Building a React.js App: Making Server Requests in React with Axios

Our app is coming together very nicely, but one thing we need to do now is we need to go and fetch the data from github in order to populate both of these components. What we're going to use is this tool called Axios. Axios allows us to make http requests or network requests in its problem space, so it's really nice. If you're coming from an Angular background it's very similar to $HTTP in Angular. Head over to your terminal and go ahead and run npm install axios.

Now once that is done, let's go ahead and we're going to make a helper file for us that is going to handle our network request. So let's go ahead and make a new folder called utils, inside this utils folder go ahead and make a file called helpers.js. In this file we're going to go ahead and require Axios, and we're really concerned about two things, we're concerned about getting the users repos, and getting their profile.

So let's go ahead and make two functions, the first one let's called getrepos, it takes in a username and it's going to return whatever axios.get returns us, and we're going to hit this endpoint and get that user's repos. So if you're not familiar with promises, don't worry about it too much right now, we'll talk a little bit more about promises here in a little bit. For now, let's just create another function called getuserinfo that takes in a username and it's going to return us whatever axios.get returns us, and we're going to append username.

In a nutshell this is how promises work. If I were to invoke the getrepos function, let's say I pass in my github username, that's going to return us this promise object, OK? This promise object then has a .then property on it, and the function that we pass to .then, the callback function, is going to get invoked whenever this promise gets resolved.

So basically the way this will work is we call getrepos, that returns us a promise that says, "OK, when we go and we fetch the data from this API, when that data is back, go ahead and invoke this callback function and then console.log data." So it's really convenient, it kind of gets around the idea of having callbacks and callback hell and all that stuff. But the way we're going to use this is actually a little bit more advanced.

We're going to create an object that we're going to export, and a property on this object is going to be called getGitHubInfo, because if you think about what we're doing, we basically need both of these functions to be invoked at the same time, and when we get the data back from both of them, when we have the repos and when we also have the user information, we then need to render the component and show all that data to the view.

What we're going to do is we're going to use a feature of Axios called axios.all. Let's make sure we passed in our username here first. All right, so what axios.all does is it takes in an array of promises, so let's invoke getrepos, and let's also invoke getuserinfo.

So then what we can do is that will return us a promise which we pass a callback function to, and now what's going to happen is instead of just waiting for one promise to be resolved and then this function will be invoked, what happens is axios will wait for both of these promises to be resolved, and then it will pass us an array of data we got back from both of these invocations.

So it's really convenient because we can make these requests the exact same time, and when both of them are ready, this function will run passing us that array. So let's go ahead from here all we want to do is return an object that has a repos property and it returns us an array, the very first property in this array is going to be the repository, the users repositories because that's the first item in the array that we passed axios, and the second property in this object is going to be bio and it's going to be at the first index.

So again, to recap what's going to happen here is when we invoke getGitHubInfo we pass it a user name, we then will invoke axios.all and pass it two promises. When both of these promises resolve, or when this data has gotten back from github, both of these pieces of data, this function's going to run and it's then going to pass us back an object with our repos and with our bio.

So now let's go ahead and head over to our profile view or profile component and let's utilize this. So let's go ahead first and we're going to require helpers, and I believe we need to go back a folder and then into utils, and then to helpers, and then let's go ahead and make it so when this component mounts, after it sets up the Firebase stuff, let's go ahead and invoke helpers.getGitHubInfo.

We're going to pass it the username from the route params and that will return us a promise which we then can pass a function which will get invoked when our data object is ready or when our github data is ready. Once it's ready we can call this.setstate and we set the bio to the bio object and we set the repos property to the repos object.

All right, so there's one little gotcha in here, if you're familiar with the this keyword in JavaScript you already know that this keyword is different than this keyword, and that sounds a little bit weird, but basically whenever you go inside of a new function a new context is created, and so this keyword is going to be a little bit different than this keyword.

So what we need to do as our goal is to basically make it so this keyword is the same as this keyword because if it's not, then this one isn't going to have a setState property. So one trick you can do is here, you can use .bindThis and in a nutshell what .bind does, it returns you a new function and you're allowed to specify the context of that new function, so all this is doing is it's saying, "Hey, return me a new function with a context, or with the this keyword inside of that function referring to this keyword instead of this keyword inside of that."

That sounds confusing, I know, but if that's still confusing go ahead and look up how the this keyword works and you will be entertained for days. One note really quick about the this keyword, if you're still confused I've made three lessons and they're actually my favorite Egghead lessons I think I've made on the this keyword. So if you're still confused go ahead and check out this playlist, and it should help you out a little bit.

All right, so if this worked correctly what's going to happen is when the component mounts it does some Firebase stuff, it goes and gets our github information, gets the data resets the state and changes our bio and our repos property. We can clear these out now too, and then as of React .14 we can no longer just get JSON and show it to the view so what we're going to do is instead of just spitting that all in the view, let's go ahead and just console.log this.props.repos so we can see what that is.

Make sure everything's working, and then same thing in our user profile component let's go ahead and remove bio and instead just console.log bio as this.props.bio. All right, webpack is running, let's see if this works. So we should see here is two responses, we also have proptype, that's fine for now. So bio.data, we have all our data and then repos.data here are all our repositories.

So now one more thing, let's go ahead and make it so we don't get the whole response object, but we just get the data. So inside of our helpers instead of returning just the first item, let's go ahead and return the first item with data then .data here as well. So that should give us just this data properties Check it out, and there we go, there's our bio and there are our repos.