condition.js

'use strict';

define(
    [
        'flight/lib/component'
    ],

    function(defineComponent) {
        return defineComponent(ConditionSet);

        function ConditionSet() {
            this.defaultAttrs({
                'childTemplate' : 'Override this',
                'conditionList' : '.conditions',
                'addCondition' : '.js-add-condition',
                'removeSelf' : '.js-remove-self'
            });

            this.after('initialize', function() {
                this.on('click', { 'addCondition' : this.appendNewCondition});
                this.on('click', { 'removeSelf' : this.removeSelf});
            });

            this.appendNewConditionSet(e, data) {
                e.preventDefault();
                // probably pre-populate the template using Mustache, underscore, etc
                this.select('conditionList').append(this.childTemplate);
                this.trigger('uiAddCondition', { foo : bar});
            };

            this.removeSelf(e, data) {
                e.preventDefault();
                this.$node.remove();
                this.trigger('uiRemoveConditionSet', { foo : bar});
            };
        }
    }
);

conditionset.js

'use strict';

define(
    [
        'flight/lib/component'
    ],

    function(defineComponent) {
        return defineComponent(ConditionSet);

        function ConditionSet() {
            this.defaultAttrs({
                'childTemplate' : 'Override this',
                'conditionList' : '.conditions',
                'addCondition' : '.js-add-condition',
                'removeSelf' : '.js-remove-self'
            });

            this.after('initialize', function() {
                this.on('click', { 'addCondition' : this.appendNewCondition});
                this.on('click', { 'removeSelf' : this.removeSelf});
            });

            this.appendNewConditionSet(e, data) {
                e.preventDefault();
                // probably pre-populate the template using Mustache, underscore, etc
                this.select('conditionList').append(this.childTemplate);
                this.trigger('uiAddCondition', { foo : bar});
            };

            this.removeSelf(e, data) {
                e.preventDefault();
                this.$node.remove();
                this.trigger('uiRemoveConditionSet', { foo : bar});
            };
        }
    }
);

Nested DOM structure as FlightJS components

- I wrote this on the train after a long day with a heavy head cold. I haven't run it, 
but regardless of likely errors I think it expresses the design well enough.

- Segment and ConditionSet look close to identical, but that's likely due to the simplified
nature of the outline you provided

- I don't like attaching components to classes unless they're `js-`, as it's coupling 
your styling and behaviour layers. We excelusively use data attributes for JS-DOM coupling 
and I've quickly grown fond of the approach.

- The components could easily listen for add and remove events from their children, 
their grandchildren etc.

- I don't know what JS background you're coming from, but in something like Backbone the 
intention would be to model the data structure and then hang Views off that data structure.
It can be hard to get out of that at first, but if you strive to only model the 
interaction/interface layer, you can keep your Model out of your javascript. 

- I wrote an article on flight last week that goes into more details if you're interested:
http://www.sitepoint.com/taking-flight-twitter-flight/

cheers,
Andrew

page.html

<script type="text/html" id="tpl-segment">
    <div class="segment" data-segment>
        <ul class="condition-sets"></ul>
        <a href="#" class="js-add-conditionset">Add condition set</a>
        <a href="#" class="js-remove-self">Remove this segment</a>
    </div>
</script>

<script type="text/html" id="tpl-conditionset">
    <li class="condition-set">
        <ul class="conditions"></ul>
        <a href="#" class="js-add-condition">Add condition</a>
        <a href="#" class="js-remove-self">Remove this condition set</a>
    </li>
</script>

<script type="text/html" id="tpl-condition">
<li class="condition">
    <input type="text" name="{{ name }}" value="{{ value }}" />
    <a href="#" class="js-remove-self">Remove this condition set</a>
</li>
</script>

page.js

'use strict';

require(
    [
    'segment',
    'condition-set',
    'condition',
    ],
    function (
        Segment,
        ConditionSet,
        Condition
    ) {
        $(function() {
            Segment.attachTo('.segment', { childTemplate : $('#tpl-conditionset').html() });
            ConditionSet.attachTo('.condition-set', { childTemplate : $('#tpl-condition').html() });
            ConditionSet.attachTo('.condition');
        });
    }
);

segment.js

'use strict';

define(
    [
        'flight/lib/component'
    ],

    function(defineComponent) {
        return defineComponent(Segment);

        function Segment() {
            this.defaultAttrs({
                'childTemplate' : 'Override this',
                'conditionSetList' : '.condition-sets',
                'addConditionSet' : '.js-add-conditionset',
                'removeSelf' : '.js-remove-self'
            });

            this.after('initialize', function() {
                this.on('click', { 'addConditionSet' : this.appendNewConditionSet});
            });

            this.appendNewConditionSet(e, data) {
                e.preventDefault();
                // probably pre-populate the template using Mustache, underscore, etc
                this.select('conditionSetList').append(this.childTemplate);
                this.trigger('uiAddConditionSet', { foo : bar});
            }

            this.removeSelf(e, data) {
                e.preventDefault();
                this.$node.remove();
                this.trigger('uiRemoveSegment', { foo : bar});
            };
        }
    }
);