使用d3-graphviz会导致无法读取null的属性“__graphviz__”
我只是想弄个DOT图来渲染。我遵循文档(https://github.com/magjac/d3-graphviz)来添加包并使用它，但是当我试图运行应用程序并访问DOT关系图时，不会呈现任何内容，并引发以下错误：
错误TypeError:无法读取属性'__graphviz__‘的null。控制台错误消息
该应用程序是一个角12项目，这里是使用的依赖项列表。
"dependencies": {
"@angular/animations": "^12.1.4",
"@angular/cdk": "^12.1.4",
"@angular/common": "^12.0.5",
"@angular/compiler": "^12.0.5",
"@angular/core": "^12.1.4",
"@angular/flex-layout": "^12.0.0-beta.34",
"@angular/forms": "^12.0.5",
"@angular/material": "^12.1.4",
"@angular/platform-browser": "^12.0.5",
"@angular/platform-browser-dynamic": "^12.0.5",
"@angular/router": "^12.0.5",
"angular2-uuid": "^1.1.1",
"chart.js": "^3.5.0",
"d3": "^7.0.0",
"d3-graphviz": "^4.0.0",
"git-describe": "^4.0.4",
"monaco-editor": "^0.26.1",
"ng2-charts": "^3.0.0-rc.4",
"ngx-monaco-editor": "^12.0.0",
"ngx-toastr": "^14.0.0",
"rxjs": "~6.6.0",
"tslib": "^2.1.0",
"xml2js": "^0.4.23",
"zone.js": "~0.11.4"
},
"devDependencies": {
"@angular-devkit/build-angular": "^12.0.5",
"@angular-eslint/builder": "12.2.0",
"@angular-eslint/eslint-plugin": "12.2.0",
"@angular-eslint/eslint-plugin-template": "12.2.0",
"@angular-eslint/schematics": "12.3.1",
"@angular-eslint/template-parser": "12.2.0",
"@angular/cli": "^12.1.4",
"@angular/compiler-cli": "^12.0.5",
"@types/chart.js": "^2.9.34",
"@types/d3": "^7.0.0",
"@types/d3-graphviz": "^2.6.7",
"@types/jasmine": "~3.6.0",
"@types/node": "^12.20.17",
"@typescript-eslint/eslint-plugin": "^4.28.5",
"@typescript-eslint/parser": "^4.28.5",
"eslint": "^7.31.0",
"eslint-config-airbnb-typescript": "^12.3.1",
"eslint-config-prettier": "^8.3.0",
"eslint-plugin-import": "^2.23.4",
"eslint-plugin-prettier": "^3.4.0",
"jasmine-core": "~3.7.0",
"karma": "^6.3.4",
"karma-chrome-launcher": "~3.1.0",
"karma-coverage": "~2.0.3",
"karma-jasmine": "~4.0.0",
"karma-jasmine-html-reporter": "^1.7.0",
"prettier": "2.3.2",
"source-map-explorer": "^2.5.2",
"typescript": "^4.2.4"
}在ngOnInit内部：
ngOnInit(): void {
wasmFolder('/assets/@hpcc-js/wasm/dist/');
console.log('file-viewer init');
}代码查看它所传递的文件的文件名，并根据扩展名执行操作。当我们有一个DOT文件时，我们执行以下操作：
else if (originalFile.filename.toLocaleLowerCase().includes('.dot')) {
console.log('dot file was given');
// this.activeType = TypeCode.DOT;
// this.dotRenderer.renderDot(contents);
// d3.select('#dotViewerElement').graphviz().renderDot(contents);
graphviz('#dotViewerElement').renderDot(contents);
// graphviz.graphviz('#dotViewerElement').renderDot(contents);
}注释行是访问“renderDot(.)”的所有不同尝试。函数。
wasmFolder已添加到位于
应用工程
-- node_modules
-- src
- app
-资产
-- @hpcc-js
回答 1
Stack Overflow用户
发布于 2022-01-27 11:14:47
更新:我找到答案了。引发错误是因为呈现关系图时还没有呈现dom对象(div)。当我使用ngAfterViewInit而不是ngOnInit时，它是有效的！
我也面临着同样的问题。如果我不使用类型记录，而只是在我的html文件正文中复制脚本标记和示例脚本(所以替换角的app根)，它就能正常工作，但是如果我在我的app根旁边使用它，它会抛出这个错误。你找到解决办法了吗？
例如：
这适用于我的index.html
<body>
<script src="//d3js.org/d3.v5.min.js"></script>
<script src="https://unpkg.com/@hpcc-js/wasm@0.3.11/dist/index.min.js"></script>
<script src="https://unpkg.com/d3-graphviz@3.0.5/build/d3-graphviz.js"></script>
<div id="graph" style="text-align: center;"></div>
<script>
d3.select("#graph").graphviz()
.renderDot('digraph {a -> b}');
</script>这不管用：
<head>
<script src="//d3js.org/d3.v5.min.js"></script>
<script src="https://unpkg.com/@hpcc-js/wasm@1.12.8/dist/index.min.js"></script>
<script src="https://unpkg.com/d3-graphviz@4.0.0/build/d3-graphviz.js"></script>
<script>
d3.select("#graph").graphviz()
.renderDot('digraph {a -> b}');
</script>
</head>
<body>
<div id="graph" style="text-align: center;"></div>
<app-root></app-root>
</body>https://stackoverflow.com/questions/68684804
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