How to achieve a snappy, cascading UX via AngularJS + ui-router - angularjs

root
/ | \
/ | \
/ | \
header content navbar
|
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library (abstract)
/ | \
/ | \
/ | \
Authors Books Movies
Using my beautiful graphic above I would like to explain a few things:
header has some API data to retrieve about the user (e.g. GET /user/me)
Authors has its own GET /authors it uses to populate that view
Books and Movies are the same as Authors, they are just their own state
Now this is what I want:
I want a cascading layout whereby the main layout of the page can be loaded first, then the "library" application can be loaded on top of it without any "lag" or blocking of the UX.
However, with how ui-router seems to work today, if I have 1 resolve in this entire application and I place it in the "library" state, what happens is the "header" and "navbar" states are blocked until the resolve completes. What I would expect to happen is the parent states load first with their views, then the "library" state blocks on the resolve. That way you could see the navbar and header in the browser as soon as the page is loaded, but you would get a loading bar or spinner until the "library" resolve finished.
Any easy way to achieve this functionality would be to not use resolves and instead just have all the API logic inside the controller, however this causes the scope of each of the 3 resources to be limited to their controller and that is it. Meaning, if you are in the Movies controller, you have no visibility into the Authors resources because Authors are scoped to only the "Authors" controller. This makes things like web sockets less efficient and even unusable.
Am I doing something wrong here which is causing me to not get the desired functionality or is this not possible with this kind of architecture?

Related

Calling a view controller from index.html

I have an index.html that has a top bar with links and a side bar with links. I want the center to be replaced with content (ng-view). Let's say the top bar is Pictures, Stats, Chat. The side bar is Tigers, Lions, Bears.
These never change. This is why index.html holds them. The top bar of Pictures, Stats, Chat I want to actually route to different views/controllers (replaces ng-view on index.html). Easy.
However, when inside a given view controller (let's say Pictures) I now want to know what side bar was clicked (I would like to default to a given side bar animal when Pictures is first clicked in the app since that would be required) and I'd also like to be able to copy the link directly to there (ie Pictures/Bears (but this always just goes to the Pictures controller but inside there I know Bears was clicked so I can act accordingly)).
So if I click Tigers, the controller will know this and I can code it to get pictures of Tigers.
I don't want to put that side bar into each page itself since it's always the same. I just want it on index.html to avoid repeating myself even though this would be more direct in terms of coding each top bar view. This would be something I'd fall back to in the case of what I'm asking to do isn't possible.
I'm also wondering if it's possible to maintain the current side bar value when they click on a different top link animal. So if I was in Pictures/Lions and they click Bears, it would know to route Pictures/Bears. Since it's staying in Pictures would it really even need to route? Can it route and then call a method on the Pictures controller passing in the animal so it can do what it needs to with that information?
Try making a service like animalService that keeps track of the selected animal. This will act like your own route handler for just that side menu.
The controller for the side menu would then be able to call animalService.selectAnimal(selectedAnimal) to update the selection.
Each main page controller could then watch the value of the selected animal from animalService. There are a few ways to do this, but it would probably be easiest to use a subscription based approach:
Each controller would call animalService.subscribeToChange('controllerName', callback) on initialization and then on destroy it would call animalService.unsubscribeFromChange('controllerName'). The animalService would keep a list/map of all of the subscribed controllers, so it can execute the callback every time the selectAnimal function is called and detects a change.
If you provide a code sample I could try to give a more detailed solution.
Alternatively
You could take advantage of $rootScope. I find this a bit more hacky, but it would be probably quicker to implement. The side menu can access a root scope variable via something like $root.currentAnimal, and it can both get and set that value. Then each controller can use $rootScope.$watch('currentAnimal', function() {}) to trigger something on change ($rootScope is a service).

Angular sidebar search directive

In my angular application I have a global sidebar navigation directive which among other things provides a global search for the user (with bunch of criteria, not just a text field).
Upon searching I'd like to show a page with the search results.
Now, the sidebar is defined in the main app html, what is the best way of sharing the search results data?
Should the sidebar be in charge of performing the search? If so how do I share it's data to the specific page results?
Or on the other hand, perhaps the specific search results page should be in charge of this data? If so how do I connect it with the sidebar search parameters when performing a search?
Any best practices of this scenario are appreciated.
Steps to make your future bright:
Separate your search module in 3 modules: main, sidebar, results
Translate data between each of them with one major SearchResultsService that will:
a) acquire collection of sidebar filters with true or false for each key (key as name for GET param that will be used for passing to search API of your back-end);
b) serialize or deserialize data depending on results module approach;
c) do some pagination;
d) hold or even cache data if you need (for infinite scroll functionality);
sidebar and results will be views of main (child modules), so you will be able to share main controller methods if needed (noob way)
When I was facing implementation of such module I've used black magic to escape $watch and $on event system. If you are young - then use $on that will allow you to notify each of modules about something important (such pagination change, item selection, etc.) and keep them separated same time.
You are free to place your existing sidebar in main module but I'd moved from directive to view with own controller and template.
Directives are used for reusable items either for pasting functionality. But dat sidebar obviously should be defined as separate part of app (aka module) but not as directive.
P.S. Keep your controllers simple.
Google list:
Multiply satisfection
Your golden chest
Root of AngularJS evil
Angular services are substitutable objects that are wired together using dependency injection (DI). You can use services to organize and share code across your app.
https://docs.angularjs.org/guide/services

is it right to do using ui-router to activate menu items. Any advices to help me understand this?

What I did is:
When a menu item is clicked, a action will be done, like deleting a user, sending emails to a group, etc. To this end, for each menu item, I define a ui-router state, and use the state url to activate the state via sref. I thought that a menu action is just a UI component for user to let users to do something, which is just a state of UI.
I was advised that I was using ui-router in a wrong way as a state url can not identify an action. For example, to delete a group of users, the state url can not tell you what group of users have been deleted.
In short, I agree with your manager while being an angular newbie myself. Angular routes are designed for managing different views of your app. I.e. define a route and corresponding view template for each view. If you add application logic into the routes, your application structure gets quickly a mess and difficult to keep clear.
To me it is much more natural that the views are managed by the routes, and each action in each view is handled by the controller of that view. If the actions grow "big", then it is worth refactoring parts of the controller into separate services. If you require some sort of "dynamic HTML" depending on the action, e.g. bootstrap modals are handy for doing that within the current view (see http://angular-ui.github.io/bootstrap/).
E.g. in my current project, I don't actually manually edit the routes at all but let yeoman angular generator to do that for me free of charge - i.e. I instantiate each new view in my dev.env using the following command (more info on this from https://github.com/yeoman/generator-angular)
yo angular:route myNewView
More info on angular philosophy can be read from angular documentation for developers: https://docs.angularjs.org/guide/concepts
You should probably be doing this actions via a method on $scope.
$scope.deleteItem = function (items) {
Service.delete(items);
};
// which is the same as:
$scope.deleteItem = Service.delete;
<a ng-click="deleteItem(item)">Delete This Item</a>
Having it in the URL just seems wrong. I mean what does that look like? www.mysite.com/delete/users?

AngularJS jquery.flot chart directive DOM collision

i'm working with angular js now for about ke 4 months and despite all the "first step failures" like not emphasising the async way anuglar thinks, I'm facing a problem I don't really understand. It's not that easy to describe.
I have a provider which registrates directives within the routeprovider's resolve function - during config phase. To compile programmatically preconfigured directives I create them on the specific controller call of each route. Acutally the directive I'm adressing here is a complex flotchart directive. It retrieves data from a rest api, transformes the retrieved data and prepares different kinds of option setups like proper stacked line charts or simple piecharts. Every single step takes its time, so I introduced promises to be sure that everthing is at it's right place before I finally call something like "$.plot".
So now I have the following situation: Imagine a singlepage app with two tabs. Each tab - like a first class menu item - refers to a new page with a new controller to process and new partials to render. For each page i have beside other directives one of these heavy flotchart directives to render. actually it takes about 5 seconds to render the chart. So we assume that we really start the app from beginning - like pressing F5. Now I enter the first page the first time and within the mentioned 5 seconds I switch tabs to enter the next page. I get to the next page, see different partials, layouts and stuff and a loading chart - but actually the directive of the first page is still bound to its link phase of that heavy flotchart directive (still preparing options for flot and calculating data to output graphically).
My problem is that this link phase actually really ends within a completely different template/route/controller context and gets stuck. It crashes with a console "replace" error from jquery.flot. I think this error means that flot tries to plot into a div which does not exist anymore. But that error occures just when I switch tabs during the link phase of the first page's heavy flot directive. It doesn't happen when the first page's chart is fully rendered and doesn't happen when the first page's directive hasn't entered its link phase (or am i missing something??). I tried placing some console.logs directly BEFORE hitting the jquery "$.plot" - remember only of the first page chart directive to dive into what's acutally happening. And the strange thing is when I manage to switch tabs within these magic 5 seconds, I still get the console log entries from the first page entry although I'm on a different page. And now guess what. That's strange - acutally two directive link phases are running side by side and one of them on a completely different view (or isn't it completely different, because its a singel page app?). Imagine I plot ("render") the chart in exactly the same div id - like $('#flot-chart'). so I have html parts containing id="flot-chart" on the first page AND on the second. when I now switch from the first to the second page (not finishing the first chart) I get the chart from the first page rendered in the #flot-chart div of the second page and like half a second later the actually correct chart rendered in that same div. So actually the link phase of the first page's chart directive ends in a completely different page in a way showing 2 charts consecutively. I know jquery.flot depends on DOM manipulation via jquery and that might be the problem (perhaps THAT'S the only real explanation for my problem), because jquery DOM manipulation is out from the angular way of life.
Or are there other explanations? I acutally solved the problem via $routeChangeStart listening and killing the $.plot process, but are there some hints, suggestions, explanations for that behaviour?
Plunker flot chart directive DOM collision
I have prepared a plunker which shows kind of a similar behaviour. i've delayed the creation of the directive and the directive's async data and option retrieval methods to somehow mock the behaviour of my app. this is non production code but describes simplified the way my problems occure. when you "fast click" the menu item one after the other many times, you can sometimes force angular to show 2 charts in one page. acutally one directive is linking and doing stuff in a different partial ? i know i'm missing something in my mind ... please give me a hint.
i used chrome for reproducing the error. stop the the plunker and press 'run'. directly after pressing 'run' click as fast as you can both links a couple of times.
Thanks a lot!

Backbone Marionette modules as Widgets similar to Twitter Flight

I'm reading up in choosing the correct client-side framework to segment/modularize my frontend code in Widgets.
Basically what I have/want is:
a complex website with multiple pagetypes, so no single-page application.
all pages are able to render a complete page WITHOUT the use of javascript. IOW: javascript is used as enrichment only.
Lots of pages have a very dynamic way in which widgets can be shown on screen. To overcome complexity at the server-side I've modularized my code into widgets (composite pattern), where each widget is responsible for it's own:
server-side controller code
server-side templating (using hogan/mustache)
routing endpoints, should it need to be called from the client
structural css (css converning the structure of the widget as opposed to the look&feel)
a server-side RegionManager ultimately decides which widgets are rendered and where they are rendered on screen. Endresults is that the RegionManager spits out the entire html (server-generated) as the composite of the rendering of all of it's widgets.
Now, some of these widgets DO have client-side logic and need rerendering on the client. Take a searchpage for instance, which needs to be able to update through ajax. (I've described this process, which uses DRY templating on client and server, here)
What I ultimately want is that, given I already use the composite pattern on the server, to extend this to the client somehow so that a Widget (1 particular logic block on the screen) contains all mentioned server-side code, plus all needed client-side code.
I hope this makes sense.
Would Marionette be suited to be used as a client side framework in this scenario? I'm asking since I'm not 100% sure if the concept of a Marionette Module is what I describe as being a Widget in above scenario. (I'm mentioning Twitter Flight in my question, since I believe this would be a fit, but it currently is so new that I'm hesitant to go with it at the moment_
I think basically what I'm asking is if anybody has some experience doing something along these lines.
I think just using Backbone.js is perfect for this type of application you are describing. You have probably already read this, but most of the backbone literature is focused around your views having associated server generated JSON models and collections, then using the View's render function to generate (on the client) the HTML UI that represents the model/collection.
However it doesn't have to be used this way. In fact there is nothing stopping you attaching views to existing elements that contain content already, which gives you all of the benefits of Backbone's modularity, events system and so on. I often use views that have no model or collection, purely because I like the conformity of style. I have also used an approach like I describe below in the cases where I have had to work with older, existing applications that have not yet got, or never will have a nice REST API, but they do provide content in HTML.
Firstly, lets assume the following HTML represents one of your widgets:
<div id="widget">
<div class="widget-title"></div>
<div class="widget-body">
<!-- assume lots more html is in here -->
Do something!
</div>
</div>
In this case, you could use backbone with a single Widget Model. This would be a very simple model, like this:
App.WidgetModel = Backbone.Model.extend({
intialize: function () {
this.url = this.options.url;
}
});
Take note of the fact the Widget receives a URL as a parameter to its constructor/initialize function. This widget model would represent many of your widgets (and of course you could adopt this general approach with more complicated models and pluck different data from the rendered HTML). So next for your views. As you probably know, normally you pass most views a model or collection when you instantiate them. However in this case, you could create the Widget model in your View's initialize Function and pass it a URL from the pre-rendered HTML as follows:
App.WidgetView = App.View.ComboboxView = Backbone.View.extend({
initialize: function () {
this.model = new App.WidgetModel({}, { url: this.$("a").attr("href") });
}
// rest of the view code
});
So instantiating the view would be something like:
new App.WidgetView({el: $("#widget")})'
By doing all of the above you can do pretty much everything else that backbone offers you and its modular and encapsulated nicely, which is what you are after.
The end result of this whole approach is:
You have rendered the Widget UI as pure HTML which (I assume) is functional without JavaScript.
You attach a View to the existing HTML.
You pass into the View as options, content by extracted (such as a URL) from the rendered HTML with jQuery.
The View is responsible for instantiating the Model passing on the relevant options the model needs (such as a URL).
This means all dynamic server side content is intially contained in the rendered HTML and your View is a modular JavaScript component that can do stuff to it, which I think is the end result you're after.
So you mentioned that you would like to have AJAX functionality for your widgets and that fine with this approach too. Using this approach, you can now use the standard Backbone fetch and save functions on the Widget model to get new content. In this example it is from the URL retrieved from the rendered HTML. When you get the response, you can use the view's, render function, or other finer grained functions to update the HTML on the page as required.
A few points:
The only thing to look out for is that you'll need to change the content type of the fetch and save functions to "text/html" if that's what the server is providing. For example:
this.model.fetch({
type: "POST",
contentType: "text/html"
});
Lastly, the model I have proposed is instantiated with no content. However if your ajax calls are a content type of "text/html", you may need to play around with you model so it can store this content in its attributes collection properly. See this answer for more information.

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