Question

所以我使用本地html和javascript文件作为视频文件的gui。它几乎是我的服务器index.php的外卖版本，供他们在别处使用。一切正常，但我试图从txt文件加载内容。我的网络服务器使用XMLHttpRequest来检索它，因为它是服务器端。但由于外卖版本不在服务器上，因此文本文件与html文件位于同一本地目录中

function loadBookmarks(){
  var infoDoc = new XMLHttpRequest()
  infoDoc.open("GET","info.bk");
  infoDoc.send();
  infoDoc.onreadystatechange = function() {
    if (infoDoc.readyState== 4 && infoDoc.status == 200) {
        document.getElementById("bookmarks").querySelector('p').innerHTML = infoDoc.responseText;
        document.getElementById("infoButton").style.backgroundColor = "#119933";
    } else {
        document.getElementById("bookmarks").querySelector('p').innerHTML = "";
        document.getElementById("infoButton").style.backgroundColor = "#993333"
    }
 }  
}

这就是我正在使用的功能。是否有另一种方法从文件中获取具有脱机非服务器javascript文件的文本？

米切尔

Answer 1

这是一种解决方法，它涉及一些限制因素，但根据您的目标，它可能符合您的需求。或者不是。

AFAIK您将无法使用XmlHttpRequest实现此功能，但您可以使用FileReader加载文件。您可以在此SO

中找到一个有效的示例

How to open a local disk file with Javascript?

缺点是必须通过手动交互触发FileReader。因此，如果没有用户（您）点击并浏览要加载的文件，您将无法加载文件。

你可以处理吗？

如果是这样，它甚至更糟，因为一旦加载，只需将文件的内容放入localeStorage，所以下次加载页面或刷新页面时，文件中的数据可能会出现从localeStorage中，您不必手动选择要再次加载的文件。当然，如果文件已更改，但由于您不在服务器/网络服务器上，则文件将自动更改的可能性很小。所以我猜想如果你必须手动更改文件，你也可以接受一次手动干预。

https://developer.mozilla.org/en-US/docs/Web/API/Window/localStorage

如果您还没有选择它，请考虑在文件中以及localeStorage中使用JSON格式的文本，它可以简化您的数据转换。

[编辑] 当然，如果您的文件永远不会改变，只需将您的数据嵌入到javascript变量中。

[编辑2] 示例

<body>
    <!-- The input widget to select a file from browse -->
    <input type="file" id="file-input" />

    <!-- testing purpose only, a markup to display the loaded file content -->
    <h3>Loading a file:</h3>
    <pre id="file-content"></pre>
    <script>

    // Place a listener to know when the page is loaded
    window.addEventListener('load',function(e){
      // If there is some persistent data on the browser called 'stored_data'
      if( localStorage.getItem('stored_data')){
        // We can do something with this data
        // without asking a user interaction at first
        // User interaction could be done in order to refresh the data ( file changed since storing in browser cache )
        doSomethingWithFileContents();
      }
    });

    /**
     * This is the callback of the addEventListener, it will be executed each time user select a file
     * It's linked below, on the addEventListener call
     */
    function readSingleFile(e) {
      //retrieve the first selected file the user has select
      var file = e.target.files[0];

      // If no file selected, abort this function execution
      if (!file) {
        return;
      }
      // If a file is selected, create a new file reader
      var reader = new FileReader();

      // Define a callback to be run when the file will be loaded
      reader.onload = function(e) {

        // You can still use some console.log for debugging purpose
        //console.log(e);

        // Retrive the content of the loaded file
        var contents = e.target.result;

        // To enable some persistency, store the contents into a localeStorage
        // It means next time you load the page, the data could come from the browser cache
        localStorage.setItem('stored_data', contents );

        // Will can now call the logic what we need to do with the file content
        doSomethingWithFileContents();
      };

      // Trigger the file reader to load the selected file
      reader.readAsText(file);
    }

    /**
     * This function will be executed when data is ready.
     * You should implements the logic that should be run with the file data
     *
     *  - Data is ready could mean:
     *      - Data was available through localStorage
     *      - Data has just been loaded through FileReader
     */
    function doSomethingWithFileContents() {

      // Retrieve the cached data
      var loadedData = localStorage.getItem('stored_data');

      // Get the element that will display the raw data
      var element = document.getElementById('file-content');
      // Set its content to the storedData
      element.textContent = loadedData;

      // Once again, I strongly recommend you to use JSON formatted value in the file
      // It will enable some easy transformation/parsing from js side


    }

    // Place a addEventListener on the file-input id element
    // When its value changed, run the readSingleFile function
    document.getElementById('file-input').addEventListener('change', readSingleFile, false);
</script>
</body>

本地html加载txt文件

1 个答案: