RECIPE WORLD FOOD RECIPE APPLICATION. A Project. Presented to the. Faculty of. California State Polytechnic University, Pomona. In Partial Fulfillment

Transcription

1 RECIPE WORLD FOOD RECIPE APPLICATION A Project Presented to the Faculty of California State Polytechnic University, Pomona In Partial Fulfillment Of the Requirements for the Degree Master of Science In Computer Science By Siavash Motalebi 2018

2 SIGNATURE PAGE PROJECT: AUTHOR: RECIPE WORLD FOOD RECIPE APPLICATION Siavash Motalebi DATE SUBMITTED: Spring 2018 Computer Science Department Dr. Yu Sun Project Committee Chair Professor of Computer Science Dr. Abdelfattah Amamra Project Committee Professor of Computer Science ii

3 ABSTRACT The use of mobile devices such as, smartphone or tablets have increased significantly in the past decade. All these devices use applications that are created for them. These applications can provide many different services including, social media, music streaming, video streaming, ride sharing, online shopping, and video games. Some of these apps need to be constantly connected to the internet to function properly, while others can work offline. This paper presents a food recipe Android application that helps users find and view different food recipes based on different categories, as well as allowing them to add their own recipes to the database. The users can filter the list of recipes based on the ingredients used in the recipe, the prep time, cook time, ready time, and the number of servings. The app aspires to run efficiently, while having an intuitive a simple design that provides the user all the necessary functionalities. iii

4 TABLE OF CONTENTS SIGNATURE PAGE... ii ABSTRACT... iii LIST OF FIGURES... vi CHAPTER 1: Introduction... 1 CHAPTER 2: Literature Survey Firebase Platform Android Studio Java Programming Language XML NoSQL... 6 CHAPTER 3: Development Challenges Retrieving Data from Database Storing Data in Database Filtering Recipes Based on User s Choice CHAPTER 4: Application Pages Main Page Add Recipe Page Courses Page Cuisines Page iv

5 4.5 Types Page View Recipe List or Filter Page Filter Page Filter by Time Page Filter by Number of Servings Page Recipe Information Page CHAPTER 5: Conclusion and Future Work REFERENCES v

6 LIST OF FIGURES Figure 1 Final Database Structure... 8 Figure 2 Example Task Class Figure 3 Storing an Object in the Database Figure 4 Passing Information from One Page to Another Figure 5 Main Page Figure 6 Add Recipe Page Figure 7 Courses Page Figure 8 Cuisines Page Figure 9 Types Page Figure 10 View Recipe List or Filter Page Figure 11 Filter Page Figure 12 Filter by Time Page Figure 13 Filter by Number of Servings Page Figure 14 Example of Recipe Information Page vi

7 CHAPTER 1 Introduction A mobile app or most commonly known simply as an app refers to an application software that is created to be run on a mobile device such as, smartphone or tablets. Mobile apps can have many different types. Some of these types include music apps, ride sharing apps, food recipe apps, online store apps, and video games. Depending on the app it might need to be connected to the internet to work properly or it might be fully functional offline. The programming language that is used to develop a mobile differs based on the operating system that the app is going to work on. For example, apps running on an android phone are mostly written in Java, while apps running on ios phones are written in Objective C or Swift. When creating an online app (mobile or web apps), the developers usually use databases. Merriam-Webster defines database as following, a usually large collection of data organized especially for rapid search and retrieval (as by a computer) [1]. Online databases are used to save different types of data which can be later updated or retrieved by different devices using the internet. This allows devices to access the information on the database from anywhere with internet access. Databases can be accessed directly or through a web-service. Web-service refers to an application or data source that accessible through standard web protocols. The important aspect of web-services is that they are designed to communicate with other programs instead of directly doing so with the user. The main benefit of using a webservice to connect to a database is that usually a web-service can communicate any application, no matter where the application resides. For example, connection to a web- 1

8 service can be implemented on an Android app, while also using the web-service on an ios app, without the need to recode the web-service or the app. The architecture used to create web-services is the Client/Server architecture. According to Technopedia a Client/Server architecture is a computing model in which the server hosts, delivers and manages most of the resources and services to be consumed by the client. This type of architecture has one or more client computers connected to a central server over a network or internet connection. This system shares computing resources. When using this architecture, a client sends a request to the web-service that transfers that request to the database. Once the request is processed, the processed data is sent back to client through the web-service. This project uses both databases and web-services to design and implement an online food recipe Android app. The app is intended to have an intuitive and simple user interface that allows the user to find and view different food recipes based on different inputs such as, the type of food, the cuisine, and the food course. The user can then filter the list of recipes based on the ingredients used in the recipe, as well as the serving size and the time it takes to make the food. He or she can then look at the information for the desired recipe by choosing that recipe from the provided list. In addition, the user can add his or her own recipes to the database. 2

9 CHAPTER 2 Literature Survey 2.1 Firebase Platform Firebase is a backend service provided by Google that offers many useful features for mobile and web apps. Some of the features provided by Firebase are as followed [2]: 1. Realtime Database allows data to be stored and synced between users and devices in a nosql database. The updated data is synced with all connected devices very quickly, and the data remains after the app goes offline. 2. Authentication provides a simple and secure way to manage users using the app. It provides multiple methods of authentication such as, and password, thirdparty providers like Google or Facebook, and using your existing account system directly. 3. Cloud Functions allows the developer to extend the app using custom backend code without the need to manage one s own servers. The functions can be triggered by events, which are produced by Firebase, Google Cloud services, and other third-party services. 4. Cloud Storage can be used to store user-generated content like images, audio, and video with object storage built for Google scale. The Firebase SDKs for Cloud Storage add Google security to file uploads and downloads for your Firebase apps. 5. Hosting simplifies web app hosting by automatically pushing the updated web assets out to Firebase s global CDN and giving them a free SSL certificate so that the app users get a secure, reliable, low-latency experience. 3

10 2.2 Android Studio Android Studio is an integrated development environment (IDE) for Google Android Operating System. It is built based on JetBrains IntelliJ IDEA Community Edition, and it specifically designed for creating applications on Android devices [3]. Some of the key features of Android Studio are as follows [4]: 1. Instant Run a feature that pushes code and resource changes to the running app. It allows changes to be made to the app without the need to restart the app, or rebuilding the APK, so that the effects can be seen instantly. 2. An Emulator a virtual android device that can simulate variety of hardware features such as GPS location, network latency, motion sensors, and multi-touch input that can be used to run and install the app. It can then be used for testing purposes. 3. Testing Tools and Frameworks extensive testing tools such as, JUnit 4 and functional UI test frameworks are included with Android Studio. Espresso Test Recorder can generate UI test code by recording the developer s interactions with the app on a device or emulator. The tests can be run on a device, an emulator, in Firebase Test Lab, or on a continuous integration environment. 2.3 Java Programming Language Java is an object-oriented programming language created by James Gosling, Mike Sheridan, and Patrick Naughton in 1991 [5]. In the paper The Java Language Specification Java SE 8 Edition James Gosling states, Java programming language is a general-purpose, concurrent, classbased, object-oriented language. It is designed to be simple enough that many programmers can achieve fluency in the language. The Java 4

11 programming language is related to C and C++ but is organized rather differently, with a number of aspects of C and C++ omitted and a few ideas from other languages included. It is intended to be a production language, not a research language [6]. Java is a very flexible programming language which is used to create many different types of applications for many different operating systems. This is possible because Java can be run on any operating system, as long as the Java Runtime Environment is available. The application created for Android devices must be coded using Java programming language. This allows these apps to work on variety of different devices, no matter the company that has manufactured the device. 2.4 XML XML or Extensible Markup Language is a text language that can be used to describe the behavior of programming languages that process them. XML was developed XML working group in According to World Wide Web Consortium there are ten design goals for XML. These design goals are [7]: 1. XML shall be straightforwardly usable over the Internet. 2. XML shall support a wide variety of applications. 3. XML shall be compatible with SGML. 4. It shall be easy to write programs which process XML documents. 5. The number of optional features in XML is to be kept to the absolute minimum, ideally zero. 6. XML documents should be human-legible and reasonably clear. 7. The XML design should be prepared quickly. 8. The design of XML shall be formal and concise. 5

12 9. XML documents shall be easy to create. 10. Terseness in XML markup is of minimal importance. XML is used when transferring data from the database to the client, and in designing the visual aspect of Android applications. When data is sent from the database, it is sent using XML. This allows the data to be processed by any programming language the same way, since the data is always sent using XML. As mentioned XML is also used to design the user interface of Android applications. This means that all the visual aspects such as, the layout of the page, the position of all button and text fields, as well as the color of anything on the page is specified using XML. Since XML is human-legible, it makes the process of designing a page in the app relatively easy and intuitive. 2.5 NoSQL There are two types of databases. Relational database and non-relational database. SQL is the best-known language used in creating relational databases, so any nonrelational database is referred to as NoSQL, also known as Non-SQL or Not Only SQL [8]. As mentioned, one of the services provided by the Firebase platform is a database. This database is a NoSQL database, which means it is non-relational and no tables exist within the database; instead all data is saved in a tree-like structure. Any storage and retrieval of data is done by using specific functions designed for the database. These functions can be called using Java, or other programming languages depending on where the database is being used. This means that there is no need for another programming language like SQL to be used to retrieve and store data within the database. 6

13 CHAPTER 3 Development Challenges 3.1 Retrieving Data from Database Although the database service within the Firebase platform attempts to make the process of sending are receiving data easy, there were still a few challenges when it came to do so. The first challenge was designing the database in a way that would allow the data to be accessed and retrieved in a logical manner. There were a few possibilities regarding the structure of the data when the database was initially designed. One possible way to structure the database was to order the food recipes based on a category such as, cuisine or course. However, this caused an issue, since accessing data outside the starting subtree (cuisine, course, etc.) based on a specific variable like the number of servings was not very efficient. This was because it required the program to backtrack within the sub trees in order the check other subtrees for the specific variable. Another way to structure the database was to have the categories as before but copy the recipes to each category. This solved the issue with backtracking since the variable within each recipe could be checked by going to the main trees. But the glaring issue with this design was that it created a large amount of duplicate data. This is one of the main things that needs to be avoided in database design, since it slows down the retrieval and storage of the data significantly, while also increasing the amount of memory used by the database. The last way to structure the database was to put all recipes within one sub tree with this sub tree being divided into different branches with branch containing a recipe. Each branch is separated based on the name of the food the recipe is based on. This was 7

14 the best way to design database, since it avoided back tracking and the need to have duplicate data due to all recipes being within the same sub tree. This was the design that was chosen as the final design for the database. Figure 1 Final Database Structure The second challenge was retrieving the data from the database. Retrieving a specific recipe is not a problem, but if the app tries to retrieve multiple recipes or a 8

15 specific branch within multiple recipes (ingredients, prep time, and so) all at the same time, it can result in saving incomplete data or crashing the app. This is due to concurrency which is used by the app. Concurrency in computer science refers to a situation where different parts of a program run independently of each other on multiple threads. These parts are executed in different orders, but the result will be the same as in a sequential system [9]. Concurrency is used mostly in systems with multiple processors, and if done correctly can lead to a significant speed-up. As mentioned, in this app the retrieval of data is done concurrently. When the app attempts to retrieve multiple recipes or branches from the database it starts by calling the functions related to this process for the first recipe or first branch. But since this is done concurrently, the program might stop before all function calls are complete, and move on to calling the functions for the second recipe or branch. The program can then go back to the process that was stopped earlier to continue or finish it. This behavior can cause a couple of problems. One of these problems is that before the first process is complete, the second process might finish and attempt to save the data using a variable already in use by the first process. The program crashes since multiple processes cannot access the same memory location at the same time. Another problem that can arise is that the retrieval of data might be left unfinished, since the process for the last recipe or branch can finish its job earlier than other processes. This will then stop all other processes before they are finished, which will result in incomplete data. The program has two functions for retrieving data. One function gets the name of all recipes that going to be accessed in the database, and processes that information, while 9

16 the other function retrieves the data from the database using the information provided by the first function. One way to solve the concurrency issue caused by these functions was to combine both into one function. This however, made the code considerably more cluttered and harder to read. Another way to solve the issue of concurrency when retrieving data from the database was by using Tasks. Tasks are a special class created for Android apps that take care of multiple processes by making sure that variables are not accessed by multiple processes at the same time. They also solve issue with the incomplete data by confirming that all processes are finished before stopping the retrieval of data. Solving the issue this way led to a cleaner code and had the benefit of asynchronous operation. This was the method that was chosen for development of the app. Figure 2 Example Task Class 3.2 Storing Data in Database Firebase provides a few functions for saving data to database. A couple of notable functions are the push and set functions. When saving data using the push 10

17 function, the platform automatically saves the data using a unique key. This function is useful for creating new values, but it cannot be used to modify or rewrite already existing values. The set function does both of those things, but one needs to be careful when using this function. Since this function will rewrite any value with the same key using the new information. Because the name of the recipe is used as key for recipes in the database, then in this app the set function is used to store data in the database. As stated, when using set one needs to be careful not rewrite already existing data incorrectly. Because of this, when the user attempts to create a new recipe, the program retrieves all recipe names from the database, and checks to see if a recipe with the same name already exists. If it does, then the user is notified, and the recipe will not be added. A functionality that the Firebase Realtime Database provides is the ability to store classes in the database. This allows multiple branches (ingredients, instructions, prep time, and so) within each recipe to be added at the same time. This is done by creating an object of the class type that is going to be added to the database, and saving it using the set function. When creating a class that is going to be used to save the data, one needs to make sure all class variables that are going to be stored in the database are set to public, and a default constructor that takes no argument is available in the class. Failure to do so, will result in the program crashing when attempting to store the data. 11

18 Figure 3 Storing an Object in the Database 3.3 Filtering Recipes Based on User s Choice The user can filter the recipes chosen based on course, cuisine, or type further by using the filtering functionality in the app. This functionality allows the user to filter the recipes based on the ingredients used in the recipe, the time it takes to make the food (prep time, cook time, and ready time), and the number of servings. There were two things to consider when this functionality was implemented. First thing to consider was that the ingredients related to all recipes chosen based on course, cuisine, or type were needed to be passed between the pages in the app. The second thing was the implementation of a method that retrieved the relevant extra information (like the prep time or number of servings) from the database, and then process the recipes based on the filters applied by the user. The passing of data between the pages in the app was done using the putextra and getserializable functions, as well as the Intent and Bundle classes. The putextra function along with the use of the Intent class allows information to be passed between one page to another. By using putextra a list of all recipes and a map 12

19 structure containing the recipes as key and the ingredients as value were passed from the pages where recipes are chosen based on course, cuisine, or type to the page were the filtering is applied. The information sent by the stated functions was retrieved in the filtering page using the getserializable function and the Bundle class. The first set of choices (course, cuisine, or type) were provided to reduce the number of recipes that go through the filtering process. Doing this led to a faster filtering process and reduced the amount of memory used by the program. Figure 4 Passing Information from One Page to Another 13

20 CHAPTER 4 Application Pages 4.1 Main Page The main page allows the user to choose to see sub menus for courses, cuisines, and types of food. This is done to limit the number of recipes that need to be retrieved from the database to increase the speed of the app. The user can also choose to go the recipe adding page from the main page. Figure 5 Main Page 4.2 Add Recipe Page The add recipe page allows the user to add their own recipes to the database. There are text fields available for recipe name, ingredients, instructions, prep time, cook time, ready time, number of servings, and web address. The text fields for recipe name, ingredients, instructions, prep time, and cook time are required to have a value. If any of them are left empty, an error message will be shown. If the text field for ready time is left 14

21 empty, then the ready time of a recipe will be its prep time plus its cook time. There are also drop-down menus available for course, cuisine, and type. The list of items within each drop-down menu is based on the items available for searching. Figure 6 Add Recipe Page 4.3 Courses Page Different courses that are available in the database are listed here. These includes appetizer, main, and dessert. The user can get the list of all recipes that are placed in any of these categories. Adding new buttons for new courses such as drinks to the app is very easy. This is due to the usage of the Task class and custom functions, as discussed in the previous chapter. 15

22 Figure 7 Courses Page 4.4 Cuisines Page Similar to the courses page, in this page the user can get the list of recipes based on the cuisine categories provided. These include, American, Italian, Mexican, and Middle Eastern. Again, adding new cuisine choices can be done very easily. Figure 8 Cuisines Page 16

23 4.5 Types Page The categories for different types of food can be found here. The user can filter the list of recipes based on these types. Some of these types include, cake, casserole, fajitas, ice cream, omelet, and pizza. Like the previous pages, adding new categories is an easy process. Figure 9 Types Page 4.6 View Recipe List or Filter Page This page appears after the user chooses a course, cuisine, or type of food. In this page the user can either look at the list of all recipes shown based on the user s choice, or he or she can choose to go to the filter page where the recipes can be filtered further based on the provided choices. 17

24 Figure 10 View Recipe List or Filter Page 4.7 Filter Page In this page, the user can filter the recipes taken from previous categories (course, cuisine, and type). The filtering options available are, filtering by ingredients, filtering by time, and filtering by number servings. Filtering by ingredients can be done by choosing one or multiple ingredients, or by typing the name of the ingredients that that the user wants to in the recipe. Filtering by time and number of ingredients can be done by pressing the available buttons. 18

25 Figure 11 Filter Page 4.8 Filter by Time Page Once the user presses the time button on the filter page, he or she will be taken to this page. Here, the user can filter recipes by prep time, cook time, or ready time. This is done by using the sliders available on the page. Figure 12 Filter by Time Page 19

26 4.9 Filter by Number of Servings Page When the servings button on the filter page is pressed by the user, he or she will be taken to this page. Here, the user can filter recipes by number of servings. This is done by using the sliders available on the page. Figure 13 Filter by Number of Servings Page 4.10 Recipe Information Page Once a recipe is chosen from the list of recipes, the recipe page will be shown. This page includes a text field that contains all the information related to a recipe. This information includes, web address (if available), course (if available), cuisine (if available), type (if available), cook time, prep time, ready time, number of servings, ingredients, and instructions. 20

27 Figure 14 Example of Recipe Information Page 21

28 CHAPTER 5 Conclusion and Future Work This project was developed to allow users to add and find food recipes using an intuitive and simple to use mobile application. The app allows the users to find recipes based on different criteria such as, course, cuisine, and type of food. It also provides a filtering system that can be used to filter the list of recipes based on the ingredients used in each recipe, the time it takes to make the food, and the number of servings. The app also allows the users to add their own recipes using the interface provided. A feature that I would like to implement is some sort of moderation system for recipe addition. Using this system recipes added by the users will be checked for validity, as well as any inappropriate remarks or words. If a recipe does not pass the check it will not be added to the database, and users will be provided an explanation as to why the recipe was not added. A set of guidelines will then be shown to users to help them add their recipes to the database. Another feature that I would like to implement in the app is a user system. This system would allow the users to create an account using an address. This would then allow the recipes to be added only by the register users, instead of anyone using the app. This would make the moderation of the app users much easier, since a user can be banned if he or she attempts to add bogus or inappropriate information to the database constantly. This system would also allow the users to update the recipes that they have already added to the database. In the end, the final goal of this mobile application is to provide a platform that allows anyone to share and find food recipes conveniently. 22

29 REFERENCES [1] Merriam-Webster. Database Definition of Database by Merriam-Webster. Retrieved May 4, 2018 from [2] Firebase. Firebase Products. Retrieved May 4, 2018 from [3] Katherine Chou, Xavier Ducrohet, Tor Norbye Android Developers Blog: Android Studio: An IDE built for Android. Retrieved May 5, 2018 from [4] Android Developers. Android Studio Features Android Developers. Retrieved May 5, 2018 from [5] Jon Byous JAVA TECHNOLOGY: THE EARLY YEARS. Internet Archive, Retrieved May 6, 2018 from day.html. [6] Gilad Bracha, Alex Buckley, James Gosling, Bill Joy, Guy Steele The Java Language Specifications Java SE 8 Edition. Oracle America Inc., Redwood City, CA [7] Tim Bray, Eve Maler, Jean Paoli, C.M. Sperberg-McQueen, Francois Yargeau Extensible Markup Language (XML) 1.0 (Fifth Edition). Retrieved May 6, 2018 from 23

30 [8] Technopedia. What is NoSQL? Definition from Technopedia. Retrieved May 7, 2019 from [9] Technopedia. What is Concurrency? Definition from Technopedia. Retrieved May 11, 2018 from 24