Trouble in understanding Angular $location - javascript

I'm having some troubles understanding Angular $location, and the difference and the HTML5 mode and the default one. (yes, I've already the guide about it).
Let's say I want to build a TODO list app.
I'd like to have one page 'myapp.com/user/#1' to display the user information. 'myapp.com/user' will perform a standard GET request and load the page while Angular will intercept the hash part and say 'perform an AJAX request to get the information about user 1'. So if I just change '#/1' to '#/2' I won't get a full reload of the page.
I'd also like a 'myapp.com/todo/#1' page with the same behaviour with the todo lists. If I come from the user page to this one I get a full reload (because they're completely different pages).
How should I configure the $location service to get this working ?
I've tried setting the HTML5 mode to true, but when I click a link, I never get a full reload, and the hash character is not in the URL.
I also tried setting HTML5 mode to false, and hashPrefix('') so I get the full reload when I change pages, but $location.hash() returns an empty string and $location.path() returns '/1'.
Bonus question: what if I also want to put the ID of an item of the todo list, something like 'myapp.com/todo/#1/#2' ? (having different hash parts or something) ?

Related

which is better to perform logical operations in angularjs controller or view?

My website contains posts something like blog posts, a registered user can post things and any other registered user can view them, here when showing individual post I kept an follow button for to the viewer so if the viewer clicked it and follow the author(post owner). Now the problem is every time when a viewer clicked and see individual post I need to check whether viewer is already following that author or not so that I have to choose follow or following button to display. In my angularjs controller I have json array of authors(following authors). How can i check the individual post author existing in following authors in controller or is there any chance to perform this on view? O am using angularjs 1.x
Anyway you have to set a flag for the buttons choice (true for follow button and false for following button).
To set the scope of this variable you need to implement the logic in JS (Since its an array collection). Now in HTML you can show the follow or following button by using ng-show and ng-hide. (ng-show="isFollow")

HTML using jQuery to send a postback?

I am creating a website for a clothing brand but am still getting started with my web dev work. I have an index page with several clothing items on it. When a user hovers over the picture of the item then a hover over effect comes into play and a small "View Item" appears over the item. When the user clicks this "View Item" text it opens a new page with that particular page's info.
The part I am struggling with is how I send the parameter to this item page as I will need some way of knowing what item was clicked. Can I write a jQuery function that will fire when the text is clicked and perform a .post() method to the item.php page passing along the item ID ?
So it would be something like
$.(document).ready( function() {
$("#itemText").click( function() {
$.post("item.php", parameters);
});
})
POST isn't the proper protocol for that. Use GET instead.
GET is vary easy to use with HTML links; it is what happens every time you click a link on a website. Say the page is "products." If the user clicked on product 1, than the URL for that page could potentially be "products/?id=1" (or products/1 if you are using mod_rewrite). The "id" variable with a value of "1" will be available to the PHP via $_GET['id']. With that variable, you can retrieve the proper information based on the id.
POST is for forms where users are submitting fields of data or images. http://html.net/tutorials/php/lesson10.php
If you are attempting to build a pure Javascript solution, then that is an entirely different matter. In that situation you would use Hash tags or HTML5 History API to change the URL. When the URL changes, Javascript is notified, and then whatever actions can occur. However, based on the fact that you specifically said "POST" I am assuming you are using a server-side language like PHP.
If you are opening a new page, you should not POST. If you must POST, you should POST then Redirect, although since you are not actually performing an action I recommend just sticking with a GET request. This way the newly opened page can easily be refreshed and shared by the viewer.
The most elegant way is to use rewrite rules or a router on your server so you can communicate which item to display, for example: http://example.com/item/1/
However you can also just use a GET parameter: http://example.com/item/?id=1
If you need to communicate to Javascript that will be executed on a page you can also use a hash: http://example.com/item/#1
There are several options using GET depending on how you display the item information, and what server-side technology you use.

How to handle pagination in Single Page Application?

On my Single Page Application (Javascript (AngularJs) webapp), I'm displaying a paginated items list.
I'm displaying 10 items per page.
In order to retain the current pagination opened by the user at any time while this one navigates on other page, I put the current page number on browser's localStorage.
Here's an example of workflow:
The user goes to myItemsList.html.
He opens the page 2 involving the url: myItemsList.html?page=2.
Then, he goes to another page: myOtherPage.html.
He goes back to the link initially pointing to myItemsList.html, that displays directly thanks to localStorage the page myItemsList.html?page=2 in order to potentially continue his navigation.
Would it confuse the user, maybe expecting to see the page 1 as a new starting navigation.
If I display at the top of the list, a kind of label like "Page 2" in order to warn him that he's seeing the preceding portion of his navigation, isn't it UX-friendly?
Or should I completely avoid persisting current pagination?
Here's what could happen if I don't persist the current viewed page:
The user goes to myItemsList.html.
He opens the page 2 involving the url: myItemsList.html?page=2
He opens an item in this page (the "show" page), leading to: myItemsList.html?id=123
He clicks on the browser's back button, causing a refresh of myItemsList.html (since a Single Page Application). The current pagination (page 2) would be lost and the user would need to restart it in order to continue its items discovery.
This seems really touchy...
What strategy should I choose for a use case like this?
saving the progress through navigation is the expected behavior in UX design of SPA, so maintaining the page he was in the correct choice, and since it is a pagination it won't be an issue even if the user wants to go back to any page, it will only take a click.
First of all I would avoid using localstorage and use a service instead to persist ur page counter.
Secondly u dont need to persist pg counter to anywhere else but in a scope variable for refreshing to mext page data. You can even think about just adding to results similar to infinitite scroll use cases. But either way, u can use local scope variable for pagination.
Whether to go directly to last viewed page - is a more business decision and will depend on needs.
But u can very easily persist or remove persisted data using broadcast and watch and decide on persistence based on event listened to.
Hope thos helps ...
How about maitaining a sort of heirerachy in JS like this :
Suppose a user navigates to a section called Customer Search
customer_search.customer_display.page = 2
Where customer_search is the a subsection , customer_display is the view with pagination you are targetting .
menu.menu_items.page=7
Where menu is the subsection , menu_items is the view with pagination
Might work if your application is organized in a reasonably hierarchical manner .
Probably you could also maintain the page in $scope for that particular controller .
The URL should dictate the navigation.
When I navigate to your website, e.g. example.com, I expect to be on the first page.
When I navigate to a (bookmarked) page of your website, e.g. example.com?page=2, I expect to be on the second page.
When I hit the back button, I expect to be presented with the previous page exactly as it was when I left it. You don't need to refresh the entire page, just listen to the history events and update accordingly.
And I strongly believe that this question doesn't belong to stackoverflow...

Handling hash with HTML5 History API

I am using the history.js plugin here: https://github.com/browserstate/history.js/ for handling HTML5 History in my application. And I want to handle both HTML5 and HTML4 versions (using the hash fallback).
You can see the demo here: http://dev.driz.co.uk/history45/
Question 1
How do I load the correct content based on the hash when a person visits a url with a hash in (hasn't clicked a link on the website) As the server won't understand what the code is and I don't want to have to double the request by checking if the hash exists and then calling the content via AJAX. So for example: http://dev.driz.co.uk/history45/#about.php doesn't load in the about.php content.
Update:
I've seen some examples here: https://gist.github.com/balupton/858093 which seem to cover loading the correct content (even optimised versions). But I'm struggling to get it to work in combination with my HTML5 version. View source: http://dev.driz.co.uk/history45/ AND it only runs when a person clicks a link instead of on page load which is the original issue.
Update 2:
Tried an example here: http://dev.driz.co.uk/history4/#/contact.php to get the content to load in contact.php content using the snippet in the source but doesn't work...? BUT according to the article here: https://github.com/browserstate/history.js/wiki/Intelligent-State-Handling#wiki-why-the-hashbang-is-unnecessary this code SHOULD be AJAX loading in the correct content if it has a hash on it. Any ideas why?
Question 2
How do I force the /#/ on the root and prefix all urls with `#/'
As currently if you try and visit a page via a link in a HTML4 browser, you end up with weird urls like:
http://dev.driz.co.uk/history45/#contact.php and http://dev.driz.co.uk/history45/#./
instead of:
http://dev.driz.co.uk/history45/#/contact.php and http://dev.driz.co.uk/history45/#/
And if I start on an inner page with:
http://dev.driz.co.uk/history45/contact.php and choose a link then I end up with: http://dev.driz.co.uk/history45/contact.php#about.php when what it should be is: http://dev.driz.co.uk/history45/#/about.php
How do I load the correct content based on the hash when a person visits a url with a hash in (hasn't clicked a link on the website) As the server won't understand what the code is
The server won't see the # or anything after it
and I don't want to have to double the request by checking if the hash exists and then calling the content via AJAX.
Your only other option is to redirect (by setting location with JavaScript) to the URL that you would have used if the history API was available.
How do I force the /#/ on the root?
You'd have to redirect to the homepage (again by setting location) if the history API isn't supported.
I take the view that if they are using a browser which doesn't support the history API (which probably means Windows XP and IE 8 these days) then they can get the non-Ajax fallbacks and I never have to deal with the hash hack.
If all you want to do is to force all browsers (both HTML4/5) to use hashes, you'd use change the History.js Options within your init
History.options.html4Mode = true
However, you may also want to consider using the $.address functionality from jQuery which can append any new URL you want with a hash.
Also within the $.address method, you could also determine where to redirect the user based on their init URL if they were accessing the site for the first time:
Say, have a user access a URL with say
http://www.site.com/#/about.php
you could then have a function which listens to any changes to any changes based on the URL changes
$.address.change(fn)
REF: http://www.asual.com/jquery/address/docs/
UPDATE
One thing I've discovered that may apply here is that if you have a click event handler which behaves by pushing a new state, even if you are currently on that same page, History js will append the same url to the end of the existing URL with a hash
e.g.
If on About Page (and your state is "about") and you click the about link -
your URL will change from
http://www.site.com/about
to
http://www.site.com/about#/about
To save yourself the hassle, have an if statement on that button that checks your History State for "about" and if not, pushState "About"
e.g.
$('.about.btn').on('click', function(e){
if(History.getState().data.State != "About") {
e.preventDefault();
History.pushState({"State": "About"}, null, "/about");
}
})

How can I find the actual link which is related to the javascript

I'm a student stuyding the bioinformatics.
I'm trying to make a crawler where I can put the lists of queries and get the results automatically.
The site I'm interested in is the GEO DataSet site.
www.ncbi.nlm.nih.gov/gds/
If I wish to send a query like 'lung cancer', I can use the following address.
http://www.ncbi.nlm.nih.gov/gds/?term=lung+cancer.
And there are 549 pages showing up.
I can get the results of the first page, but I don't know how to move to the next page.
I mean, how can I move to the next page by changing the URL?
The Next button is linked as "www.ncbi.nlm.nih.gov/gds/?term=lung+cancer#" and I don't think it's the actual URL that button is linked to.
I'm new to the JavaScript, but I heard the hash sign (#) is processed in the JavaScript
I wonder if there is something I can do like
"http://www.ncbi.nlm.nih.gov/gds/?term=lung+cancer&page=2"
so that I can move to the second page.
If you use any debugger tool (Firebug for Firefox, WebDeveloper for Chrome) you should be able to monitor the network traffic. If you do that, you'll see, that by clicking the next button a form is submitted, sending data via post method. However, when concatenating the post data to a get string you can also get to the next page. The following url lets you access to second page of the result set (warning: really, really long!):
http://www.ncbi.nlm.nih.gov/gds/?term=lung+cancer?term=lung+cancer&EntrezSystem2.PEntrez.Gds.Entrez_PageController.PreviousPageName=results&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.sPresentation=docsum&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.sPageSize=20&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.sSort=none&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.FFormat=docsum&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.FSort=&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.FileFormat=docsum&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.LastPresentation=docsum&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.Presentation=docsum&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.PageSize=20&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.LastPageSize=20&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.Sort=&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.LastSort=&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.FileSort=&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.Format=&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.LastFormat=&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Entrez_Pager.cPage=1&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Entrez_Pager.CurrPage=2&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_ResultsController.ResultCount=10973&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_ResultsController.RunLastQuery=&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Entrez_Pager.cPage=1&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.sPresentation2=docsum&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.sPageSize2=20&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.sSort2=none&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.FFormat2=docsum&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_DisplayBar.FSort2=&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Entrez_Filters.CurrFilter=all&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Entrez_Filters.LastFilter=all&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_MultiItemSupl.Taxport.TxView=list&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_MultiItemSupl.Taxport.TxListSize=5&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_MultiItemSupl.RelatedDataLinks.rdDatabase=rddbto&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Gds_MultiItemSupl.RelatedDataLinks.DbName=gds&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Discovery_SearchDetails.SearchDetailsTerm=%22lung+neoplasms%22%5BMeSH+Terms%5D+OR+lung+cancer%5BAll+Fields%5D&EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.HistoryDisplay.Cmd=PageChanged&EntrezSystem2.PEntrez.DbConnector.Db=gds&EntrezSystem2.PEntrez.DbConnector.LastDb=gds&EntrezSystem2.PEntrez.DbConnector.Term=lung+cancer&EntrezSystem2.PEntrez.DbConnector.LastTabCmd=&EntrezSystem2.PEntrez.DbConnector.LastQueryKey=1&EntrezSystem2.PEntrez.DbConnector.IdsFromResult=&EntrezSystem2.PEntrez.DbConnector.LastIdsFromResult=&EntrezSystem2.PEntrez.DbConnector.LinkName=&EntrezSystem2.PEntrez.DbConnector.LinkReadableName=&EntrezSystem2.PEntrez.DbConnector.LinkSrcDb=&EntrezSystem2.PEntrez.DbConnector.Cmd=PageChanged&EntrezSystem2.PEntrez.DbConnector.TabCmd=&EntrezSystem2.PEntrez.DbConnector.QueryKey=&p%24a=EntrezSystem2.PEntrez.Gds.Gds_ResultsPanel.Entrez_Pager.Page&p%24l=EntrezSystem2&p%24st=gds
This complete GET string contains all search parameters like items per page, search terms, display and way more. You should be able to figure out which parameter is used for the offset (cPage and CurrPage are your friends) and then alter it to your needs.
EDIT: Btw, to find javascript events bound to an HTML element, you can use the bookmarklet found at http://www.sprymedia.co.uk/article/Visual+Event+2

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