Vscode-restclient: A way for empty string as value of variable

[lihuanshuai]

empty string '' is widely used in url parameters, is there any way to declare a variable to be empty string?

maybe something like

@q={{$empty}}

I am using a workaround now, config

    "rest-client.environmentVariables": {
        "$shared": {
            "empty": ""
        }
    },

then {{empty}} could be used inside .rest file.

but it is not elegant enough, so a system variable may be necessary

[Huachao]

@lihuanshuai Can you provide me with more details about the usage of empty string?

[lihuanshuai]

@Huachao sorry for late reply. I am testing an api with different parameter groups. The code looks like:

@param1 = test1
@param2 = test2

# @param1 = default
# @param2 = {{empty}}

GET https://{{host}}/api/items
        ?param1={{param1}}
        &param2={{param2}}

In this way, I could comment/uncomment some lines to switch parameters. yet, some parameter may be '' as a default value, if there is no {{empty}}, there won't be a way to declare such variable.

You may say, comment/uncomment &param2={{param2}} line is an option, yet isn't it too complicated? (linter will complain too). So, I think a variable for empty string will be useful.

[Huachao]

@lihuanshuai thanks for your reply, in my view, the two methods provided from you, that a query parameter like param2= and without param2 query parameter may be different for some server web frameworks. So if they act the same, they uri may look like GET https://api.example.com?param1=, right?

[lihuanshuai]

@Huachao right. even they act the same, I prefer using the {{empty}} way.

[borekb]

We have an API that looks like this:

/products?filter=some-filter

When some-filter is empty, all products (unfiltered) are returned.

The proposed feature would allow for a .http file like this:

@filter =
# or `@filter = {{EMPTY}}` or something

GET {{apiroot}}/products?filter={{filter}}

This is currently invalid (and setting @filter = '' is a different thing).

UPDATE: @filter = (no space at the end of line) is invalid while @filter = _ (the _ indicates an empty space at the end of the line) is syntactically valid, but still doesn't work.

[Huachao]

@borekb I am in favor of the proposed syntax without trailing space like Shell variables. If you have interest, a PR is welcomed

[Huachao]

@lihuanshuai @borekb @pranayrauthu I have implemented this feature, and you can define empty file variables as following:

@empty =

The trailing whitespaces are allowed, that means you can add some whitespaces after the equal sign, and the spaces will be removed in the evaluated result

[borekb]

Sounds great! Will test it out when a new version is out. Thank you.

[Huachao]

@lihuanshuai @borekb @pranayrauthu I have published this in the latest release 0.23.1 and you can verify it with the following syntax.

http @empty =
The trailing whitespaces are allowed, that means you can add some whitespaces after the equal sign, and the spaces will be removed in the evaluated result