I am trying to get some information from twitter using CasperJS. And I'm stuck with infinite scroll. The thing is that even using jquery to scroll the page down nothings seems to work. Neither scrolling, neither triggering the exact event on window (smth like uiNearTheBottom) doesn't seem to help.
Interesting thing - all of these attempts work when injecting JS code via js console in FF & Chrome.
Here's the example code :
casper.thenEvaluate(function(){
$(window).trigger('uiNearTheBottom');
});
or
casper.thenEvaluate(function(){
document.body.scrollTop = document.body.scrollHeight;
});
If casper.scrollToBottom() fails you or casper.scroll_to_bottom(), then the one below will serve you:
this.page.scrollPosition = { top: this.page.scrollPosition["top"] +
document.body.scrollHeight, left: 0 };
A working example:
casper.start(url, function () {
this.wait(10000, function () {
this.page.scrollPosition = { top: this.page.scrollPosition["top"] + document.body.scrollHeight, left: 0 };
if (this.visible("div.load-more")) {
this.echo("I am here");
}
})});
It uses the underlying PhantomJS scroll found here
CasperJs is based on PhantomJS and as per below discussion no window object exist for the headless browser.
You can check the discussion here
On Twitter you can use:
casper.scrollToBottom();
casper.wait(1000, function () {
casper.capture("loadedContent.png");
});
But if you include jQuery... , the above code won't work!
var casper = require('casper').create({
clientScripts: [
'jquery-1.11.0.min.js'
]
});
The script injection blocks Twitter's infinite scroll from loading content. On BoingBoing.net, CasperJS scrollToBottom() works with jQuery without blocking. It really depends on the site.
However, you can inject jQuery after the content has loaded.
casper.scrollToBottom();
casper.wait(1000, function () {
casper.capture("loadedContent.png");
// Inject client-side jQuery library
casper.options.clientScripts.push("jquery.js");
// And use like so...
var height = casper.evaluate(function () {
return $(document).height();
});
});
I have adopted this from a previous answer
var iterations = 5; //amount of pages to go through
var timeToWait = 2000; //time to wait in milliseconds
var last;
var list = [];
for (i = 0; i <= iterations; i++) {
list.push(i);
}
//evaluate this in the browser context and pass the timer back to casperjs
casper.thenEvaluate(function(iters, waitTime) {
window.x = 0;
var intervalID = setInterval(function() {
console.log("Using setInternal " + window.x);
window.scrollTo(0, document.body.scrollHeight);
if (++window.x === iters) {
window.clearInterval(intervalID);
}
}, waitTime);
}, iterations, timeToWait);
casper.each(list, function(self, i) {
self.wait(timeToWait, function() {
last = i;
this.echo('Using this.wait ' + i);
});
});
casper.waitFor(function() {
return (last === list[list.length - 1] && iterations === this.getGlobal('x'));
}, function() {
this.echo('All done.')
});
Essentially what happens is I enter the page context, scroll to the bottom, and then wait 2 seconds for the content to load. Obviously I would have liked to use repeated applications of casper.scrollToBottom() or something more sophisticated, but the loading time wasn't allowing me to make this happen.
Related
I am writing tests using Protractor (with Cucumber.js, Chai and Chai As Promised, though I think these details don't matter). I would like to write a test that checks whether an image element is valid and loaded - i.e. that it has a src attribute and has not errored out while loading.
There are some nice-looking answers elsewhere to the question of how to check if an image is loaded from within a browser, via the DOM API. But how can I cleanly perform this check using Protractor's API?
I expect my test will look something like:
this.Then(/^I should see the "([^"]*)" image$/, function (imageId, callback) {
expect(
element(by.id(imageId))
).to.eventually.satisfy(isImageOk).notify(callback);
});
but I don't know how to implement the isImageOk function via the Protractor API.
You need to evaluate a JavaScript expression in the context of the browser, using Protractor's executeAsyncScript function.
Here is the code from my answer to a similar question:
it('should find all images', function () {
browser.executeAsyncScript(function (callback) {
var imgs = document.getElementsByTagName('img'),
loaded = 0;
for (var i = 0; i < imgs.length; i++) {
if (imgs[i].naturalWidth > 0) {
loaded = loaded + 1;
};
};
callback(imgs.length - loaded);
}).then(function (brokenImagesCount) {
expect(brokenImagesCount).toBe(0);
});
});
The function executed within the browser returns the number of non-loaded images.
Just an updated version of the previous answer - test is made to fail if there are broken images, because we expect 0
it('should check if there are broken images', function () {
browser.executeAsyncScript(function (callback: (arg0: number) => void) {
const imgs = document.getElementsByTagName("img");
let loaded = 0;
for (let i = 0; i < imgs.length; i++) {
if (imgs[i].naturalWidth > 0) {
loaded = loaded + 1;
}
}
callback(imgs.length - loaded);
})
.then(function (brokenImagesCount) {
expect(brokenImagesCount).toBe(0);
});
});
I have a bunch of nodes that will contain markup in an unpredictable structure. I want to be able to watch these nodes and see if the html of the any of the child nodes or their descendants change, no matter how slightly. If they do, then I want to fire an event.
Can I do this through dojo? I'm using 1.10, the latest one.
Thanks.
It sounds like you're looking for dom mutations. As far as I'm aware dojo does not provide an api for this, but they're pretty simple to set up. The problem is different browsers have different ways of doing this.
var observeNode = document.getElementById('observeMe');
// Check for vendor-specific versions of MutationObserver.
MutationObserver = (function() {
var prefixes = ['WebKit', 'Moz', 'O', 'Ms', ''];
for (var i=0, il=prefixes.length; i<il; i++) {
if (prefixes[i] + 'MutationObserver' in window) {
return window[prefixes[i] + 'MutationObserver'];
}
}
}());
// Sniff for MutationObserver support
if (MutationObserver) {
var observer = new MutationObserver(function(mutations) {
alert('Something changed!');
});
observer.observe(observeNode, {attributes: true, childList: true, characterData: true});
} else {
// Fall back to mutation events
if (observeNode.addEventListener) {
observeNode.addEventListener('DOMSubtreeModified', function() {
alert('Something changed!');
});
}
// IE8 and below has its own little weird thing
else {
observeNode.onpropertychange = function() {
alert('Something Changed!');
}
}
}
We are using Durandal for our SPA application and came to a, in my opinion, common use case. We have two pages: one page is a list of entities (with filters, sorting, virtual scroll) and another is detail preview of an entity. So, user is on list page and set a filter and a list of results comes out. After scrolling a little bit down user notice an entity which he/she would like to see details for. So clicking on a proper link user is navigated to details preview page.
After "work finished" on preview page user click back button (in app itself or browser) and he/she is back on the list page. However, default 'entrance' transition scroll the page to the top and not to the position on list where user pressed preview. So in order to 'read' list further user have to scroll down where he/she was before pressing preview.
So I started to create new transition which will for certain pages (like list-search pages) keep the scroll position and for other pages (like preview or edit pages) scroll to top on transition complete. And this was easy to do however, I was surprised when I noticed that there are strange behavior on preview pages when I hit navigateBack 'button'. My already long story short, after investigation I found out that windows.history.back is completing earlier then the transition is made and this cause that preview pages are scrolled automatically down to position of previous (list) page when back button is hit. This scrolling have a very unpleasant effect on UI not mentioning that it is 'total catastrophe' for my transition.
Any idea or suggestion what could I do in this case?
Here is the code of transition. It is just a working copy not finished yet as far as I have this problem.
define(['../system'], function (system) {
var fadeOutDuration = 100;
var scrollPositions = new Array();
var getScrollObjectFor = function (node) {
var elemObjs = scrollPositions.filter(function (ele) {
return ele.element === node;
});
if (elemObjs.length > 0)
return elemObjs[0];
else
return null;
};
var addScrollPositionFor = function (node) {
var elemObj = getScrollObjectFor(node);
if (elemObj) {
elemObj.scrollPosition = $(document).scrollTop();
}
else {
scrollPositions.push({element: node, scrollPosition: $(document).scrollTop()});
}
};
var scrollTransition = function (parent, newChild, settings) {
return system.defer(function (dfd) {
function endTransition() {
dfd.resolve();
}
function scrollIfNeeded() {
var elemObj = getScrollObjectFor(newChild);
if (elemObj)
{
$(document).scrollTop(elemObj.scrollPosition);
}
else {
$(document).scrollTop(0);
}
}
if (!newChild) {
if (settings.activeView) {
addScrollPositionFor(settings.activeView);
$(settings.activeView).fadeOut(fadeOutDuration, function () {
if (!settings.cacheViews) {
ko.virtualElements.emptyNode(parent);
}
endTransition();
});
} else {
if (!settings.cacheViews) {
ko.virtualElements.emptyNode(parent);
}
endTransition();
}
} else {
var $previousView = $(settings.activeView);
var duration = settings.duration || 500;
var fadeOnly = !!settings.fadeOnly;
function startTransition() {
if (settings.cacheViews) {
if (settings.composingNewView) {
ko.virtualElements.prepend(parent, newChild);
}
} else {
ko.virtualElements.emptyNode(parent);
ko.virtualElements.prepend(parent, newChild);
}
var startValues = {
marginLeft: fadeOnly ? '0' : '20px',
marginRight: fadeOnly ? '0' : '-20px',
opacity: 0,
display: 'block'
};
var endValues = {
marginRight: 0,
marginLeft: 0,
opacity: 1
};
$(newChild).css(startValues);
var animateOptions = {
duration: duration,
easing : 'swing',
complete: endTransition,
done: scrollIfNeeded
};
$(newChild).animate(endValues, animateOptions);
}
if ($previousView.length) {
addScrollPositionFor(settings.activeView);
$previousView.fadeOut(fadeOutDuration, startTransition);
} else {
startTransition();
}
}
}).promise();
};
return scrollTransition;
});
A simpler approach could be to store the scroll position when the module deactivates and restore the scroll on viewAttached.
You could store the positions in some global app variable:
app.scrollPositions = app.scrollPositions || {};
app.scrollPositions[system.getModuleId(this)] = theCurrentScrollPosition;
In my ExtJS 4.0.7 app I have some 3rd party javascripts that I need to dynamically load to render certain panel contents (some fancy charting/visualization widgets).
I run in to the age-old problem that the script doesn't finish loading before I try to use it. I thought ExtJS might have an elegant solution for this (much like the class loader: Ext.Loader).
I've looked at both Ext.Loader and Ext.ComponentLoader, but neither seem to provide what I'm looking for. Do I have to just "roll my own" and setup a timer to wait for a marker variable to exist?
Here's an example of how it's done in ExtJS 4.1.x:
Ext.Loader.loadScript({
url: '...', // URL of script
scope: this, // scope of callbacks
onLoad: function() { // callback fn when script is loaded
// ...
},
onError: function() { // callback fn if load fails
// ...
}
});
I've looked at both Ext.Loader and Ext.ComponentLoader, but neither
seem to provide what I'm looking for
Really looks like it's true. The only thing that can help you here, I think, is Loader's injectScriptElement method (which, however, is private):
var onError = function() {
// run this code on error
};
var onLoad = function() {
// run this code when script is loaded
};
Ext.Loader.injectScriptElement('/path/to/file.js', onLoad, onError);
Seems like this method would do what you want (here is example). But the only problem is that , ... you know, the method is marked as private.
This is exactly what newest Ext.Loader.loadScript from Ext.4-1 can be used for.
See http://docs.sencha.com/ext-js/4-1/#!/api/Ext.Loader-method-loadScript
For all you googlers out there, I ended up rolling my own by borrowing some Ext code:
var injectScriptElement = function(id, url, onLoad, onError, scope) {
var script = document.createElement('script'),
documentHead = typeof document !== 'undefined' && (document.head || document.getElementsByTagName('head')[0]),
cleanupScriptElement = function(script) {
script.id = id;
script.onload = null;
script.onreadystatechange = null;
script.onerror = null;
return this;
},
onLoadFn = function() {
cleanupScriptElement(script);
onLoad.call(scope);
},
onErrorFn = function() {
cleanupScriptElement(script);
onError.call(scope);
};
// if the script is already loaded, don't load it again
if (document.getElementById(id) !== null) {
onLoadFn();
return;
}
script.type = 'text/javascript';
script.src = url;
script.onload = onLoadFn;
script.onerror = onErrorFn;
script.onreadystatechange = function() {
if (this.readyState === 'loaded' || this.readyState === 'complete') {
onLoadFn();
}
};
documentHead.appendChild(script);
return script;
}
var error = function() {
console.log('error occurred');
}
var init = function() {
console.log('should not get run till the script is fully loaded');
}
injectScriptElement('myScriptElem', 'http://www.example.com/script.js', init, error, this);
From looking at the source it seems to me that you could do it in a bit of a hackish way. Try using Ext.Loader.setPath() to map a bogus namespace to your third party javascript files, and then use Ext.Loader.require() to try to load them. It doesn't look like ExtJS actually checks if required class is defined in the file included.
I can't seem to get a handle on my list of sortables. They are a list of list elements, each with a
form inside, which I need to get the values from.
Sortables.implement({
serialize: function(){
var serial = [];
this.list.getChildren().each(function(el, i){
serial[i] = el.getProperty('id');
}, this);
return serial;
}
});
var sort = new Sortables('.teams', {
handle: '.drag-handle',
clone: true,
onStart: function(el) {
el.fade('hide');
},
onComplete: function(el) {
//go go gadget go
order = this.serialize();
alert(order);
for(var i=0; i<order.length;i++) {
if (order[i]) {
//alert(order[i].substr(5, order[i].length));
}
}
}
});
the sortables list is then added to a list in a loop with sort.addItems(li); . But when I try to get the sortables outside of the sortables onComplete declaration, js says this.list is undefined.
Approaching the problem from another angle:
Trying to loop through the DOM gives me equally bizarre results. Here are the firebug console results for some code:
var a = document.getElementById('teams').childNodes;
var b = document.getElementById('teams').childNodes.length;
try {
console.log('myVar: ', a);
console.log('myVar.length: ', b);
} catch(e) {
alert("error logging");
}
Hardcoding one li element into the HTML (rather than being injected via JS) changes length == 1, and allows me to access that single element, leading me to believe that accessing injected elements via the DOM is the problem (for this method)
Trying to get the objects with document.getElementById('teams').childNodes[i] returns undefined.
thank you for any help!
not sure why this would fail, i tried it in several ways and it all works
http://www.jsfiddle.net/M7zLG/ test case along with html markup
here is the source that works for local refernece, using the native built-in .serialize method as well as a custom one that walks the dom and gets a custom attribute rel, which can be your DB IDs in their new order (I tend to do that)
var order = []; // global
var sort = new Sortables('.teams', {
handle: '.drag-handle',
clone: true,
onStart: function(el) {
el.fade('hide');
},
onComplete: function(el) {
//go go gadget go
order = this.serialize();
}
});
var mySerialize = function(parentEl) {
var myIds = [];
parentEl.getElements("li").each(function(el) {
myIds.push(el.get("rel"));
});
return myIds;
};
$("saveorder").addEvents({
click: function() {
console.log(sort.serialize());
console.log(order);
console.log(mySerialize($("teams")));
}
});