).
242 ### Responsive design
244 Metasearching applications may need to appear differently on
245 small-screened mobile devices, or change their appearance when
246 screen-width changes (as when a small device is rotated). To achieve
247 this, MKWS supports responsive design which will move the termlists to
248 the bottom on narrow screens and to the sidebar on wide screens.
250 To turn on this behaviour, set the `responsive_design_width` to the desired
251 threshhold width in pixels. For example:
253 <script type="text/javascript">
255 responsive_design_width: 990
259 If individual result-related components are in use in place of the
260 all-in-one mkwsResults, then the redesigned application needs to
261 specify the locations where the termlists should appear in both
262 cases. In this case, wrap the wide-screen `mkwsTermlists` element in a
263 `mkwsTermlistContainer1` element; and provide an
264 `mkwsTermlistContainer2` element in the place where the narrow-screen
265 termlists should appear.
268 ### Popup results with jQuery UI
270 The [jQuery UI library](http://en.wikipedia.org/wiki/JQuery_UI)
271 can be used to construct MKWS applications in which the only component
272 generally visible on the page is a search box, and the results appear
273 in a popup. The key part of such an application is this invocation of
274 the MKWS jQuery plugin:
276 <script type="text/javascript">
277 jQuery.pazpar2({ "layout":"popup", width:800, height:500 });
280 The necessary scaffolding can be seen in an example application,
281 http://example.indexdata.com/index-popup.html
284 ### Authentication and target configuration
286 By default, MKWS configures itself to use a demo account on a service
287 hosted by mkws.indexdata.com. This demo account provides access to
288 about a dozen free data sources. Authentication onto this service is
289 via an authentication URL on the same server, which MKWS uses by
290 default so no configuration is needed.
292 Access to a customised set of resources (including resources that
293 require authentication) can be provided. In this case, a
294 customer-specific authentication URL is used to gain access to these
295 rather than the default set. Contact Index Data on info@indexdata.com
302 ### Configuration object
304 The configuration object `mkws_config` may be created before including
305 the MKWS JavaScript code to modify default behaviour. This structure
306 is a key-value lookup table, whose entries are described in the table
307 below. All entries are options, but if specified must be given values
308 of the specified type. If ommitted, each setting takes the indicated
309 default value; long default values are in footnotes to keep the table
313 Element Type Default Description
314 -------- ----- --------- ------------
315 debug_level int 1 Level of debugging output to emit. 0 = none, 1 = messages, 2 = messages with
316 datestamps, 3 = messages with datestamps and stack-traces.
318 facets array *Note 1* Ordered list of names of facets to display. Supported facet names are
319 `sources`, `subjects` and `authors`.
321 lang string en Code of the default language to display the UI in. Supported language codes are `en` =
322 English, `de` = German, `da` = Danish, and whatever additional languages are configured
323 using `language_*` entries (see below).
325 lang_options array [] A list of the languages to offer as options. If empty (the default), then all
326 configured languages are listed.
328 language_* hash Support for any number of languages can be added by providing entries whose name is
329 `language_` followed by the code of the language. See the separate section below for
332 pazpar2_url string *Note 2* The URL used to access the metasearch middleware. This service must be configured to
333 provide search results, facets, etc. It may be either unmediated or Pazpar2 the
334 MasterKey Service Proxy, which mediates access to an underlying Pazpar2 instance. In
335 the latter case, `service_proxy_auth` must be provided.
337 perpage_default string 20 The initial value for the number of records to show on each page.
339 perpage_options array *Note 3* A list of candidate page sizes. Users can choose between these to determine how many
340 records are displayed on each page of results.
342 query_width int 50 The width of the query box, in characters.
344 responsive_design_width int If defined, then the facets display moves between two locations as the screen-width
345 varies, as described above. The specified number is the threshhold width, in pixels,
346 at which the facets move between their two locations.
348 service_proxy_auth url *Note 4* A URL which, when `use_service_proxy` is true, is fetched once at the beginning of each
349 session to authenticate the user and establish a session that encompasses a defined set
350 of targets to search in.
352 show_lang bool true Indicates whether or not to display the language menu.
354 show_perpage bool true Indicates whether or not to display the perpage menu.
356 show_sort bool true Indicates whether or not to display the sort menu.
358 sort_default string relevance The label of the default sort criterion to use. Must be one of those in the `sort`
361 sort_options array *Note 6* List of supported sort criteria. Each element of the list is itself a two-element list:
362 the first element of each sublist is a pazpar2 sort-expression such as `data:0` and
363 the second is a human-readable label such as `newest`.
365 use_service_proxy bool true If true, then a Service Proxy is used to deliver searching services rather than raw
369 Perhaps we should get rid of the `show_lang`, `show_perpage` and
370 `show_sort` configuration items, and simply display the relevant menus
371 only when their containers are provided -- e.g. an `mkwsLang` element
372 for the language menu. But for now we retain these, as an easier route
373 to lightly customise the display than my changing providing a full HTML
378 1. ["sources", "subjects", "authors"]
380 2. /pazpar2/search.pz2
384 4. http://mkws.indexdata.com/service-proxy-auth
386 5. http://mkws.indexdata.com/service-proxy/
388 6. [["relevance"], ["title:1", "title"], ["date:0", "newest"], ["date:1", "oldest"]]
391 ### Language specification
393 Support for another UI language can be added by providing an entry in
394 the `mkws_config` object whose name is `language_` followed by the
395 name of the language: for example, `language_French` to support
396 French. Then value of this entry must be a key-value lookup table,
397 mapping the English-language strings of the UI into their equivalents
398 in the specified language. For example:
402 "Authors": "Auteurs",
403 "Subjects": "Sujets",
404 // ... and others ...
408 The following strings occurring in the UI can be translated:
424 In addition, facet names can be translated:
430 Finally, the names of fields in the full-record display can be
431 translated. These include, but may not be limited to:
441 ### jQuery plugin invocation
443 The MasterKey Widget Set can be invoked as a jQuery plugin rather than
444 by providing an HTML skeleton explicitly. When this approach is used,
445 the invocation is a single line of JavaScript:
447 <script>jQuery.pazpar2();</script>
449 This code should be inserted in the page at the position where the
450 metasearch should occur.
452 When invoking this plugin, a key-value lookup table of named options
453 may be passed in to modify the default behaviour, as in the exaple
454 above. The available options are as follows:
457 Element Type Default Description
458 -------- ----- --------- ------------
459 layout string popup Specifies how the user interface should
460 appear. Options are `table` (the default,
461 with facets at the bottom), `div` (with
462 facets at the side) and `popup` (to
463 obtain a popup window).
465 width int 880 Width of the popup window (if used), in
468 height int 760 Height of the popup window (if used), in
471 id_button string input#mkwsButton (Never change this.)
473 id_popup string #mkwsPopup (Never change this.)
476 Note that when using the `popup` layout, facilities from the jQuery UI
477 toolkit are used, so it's necessary to include both CSS and JavaScript
478 from that toolkit. The relevant lines are:
480 <script src="http://code.jquery.com/ui/1.10.3/jquery-ui.min.js"></script>
481 <link rel="stylesheet" type="text/css" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css" />
484 ### The structure of the HTML generated by the MKWS widgets
486 In order to override the default CSS styles provided by the MasterKey Widget
487 Set, it's necessary to understand that structure of the HTML elements that are
488 generated within the components. This knowledge make it possible, for example,
489 to style each `<div>` with class `term` but only when it occurs inside an
490 element with ID `#mkwsTermlists`, so as to avoid inadvertently styling other
491 elements using the same class in the non-MKWS parts of the page.
493 The HTML structure is as follows. As in CSS, #ID indicates a unique identifier
494 and .CLASS indicates an instance of a class.
504 input#mkwsQuery type=text
505 input#mkwsButton type=submit
508 (no contents -- used only for masking)
529 span (for sequence number)
531 span (for other information such as author)
532 div.details (sometimes)
555 Copyright (C) 2013 by IndexData ApS, <http://www.indexdata.com>