Technology

Eleni Chappen

Uploading images from React Native to your server

Aug. 25, 2017

If you’ve ever felt the need to convert an image in React Native to base64 in order to upload it to your server, there may be a better way.

We typically use react-native-camera for our photo-taking needs. With this package, you can store images on a device in a few ways. We use the option to save the image to disk if we plan to upload it:

<Camera captureTarget={Camera.constants.CaptureTarget.disk} ... >  

The data returned from capturing an image will be a file path to your saved image, something like:

var filePath = 'Developer/CoreSimulator/Devices/8B8CBF19-7B64-4C21-8FFF-BB835254C77D/data/Containers/Data/Application/EE3FFDA1-A0FC-43F4-85A8-435CDA35731A/Documents/test.pdf';  

When it’s time to send the image to your server, create a new FormData object using this file path:

var data = new FormData();  
data.append('my_photo', {  
  uri: filePath, // your file path string
  name: 'my_photo.jpg',
  type: 'image/jpg'
}

Then for your request, set the body to this data object:

fetch(path, {  
  headers: {
    'Accept': 'application/json',
    'Content-Type': 'multipart/form-data'
  },
  method: 'POST',
  body: data
});

By uploading images this way, we don’t have to configure our server image libraries (like Paperclip) to handle base64, saving us time and effort.

Eleni Chappen

What People Are Reading

Operations

8/1/16

Good Founders Make Good Clients - 5 Traits We Look For

“Ideas are easy. Implementation is hard.” – Guy Kawasaki

As a development agency that primarily works with early stage startups, we hear all kinds of business ideas. You could even say that we're in the business of building business ideas; but only one's we believe will succeed, and not on our own. We know that, without a good founder to drive implementation, even the best ideas will surely fail. In fact, most give up at the first sign of real challenge, and their ideas never see the light of day. So while we spend time evaluating the viability of the idea, we must also consider if the founder has what it takes. Here are the 5 traits we look for:

1. Tenacious belief. Some traits can be learned or honed; this is not one of them. Startups are inherently difficult, demanding, and full of unknowns and disappointment. To make it through, a founder needs confidence, determination, passion, and the like - things you can't have without first believing. We're not talking about simply believing you have a good idea. We're also not talking about blind belief to the point of delusion. This is believing strongly enough in your vision that, despite the uncertainties and inevitable struggles in your path, you will do whatever it takes to see it through.

2. Domain expertise. Serious founders need to understand their market as much as possible. Ideally, you can directly relate to the problem you're trying to solve - or - you have extensive experience that gives you insight on your target market. Even then, the best founders do everything they can to consistently learn and absorb new information.

3. Communication. The greatest entrepreneurs are masters of communication. Not all start out that way, but its something to be conscious of and constantly improve. A good founder has the ability to communicate clearly, confidently, and candidly. They can clearly explain their thoughts and ideas. They use confidence to sell themselves and their vision, as well as to lead others. They can candidly express their feelings, while maintaining control of their emotions.

4. Head in the clouds, feet on the ground. Growing a startup requires constant innovation. A good founder has vision; they dream big and consistently ask themselves, "what's next?" However, that vision will never materialize unless a founder can execute in the present. A good founder can keep their eyes to the future while practicing self awareness, focus, patience, and responsible decision making.

5. Flexibility. The survival of a business, like in nature, depends on its ability to adapt. No matter how much a founder plans, new information will arise and circumstances will change; a good founder is prepared and willing to respond. Some changes will inevitably result in failures. A founder must have the resilience to pick themselves up, learn from the failures, and push on.

6. Enjoys the ride. I know I said 5 traits, but this one's pretty important too. Yes, starting a business is difficult, risky, blah blah blah...but what's the point if you can't enjoy it? Having fun will not only make your life (feel) easier; attracting advocates, customers, employees, and investors will be easier as well.

Now these aren't the ONLY things a founder needs to build a successful business, nor do they guarantee success, but we'd bet on you. So if you have a great idea and "what it takes" (see above), we should meet.

Technology

1/6/17

React Lessons for Newcomers

At 20spokes, developers spend a roughly equal amount of time between Ruby on Rails and React. While we enjoy working in both frameworks, they are quite different in approach, and going from a Rails way of thinking to a React way of thinking can be an adjustment.

One major way in which these frameworks are different is that Rails takes care of a lot of architectural issues that React leaves open for interpretation. Coming from a Rails background, I found the openness of React to be a bit anxiety-inducing at first, but I've come to really embrace it, because it's forced me to think more carefully than ever about how other developers would approach my code.

As a team, we've also considered what our best practices should be towards React, as we all want to make our code understandable and friendly to anyone who encounters it. To that end, below is a (growing) list of our approaches to making our React projects not only maintainable, but enjoyable to work with.

Be relentless with components

The basic building block of React is the component. To those new to React, they can best be thought of as modules.

As a developer, I start to get nervous when I see large components that perform various functions. The solution to keeping your files short and sweet is to take every opportunity to break your objects into re-useable components. Having larger components may not seem like a big deal when starting a project from scratch, but if you relentlessly component-ize you'll thank yourself as your project grows.

There are some code smells to recognize when you should create new components. If you see lots of groups of markup within a single div, those groups should probably be their own component.

If we have lots of renderXXX functions within in one component that render more markup, that's usually a code-smell that whatever is being returned from those functions should be their own component.

Make components as reusable as possible by passing dynamic data as props.

Privilege functional components over class-based ones

In many cases, it's overkill to Use React's Component class for every component you create. Not all components need access to the Lifecycle Methods or local state that Component provides. Start with stateless functional components and turn them into React Component instances as needed.

Take advantage of PropTypes

We started the practice of listing out PropTypes at the bottom of every component, so other developers can quickly reference what props are needed or optional. Oftentimes, we'd investigate what data we should expect in a component by looking up examples of that component elsewhere in the codebase. This easily can be avoided by using PropTypes, which provide a quick way to see what data is being passed, and of what type that data should be. Here's an example from our reusable Button component:

Button.propTypes = {  
  text: PropTypes.string.isRequired,
  onPress: PropTypes.func.isRequired,
  disabled: PropTypes.bool,
  icon: PropTypes.string,
}

We're pointing this out because, while Facebook already notes it as a best practice in their documentation, it's something that's easy to skip over or forget to do. But for something that's not hard to do at all, it provides a lot of value when developing and maintaining your app.

Use Lifecycle Methods with care

Despite being incredibly powerful, lifecycle methods (like ComponentDidUpdate) can cause a lot of headaches to those new to React. Be careful when updating state or props within these methods, as it may cause infinite looping.

For this reason, I prefer to place lifecycle methods at the very top of a component declaration, so I can see all of that logic together when debugging.

Check out part 2 of this series, Redux Lessons for Newcomers.

Technology

11/20/17

Cross-Platform mobile development is cost-effective and faster to launch

Two years ago, if a person approached us for mobile app development, the first question would be what platform to launch on first - iOS or Android. It was almost double the cost to deploy on both and double the maintenance.

Fast forward to today, we can deploy on iOS and Android quicker before, at the same time, and with the expected native quality.

So what has changed? Technology has gotten a lot better. We particularly use React Native, an open source framework from Facebook, that allows developers to develop in a common language, Javascript, and deploy on both iOS and Android.

And it is native! Previous technologies for cross platform mobile apps would create a wrapper of a web view. Think of the older experience as using the browser on your phone for a site with a few more bells and whistles. It was close but the difference is noticeable when switching to native applications, from scrolling to the overall experience.

How does this impact everything now?

Cost is no longer double for both platforms. It can even cost less due to wide spread community support developing open source libraries.

Maintenance is a lot easier. A majority of the issues can be fixed in one code base and of the same language.

Recruitment and team knowledge is easier. Your team only need to know one language and most developers know Javascript. iOS is written in Objective C or Swift and Android is written in Java.

Reusable code for desktop web views. With React Native, we are able to share over 50% of the code with the web view, saving all of the above even more.

Stay tuned, as I’ll be going more into the technologies and other benefits.