在网页中显示来自Firefox附加组件数据目录的图像

Question

I am writing a firefox addon and have a content script that does my DOM manipulation as I want, but I now want to display some images from my add-on's data directory in the manipulated webpage (rather than link to them on a remote server) but I'm not sure how to do it.

I see that communication between the add-on module and content script should be done via port.emit, but the API says that the parameter has to be JSON serializable.

Has anyone done this before? I feel that I've missed something.

Answer 1

Although you can hard code the resource: uri to the data directory, it is better to construct it at runtime. This is done with the help of the @loader/options pseudo module, but a forward compatible way would be through the self module. If you don't have other reason to use the port mechanism, then you can pass the uri to the content script through the contentScriptOptions parameter. Your content script can access it from self.options . The following code will insert the mylogo.jpg at every page of the mozilla.org domain.

// var options = require("@loader/options");
// options.prefixURI + options.name + "/data/" works now but may change in the future
var pageMod = require("sdk/page-mod");
var self = require("sdk/self");

pageMod.PageMod({
  include: "*.mozilla.org",
  contentScriptOptions: {prefixDataURI: self.data.url("")},
  contentScriptWhen: "ready",
  contentScript: "var img = document.createElement('img');" +
                 "img.src = self.options.prefixDataURI + 'mylogo.jpg';" +
                 "document.body.appendChild(img);"
});

Answer 2

I've done this in a bootstrap addon with the contentaccessible param in the chrome.manifest here: https://gist.github.com/Noitidart/9406437

For addon-sdk, which it sounds like you are doing, I think do this: just drop your images into your data folder. Then with the self.data.url('img_name') it gives you a resource:// path, use that path in the webpages. It should work, resource paths don't have the security issue Im pretty sure.