Including ingredients, meal types, cuisines

Prolog and Patterns

We need to refine our logic now for retrieving only those recipes that satisfy specific filters. We already introduced a recipeFiltered/3 predicate for [TBU]Request a Recommendation but there it did not have to do any serious work yet. We only introduced the base case without any filters (an empty list of filters) but now need to deal with the case where we have some filters that a user provided. The basic idea to define a recursive clause for recipeFiltered/3 is simple: apply the first filter in the list to the recipes and recursively filter the remaining recipes using the remaining filters. We provide you below with the recursive clause that you should add below the base clause that we added earlier in the recipe_selection.pl file:

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The bodies of the rules can be designed as exact copies of each other. You must find all (Hint for what Prolog built-in predicate you should use) recipes from the list that you start with that satisfy the filter and return these recipes in the output argument list. Add your rules to the recipe_selection.pl file at the location indicated in the file; there you will also find the heads of the rules that you need to define. The rule for filtering on cuisine is very similar too but instead of the hasIngredient/2 predicate you should use the cuisine/2 predicate (see the recipe_database.pl for examples).

Add mealType and cuisine and ingredient - ingredientType removed

Requesting a recipe feature

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Let’s inspect this interaction in more detail and analyse how it is organized. In Moore and Arar’s taxonomy, the parts of the dialog in this example where the user adds a feature request in the second and fourth move can be classified as Pattern A2.1: Open Request. We will use the a21featureRequest label for this pattern and define different variants of it below. The agent initiates with an inquiry about what the user is looking for. This move is part of the a50recipeSelect pattern, a top level pattern that we added to the agent’s agenda. We previously defined variants for that pattern for [TBU]Select Recipes by Name . The user responds by informing the agent that they are interested in a particular cuisine (Japanese). This is a feature request that we want the agent to manage by means of a new a21featureRequest pattern. The idea is that this pattern is inserted while the user and agent are still performing the top level a50recipeSelect pattern. The a21featureRequest pattern is inserted as a subdialog, which we indicated in the example above by adding indentation. The response of the agent is an acknowledgement move combined with a renewal of the question whether the user wants to add any other feature. We’ll take it that this move is also part of the a21featureRequest pattern and ends this pattern. The fourth user move (a second feature request for the an ingredient type pasta) and the fifth agent move repeats the same a21featureRequest pattern. The interaction concludes with a move of the user mentioning a specific recipe title (Teriyaki salmon). That last move and the agent move following it are both part of the a50recipeSelect pattern we specified for [TBU]Select Recipes by Name . That pattern added the a50recipeConfirm pattern into the current session of the agent. This pattern asks the user to check the recipe (while showing all relevant details). You still need to add this pattern to implement the capability we are working on right now below.

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For the featureRemovalRequest intent, you should add a simple text/2 fact. Use as response text, for example, "Can you have a look again and remove one of your recipe requirements?".

Visuals

We want to differentiate what we show to a user depending on the number of recipes that still meet the user’s requests. The basic idea is that we should not show a large number of recipes to a user but we can show recipe details when the number of remaining recipes becomes sufficiently small (we chose <16, see also above). As a consequence, we want to create two different versions of the a50recipeSelect page that we created for [TBU]Request a Recommendation : one that just shows the feature requests made when there are more than 15 recipes that meet these requests, and another for when there are less that 16 which shows the recipe details (titles and pictures) for all of the remaining recipes.

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