php - 使用 d3.json 从 PHP 输出 JSON

Question

我创建了一个 PHP 文件来查询 JSON 输出。特定过滤器“testPHP.php?number=123”的 PHP 文件的 JSON 输出是

[{"source":"AB","target":"AC","type":"true"},{"source":"UB","target":"EP","type":"true"},{"source":"US","target":"UR","type":"lie"},{"source":"BS","target":"QW","type":"lie"},{"source":"UW","target":"EA","type":"lie"}]

我已经在 html 文件中尝试过将 JSON 输出读取到链接变量

var links; // a global
d3.json("testPHP.php?number=123", function(error, json) {
  if (error) return console.warn(error);
  links = json;
});

但是，数据似乎没有存储在链接中。 如何将数据存储在 var links 中？

基本上，我想替换此 https://gist.github.com/mbostock/1153292 中的 var links从 PHP 的 JSON 输出。

编辑: 还是 http://localhost:8080 导致了问题？

Answer 1

d3.json 调用是异步的；在填充“链接”变量之前执行回调后包含的代码。

var links; // a global
d3.json("testPHP.php?number=123", function(error, json) {
  if (error) return console.warn(error);
  links = json;

  console.log(links); // your links are populated here

  // include the rest of your app here
});

// links is still undefined here because the success callback hasn't been run yet