I have a SPA Angular Application. I need to hide or show certain sections of a particular template based on the Tenant ID of the logged in user. The problem is, Tenant A may want to hide some controls and add some extra attrbutes, where as Tenant B may have a altogther separate requirement on the same page.
I may end up writing lots of If else on the same template and may also need to modify controllers to handle conditions of various Tenants.If number of tenants increases, The solution becomes messier.
One more Approach is to introduce redundancy and make separate copies of templates for each Tenant and maintain a configuration mapping of tenant to Templates. This way code is segregated.but still Controllers would be same. If I duplicate controllers, Even test suite has to be duplicated and will take time if Test suite is ran for every tenant.
Can somebody give me a better approach, how can this be achieved in a optimal way ?
Related
Take a SaaS company that wants to pack all its services into a single, uhm.. Single Page Application using Angular (1). Now there is a public area (landing page, etc.) and an internal area. There are various layers of protection in the backend. There are different user groups with different privileges.
If the complete app is compiled into a single javascript file, hints for all routes can be found in the JS file quite easily. Then, there are services / $resources for interacting with the API, which again contain quite essential information on the functionality of the application.
Now the question: How could someone put modules on a certain non-binary protection level, and only load this particular module when the user is authorized to see it, all while not reloading the page?
I can find a way to lazily add modules to an angular application. I can also protect single files server sided and only send them to authorized users. But that seems like an unscalable hassle when there are more and more user groups.
Do you know any generic libraries for that purpose, ideally in sync with koa, which do not create a vast overhead? Do you know of some grunt / gulp / whatever processes, which help with that?
Thanks!
You can use latest ui.router which allows you to lazy load routes.
https://ui-router.github.io/ng1/docs/latest/interfaces/state.statedeclaration.html#lazyload
Also you can use web pack and use multiple entry points to create seperate bundles. https://webpack.github.io/docs/multiple-entry-points.html
By following above steps you can optimise the app but I don't think that this will add any protection to the web assets. You can minify to make life bit difficult to understand what your JS code is doing.
Well, I have never used and never felt like that I should use the UI router. I was asked in one of the interviews about this and so felt like reading if I am missing something out as an AngularJs developer.
Now, the explanations on internet displays it's strength based on the modularity and reusability of the components. Nesting of views etc.
If I want to reuse components in my view, then can't I use directive instead of a new state? According to this article by scotch.io(top google result) for ui router we can use separate data /controllers in my view. Well, can't I do the same via directive's controller and template. I can still reuse as many times as I want it.
Please let me know if I am missing some cool feature and makes it quintessential to use it in an AngularJs application (yeah a larger one with lots of reusable components of course) .
The whole point of the router is that it uses the URL to change states. If you just used directives, you would have to write your own mechanism for syncing up URLs with specific directives.
AngularJS is a framework for Single Page Application.
Single Page Application (SPA)
Single Page Application is a web application that loads single HTML page and dynamically updates a fragment in the page as the user interacts with the app.
John Papa's blog explains SPA in simple terms.
The biggest advantage of SPA that I see is
once the application is loaded, the state is maintained without
requiring server roundtrip when user navigates.
Users can bookmark deep link into your application. SPA framework (AngularJS) will take care of loading the required state when user open bookmark.
Although it is technically possible to achieve the above in a non-SPA application, it was never as simple as SPA.
SPA is useful for highly complex applications with many pages. For simple applications with 2-3 pages jQuery is the way to go.
Read Single Page Application: advantages and disadvantages for more discussions
You probably know all these and I think you are trying to achieve SPA using directive.
Routing
Routing framework loads a view dynamically based on user action into the main page without refreshing the whole application; providing SPA effect.
There are two popular AngularJS routing frameworks available.
ngRoute
UI-Router
ngRoute is based on URL mapping and UI-Router is based on state name mapping. I prefer UI-Router.
Routing vs Directive
Now, the explanations on internet displays it's strength based on the
modularity and reusability of the components. Nesting of views etc.
Yes directive is used for modularity and reusability and can load views dynamically but cannot choose a view dynamically based on user action. You have to write complex conditions within directive to choose a view dynamically.
For example, if you have an application with 3 links and you need to show a view based on the link user clicked.
Using directive you need to keep track of what the user clicked and write a mucky condition to choose a view to display. Most of the time you will fail to achieve the effect because the link can be accessed in multiple ways.
On the other hand, once routing is configured, the corresponding template will be dynamically loaded when user clicks the link. It is way easier to change the view based on user action.
Another advantage. When user opens a bookmark deep linked into the application, routing framework will take care of loading the sate (It is impossible to achieve this using directive). It feels more natural way of designing an application.
Choice is yours.
I would like to know when does it make sense to use multiple controllers on the same page in angularjs. Also, when should one think about separating a controller into multiple controllers?
You should largely have your functionality in providers (services or factories typically) and your controllers should have very little in them aside from getting the providers injected (and exposing models and functions for use in the view) and possibly some view specific functionality (configuration for directives used only in one place etc.). You can have multiple controllers on the page if you decide to build the views within a page to be portable.
If you have one controller that shares the functionality needed for disparate parts of a page and later decide to move one part of the view to another route/state/view then you'll need to piece apart the controller. I don't think there are any hard rules really but if your controller is more than 100 lines you're probably making it responsible for too much and should "promote" some things to be handled by providers and/or start splitting things up a bit more.
The answer would be dependent on your page requirement. Having multiple controllers can easily be done.. But issues pop-up when you wanted to have page flows.
Controllers are just a part of AngularJS.. Usage of services, factories and filters is a recommended way of splitting your code along with controllers. If multiple controllers per page becomes imperative.. try utilizing directives. Also consider using Views provider by UI router.
I use multiple controllers when my page has got multiple pop-ups with complex functionality and i want separate controllers for them so that logic behind each-pop is in its own controller.
Similarly, I create separate controllers for sidebars and header and footers on the same page.
These are few examples which comes in my mind when using multiple controllers on same page makes sense.
But as others have mentioned, you should use providers and services/factory for splitting your code.
I have a SPA here and I´m wondering what should I do to get it properly indexed by Google bot.
I read a lot on multiple views angularjs apps (hashbanging and that stuff) but my app has just one view / controller.
Should I create an html copy for each of the items being shown and link them together?
Thanks in advance,
Ariel
In AngularJS, you can compile templates & cache them using a variety of techniques - you'll need to write a process or build into your runtime logic building these templates & binding them to data, writing them out as static files.
Google allows for special handling based on user-agent. I have a friend who says, "This was called cloaking, before Google owned Angular." This is true. You need to setup server logic that re-directs any Google-bot user agent (or other search engine agents you care about) dynamically to one of these static "Search-Bot Friendly" pages.
Although this is more work, there are obviously bonuses to being able to maintain a set of content that search crawlers "see" and a (potentially different) set of content consumed by real users.
This is also the reason why AngularJS as a client-side framework quickly falls down the rank list when search visibility is a primary objective of the project.
I have a nontrivial Angular SPA that uses ui-router to manage multiple views, many of which are visible at the same time. I need models to be visible across controllers, so I have services written that allow me to have controllers pull down fresh copies of model data that has been updated.
I apologize in advance for the length of the question, but I will state the problem then state what I have done to address issues I'm sure others in the Angular community have struggled with.
I believe my problem is not understanding the lifecycle of controllers / views, because I get behavior where a controller initializes correctly the first time I go there, but then seems to never run again, even when I navigate to it using something like $state.go("state name").
In one view (contrived example), I show a summary of information about a customer, and in another view I allow a user to update that customer's more detailed profile. I want a user to edit, say, the customer last name in the detailed view, and have the summary view automatically recognize the change and display it.
I have a fiddle that shows 3 views and a simple password changing Service. The flow goes like this:
You can see each view gets initialized and displays the initial password retrieved from the service. All views are in sync with the DataService.
The middle view allows you to enter a new password and change the one stored in the service. Console logging confirms that the service picks up the new password just like you would expect.
(odd behavior #1) When the DataService receives the new password, I would expect the other 2 views (top and bottom) to display the new one. They don't... they still display the initial password.
There is a button to allow a user to go to another state via $state.go("state name") (a child state of the original) which also retrieves the password and displays it. This works the first time (see #5). Now the top view shows the outdated password, the middle view shows the new one, and the bottom one shows the new one as well. This seems normal, since the new view is invoked after the DataService contains a new password value.
(odd behavior #2) If I click back in the middle view and change the password again, and click the button to change states again, the bottom view (which updated just fine in step #4) no longer updates its copy of the password. Now all 3 views show different passwords, even though I am using a single service to pass values between controllers as suggested pretty much everywhere you look for Angular best practices.
Some possible solutions:
Tim Kindberg has an excellent slideshow here that seems to recommend using ui-router's state heirarchy to "pass" data among views that need to pick up values from other views. For a smaller-scale app I think I would settle on this, but I expect our application to have 30+ views displaying data from over 100 REST endpoints. I don't feel comfortable maintaining an application where all the data is being shared by a complex inheiritance tree. Especially using a routing framework that is at version 0.2.8.
I can use events to have controllers listen for changes in the data model. This actually works well. To accommodate performance concerns, I am using $rootScope.emit() and a $scope.$onRootScope('event name') decorator I found on here. With this approach I am less concerned about event performance than I am about wiring this huge app with a bunch of event listeners tying everything together. There is a question about the wisdom of wiring a large app using angular events here.
Using $watch on the value in the DataService? I have not tried this but I am hesitant to hinge an app this size on hundreds of $watches for performances reasons.
A third-party library like bacon.js (or any of a dozen others) that may simplify the event spaghetti, or create observable models that my controllers can watch without the risk of $digestageddon. Of course, if there is a concise way to handle my issue using Angular, I'd prefer not to muddy the app with 3rd party dependencies.
Something that lets controllers actually reference .service modules by reference, so I don't have to depend on tons of event wiring, complex state hierarchies, 3rd party libraries, or seeding the app with hundreds of $watches and then kicking off $digests to update controllers' references to Angular services?
Some solution that relies on time-tested OO and design patterns and not a 3rd-party library or framework that has a version that starts with 0.*.
Thanks in advance... I appreciate the help!
This is no problem of ui.router. If you intend for your model (your data service) to be a single source of truth, you have to refrain from destroying it.. err.. the reference to it that is. And in your case, assigning a primitve (a string) directly to the scope, instead of a reference to it. In other words...
var password = {pw:'initial value'};
and then later setting/binding only on
password.pw = newpassword
{{password.pw}}
Heres a fiddle. And also here is a short little read on scopes, It also includes a video of an angular meetup where Misko talks about "always have(ing) a dot in your model" link and how the $scope is a place to expose your model, not be your model. (aka not a place to assign primitives like password = 'initial value')
Hope this helps!
try remove the animation property of your ion nav view.
remove the property
animation="slide-left-right"
it would be ok.