Select fields in API request

[salvadorperez]

Hello, everyone.

I was wondering whether it is possible to select the fields I need instead of receiving full objects when doing API calls. For example, let us assume that I want to get an assignment list for a course, but I only require the id, name and  due date, because descriptions and rubrics data are too long and I don't really need them.

I know this might sound a bit pointless; yet consider that in some cases I need to generate Excel sheets using WEBSERVICE formula, and Excel has a cell size limit that triggers an error when the JSON longitude exceeds it.

Any help would be really appreciated.

Regards.

[chriscas · Accepted solution]

Hi @salvadorperez,

With the REST API, there isn't a way I know of to limit the information returned.  You could look at using the GraphQL API, which is much more customizable and does allow you to select what results you'd like returned, but in my opinion might not be quite as friendly for new/amateur users.

I hope this at least answers the question!

-Chris

[chriscas · Accepted solution]

Hi @salvadorperez,

With the REST API, there isn't a way I know of to limit the information returned.  You could look at using the GraphQL API, which is much more customizable and does allow you to select what results you'd like returned, but in my opinion might not be quite as friendly for new/amateur users.

I hope this at least answers the question!

-Chris

[salvadorperez]

Dear Chris, 

thank you for your quick reply. Yet, I am a bit lost here, because I was quite capable of finding and reviewing the documentation of the REST API here (Canvas LMS REST API Documentation); however, I can't find any information about GraphQL. 

Please, forgive me if my question is a bit dumb, but how can I do a simple cURL request using this API? 

With the REST API I do the following (for testing purposes, only):

curl "http://$MYDOMAIN/api/v1/courses/(etc...)"

Any help will be really appreciated.

Thank you.

Regards.

[salvadorperez · Accepted solution]

I fell under the temptation, and I went to ChatGPT. Now I understand how to do it.

Thank you all, nevertheless.

In short:

- All queries using GraphQL are POST methods (you send the query to the server)
- The URL is this: https://your_canvas_instance/api/graphql
- You need to construct the query JSON in order to select the fields you want (the same fields described in the REST API documentation)

Regards.

[JamesSekcienski]

@salvadorperez 

I agree with Chris about using GraphQL if you want the API response to only include select data.

Based on that limitation with the WEBSERVICE formula, have you looked into other options for how to get data from an API into Excel?  Based on quick initial research, it looks like Power Query might be a better option to get the data and then parse the JSON data into a table.  This could allow you to still use the REST API which is easier, but also allow you to manage the data that you want in Excel.  Here are some example resources I found, but if anyone else has any advice, please share your experience/recommendations too:

• https://www.howtoexcel.org/how-to-access-a-json-api-with-power-query/ 
• https://theexcelclub.com/how-to-parse-custom-json-data-using-excel/ 

[salvadorperez]

Hello, James, 

thank you for your answer. I am a little constrained in terms of resources here, so Excel seemed to be the best approach at that time.

Nevertheless, I appreciate the information you have shared with me. I will be taking a look of it really soon.

Thank you, very much.

Regards.