gristlabs_grist-core/app/client/components/AceEditorCompletions.ts

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import * as ace from 'brace';
// Suggestion may be a string, or a tuple [funcname, argSpec, isGrist], where:
// - funcname (e.g. "DATEADD") will be auto-completed with "(", AND linked to Grist
// documentation.
// - argSpec (e.g. "(start_date, days=0, ...)") is to be shown as autocomplete caption.
// - isGrist determines whether to tag this suggestion as "grist" or "python".
export type ISuggestion = string | [string, string, boolean];
export interface ICompletionOptions {
getSuggestions(prefix: string): Promise<ISuggestion[]>;
}
const completionOptions = new WeakMap<ace.Editor, ICompletionOptions>();
export function setupAceEditorCompletions(editor: ace.Editor, options: ICompletionOptions) {
initCustomCompleter();
completionOptions.set(editor, options);
// Create Autocomplete object at this point so we can turn autoSelect off.
// There doesn't seem to be any way to get ace to respect autoSelect otherwise.
// It is important for autoSelect to be off so that hitting enter doesn't automatically
// use a suggestion, a change of behavior that doesn't seem particularly desirable and
// which also breaks several existing tests.
const {Autocomplete} = ace.acequire('ace/autocomplete'); // lives in brace/ext/language_tools
const completer = new Autocomplete();
completer.autoSelect = false;
(editor as any).completer = completer;
// Patch updateCompletions and insertMatch so that fresh completions are fetched when the user types '.' or '('
const originalUpdate = completer.updateCompletions.bind(completer);
completer.updateCompletions = function(this: any, keepPopupPosition: boolean) {
// The next three lines are copied from updateCompletions() in the ace autocomplete source code.
if (keepPopupPosition && this.base && this.completions) {
const pos = this.editor.getCursorPosition();
const prefix = this.editor.session.getTextRange({start: this.base, end: pos});
// If the cursor is just after '.' or '(', prevent this same block from running
// in the original updateCompletions() function. Otherwise it will just keep any remaining completions that match,
// or not show any completions at all.
// But the last character implies that the set of completions is likely to have changed.
if (prefix.endsWith(".") || prefix.endsWith("(")) {
this.completions = null;
}
}
return originalUpdate(keepPopupPosition);
}.bind(completer);
// Similar patch to the above.
const originalInsertMatch = completer.insertMatch.bind(completer);
completer.insertMatch = function(this: any) {
const base = this.base; // this.base may become null after the next line, save it now.
const result = originalInsertMatch.apply(...arguments);
// Like in the above patch, get the current text in the editor to be completed.
const pos = this.editor.getCursorPosition();
const prefix = this.editor.session.getTextRange({start: base, end: pos});
// This patch is specifically for when a previous completion is inserted by pressing Enter/Tab,
// and such completions may end in '(', which can lead to more completions, e.g. for `.lookupRecords(`.
if (prefix.endsWith("(")) {
this.showPopup(this.editor);
}
return result;
}.bind(completer);
aceCompleterAddHelpLinks(completer);
// Explicitly destroy the auto-completer on disposal, since it doesn't not remove the element
// it adds to body even when it detaches itself. Ace's AutoCompleter doesn't expose any
// interface for this, so this takes some hacking. (One reason for this is that Ace seems to
// expect that a single AutoCompleter would be used for all editor instances.)
editor.on('destroy', () => {
if (completer.editor) {
completer.detach();
}
if (completer.popup) {
completer.popup.destroy(); // This is not enough, but seems relevant to call.
completer.popup.container.remove(); // Removes the element from DOM.
}
});
}
let _initialized = false;
function initCustomCompleter() {
if (_initialized) { return; }
_initialized = true;
// Add some autocompletion with partial access to document
const aceLanguageTools = ace.acequire('ace/ext/language_tools');
aceLanguageTools.setCompleters([]);
aceLanguageTools.addCompleter({
// Default regexp stops at periods, which doesn't let autocomplete
// work on members. So we expand it to include periods.
// We also include $, which grist uses for column names,
// and '(' for the start of a function call, which may provide completions for arguments.
identifierRegexps: [/[a-zA-Z_0-9.$\u00A2-\uFFFF(]/],
// For autocompletion we ship text to the sandbox and run standard completion there.
async getCompletions(editor: ace.Editor, session: ace.IEditSession, pos: number, prefix: string, callback: any) {
const options = completionOptions.get(editor);
if (!options || prefix.length === 0) { callback(null, []); return; }
const suggestions = await options.getSuggestions(prefix);
// ACE autocompletions are very poorly documented. This is somewhat helpful:
// https://prog.world/implementing-code-completion-in-ace-editor/
callback(null, suggestions.map(suggestion => {
if (Array.isArray(suggestion)) {
const [funcname, argSpec, isGrist] = suggestion;
const meta = isGrist ? 'grist' : 'python';
return {value: funcname + '(', caption: funcname + argSpec, score: 1, meta, funcname};
} else {
return {value: suggestion, score: 1, meta: "python"};
}
}));
},
});
}
/**
* When autocompleting a known function (with funcname received from the server call), turn the
* function name into a link to Grist documentation.
*
* This is only applied for items returned from getCompletions() that include a our custom
* `funcname` attribute.
*
* ACE autocomplete is poorly documented, and poorly customizable, so this is accomplished by
* monkey-patching it. Further, the only text styling is done via styled tokens, but we can style
* them to look like links, and handle clicks to open the destination URL.
*
* This implementation relies a lot on the details of the implementation in
* node_modules/brace/ext/language_tools.js. Updates to brace module may easily break it.
*/
function aceCompleterAddHelpLinks(completer: any) {
// Replace the $init function in order to intercept the creation of the autocomplete popup.
const init = completer.$init;
completer.$init = function() {
const popup = init.apply(this, arguments);
customizeAceCompleterPopup(this, popup);
return popup;
};
}
function customizeAceCompleterPopup(completer: any, popup: any) {
// Replace the $tokenizeRow function to produce customized tokens to style the link part.
const origTokenize = popup.session.bgTokenizer.$tokenizeRow;
popup.session.bgTokenizer.$tokenizeRow = function(row: any) {
const tokens = origTokenize(row);
return retokenizeAceCompleterRow(popup.data[row], tokens);
};
// Replace the click handler with one that handles link clicks.
popup.removeAllListeners("click");
popup.on("click", function(e: any) {
if (!maybeAceCompleterLinkClick(e.domEvent)) {
completer.insertMatch();
}
e.stop();
});
}
interface TokenInfo extends ace.TokenInfo {
type: string;
}
function retokenizeAceCompleterRow(rowData: any, tokens: TokenInfo[]): TokenInfo[] {
if (!rowData.funcname) {
// Not a special completion, pass through the result of ACE's original tokenizing.
return tokens;
}
// ACE's original tokenizer splits rowData.caption into tokens to highlight matching portions.
// We jump in, and further divide the tokens so that those that form the link get an extra CSS
// class. ACE's will turn token.type into CSS classes by splitting the type on "." and prefixing
// the resulting substrings with "ace_".
// Funcname may be the recognized name itself (e.g. "UPPER"), or a method (like
// "Table1.lookupOne"), in which case only the portion after the dot is the recognized name.
// Figure out the portion that should be linkified.
const dot = rowData.funcname.lastIndexOf(".");
const linkStart = dot < 0 ? 0 : dot + 1;
const linkEnd = rowData.funcname.length;
const newTokens = [];
// Include into new tokens a special token that will be hidden, but include the link URL. On
// click, we find it to know what URL to open.
const href = 'https://support.getgrist.com/functions/#' +
rowData.funcname.slice(linkStart, linkEnd).toLowerCase();
newTokens.push({value: href, type: 'grist_link_hidden'});
// Go through tokens, splitting them if needed, and modifying those that form the link part.
let position = 0;
for (const t of tokens) {
// lStart/lEnd are indices of the link within the token, possibly negative.
const lStart = linkStart - position, lEnd = linkEnd - position;
if (lStart > 0) {
const beforeLink = t.value.slice(0, lStart);
newTokens.push({value: beforeLink, type: t.type});
}
if (lEnd > 0) {
const inLink = t.value.slice(Math.max(0, lStart), lEnd);
const newType = t.type + (t.type ? '.' : '') + 'grist_link';
newTokens.push({value: inLink, type: newType});
}
if (lEnd < t.value.length) {
const afterLink = t.value.slice(lEnd);
newTokens.push({value: afterLink, type: t.type});
}
position += t.value.length;
}
return newTokens;
}
// On any click on AceCompleter popup, we check if we happened to click .ace_grist_link class. If
// so, we should be able to find the URL and open another window to it.
function maybeAceCompleterLinkClick(domEvent: Event) {
const tgt = domEvent.target as HTMLElement;
if (tgt && tgt.matches('.ace_grist_link')) {
const dest = tgt.parentElement?.querySelector('.ace_grist_link_hidden');
if (dest) {
window.open(dest.textContent!, "_blank");
return true;
}
}
return false;
}