How to document callbacks using JSDoc? - jsdoc

Given a Javascript function that takes callback functions as parameters:
var myFunction = function(onSuccess, onFailure) {...}
How do I document onSuccess's return type and arguments?

In JSDoc 3.1 and later, you can use the new #callback tag to describe the callback function in a separate comment block. You can then refer to the callback in the docs for your method.
Here's an example:
/** #class */
function MyClass() {}
/**
* Do something.
* #param {MyClass~onSuccess} cb - Called on success.
*/
MyClass.prototype.myFunction = function(cb) {
// code
};
/**
* Callback used by myFunction.
* #callback MyClass~onSuccess
* #param {number} resultCode
* #param {string} resultMessage
*/
See Use JSDoc for more information.

It seems this functionality does not exist yet.
This functionality was added as of JSDoc 3.1. See:
http://code.google.com/p/jsdoc-toolkit/issues/detail?id=319
https://github.com/jsdoc3/jsdoc/issues/260
for a related discussion.

Related

How does one make jsdoc actually output docs?

I'm trying to get jsdoc (version 3.6.7, using node 16) to turn my documented js code into actual documentation, but no matter what I do it just generates an out directory with an index.html that is primarily empty lines, rather than documentation. I've asked about this over on the issue tracker (after I searched the docs and the web for information on what one might be doing wrong to get jsdoc to generate empty files, but I can't for the life of me find anything useful that addresses that) but since it's been a few days, it feels useful to ask here as well, so that an answer in either place can be cross posted.
Running the jsdoc command does not flag any errors with the input, and completes with a normal zero exit code but generates nothing useful, so hopefully someone here's run into his before and can explain what is necessary in addition to the follow code to actually get jsdoc to generate docs.
An example of code that has no errors according to jsdoc, but also yields no docs whatsoever:
import { Errors } from "../errors.js";
import { Models } from "./models.js";
/**
* Several paragraphs of text that explain this class
*
* #class
* #namespace model
*/
export class Model {
/**
* #ignore
*/
static ALLOW_INCOMPLETE = Symbol();
/**
* Also several paragraphs explaining the use of this function.
*
* #static
* #param {*} data
* #param {*} allowIncomplete (must be Model.ALLOW_INCOMPLETE to do anything)
* #returns {*} a model instance
* #throws {*} one of several errors
*/
static create = function (data = undefined, allowIncomplete) {
return Models.create(
this,
data,
allowIncomplete === Model.ALLOW_INCOMPLETE
);
};
/**
* code comment that explains that if you're reading
* this source, you should not be using the constructor,
* but should use the .create factory function instead.
*
* #ignore
*/
constructor(caller, when) {
if (!caller || typeof when !== "number") {
const { name } = this.__proto__.constructor;
throw Errors.DO_NOT_USE_MODEL_CONSTRUCTOR(name);
}
}
}
Running this with jsdoc test.js yields an out dir with an index.html and test.js.html file, the first containing some thirty newlines of "no docs here" with boilerplate wrapper HTML code, and the second containing the original source code with nothing else useful either.
What else does one need to do to get jsdoc to actually generate documentation here?
I have fixed it by not using export infront of classes, instead exporting them at the end of the file. like this:
import { Errors } from "../errors.js";
import { Models } from "./models.js";
/**
* Several paragraphs of text that explain this class
*
* #class
* #namespace model
*/
class Model {
/**
* #ignore
*/
static ALLOW_INCOMPLETE = Symbol();
/**
* Also several paragraphs explaining the use of this function.
*
* #static
* #param {*} data
* #param {*} allowIncomplete (must be Model.ALLOW_INCOMPLETE to do anything)
* #returns {*} a model instance
* #throws {*} one of several errors
*/
static create = function (data = undefined, allowIncomplete) {
return Models.create(
this,
data,
allowIncomplete === Model.ALLOW_INCOMPLETE
);
};
/**
* code comment that explains that if you're reading
* this source, you should not be using the constructor,
* but should use the .create factory function instead.
*
* #ignore
*/
constructor(caller, when) {
if (!caller || typeof when !== "number") {
const { name } = this.__proto__.constructor;
throw Errors.DO_NOT_USE_MODEL_CONSTRUCTOR(name);
}
}
}
export {Model}
Turns out this was posted too early: taking the time to start at the official documentation for classes over on https://jsdoc.app/tags-class.html and running that example through jsdoc works perfectly fine, and subsequently building out that example to match the actual file's code yields working documentation just fine, too.
And in this specific case, there were several problems:
adding #namespace paired with #class was the main problem. Neither were necessary, but the #namespace entry changes how jsdoc parses the rest of a file's documentation, where if methods are to show up, they must use a #name property that includes that namespace. As that was not the case here, nothing ended up showing in the documentation.
having an #ignore on the constructor function, rather than using the #hideconstructor property on the class meant that even with #namespace removed, no documentation got written. JSdoc treats the class docs heading and the constructor as the same thing, so #ignoreing the constructor is treated the same as ignoring the entire class.
Fixing both mistakes, and removing the unnecessary #class at the top, gives perfectly fine documentation:
import { Errors } from "../errors.js";
import { Models } from "./models.js";
/**
* Several paragraphs of text that explain this class
*
* #hideconstructor
*/
export class Model {
/**
* #ignore
*/
static ALLOW_INCOMPLETE = Symbol();
/**
* Also several paragraphs explaining the use of this function.
*
* #static
* #param {*} data
* #param {*} allowIncomplete (must be Model.ALLOW_INCOMPLETE to do anything)
* #returns {*} a model instance
* #throws {*} one of several errors
*/
static create = function (data = undefined, allowIncomplete) {
return Models.create(
this,
data,
allowIncomplete === Model.ALLOW_INCOMPLETE
);
};
/**
* code comment that explains that if you're reading
* this source, you should not be using the constructor,
* but should use the .create factory function instead.
*/
constructor(caller, when) {
if (!caller || typeof when !== "number") {
const { name } = this.__proto__.constructor;
throw Errors.DO_NOT_USE_MODEL_CONSTRUCTOR(name);
}
}
}

How to document a HTML node function in jsDoc?

I need to add a function attached to a node in this way:
myElement = querySelector('#myElement');
myElement.moveMe = () =>{
//move Me Code;
}
But I do not know how to document this function (and also prevent lint errors), I tried use #extends with a #typedef but it says that it just works with constructors.
I might suggest that the right way to do this would be to create an object with {el: myElement, moveMe: ()=>{}} myself, but if you must extend, it looks like this:
/**
* #constructor
* #extends {HTMLElement}
*/
const NewType = function() {};
/** #type {function()} */
NewType.prototype.moveMe = function(){};
/** #type {NewType} */
const myElement = /** #type {NewType} */ (document.querySelector('body div'));
myElement.moveMe = () =>{
//move Me Code;
console.log('dont remove me');
}
Error free
(Not sure about your stack, just noting my 2C from recent (2019-Q1) personal VSCode JSDoc struggles.)
In theory, it seems it should be possible to use simple #typedef with "parent" type declaration: (this does not work)
/**
* #typedef {HTMLElement} movableElement
* #property {function} moveMe
*/
/** #type movableElement */
var myElement = document.querySelector('#myElement');
myElement.moveMe; // NOPE, not present for some reason :(
myElement.tabIndex; // ok, this is from HTMLElement
Closest to intention of extending native HTML elements with custom properties was to & "Intersection Type notation" I learned about from this comment either using helper type:
/**
* #typedef movable
* #property {function} moveMe
*/
/**
* #typedef {HTMLElement & movable} movableElement
*/
/** #type movableElement */
var myElement = document.querySelector('#myElement');
myElement.moveMe; // ok
myElement.tabIndex; // ok (HTMLElement properties are present as well)
Or even without helper type, with direct intersection:
/**
* #typedef {HTMLElement & {moveMe: function}} movableElement
*/
/* ... */
Strangely, any #property declaration added to such extended type seems to be completely ignored (just like our property in the first failed attempt, I'm still not sure why).
I've been struggling to achieve something similar - extend HTMLElement with some hacky custom properties in JavaScript in VSCode - and after exhaustive SO / github / docs diving this workaround-ish solution quite worked for me.

How do document a class that is returned from a function call with jsDoc

I have a large existing Javascript codebase, most of which is organized in classes created by a custom library. Most of it is similar to this:
/**
* #memberOf nameSpace.subNameSpace1
* #class
*/
nameSpace.subNameSpace1.ClassName1 = nameSpace.subNameSpace2.ClassName2.subClass({
ctor: function () {
},
/**
* method1 is a special method that does special things.
* #param config {Object}
* #returns {Boolean}
*/
method1: function (config) {
},
method2: function () {
}
})
The subClass method is defined on the Object prototype and creates a class that inherits from the object it's called on. I want to document the methods of classes that are created in this way, but unfortunately documentation like above documentation for method1 is not picked up by jsDoc (the documentation for the class itself works fine). How can I document these methods in a way that jsDoc will understand?
It turns out that using the latest version of jsdoc from npm solved the problem, and it recognizes that these methods are part of the given class if properly annotated with #function

JSDoc Class suggested layout

I'm brand new to JSDoc, and I'm trying to figure out the best way to tag my code. For some reason after I label something as a #class, I can't get anything to appear as #inner:
/**
* The logger, to simply output logs to the console (or potentially a variable)
* #class Logger
* #requires 'config/globalConfig'
*/
define(["config/globalConfig"], function (config) {
/**
* Instantiate a new copy of the logger for a class/object
* #constructor
* #param name {string} - The name of the class instantiating the logger
*/
return function (name) {
/**
* #memberOf Logger
* #type {string}
*/
this.name = name;
/**
* Place the message on the console, only for "DEV" level debugging
* #function
* #memberOf Logger
* #param message {string}
*/
this.debug = function (message) {
... some code ...
};
};
});
Right now all the members are appearing as <static>. If I add the #inner tag to any of the attributes/functions they vanish completely from the output.
Edit: I also forgot to mention. The #constructor flag doesn't seem to be working either. If I remove that entire section, it appears the same in the output. The output does not include the #param that I would like to mention with my constructor.
Please let me know if this is completely off, I'm just kind of guessing here since the JSDoc3 documentation is a bit difficult to read.
So I figured it out, still not sure if it's absolutely correct. I had to use "Logger~name" to have it appear correctly as an inner function. According to the JSDoc documentation, this ~ is "rarely used". Seems to be the only thing that works for me.
define(["config/globalConfig"], function (config) {
/**
* The logger, to simply output logs to the console (or potentially a variable)
* #class Logger
* #param name {string} - The name of the class instantiating the logger
*/
return function (name) {
this.name = name;
/**
* Place the message on the console, only for "DEV" level debugging
* #function Logger~debug
* #param message {string}
*/
this.debug = function (message) {
... code ...
};
};
});

How to Document following function in JSDoc JS-Toolkit

*How to Document following function in JSDoc JS-Toolkit *
I want to document try and help method in this main function
but i did not figure it out how to do that.
/** Sample doc
* #class
* #constructor
* #name Sample
*/
var main=function(){
this.value="";
/** help function
* #param {String} Name
*/
this.help=function(name){
console.log('help me'+name);
}
/** help function
* #param {String} Name
*/
this.try=function(name){
console.log('try me'+name);
}
}
I just struggled with this for several hours. I tried:
#member
#augments
#method
#this
From the examples and tutorials I found, member functions and variables should appear in the output simply by having /** description/* comments above them, but I found that was not the case. Like you, I'm using standard JavaScript constructors, where this should be able to be inferred automatically due to the #constructor being in place. Maybe there's some wrinkle I'm not seeing.
In the end, I found two tags that worked for me, #name and#memberof. They both allow you to specify the object that the property is a member of. Using #name in this way is undocumented (at least, I didn't see it anywhere), but very straightforward. You'll also need to use #function.
Here's an example with the #name tag:
/** help function
* #name Sample.try
* #function
* #param {String} Name
*/
this.try=function(name){
console.log('try me'+name);
};
And here's an example with the #memberof tag:
/** help function
* #memberof Sample
* #function
* #param {String} Name
*/
this.try=function(name){
console.log('try me'+name);
};
As you can see the output is almost the same. The only difference that I see is that #memberof includes this. in the method name. For that reason I've settled on using #name.
The remaining issue is that the functions are per-instance, not <static>.
Hope this helps!