Display 0.x for Express Lane

Display provides an API for displaying a view results in express. Each display can be defined in a static settings object defining what fields to display and how. The field system is pluggable allowing for additional field handlers to be defined by other modules.

Assumptions

Display inherits some assumptions from its required environment expresslane. In particular:

• View result sets are expected to be generated via CouchDB. The result set should be an array of objects where each object has a value key. For example:

  array [ value: { title: 'Foo', description: 'This is some foo', }, value: { title: 'Bar', description: 'This is some bar', }, ]

• The template engine used is hbs a light wrapper around handlebars.js.

Requirements

• node.js 0.2.x
• express 1.x
• expresslane
• hbs
• cradle for use with CouchDB.

Using display

Displays should be defined in settings.js or a sub module file required by the main expresslane settings file like settings.display.js. Display expects an object keyed by display name to be present at require('settings').display:

module.exports = {
    display: {
        // Defines the `dataListing` display
        dataListing: {
            name: {
                title: 'Name',
                description: 'Lorem ipsum dolor sit amet',
                type: 'value',
                fields: [
                    { field: 'name' }
                ]
            }
            // ... more fields
        }
        // ... more displays
    }
    // ... settings for other expresslane modules
};

Defining fields

Each display object contains a keyed list of field objects. Each field object can have the following fields:

• title: Optional. A title or label to display with this field.
• description: Optional. A short description to display with the field label.
• help: Optional. Help text or other notes.
• type: The field handler type to use for rendering. A list of available field handlers can be found below.
• settings: Optional. An object containing settings specific to each field handler type.
• fields: An array of one or more fields to be used for display. Each reference is an object with the following keys:
  • field: The document key where this field value can be found. For example, name will retrieve the value from doc.value.name. You may retrieve nested properties with a string like phone.mobile.
  • title: An optional label for this specific field value. Used by some field types like graphCompare.

Example:

phone:  {
    title: 'Phone',
    description: 'The main contact number(s) of this individual',
    help: 'Reach this person by dialing one of the numbers.',
    type: 'value',
    fields: [
        { field: 'phone.home' },
        { field: 'phone.office' },
        { field: 'phone.mobile' }
    ]
}

Styles

Each display can be used in conjunction with a display style. The style determines how to template the collection of fields defined in the display. The styles currently available with display are:

• table: Displays each document as a row and each field as a cell in an HTML table. Field titles are displayed as table headers.
• item: Displays each document in a wrapping div and each field with a wrapping field div.

Usage

The main function exposed by display is style(req, style, name, rows):

• req: The request object for the current request.
• style: String name of the style to display, e.g. table.
• name: String name of the display configuration to use, e.g. dataListing.
• rows: An array of CouchDB rows returned by a query.

Returns an object that can be included in an express template's locals that can be templated directly using the expresslane template helper function.

// Show all user profiles at /profiles. Assume the loadAllProfiles router
// middleware queries CouchDB for profile records and places them at
// res.data.profiles.
app.get('/profiles', loadAllProfiles, function(req, res, next) {
    var display = require('display');
    var profiles = res.data.profiles;
    var locals = {};
    locals.profiles = display.style(req, 'table', 'profiles', profiles);
    res.render('mypage', { locals: locals });
});

In the mypage.hbs template:

<div class='profiles'>
    {{#profiles}}{{{../template .}}}{{/profiles}}
</div>

Field handlers

The following field handlers are provided with display:

• boolean
• value
• link
• percent
• image
• graphHistogram
• graphDivisible
• graphCompare

@TODO descriptions, usable settings.