nextFilePath method

String nextFilePath(

String path, {
String v_root = "",

})

Calculate the file path of the next Encrust file.

Return Value

Return the URL string to get the Enclst file indicated by the parameter path. Depending on what the parameter path is like, it is evaluated as following:

Full URL

In the case of the path is the full version of the URL string like a "https:www.a.com/b.enlist" which can be used as the parameter of the HTTP Get for fetching a new enclist file, this function returns the same string of the input parameter path as is.

Absolute Path

In the case of the path is the absolute path string start with "/" like a "/b.enlist", return value is depend on the presence of an additional named parameter "v_root" indicating a virtual root.

without v-root

Calculate subsequent URL from the current URL that storeed in the member valuable of this enclst, and a parameter path that indicate a next enclst which is loading. Retuned nextURL is calculated as joind of the current url and path. You can optionally specify a base_url, which will be used instead of the current url.

with v-root

Relative Path

Implementation

String nextFilePath(String path, {String v_root = ""}) {
    // path is full url, use it as is.
    if (isURL(path)) {
      return path;

      // path is absolute
    } else if (path[0] == "/") {
      // Get origin (protocol:port//server name) from current file path.
      String origin = (Uri.parse(filepath ?? "")).origin;

      // The virtual root is specified.
      if (v_root != "") {
        // if it end with `/`
        if (v_root[v_root.length - 1] == '/') {
          // remove trailing '/'
          v_root = v_root.substring(0, v_root.length - 1);
        }
        // Set specified virtual root as origin
        origin = v_root;
      }

      // note: THe path string is start with `/`.
      return origin + path;

      // path is relative
    } else {
      // set path context for url
      var context = p.Context(style: p.Style.url);
      // join current parent path (..) and filepath
      return (context.canonicalize(context.join(filepath ?? "", "..", path)));
    }
  }