React: Form for Contact Add

Last week’s post covered adding a read-only view of a contact’s details. As before the goal is to get the React project’s features in line with the Aurelia and Angular samples. This week we will be adding a form to all addition of a new contact. The code before any changes can be found here.

Contact List

On the contact list page, we need to add a link to create a contact. This will be added just after the header in the  ContactList.tsx file.

Routing

In order to stay in line with the other sample, the  ContactDetail component is going to be handling both the read-only view and the view to add a contact. This means the ID that is currently part of the contact detail needs to be optional. The following is the change to make ID optional by adding a question mark.

Contact Service

In the  ContactService class, we need to add a  save function. This new function will make a post request to the contacts API and return the new contact with the ID from the API to the caller.

Contact Detail

The  ContactDetail class is where most of the changes are. I had some trouble getting React’s forms to work directly with the instance of the contact class and ended up just storing the parts of a contact directly in state instead of as an object. I expect this is a failure on my part and not an issue with React. I may revisit this in the future. Below is the new structure of the state used by contact details.

Next, the  constructor needed to be changed to handle the new state structure and to handle being called without an ID.

Again, this is way more code than it would be the contact class were being used. Next, the render function needs to be adjusted to render the UI for the read-only view or the contact creation. The decision is based on the ID being set or undefined.

The render of an existing contact needs to be changed to use state instead of an instance of a contact.

The following is the render of the add contact UI. I will call out a couple of parts after. The bulk of the code is just rending of the form.

The following is the input for the contact’s name.

Since I decided to go with the controlled component route React will be responsible for being the source of truth, not the form its self. To accomplish this it is important that the input has a  name and an  onChange event handler set up. The following is the  handleChange function which uses the name from the on change event to update the proper property in the component’s state.

The following line is the reset button which will reset the state to blank out all the fields in the form.

<button className="btn btn-danger btn-lg" onClick={() => this.reset()}>Reset</button>

The  reset function just uses  setState to blank out all the fields.

Not surprisingly the submit button triggers a submit of the form. What happens on submit is defined in the opening form tag.

The  handleSubmit function takes the contact information in state and uses it to create a new instance of a  Contact which is then passed to the  ContactService to be saved. The service returns a new contact object from the server and the ID is stored to state.

If the server does return an ID for the new contact then the  redirect is set to true. Then will case the following code to run in  renderNewContact which will redirect the user back to the read-only view of the new contact.

Wrapping Up

This pretty much gets the React application in line with the Aurelia and Angular sample applications. It has been fun getting a handle on the very, very basics of React. While I am back in the basics sample projects I may go ahead and tackle a Vue sample next.

The finished code can be found here.

React: Contact Detail

Last week’s post covered adding a React project to the ASP.NET Core Basics solution. As I stated last week the goal is to get the React project’s features in line with the Aurelia and Angular samples. This week we will be adding a read-only view of a contact’s details. The code before any changes can be found here.

Contact Class

The  Contact interface in the  ContactList.tsx should be deleted and in its please we will add a  Contact class. As part of this change, I also moved the contact related items to a contact directory. Add a  contact.ts file to the  ClientApp/components/contacts/ directory with the following contents.

This class is very simple and will be used later to show how a function call can be used as part of rendering.

Contact Service

Since the application will now have two places that need to access the ASP.NET Core API I decided to refactor the API access behind a service. This is the same style used by the Aurelia and Angular applications. Add a  contactService.ts file to the  Contacts directory. The service will provide functions to get all contacts or a single contact using its ID. The following is the full class.

The final step in this refactor is to use the new service in the  ContactList class. First, add imports for the service and  Contact class.

Then, replace the fetch call with the service.

Contact Detail Component

Add a  ContactDetail.tsx file which will be used to show the details of a contact including using the  getAddress function of the  Contact class. The following is the full contents of the file.

This is all very similar to the things I have covered before. Now that we have a contact detail component we need a way to display it.

Routing with a Parameter

Import the contact detail in the  route.tsx file.

Next, add a route path for contact detail that expects an ID.

Back in the  ContactList component change the ID to be a link to the new contact detail route using the ID of the contact.

The code for pulling the route parameter was in the  ContactDetail component above, but I am going to show it again just so all the route with parameter information is together. The route parameters can be accessed using  props.match.params.{parameter name} which in this case ends up being  props.match.params.id. The following is the constructor of the  ContactDetail component which is using a route parameter.

Wrapping Up

This brings the projects one step closer to being on the same level feature-wise. I expect at least one more post to get the project features lined up so make sure and keep a lookout for the next post.

Keep in mind that this is my first look at React and my examples may or may not be idiomatic. So far I am really enjoying working with React.

The code in a finished state can be found here.

ASP.NET Core Basics: React with an API

In the past, I have done some exploration on Aurelia and Angular via the ASP.NET Core Basics series. This post is going to take a similar approach as I start doing some exploration with React. The code for the project will be in the same repo as the previous basics examples and will be utilizing the same API to pull data. The code before adding the React project can be found here.

This post is going to cover adding a React project to the existing using the React template that is now built into Visual Studio. The same thing can be accomplished using the .NET CLI so don’t feel like Visual Studio is required. The goal for the React project in this initial post will be to connect to the contacts API and download a list of contacts and render that to the screen. In future posts, I hope to expand this functionality to match that of the Aurelia and Angular projects.

Project Creation

Right-click and select Add > New Project.

In the Add New Project dialog select the ASP.NET Core Web Application. In the case of the sample, the project will be named React. Click OK to continue.

On the next screen make sure and select ASP.NET Core 2.0 and the React.js template. Then click OK.

The following is the resulting React project in the context of the full solution.

Next, make sure and run npm install from a command prompt in the React project’s directory to ensure all the npm packages get restored.

Adding the Contact List

Inside the  ClientApp/components/ directory add a file name  ContactList.tsx. TSX is the TypeScript version of the React JSX file type. The official docs on JSX can be found here. Since this is my first time working with React I took the  FetchData.tsx file and copied the contents and used that as the starting point for my contact list. To lead with there is an interface for what should define a contact.

Next, we have an interface for the state of this component with contains a loading flag and an array of contacts.

In the constructor for the component is where the data is pulled from the API using  fetch. The data from the API is then saved to the state of the component using the  setState function.

Next, the component has a function named  renderContactsTable which takes an array of contacts and returns how they should be rendered. In this case, the contacts are rendered to a table that displays the contact ID and Name.

Finally, there is the render function. As you can guess this is what gets called to render the component. In this case, either “Loading” or the contact list gets displayed depending on if the contact list data has been loaded or not.

The following is the full file for reference.

Add Contact List to Navigation

Now that we have the contact list component it needs to be added to the navigation menu. The first step is to add it to the application’s router. This can be found in the  routes.tsx file. The file is short so I am going to include the full content. Lines 7 and 13 are the ones added to handle our contact list.

The last change is to add a navigation link to the  NavMenu found in the  NavMenu.tsx file. As I am sure most of us are used to adding an item to the nav menu is just adding a new li, but with the React specific  NavLink bit.

Wrapping Up

React is different than both Aurelia and Angular. Don’t take that as a good or bad thing. I don’t plan to pick on a side on the Angular vs React debate I just want to get a good feel for the different frameworks. So far the React experience has been pretty nice and I look forward to doing more exploration.

You can find the finished code for this post here.