The Script Editor in Servoy Developer offers full code completion (a.k.a. IntelliSense or autocomplete) and designtime code validation.
As JavaScript has no means to declare the type of a variable, the type of a function parameter or the return type of a function, it is not possible to get 100% correct results by just analyzing the JavaScript code itself.
In order to improve the quality of the code completion and code validation, functions and variables can be annotated with JSDoc to provide the missing information.
Besides the benefits for code completion and validation, adding JSDoc to JavaScript code also improves the readability of the code for other developers, as JSDoc allows for adding more info than just the typing info.
Using the JSDoc plugin hosted on ServoyForge it is also possible to generate HTML documentation of the JavaScript code in a Solution, based on the JSDOc supplied.
The JSDoc syntax consists of a set of JSDoc tags, contained in JSDoc comments.
JSDoc comments are like multi-line JavaScript comments, but the opening tag is '/*' instead of just '/'
Some of the JSDoc tags require a Type Expression as one of the parameters and most allow for an extra description behind the tag and it's parameters.
Example
/** * A simple demo function that outputs some text * @author Tom * @private * * @param {String} text The text that will be written to the output * @throws (String) * returns Boolean * * @example try { * saySomething('Hello world!'); * } catch(e) { * * } * * @see application.output * @since 1.0 * @version 1.0.1<br> * - Added some more JSDoc tags for the demo */ function saySomething(text) { if (text == null || text.length == 0) { throw "Invalid input!" } application.output(text); return true; } |
JSDoc is not a official standard, but the defacto standard is is defined by the JSDoc Toolkit project. The other major definer of JSDoc is Google Closure Compiler's support for JavaScript annotation.
The JSDoc syntax supported by the Servoy Developer IDE is derived from the JSDoc Toolkit and Google Closure Compiler's support for JavaScript annotation, plus some custom Servoy extensions.
See #JSDoc Tags and #Type Expressions below for the supported tags and their syntax.
As mentioned in the intro, the Script Editor in Servoy Developer utilizes JSDoc to improve the quality of code completion and validation.
The Script Editor and Servoy Developer in general also facilitates the creation of JSDoc comments:
When hovering over a reference to the variable of function somewhere in the Solution, the tooltip will show the JSDoc for the variable/function.
Note that the Script Editor will always generate a JSDoc comment block with a @properties tag when saving the Script editor, if no JSDoc comments have been defined. The @properties tag is a tag containing information for Servoy to provide proper linking and versioning.
The following JSDoc tags are supported in the Script Editor. This means that the JSDoc tags will be rendered without the "@" sign when hovering over a reference tot he function or variable.
The developer can add any custom tag to the JSDoc comment, but besides being shown in the tooltip when hovering over references it will not do anything.
Tag |
Syntax & Examples |
Context |
Impact |
Description |
||
---|---|---|---|---|---|---|
@AllowToRunInFind |
@AllowToRunInFind |
function |
Determines if the function will be executes in FindMode when used as an event handler |
Custom Servoy JSDoc tag to annotate a function that it can be run if the Form on which the function is ran is in FindMode |
||
@author |
@author userName |
function, variable |
none |
Indicates the author of the code |
||
@constructor |
@constructor |
function |
This will show a different icon on the Script Outline view. besides that no further impact |
|
||
@deprecated |
@deprecated description |
function, variable |
Accessing a deprecated variable or calling a deprecated function will produce a builder marker in Servoy Developer |
Indicates that the function or variable is obsolete or has been replaced and should be used anymore. |
||
@example |
@example |
function, variable |
none |
Tag allowing to provide some sample code how to use the function or variable. Multiline content is possible by including "<br>" as line-breaks behind each line of content. |
||
@override |
@override |
functions, variables |
none |
Tag to describe that the function is overriding a similar named function on a super form |
||
@param |
@param {Type} name parameterDescription |
function |
Builder markers will be generated in Servoy Developer if the function is called with values for the parameters that do not match the specified types |
Describe function parameters. |
||
@private |
@private |
function, variable |
Accessing a private variable/function from outside the scope in which it is declared will generate a builder marker in Servoy Developer |
Annotates a variable or function as accessible only from within the file in which it is declared |
||
@protected |
@protected |
function, variable |
Accessing a protected variable/function from outside the scope in which it is declared or a child scope will generate a builder marker in Servoy Developer |
Annotates a variable or function as accessible from within the same file in which it is declared and all files that extend this file |
||
@return |
@return {Type} |
function |
The specified type is used by the build process to determine the correctness of the code that uses the returned value and offer Code Completion |
Annotates the type of the returned value. |
||
@returns |
@returns {Type} |
function |
see @return |
alias for @return |
||
@see |
@see seeDescription |
function, variable |
none |
Tag to provide pointers to other parts of the code that are related |
||
@since |
@since versionDescription |
function, variable |
none |
Tag to provide information about in which version of the code the variable or function was introduced |
||
<ac:structured-macro ac:name="unmigrated-wiki-markup" ac:schema-version="1" ac:macro-id="f8ad454d-6287-49dd-822f-713142eb2d4e"><ac:plain-text-body><![CDATA[ |
@SuppressWarnings |
@SuppressWarnings ([deprecated], [hides], [wrongparameters], [undeclared], [unused], [nls]) |
function |
Stop the generation of builder markers in Servoy Developer for the specified warnings |
Custom Servoy JSDoc tag to suppress builder markers of a certain type within a function. |
]]></ac:plain-text-body></ac:structured-macro> |
@this |
@this {Type} |
function |
The specified type is used by the build process for the "this" object available inside functions to determine the correctness of the code that uses the object and offer Code Completion |
Tag to specify the type of the "this" object inside functions. |
||
@throws |
@throws {Type} |
function |
none |
Tag to describe the type of Exceptions that can be raised when the function is called. |
||
@type |
@type {Type} |
variable, inline variable, (function*) |
The specified type is used by the build process to determine the correctness of the code that uses the variable and offer Code Completion |
Tag to specify the type of the value that a variable can hold. |
||
@version |
@version versionDescription |
function, variable |
none |
Tag to provide information about the version of the code |
A file can be either a Form JavaScript file or the globals JavaScript file. Only Form can be extended, thus the @protected tag is not relevant for annotating variables and functions within the globals JavaScript file
Type Expressions are used to describe the type and/or structure of data in the following cases:
Use case |
Tag |
Example |
---|---|---|
function parameters |
@param |
/** |
function return type |
@return |
/** |
functions exceptions |
@throws |
/** |
variables |
@type |
/** |
|
|
|
A Type Expression is to always be surrounded by curly braces: {typeExpression}. Note that when using the Object Type expression variation that start and stops with curly braces as well, this results in double opening and closing braces.
Expression name |
Syntax example |
Context |
Comments |
|
---|---|---|---|---|
Named type |
{String} |
@param, @return, @type, @throws |
The complete list of available types can be seen by triggering Code Completion inside the curly braces in the Script Editor |
|
Any type |
{*} |
@param, @return, @type, @throws |
|
|
OR type |
{String|Number} |
@param, @return, @type, @throws |
|
|
REST type |
{...String} |
@param |
|
|
Array type |
|
@param, @return, @type, @throws |
|
|
Object type |
{Object<String>} |
@param, @return, @type, @throws |
|
|
Object type with optional properties |
|
@param, @return, @type, @throws |
|
|
Function type |
{function(String, Number, Array<Object>):Boolean} |
@param, @return, @type |
|
|
JSFoundset type |
{JSFoundset<db:/udm/contacts>}1 |
@param, @return, @type |
|
|
JSRecord type |
{JSRecord<db:/udm/contacts>}1 |
@param, @return, @type |
|
|
JSDataSet type |
{JSDataSet<{name:String, age:Number}>} |
@param, @return, @type |
|
|
RuntimeForm type |
{RuntimeForm<superFormName>} |
@param, @return, @type |
|
1 the value in between <..> is the datasource notation that is built up of the database server and tablename: db:/{serverName}/{tableName}
JSDoc can be used inside JavaScript code to specify the type of variables. This can be necessary if the correct type can't be automatically derived.
An example of such scenario is for example the databaseManager.getFoundSet() function. This function returns an object of the generic type JSFoundSet. In most if not all scenario's however, it is known for which specific datasource the JSFoundSet was instantiated and the foundset object will be used as such in code, accessing dataproviders on the foundset object that are specific to the datasource. This will result in builder markers, because those dataproviders are not know on the generic JSFoundSet type. Through JSDoc casting however, it's possible to specify the type of the foundset object more specifically
/**@type {JSFoundset<db:/udm/contacts>}*/ var fs = databaseManager.getFoundSet('db:/udm/contacts') |
The difference between Code Completion with and without Type Casting can be seen in the two screenshots below. whent he Type casting is omitted, the offered Code Completion related only to the generic JSFoundset type. With the Type Casting in place, all the dataproviders of the specific datasource are also available in Code Completion:
With Type Casting:
Without Type Casting:
Another example is entries in Objects and/or Arrays: if every entry is of the same type, this can be specified on the Object/Array declaration using JSDoc, for example:
/**@type {Array<String>}*/ var myStringArray = \[\] |
If the Object/Array contains entries of different types, the type of the entries cannot be specified when declaring the Object/Array, or only a more generic type can be specified.
An example of a generic type would be RuntimeComponent, which is the super type for RuntimeLabel, RuntimeField etc. RuntimeComponent defines all the properties and methods that all the other RuntimeXxxx types have in common. When the need arises to call methods or set properties that are specific to a specific RuntimeXxx type, the generic type can be casted:
if (elements\[1\] instanceof RuntimeLabel) { /**@type{RuntimeLabel}*/ var myLabel = elements\[1\] var elementNames = myLabel.getLabelForElementName() //Calling method specific for labels } |
Type Casting can only be performed on variable declarations. It is not possible switch the type of an already declared variable later in code |