Monaco Editor 使用入门

以前项目是用ace编辑器的，但是总有些不敬人意的地方。前端事件看见的VS Code编辑器Monaco Editor准备更换下，下面介绍一些使用中遇到的一点问题。代码提示

　1.项目引用

import * as monaco from 'monaco-editor/esm/vs/editor/editor.api';

项目中引用了editor.api.js，但是这个文件不包含一些默认的语言和插件，所以在使用的时候，还需要我们自己import

import 'monaco-editor/esm/vs/basic-languages/mysql/mysql.contribution';
import 'monaco-editor/esm/vs/editor/contrib/suggest/suggestController.js';
import 'monaco-editor/esm/vs/editor/contrib/bracketMatching/bracketMatching.js';
import 'monaco-editor/esm/vs/editor/contrib/hover/hover.js';

如果嫌麻烦我们也可以使用editor.all.js

2.react组件封装

可以使用github项目，https://github.com/superRaytin/react-monaco-editor，也可以拿来项目里面改下，比较简单

其实在componentDidUpdate的方法中，使用这个方法this.editor.setValue，undo不能撤回上次的value,

如果项目中有别的需求可以使用

var model = this.editor.getModel();
model.pushEditOperations(
    [],
    [
        {
            range: model.getFullModelRange(),
            text: prevProps.value
        }
    ]
);

onDidChangeModelContent，方法产生的监听需要在组件销毁的时候dispose下

3.编辑器参数配置

查看以下代码文件 monaco-editor/esm/vs/editor/common/config/commonEditorConfig.js

minimap，scrollBeyondLastLine，Suggestion，snippet相关的

4.在光标处插入文本

　 跟ace使用差别比较大

var position = editor.getPosition();
editor.executeEdits('', [
    {
        range: {
            startLineNumber: position.lineNumber,
            startColumn: position.column,
            endLineNumber: position.lineNumber,
            endColumn: position.column
        },
        text: 'test'
    }
]);

5.代码自动完成

下面代码是引用了monaco-editor自带的mysql的语法高亮里面的定义，设置的代码提示

import { language as mysqlLanguage } from 'monaco-editor/esm/vs/basic-languages/mysql/mysql.js';
monaco.languages.registerCompletionItemProvider('mysql', {
    provideCompletionItems: function(model, position) {
        // get editor content before the pointer
        var textUntilPosition = model.getValueInRange({
            startLineNumber: position.lineNumber,
            startColumn: 1,
            endLineNumber: position.lineNumber,
            endColumn: position.column
        });
        var match = textUntilPosition.match(/(\S+)$/);
        if (!match) return [];
        match = match[0].toUpperCase();
        var suggestions = [];
        mysqlLanguage.keywords.forEach(item => {
            if (item.indexOf(match) !== -1) {
                suggestions.push({
                    label: item,
                    kind: monaco.languages.CompletionItemKind.Keyword,
                    insertText: item
                });
            }
        });
        mysqlLanguage.operators.forEach(item => {
            if (item.indexOf(match) !== -1) {
                suggestions.push({
                    label: item,
                    kind: monaco.languages.CompletionItemKind.Operator,
                    insertText: item
                });
            }
        });
        mysqlLanguage.builtinFunctions.forEach(item => {
            if (item.indexOf(match) !== -1) {
                suggestions.push({
                    label: item,
                    kind: monaco.languages.CompletionItemKind.Function,
                    insertText: item
                });
            }
        });
        return {
            suggestions
        };
    }
});

如果你想增加代码片段，也可以直接添加下面的信息

            {
                label: 'ifelse',
                kind: monaco.languages.CompletionItemKind.Snippet,
                insertText: ['if (${1:condition}) {', '\t$0', '} else {', '\t', '}'].join('\n'),
                insertTextRules: monaco.languages.CompletionItemInsertTextRule.InsertAsSnippet,
                documentation: 'If-Else Statement'
            }

使用中发现，编辑器自带的默认的变量提示，在提供了自定义的registerCompletionItemProvider后会失效，暂时没找到什么好方法

默认的变量提示 monaco-editor/esm/vs/editor/common/services/editorWorkerServiceImpl.js

_this._register(modes.CompletionProviderRegistry.register('*', new WordBasedCompletionItemProvider(_this._workerManager, configurationService, _this._modelService)));

monaco-editor/esm/vs/editor/contrib/suggest/suggest.js

会根据注册的Provider的分组，语言默认的优先级不高，没有分到一组，找到了结果就不再会执行下面的组

6.语法高亮

官网的文档蛮详细的，和ace的差别不是很大，虽然我也没怎么看懂

　　https://microsoft.github.io/monaco-editor/monarch.html

可以在项目中找个相似的语言抄抄改改，结合着看官方文档

monaco-editor/esm/vs/basic-languages

高亮的样式需要在定义主题来对应，不是完全通过css处理的

monaco.editor.defineTheme('ace', {
  base: 'vs',
  inherit: true,
  rules: [
    { token: '', foreground: '5c6773' },
    { token: 'invalid', foreground: 'ff3333' },
    { token: 'emphasis', fontStyle: 'italic' },
    { token: 'strong', fontStyle: 'bold' },
    { token: 'variable', foreground: '5c6773' },
    { token: 'variable.predefined', foreground: '5c6773' },
    { token: 'constant', foreground: 'f08c36' },
  ]
});

　　7.语法检测

语法检测，就需要编写对应的语法编译逻辑，这个不同语言不同的写法，一些也有现成的。这边主要介绍下怎么和编辑器交互，显示错误信息

错误信息hover显示需要插件 import 'monaco-editor/esm/vs/editor/contrib/hover/hover.js';

//清楚mark
monaco.editor.setModelMarkers(model, 'eslint', []);
//添加mark
monaco.editor.setModelMarkers(model, 'eslint', [
    {
        startLineNumber: 2,
        endLineNumber: 2,
        startColumn: 2,
        endColumn: 4,
        message: 'Syntax error',
        severity: 3,
        source: 'ESLint',
        code: 'asdasdas'
    }
]);

对于上面的一些配置信息会对提示框有什么影响可以看下面的源码

monaco-editor/esm/vs/editor/common/services/modelServiceImpl.js  ModelMarkerHandler._createDecorationOption

    ModelMarkerHandler._createDecorationOption = function (marker) {
        var className;
        var color = undefined;
        var zIndex;
        var inlineClassName = undefined;
        switch (marker.severity) {
            case MarkerSeverity.Hint:
                if (marker.tags && marker.tags.indexOf(1 /* Unnecessary */) >= 0) {
                    className = "squiggly-unnecessary" /* EditorUnnecessaryDecoration */;
                }
                else {
                    className = "squiggly-hint" /* EditorHintDecoration */;
                }
                zIndex = 0;
                break;
            case MarkerSeverity.Warning:
                className = "squiggly-warning" /* EditorWarningDecoration */;
                color = themeColorFromId(overviewRulerWarning);
                zIndex = 20;
                break;
            case MarkerSeverity.Info:
                className = "squiggly-info" /* EditorInfoDecoration */;
                color = themeColorFromId(overviewRulerInfo);
                zIndex = 10;
                break;
            case MarkerSeverity.Error:
            default:
                className = "squiggly-error" /* EditorErrorDecoration */;
                color = themeColorFromId(overviewRulerError);
                zIndex = 30;
                break;
        }
        if (marker.tags) {
            if (marker.tags.indexOf(1 /* Unnecessary */) !== -1) {
                inlineClassName = "squiggly-inline-unnecessary" /* EditorUnnecessaryInlineDecoration */;
            }
        }
        var hoverMessage = null;
        var message = marker.message, source = marker.source, relatedInformation = marker.relatedInformation, code = marker.code;
        if (typeof message === 'string') {
            message = message.trim();
            if (source) {
                if (/\n/g.test(message)) {
                    if (code) {
                        message = nls.localize('diagAndSourceAndCodeMultiline', "[{0}]\n{1} [{2}]", source, message, code);
                    }
                    else {
                        message = nls.localize('diagAndSourceMultiline', "[{0}]\n{1}", source, message);
                    }
                }
                else {
                    if (code) {
                        message = nls.localize('diagAndSourceAndCode', "[{0}] {1} [{2}]", source, message, code);
                    }
                    else {
                        message = nls.localize('diagAndSource', "[{0}] {1}", source, message);
                    }
                }
            }
            hoverMessage = new MarkdownString().appendCodeblock('_', message);
            if (!isFalsyOrEmpty(relatedInformation)) {
                hoverMessage.appendMarkdown('\n');
                for (var _i = 0, _a = relatedInformation; _i < _a.length; _i++) {
                    var _b = _a[_i], message_1 = _b.message, resource = _b.resource, startLineNumber = _b.startLineNumber, startColumn = _b.startColumn;
                    hoverMessage.appendMarkdown("* [" + basename(resource.path) + "(" + startLineNumber + ", " + startColumn + ")](" + resource.toString(false) + "#" + startLineNumber + "," + startColumn + "): ");
                    hoverMessage.appendText("" + message_1);
                    hoverMessage.appendMarkdown('\n');
                }
                hoverMessage.appendMarkdown('\n');
            }
        }