The ABCs of Canvas Dev

[kevinw]

Hello geniuses, 

I am really in need of some help. I work for a small non-profit and when it comes to Canvas, I do it all. Course design, administration, training. Jack of all trades, master of none 

I am really in need of some bare bones, basic beginner stuff about how to set up OAuth2 between Canvas and Postman. It seems like being able to move towards something like this could make my job much easier once I'm past the learning curve. 

Can anyone point me in the direction where I can learn about this for like, complete and total newbs. A mooc, a youtube series, a blog, a website. I'm really up for anything. Everything on instructure seems to be aimed towards people who already know what they're doing. 

[ColinMurtaugh]

Hi Kevin --

If you're trying to use Postman to make Canvas API calls, then you probably don't want to use OAuth.  It'd be much simpler to use token authentication, and it's not too hard to set up.  The first step is to generate a token for yourself in Canvas: go into your User Settings page, and look for the "+ New Access Token" button at the bottom. Click that, and it'll ask you to enter purpose and an optional expiration date. You can set the purpose to be whatever you like -- maybe "Postman" in this case. Click the "Generate Token" button and copy your new token from the next screen. 

Now you have an access token that can be used to make Canvas API calls as you. This means that calls made with this token will have the exact same permissions as you do when you're using Canvas in the browser. 

Here's an example of what you'd need to put into Postman in order to make a GET request (using your token) to get a single course:

When you click "Send" you should get a response that includes the JSON-formatted course details (you may need to change the numeric course ID at the end of the URL to an actual course ID in your system). 

There's a great post on the community from  @garth ‌ that has much more detail, including examples of POST requests, etc., here: API Testing: Postman 

I hope I've understood your question properly and this is helpful, but please let me know if you still have questions!

--Colin

[kevinw]

Thank you for that resource. Since I posted this I had actually been able to dig that up and get it up and running but I'm still trying to get past the learning curve. I'm kind of surprised that with all the free "learn how to code" stuff that there is, there's nothing online designed for beginners for API calls, save maybe Garth's post. 

Are there any other resources you can point me to? 

[ColinMurtaugh]

Yeah, I know what you mean - most people using the Canvas API (and APIs in general) are going to be writing code to do that, and they generally come into it with some experience using one programming language or other.  Most of the documentation and tutorials you'll find out there will be focused on a particular API (and possibly a particular programming language), so it's going to be difficult to find something generic. I haven't read through it all, but there seems to be some decent background information on REST APIs in general here: REST API Tutorial 

If you've got experience using a particular programming language, or if you've got one in mind that you're thinking of learning, I or someone else in this group might be able to point you to some more specific resources.

--Colin

[garth]

 @kevinw ‌ I agree with 50581462, if you're using Postman with the API, you don't want to use OAuth.

T‌his article will walk you through creating an access token for your account:

• How do I obtain an API access token for an account? 

The access token is really all you need if all you're doing is making API calls.

If you have questions about specific API calls, don't hesitate to post specific questions back to the Community, people here are pretty good about responding.

If you have any experience with .NET, I have posted a sample app in C# illustrating how to utilize the API with your access token here:

• .NET - Canvas API Implementation‌

The C# project gives examples of making POST / PUT / DELETE calls through code.  You could easily take that project and create your own business logic around it to generate custom reports or execute custom workflows to automate tasks in Canvas.  This project in coordination with the API documentation will give you a lot of bang for the buck.

OAuth comes into play when a third party application needs to authenticate on behalf of a user.  It is very useful, required, if you are going to develop an LTI app, which you may find useful down the road.

A beginners tutorial to LTI can be found here:

• .NET LTI Project - Part 1 - Connect to Canvas‌

And I've started a tutorial on the OAuth2 workflow here:

• .NET - OAuth2 Workflow: Part 1 - Authrorize Redirect‌

Work has interferred lately, I need to add at least one more, maybe two, parts to the OAuth2 posts.

I hope any of this helps. Again, post specific questions and I'm sure you'll get help.

[kevinw]

Thank you for this! Bookmarked