Can I use embedded Javascript in a ghost blog entry? - javascript

I am using the Ghost Blogging Software and tumbled over Tangle these days. So it would be great to be able to use that in some of my Blog posts.
I have included the Tangle-files in my theme and load them in default.hbs. However, I cannot find a way to embed some javascript (to be executed, but not displayed) in the markdown document. I would like to write the javascript in the markdown document too as I do not want to add js-Files to my theme each time I write a blog post with reactive content.
Is there a way to do this?

It seems there is. You should be able to include the JavaScript you want to run by just placing it inside of <script> tags like they talk about on this post
Edit: To further explain, a markdown file is just different syntax for creating html tags, but you can use regular html and script tags inside them. To get an script to run per the above link, you should only need to include whatever js you want to run inside of the script tags. This example should work inside of a markdown post file to replicate the Tangle example on the doc page
When you eat <span data-var="cookies" class="TKAdjustableNumber"> cookies</span>,
you consume <span data-var="calories"> calories</span>.
<script>
var tangle = new Tangle(document, {
initialize: function () { this.cookies = 3; },
update: function () { this.calories = this.cookies * 50; }
});
</script>

Related

Add Javascript in AMP Pages

Please help me understand how to add javascript in the AMP (Accelerated Mobile Pages). My requirement is I get an ID in URL. For example localhost:8080/home?id=1.I would like to access that id in my html file.
or else please let me know how to add any javascript file.
Thank you.
Unfortunately, you cannot add arbitrary scripts in AMP. From the specification, under "HTML Tags," for the tag script:
Prohibited unless the type is application/ld+json. (Other non-executable values may be added as needed.) Exception is the mandatory script tag to load the AMP runtime and the script tags to load extended components.
So, if you want to use JavaScript from AMP, you have to use AMP's predefined components. I don't see a component that does what you want.
As of 11th of April 2019 Official Announcement,
it is now possible using your JS inside an AMP project with amp-script component.
First you need to import it to your project:
At the top of your .html file import:
<script async custom-element="amp-script" src="https://cdn.ampproject.org/v0/amp-script-0.1.js"></script>
Wrap the html element/s with the amp-script component:
<!-- hello-world.html -->
<amp-script layout="container" src="https://yourdomain.com/hello-world.js">
<button id="hello">Insert Hello World!</button>
</amp-script>
Now you can create the JS file
// hello-world.js
const button = document.getElementById('hello');
button.addEventListener('click', () => {
const el = document.createElement('h1');
el.textContent = 'Hello World!';
// `document.body` is effectively the <amp-script> element.
document.body.appendChild(el);
});
You can find more details and how it works in the
AMP git repo amp-script.md
As far as I know, you can add Javascript to AMP by hosting the AMP script on your origin and intercept the request to get the script using a Service Worker. This technique is called "AMP as PWA". Here is the code
function createCompleteResponse (header, body) {
return Promise.all([
header.text(),
getTemplate(RANDOM STUFF AMP DOESN’T LIKE),
body.text()
]).then(html => {
return new Response(html[0] + html[1] + html[2], {
headers: {
'Content-Type': 'text/html'
}
});
});
}
More explanation here: https://www.smashingmagazine.com/2016/12/progressive-web-amps/#amp-as-pwa
Javascript blocks DOM construction and delays page rendering, so AMP allows only asynchronous Javascript - AMP pages can't include any custom Javascript. Interactive page features can be handled in custom AMP elements instead of using Javascript.
Custom javascript is disallowed on AMP pages, and is one of the founding principles of AMP. You can put custom js within an amp-iframe, as long as the amp-iframe is xdomain'd from the main page.

AngularJS - inject trusted code from loaded content

I've hooked up a lazy loader in Angular. It pulls in full templates and extracts key information from that full template in order to populate a partial. This full page template has script tags which load in and then register with the existing app. All of this works fine. My problem is that I'd like to remove the only use of jQuery in this approach.
The root issue is that the JS inside of something.js doesn't execute when using $element.html(), but it does execute when using $.html(), despite the script tag being placed in the DOM in both approaches.
Working code, including lazy loader and post-bootstrap registration of lazy-loaded JS:
$http.get("/path/to/file.html").success(function(response) {
// response is a full HTML page including <doctype>
var partial = getOnlyWhatWeNeed(response);
// partial is now something like: '<script type="text/javascript" src="/path/to/something.js"></script><div ng-controller="somethingCtrl">{{something}}</div>'
// i'd like the following to not rely on full jQuery.
$("#stage").html(partial);
$("#stage").html($compile(partial)($scope)); // it is necessary to do it once before compile so that the <script> tags get dropped in and executed prior to compilation.
});
I've tried what seems like the logical translation:
$element.html($compile(partial)($scope));
and the DOM is created properly, but the JS inside of the loaded <script> tag doesn't actually execute. My research suggested this was an $sce issue, so I tried:
$element.html($compile($sce.trustAsHtml(partial)($scope));
but i get the same result. the DOM is fine, but the JS doesn't actually execute and so I get undefined controller issues.
I've tried playing with $sce.JS and $sce.RESOURCE_URL but the docs didnt elaborate much so I'm not sure I know whether or not what I'm trying is even right.
I've also tried $element[0].innerHTML but I get the same result as $element.html().
Preemptive disclaimer: I can trust the incoming HTML/JS. I know it's inadvisable. This isn't my baby and it is much more complicated than I explained so please try to stay on topic so other people in this position may not have as hard of a time as I am :)
The $http.get happens in a provider, and the $element.html happens in a directive. I consolidated them to remove noise from the problem.
Jquery will find any script tags and evaluate them (either a direct eval or appending them to the head for linked scripts) when calling html(), see this answer. I'm assuming angular's jquery lite doesn't do this. You would need to effectively replicate what jquery is doing and look for script tags in the html you are appending.
Something like this (although I haven't tested it):
$http.get("/path/to/file.html").success(function(response) {
// response is a full HTML page including <doctype>
var partial = getOnlyWhatWeNeed(response);
// partial is now something like: '<script type="text/javascript" src="/path/to/something.js"></script><div ng-controller="somethingCtrl">{{something}}</div>'
var d = document.createElement('div');
d.innerHTML = partial;
var scripts = d.getElementsByTagName('script');
for (var i = 0; i < scripts.length; i++) {
document.head.appendChild(scripts[0]);
}
$("#stage").html($compile(partial)($scope)); // it is necessary to do it once before compile so that the <script> tags get dropped in and executed prior to compilation.
});
This is far from an ideal solution as it gives you no guarantee of when things are loaded and doesn't really handle dependencies across scripts. If you can control the templates it would be simpler to remove the scripts from them and load them independently.

what happens when you use javascript to insert a javascript widget?

can anyone explain what happens when you use javascript to insert a javascript based widget?
here's my js code:
var para = document.getElementsByTagName("p");
var cg = document.createElement("div");
cg.setAttribute("class", "twt");
cg.innerHTML='<a href="http://twitter.com/share" class="twitter-share-button"
data-count="vertical" data-via="xah_lee">Tweet</a>
<script type="text/javascript" src="http://platform.twitter.com/widgets.js"></script>';
document.body.insertBefore(cg, para[1]);
it inserts the twitter widget, before the first paragraph. As you can see above, the twitter widget calls for a javascript that shows how many time the page has been tweeted.
doesn't work in Firefox, Chrome, but semi-works in IE8. What should be the expected behavior when this happens? Does the newly inserted js code supposed to execute? If so, how's it differ from if the code is on the page itself?
In order to execute the JS code you insert into a DIV via innerHTML, you need to do something like the following (courtesy of Yuriy Fuksenko at http://www.coderanch.com/t/117983/HTML-JavaScript/Execute-JavaScript-function-present-HTML )
function setAndExecute(divId, innerHTML) {
var div = document.getElementById(divId);
div.innerHTML = innerHTML;
var x = div.getElementsByTagName("script");
for (var i=0;i<x.length;i++) {
eval(x[i].text);
}
}
A slightly more advanced approach is here: http://zeta-puppis.com/2006/03/07/javascript-script-execution-in-innerhtml-the-revenge/ - look for <script> tags, take their con­tent and create a new ele­ment into the <head>.
innerHTML does not work to insert script tags (because the linked script, in most browsers, will fail to execute). Really, you should insert the script tag once on the server side and insert only the link at the location of each post (that is, if you are adding this to a blog home page that shows multiple posts, each with their own URLs).
If, for some reason, you decide that you must use one snippet of JavaScript to do it all, at least import the tweet button script in a way that will work, for example, the Google Analytics way or the MediaWiki way (look for the importScriptURI function). (Note that I do not know the specifics of the tweet button, so it might not even work.)

Injecting JavaScript into head element of website using Fiddler

I was thinking of using Fiddler for the following purpose...
I have a JavaScript based service I want to demonstrate to potential clients. In order to show them what their website could look like if they install (i.e. include) my script, I want to set up Fiddler on my PC, so that when fetching the client's website, the
<script type="text/JavaScript" src="myscript.js"></script>
line will be included in the HTML <head> section.
Can this be easily done with Fiddler? Could someone point me to where I may find the documentation covering that, if it is?
Thanks!
----Update----
For the time being I have resorted to using a BHO to add my script to the page. I use execScript(), upon onDocumentComplete, to run a simple piece of JavaScript which appends the .js file I need to the page. But EricLaw's pointers and jitter's answer seem like the way to go for a more complete (and elegant) way to do what I need.
If someone is interested I could upload the BHO code here.
-Thanks!
Open fiddler -> Menu Rules -> Customize Rules (or hit Ctrl+R)
The CustomRule.js file opens. Scroll down until you find the line
static function OnBeforeResponse(oSession: Session)
This is where your code goes. Here you can change the server response before the browser sees it.
The following code sample shows how to include a custom piece of jQuery code which replaces the Unanswered link in the horizontal menu with a link which serves as short cut to Unanswered jQuery Questions
I first show you the jQuery code I want to include
<script type='text/javascript'>
$(function() {
var newLink = 'Unanswered jQuery';
$('div#hmenus div.nav:first ul li:last a').replaceWith(newLink);
});
</script>
Now the fiddler code (based on code found in CustomRules.js and code samples from the FiddlerScript CookBook)
//is it a html-response and is it from stackoverflow.com
if (oSession.oResponse.headers.ExistsAndContains("Content-Type", "html") &&
oSession.HostnameIs("stackoverflow.com")) {
// Remove any compression or chunking
oSession.utilDecodeResponse();
var oBody = System.Text.Encoding.UTF8.GetString(oSession.responseBodyBytes);
// Match the jQuery script tag
var oRegEx = /(<script[^>]*jquery.min.js"><\/script>)/gi;
// replace the script tag withitself (no change) + append custom script tag
oBody = oBody.replace(oRegEx, "$1<script type='text/javascript'>$(function() {$('div#hmenus div.nav:first ul li:last a').replaceWith('Unanswered jQuery');})</script>");
// Set the response body to the changed body string
oSession.utilSetResponseBody(oBody);
}
I think you should now able to hackyourself together a piece of code which fits your problem.
Example
// Match the head end
var oRegEx = /(<\/head>)/gi;
// replace with new script
oBody = oBody.replace(oRegEx, "<script type='text/javascript' src='http://url/myscript.js'></script>$1");
if you use jQuery you can add js on the fly. I would probably think you can have a method which would include/exclude your script based on some query param. This is how you would include JS with jQuery
$.getScript('someScript.js',function(){
//Do something here after your script loads
});
Haven't tried it, but how about GreaseMonkey for IE?

How to handle localization in JavaScript files?

I want JavaScript code to be separated from views.
I got the requirement to implement localization for a simple image button generated by JavaScript:
<img src="..." onclick="..." title="Close" />
What's the best technique to localize the title of it?
PS: I found a solution by Ayende. This is the right direction.
Edit:
I got Localization helper class which provides the Controller.Resource('foo') extension method.
I am thinking about to extend it (helper) so it could return all JavaScript resources (from "ClientSideResources" subfolder in App_LocalResources) for the specified controller by its name. Then - call it in BaseController, add it to ViewData and render it in Layout.
Would that be a good idea?
EDIT
Consider writing the necessary localized resources to a JavaScript object (hash) and then using it for lookup for your dynamically created objects. I think this is better than going back to the server for translations. This is similar to adding it via viewdata, but may be a little more flexible. FWIW, I could consider the localization resources to be part of the View, not part of the controller.
In the View:
<script type="text/javascript"
src='<%= Url.Content( "~/Resources/Load?translate=Close,Open" %>'></script>
which would output something like:
var local = {};
local.Close = "Close";
local.Open = "Open";
Without arguments it would output the entire translation hash. Using arguments gives you the ability to customize it per view.
You would then use it in your JavaScript files like:
$(function(){
$('#button').click( function() {
$("<img src=... title='" + local.Close + "' />")
.appendTo("#someDiv")
.click( function() { ... } );
});
});
Actually, I'm not too fussed about keeping my JavaScript code out of my views as long as the JavaScript code is localized in a container. Typically I'll set my master page up with 4 content area: title, header, main, and scripts. Title, header, and main go where you would expect and the scripts area goes at the bottom of the body.
I put all my JavaScript includes, including any for viewusercontrols, into the scripts container. View-specific JavaScript code comes after the includes. I refactor shared code back to scripts as needed. I've thought about using a controller method to collate script includes, that is, include multiple scripts using a single request, but haven't gotten around to that, yet.
This has the advantage of keeping the JavaScript code separate for readability, but also allows me to easily inject model or view data into the JavaScript code as needed.
Actually ASP.NET Ajax has a built-in localization mechanism: Understanding ASP.NET AJAX Localization
If you insist on keeping it separate, you could do something like:
//keep all of your localised vars somewhere
var title = '{title_from_server}';
document.getElementById('someImage').title = title;
Remember, if you use JavaScript code to initialize any text of elements, your site will degrade horribly where JavaScript isn't available.

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