A pretty interesting example of adding custom buttons to tmcgee's search widget

search.js

define([
    'dojo/_base/lang',
    'dojo/topic',
    'tmcgee/Search',
    'dijit/form/Button',
    './auth_util'
], function (lang, topic, Search, Button, Auth) {

    var workorderButton = {
        include: Auth.hasOneRole(['workorders_create', 'admin']),
        layerMap: {
            'Storm Pipe': 'storm_pipe',
            'Storm Structures': 'storm_struc',
            'Sanitary Pipe': 'san_pipe',
            'Sanitary Structures': 'san_struc',
            'Sanitary Service': 'san_service',
            'Water Structures': 'water_struc',
            'Water Pipes': 'water_pipe',
            'Wells and Reservoirs': 'water_well_res',
            'Water Serivce Lines': 'water_service',
            'Curb Stops': 'water_curbstop',
            'Parcels': 'city_parcel'
        },
        label: '<i class="fa fa-wrench"></i> Create Workorder',
        onClick: function () {
            var tableName = this.layerMap[this.tab.title];
            var idField = this.workorderLayers.filter(function (l) {
                return l.tablename === tableName;
            })[0].id_field;
            window.location.hash = window.can.route.url({
                view: 'all_wo',
                page: 'add',
                featureType: tableName,
                featureIds: this.tab.grid.store.data.map(function (row) {
                    return row[idField];
                })
            }, true);
        }
    };

    return {
        // layerControlLayerInfos: true,
        map: true,

        layers: [{
            title: 'Storm Pipe',
            name: 'Storm Pipe',
            topicID: 'storm_pipe',
            queryParameters: {
                type: 'spatial',
                layerID: 'assets',
                sublayerID: 11
            },
            buttons: [workorderButton],
            attributeSearches: []
        }, {
            title: 'Curb Stops',
            name: 'Curb Stop (Tap Cards)',
            topicID: 'curbStop',
            queryParameters: {
                type: 'spatial',
                layerID: 'assets',
                sublayerID: 26
            },
            attributeSearches: [],
            buttons: [{
                label: '<i class="fa fa-file-text-o"></i> Tapcard Report',
                onClick: function () {
                    window.open('/utilities/tap_report/tap/' +
                        this.tab.grid.store.data.map(function (row) {
                            return row['gis.DBO.water_curbstop.cid'];
                        }).join('+'));
                }
            }]
        }, {
            title: 'Parcels',
            topicID: 'parcels',
            name: 'Parcels',
            queryParameters: {
                type: 'spatial',
                layerID: 'assets',
                sublayerID: 1
            },
            attributeSearches: [],
            buttons: [{
                label: '<i class="fa fa-file-text-o"></i> Tapcard Report',
                onClick: function () {
                    window.open('/utilities/tap_report/parcel/' +
                        this.tab.grid.store.data.map(function (row) {
                            return row.PARCELID;
                        }).join('+'));
                }
            }]
        }],
        tabsWithButtons: {},

        startup: function () {
            Search.prototype.startup.apply(this, arguments);
          
            //subscribe a topic to modify the attributes container add tab
            topic.subscribe('attributesContainer/tableAdded', lang.hitch(this, function (tab) {
                if (this.tabsWithButtons[tab.title]) {
                    return;
                }

                this.layers.forEach(lang.hitch(this, function (l) {
                    if (l.title === tab.title && l.buttons) {
                        l.buttons.forEach(lang.hitch(this, function (b) {
                          
                            // only include if the buttons include property is not false
                            if (b.include !== false) {
                                this.addButton(tab, b);
                            }
                        }));
                    }
                }));
            }));
        },

        addButton: function (tab, options) {
            tab.attributesTableToolbarDijit.addChild(new Button(lang.mixin(options, {
                tab: tab
            })));
        }
    };
});