In this assignment, your overall task will be to develop a web application that makes crime statistics available to the user, based on the data set that we have previously discussed in class and in the API guide. This initial document concerns the client side of the application, in which you will query the API and present the information in a form that is helpful to the user. Subsequently, you will be required to replicate the services that we are (and will be) providing on the server side, but it makes no sense to talk about that until we have at least introduced you to node.js.
The aims of this assignment are to:
- Introduce you to full web application development - both client and server side
- Provide experience in querying REST APIs and manipulating the results
- Provide experience in developing modern client applications
- Introduce you to developing modern data oriented REST APIs
- Provide experience in exposing a SQL database source as a REST API
- Provide experience in authentication and security
- Provide experience with application deployment
- Provide experience with modern web technologies including JS, React, Node.js and MySQL.
In this specification, we will not be too prescriptive, but we necessarily have to focus around some technologies, as otherwise we cannot support you in learning the material and debugging problems. You should see the development of the client for this application as a series of steps, with each one of those steps corresponding to an increase in sophistication, and in the possibility of a higher grade. We will consider these in turn below, and you can get more of an idea from the podcast which you find nearby on BB.
The dataset is drawn from the Queensland Government open data initiative, showing criminal offences across the state over a period, organised according to offence type, local government area and type of offender.
When we preview the data - use the visualisation button - we will see that there are a massive number of columns.
The REST API
We have re-organised the data so that the endpoints can remain sane. The Data API button also allows the user to query via standard SQL syntax, but we have taken a slightly different approach, offering a search facility that does not require that the user know any SQL. As discussed in the API guide, we will offer the following endpoints:
- /register (POST) - Register using email and password
- /login (POST) - Logging into your account using the details provided. This allows access to authenticated routes via a JSON Web Token.
- /offences (GET) - returns an array of offences recorded. (Open endpoint).
- /search?offence=xxx(GET)-Theprimarysearchroute.Notethatquery params need to be url encoded. (Requires authentication).
The /search route will shortly (early in the first week of April) support an optional filter parameter, with the obvious syntax:
Note that the filter parameter cannot be used by itself, and it must be coupled as shown with the offence parameter if the request is to be valid. The list of offences is available from the offences endpoint, and we will update the documentation on the main page at http://hackhouse.sh:3000 to show these, and the valid values for the filter parameter. We will subsequently serve these endpoints via https, and the http addresses will disappear or be redirected. In the server side aspect of the assignment you will be required to implement the REST API and serve the content via HTTPS.
The requirements for the client side of this assignment are ultimately pretty straightforward. The complications come because for most of you it is the first time that you have done something like this. At the most basic level, you must develop a client side web application that allows the user to work with each of the endpoints. The overall design of the site is up to you, but we will make some comments about clean and modern looking sites below.
Broadly speaking, the grade levels for this part of the assignment will correspond to the following feature levels. We will assume here of course that things are working perfectly, and you should understand that the grade levels can go down a little if there are errors or some elements are incomplete. But the basic passing levels are as follows:
- A simple web page with limited formatting that implements the endpoint queries discussed below, and displays the results on the page using AJAX calls and HTML. As discussed in the podcast, much of this can be achieved by adapting the sample code from the API guide. Functionality must include proper registration, login and queries of the open and authenticated routes. React is not used at this level - although of course it is possible to get a 4 level mark by doing a bad job of a 5 level requirement. Similarly, if you do a bad job of this 4 level requirement, then you are likely to get a 3 level mark.
- At the next level, we expect you to use React. The essential requirements here are that the responses to the queries should use the techniques that you will learn in the pracs of week 6 and week 7. We expect that the data tables should be readily sortable via the column headers, and this level includes successful processing of all of the endpoints discussed. For bonus credit you should include some in-page filtering - essentially you supply some text and only those results which match should remain. We will give you some latitude in this, and you can also get some ideas from the discussion below.
- At the higher grade levels, we will expect one or more features drawing on graphing and mapping. At the grade of 6 level, we will expect at least one of them to be implemented properly. We don’t really care which, but the functionality should be in line with the examples discussed below. These components are visual in nature, and it is far better just to show you what we mean.
- At the 7 level, you will need to implement both graphing and mapping, and to do both of them well. Ultimately we are not asking for more than a standard application of these libraries, but there is a fair bit of work for the novice to get on top of the data handling.
The endpoints are divided up in a couple of ways - how often they are used and whether or not they require authentication. We will consider each of them in turn.
Registration and Login
The /register and /login routes are best seen as prerequisites. We register only once, and we login once at the start of each usage period. You must use a form for each of these endpoints, as the user needs to supply an email and a password. The main elements of the form should be the same for each of them, and if the user has just registered, then their details should pre-populate the email and password fields for the login screen. Passwords should not be shown, and appropriate error messages should be displayed if the request fails. You should explore the response of the API to each of the obvious cases. If the email and password already exist in the database, then the registration will fail and the user needs to know this, and similar messages will be needed for errors involving login.
As in the example code from the API guide, you must propagate the login JWT in order to access the authenticated routes.
The Offences Information Endpoint
The next endpoint is the simplest - an open /offences API that just lists the offence categories available in the database. Here, your basic task is simple - just display the offences in a table, with the functionality as listed above in the discussion of grade levels.
The Search Endpoint
Finally, we get down to business. In this case, our basic level of functionality is to support the queries according to offence category with filters according to other attributes such as Local Government Area. These are extended as described above to reach the grade of 5 level. We now take a look at some possibilities for graphing and mapping and filtering. If we look at the grid display, we can quickly see a text box at the top, allowing us to search the data. On load, the data seems to be organised according to the ID field, and so at the top of the table I see mainly the entries from Aurukun and surrounding areas. If we type ‘Winton’ into the search box at the top, then this has the effect of selecting specific records in the page. Note that this should not require that you hit the server again - this should be local processing of the collection of records that you have available. We see the result on the next page, dominated by Winton:
We are now going to work with the graphs and the maps. Click on the graph button and make the selections as shown. Here axis 1 is the X axis, and axis 2 is the Y axis. We have selected assault as a column chart over time.
You may find the following links useful:
- Chart.js: https://www.chartjs.org/
- D3.js: https://d3js.org/
The approach to mapping is similar, but the Queensland Government page is not very intuitive. Here we will want you to show the relative levels for a particular time period for all the local government areas. Getting the full co-ordinates for a council region in Queensland is likely to be very tricky. We will update our SQL tables to include the latitude and longitude of the main centre for each Local Government Area, and requite that you place markers and/or a heat map blob on the map showing the values for the offences selected. We will give you an example once the tables are updated.
You may find the following links useful. We do not mandate a particular API, but many will use Google or Bing. Mapping products vary in their terms and conditions. It is not required that you purchase any product in order to complete this assignment. Some APIs may require your credit card prior to giving you an API key, but there are alternatives that don’t require this. If you have any concerns, please talk to me at the lecture on Wednesday.
- Google Maps: https://cloud.google.com/maps-platform/
- Leaflet JS library: https://leafletjs.com/
- Bing Maps: https://www.bingmapsportal.com/
Which brings us finally to the submission. Your client application will be submitted as part of an overall package, which will include the server side code as well. Actual Blackboard submission will thus not take place until week 13. However, there are some steps that you will need to take in the interim. The image below is from the first lecture. The timetable remains unchanged in respect of the demos - you can demo to us before the holidays or just after, but you must demonstrate to us that your assignment actually works to a passing level. We will award 10 of the 60% allocated to the assignment if you can show us that you have a system that meets the requirements. If you do not demo, then the maximum you can get will be 50/60 overall. The purpose of this requirement is to encourage people to start early and to show us your work so that we can help you get on track for the highest mark possible.
If your demo is not satisfactory, your tutor will allow you to demo a second time up until the end of week 10. After that, the marks will be lost. The overall assessment of the assignment will be based on the server and the client side for 50 marks against the criteria sheets. There will be 30 marks attached to the server component and 20 attached to the client side. With 10 marks from the checkpoint demo, this will leave us with 60% overall.
There is one final requirement that you will need to look at before turning your attention to the server code. We will expect a short report and user guide, generally running to 5 pages or so, including screenshots. Your report must include the following sections:
- Introduction - telling us what was implemented and what wasn’t, showing a few screenshots to illustrate the functionality. This will probably occupy a page or a bit more.
- Technical description of the application. This section is to allow you to talk about the APIs used for graphing or mapping, to show us any tricky data flows, and to discuss technical issues that caused you problems. This is especially important if something doesn’t actually work.
- Testing and limitations - test plan, results, compromises.
- Appendix: brief user guide
We will require a similar report for the server side. For now, time to get working. The CRA rubric will be released as a separate file.