# Documentation

YASHE extends the CodeMirror Library. For a complete overview of the functionality they offer (such as event hooks), check out the CodeMirror Documentation. Below we elaborate on the functionality YASHE offers (in addition to the CodeMiror API).
Note: Where CodeMirror provides `CodeMirror` in the global namespace, we provide `YASHE`.

## Getting Started

Initialize YASHE via its constructor, or via the command `fromTextArea`. Both return in instance of YASHE, from now on referred to as `yashe` (lowercase). Both function take as argument a config object. See the section on defaults for more information on this config object.

`YASHE(parent: DOM-Element, settings: Object) → YASHE instance: yashe`

Main YASHE constructor. Pass a DOM element as argument to append the editor to, and (optionally) pass along config settings (see the YASHE.defaults object below, as well as the regular CodeMirror documentation, for more information on configurability)

`YASHE.fromTextArea(textArea: DOM element, config: Object) → YASHE instance: yashe`

Initialize YASHE from an existing text area (see CodeMirror for more info)

### Examples

## API

API methods accessible via the `yashe` instance
`yashe.setValue(query: String)`

Set query value in editor (see also)

`yashe.getValue() → query: String`

Get query value from editor (see also)

`yashe.getDefinedPrefixes() → object:`

Fetch defined prefixes

`yashe.addPrefixes(prefixes: object)`

Add prefixes to the query. The prefixes are defined as `{"rdf: "http://www.w3.org/1999/02/22-rdf-syntax-ns#"}`

`yashe.removePrefixes(prefixes: object)`

Remove prefixes from query. The prefixes are defined as `{"rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#"}`

`yashe.setSize(width: Number|string, height: Number|string)`

Set size. Use null value to leave width or height unchanged. To resize the editor to fit its content, see http://codemirror.net/demo/resize.html

`yashe.enableCompleter(completerName: String)`

Enable an autocompleter with this name. Only makes sense if you've programatically disabled this completer before, as a plugin is automatically enabled when registering it (see this function)

`yashe.disableCompleter(completerName: String)`

Disable an autocompleter with this name.

`yashe.storeBulkCompletions(type: String)`

Store bulk completions in memory as trie, and in localstorage as well (if enabled). The argument should be a key from the autocompletion settings

`yashe.collapsePrefixes(collapse: boolean)`

Collapsing prefixes if there are any. Use false to expand them.

## Statics

Static functions YASHE
`YASHE.registerAutocompleter(name: String, autocompleter: function)`

Register an autocompleter in YASHE. This automatically enables the completer as well

`YASHE.getCompleteToken(doc: yashe, token: Object, cursor: Object) → token: Object`

When typing a shape, this shape is sometimes syntactically invalid, causing the current tokens to be incorrect This causes problem for autocompletion. http://bla might result in two tokens: http:// and bla. We'll want to combine these

## Configuration

This configuration object is accessible/changeable via `YASHE.defaults` and `yashe.options`, and you can pass these along when initializing YASHE as well. Other than the configuration we describe here, check the CodeMirror documentation for even more options you can set, such as disabling line numbers, or changing keyboard shortcut keys.

### Defaults

`value: PREFIX : PREFIX schema: PREFIX xsd: :User IRI { schema:name xsd:string ;schema:birthDate xsd:date? ;schema:gender [ schema:Male schema:Female ] ;schema:knows @:User* }`

Shape string

`autocompleters: array (default: ["prefixDefinition", "wikidata", "prefixesAndKeywords"])`

The list of enabled autocompletion plugins (See this section on how to write your own)

`syntaxErrorCheck: boolean (default: true)`

Whether to validate the ShEx syntax

`collapsePrefixesOnLoad: boolean (default: false)`

Collapse prefixes on page load

`extraKeys: object`

Extra shortcut keys. Check the CodeMirror manual on how to add your own

Note: To avoid colissions with other browser shortcuts, these shortcuts only work when the YASHE editor is selected (has 'focus').
The list of shortcuts provided by YASHE:

- `[Ctrl|Cmd]-Space`: Trigger Autocompletion
- `[Ctrl|Cmd]-D`: Delete current/selected line(s)
- `[Ctrl|Cmd]-/`: Comment or uncomment current/selected line(s)
- `[Ctrl|Cmd]-Down`: Copy line down
- `[Ctrl|Cmd]-Up`: Copy line up
- `[Ctrl|Cmd]-Shift-F`: Auto-format/indent selected lines
- `[Ctrl|Cmd]-S`: Save current content in local storage
- `F11`: Set query editor full-screen (or leave full-screen)
- `Esc`: Leave full-screen

`persistent: function|string`

Change persistency settings for the YASHE content value. Setting the values to null, will disable persistancy: nothing is stored between browser sessions. Setting the values to a string (or a function which returns a string), will store the query in localstorage using the specified string. By default, the ID is dynamically generated using the `YASHE.determineId` function, to avoid collissions when using multiple YASHE instances on one page

### Writing an Autocompletion Plugin

To register an autocompletion, one needs to execute the `YASHE.registerAutocompleter` function. Below, we describe the autocompletion function in more detail, and the object it should return.
`constructor(doc: yashe) → configurationObject: Object`

Autocompleter constructor, which should return the object described below

`get: function|array` Required

Get the autocompletions. Either a function which returns an array, or an actual array. The array should be in the form ["<completionsString1>", "<completionsString2>"].

If used as a function, the parameters it receives are

1. `token: object` If 'bulk' loading is disabled, use this token to return the appropriate list of suggestions for
2. `callback: function` If 'async' is enabled, return the suggestions by passing it on to this callback

`isValidCompletionPosition: function() → boolean` Required

Check whether the cursor is in a proper position for this autocompletion.

`preProcessToken: function(token: object|string) → token: object` Optional

Preprocesses the codemirror token before matching it with the autocompletions list. Use this for e.g. autocompleting prefixed resources when your autocompletion list contains only full-length URIs E.g., foaf:name -> http://xmlns.com/foaf/0.1/name

`postProcessToken: function(token: object|string, suggestion: string) → string` Optional

Postprocesses the autocompletion suggestion. Use this for e.g. returning a prefixed URI based on a full-length URI suggestion E.g., http://xmlns.com/foaf/0.1/name -> foaf:name

`async: boolean` Required

Specifies that the get function is asynchronous

`bulk: boolean` Required

Use bulk loading of completions: all completions are retrieved onLoad using the get() function. Alternatively, disable bulk loading, to call the get() function whenever a token needs autocompletion (in which case the completion token is passed on to the get() function). whenever you have an autocompletion list that is static, and that easily fits in memory, we advice you to enable bulk for performance reasons (especially because the autocompletions are stored in a trie)

`autoShow: boolean` Optional

Auto-show the autocompletion dialog. Disabling this requires the user to press [ctrl|cmd]-space to summon the dialog. Note: this only works when completions are not fetched asynchronously

`persistent: string|function` Optional

Automatically store autocompletions in localstorage. This is particularly useful when the get() function is an expensive ajax call. Autocompletions are stored for a period of a month. Set this property to null to disable persistency. Otherwise, set a string value (or a function returning a string val), returning the key in which to store the data. Note: this feature only works when completions are loaded in memory (i.e. `bulk`: true)

`callbacks: object` Optional

A set of callbacks. Most, taken from the CodeMirror showhint plugin

`validPosition: function` Optional

Fires when a codemirror change occurs in a position where we can show this particular type of autocompletion

`invalidPosition: function` Optional

Fires when a codemirror change occurs in a position where we can not show this particular type of autocompletion

`showHint: function` Optional

See CodeMirror manual

`select: function` Optional

See CodeMirror manual

`pick: function` Optional

See CodeMirror manual

`close: function` Optional

See CodeMirror manual

### Configuring Autocompletion Plugins

To modify how autocompletion plugins work, you can simply overwrite the settings and/or function that are explained in the section above. To e.g. modify the `autoShow` setting for the prefix autocompleter, set `YASHE.Autocompleters.prefixes.autoShow = false` before you initialize YASHE. Some plugins may come with extra configuration options such as the prefix autocompleter, that allows you to change the url from where the prefix json is fetched:
`YASHE.Autocompleters.prefixes.fetchFrom: string (default: //prefix.cc/popular/all.file.json)`

Where to fetch the prefix json from. Change this when you'd like to host the json yourself. This might be useful when you run YASHE on an `https` site, considering that prefix.cc currently does not support `https`