When I study the feature of Vue.js's component system. I feel confused when and where should we use this? In Vue.js's doc they said
Vue.js allows you to treat extended Vue subclasses as reusable
components that are conceptually similar to Web Components, without
requiring any polyfills.
But based on their example it doesn't clear to me how does it help to reuse. I even think it complex the logic flow.
For example, you use "alerts" a lot in your app. If you have experienced bootstrap, the alert would be like:
<div class="alert alert-danger">
<button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>
<strong>Title!</strong> Alert body ...
</div>
Instead of writing it over and over again, you can actually make it into a component in Vue:
Vue.component('alert', {
props: ['type','bold','msg'],
data : function() { return { isShown: true }; },
methods : {
closeAlert : function() {
this.isShown = false;
}
}
});
And the HTML template (just to make it clear, I separate this from the Vue Comp above):
<div class="alert alert-{{ type }}" v-show="isShown">
<button type="button" class="close" v-on="click: closeAlert()">×</button>
<strong>{{ bold }}</strong> {{ msg }}
</div>
Then you can just call it like this:
<alert type="success|danger|warning|success" bold="Oops!" msg="This is the message"></alert>
Note that this is just a 4-lines of template code, imagine when your app uses lot of "widgets" with 100++ lines of code
Hope this answers..
Related
I am using iron router to render a template within meteor framwork, as i was following probably an outdated tutorial, it seems to me there is a change in syntaxes which i could not figure out.
layout.html
<div class="container">
<div class="row">
<div class="span2">
<p>cell</p>
</div>
<div class="span7">
<p>cell</p>
</div>
<div class="span3">
<p>cell</p>
</div>
</div>
</div>
index.js
function.setDefault ('category', null );
Router.configure({
layoutTemplate:'layout',
yieldTemplates:{
'products':{to:'products'},
'cart':{to:'cart'},
'categories':{to:'categories'}
}
});
Router.route(function(){
this.route('/', layout);
this.route('/products',{
data:function(){
Session.set('category',this.params.name);
},
template:'layout',
path:'/:name'
})
});
The following error occurs
unexpected token (1:8)
Where you have Router.route and use this.route in a function, Router.route should read Router.map however this is deprecated in favour of Router.route (without the map wrapper) as below:
Session.setDefault ('category', null );
Router.configure({
layoutTemplate:'layout',
yieldTemplates:{
'products':{to:'products'},
'cart':{to:'cart'},
'categories':{to:'categories'}
}
});
//You will need to declare a template at the least here so it knows what to render to main area
Router.route('/', {template: "template_name");
Router.route('/products/:name',{
onBeforeAction:function(){
Session.set('category',this.params.name);
this.next ();
},
//you don't need this to be layout
//as you are defining a default layout above
//but you will need to specify a template for the main yield area
template:'template_name'
// you don't need to specify path here as it will use '/products'
//if you want to specify a route name use line below
//,name: 'routename'
});
Where url would be /products/product_name
Where template_name is the template you want to render in your main {{> yield}}
In your layout template you need to place the following for your yields wherever you want to display them
{{> yield 'products'}}
{{> yield 'categories'}}
{{> yield 'cart'}}
{{> yield }} //this is the template you specify in template: 'template_name'
(Done from my phone so can't test but can update later if it doesn't work for you)
I have installed meteor-typeahead via npm. https://www.npmjs.org/package/meteor-typeahead
I have also installed
meteor add sergeyt:typeahead
from https://atmospherejs.com/sergeyt/typeahead
I am trying to get the data-source attribute example to function so I can display a list of countries when the user begins to type. I have inserted all countries into the collection :-
Country = new Meteor.Collection('country');
The collection is published and subscribed.
When I type into the input field, no suggestions appear. Is it something to do with activating the API? if so how do I do this? Please reference the website https://www.npmjs.org/package/meteor-typeahead
My form looks like this:
<template name="createpost">
<form class="form-horizontal" role="form" id="createpost">
<input class="form-control typeahead" name="country" type="text" placeholder="Country" autocomplete="off" spellcheck="off" data-source="country"/>
<input type="submit" value="post">
</form>
</template>
client.js
Template.createpost.helpers({
country: function(){
return Country.find().fetch().map(function(it){ return it.name; });
} });
In order to make your input to have typeahead completion you need:
Activate typeahead jQuery plugin using package API
Meteor.typeahead call in template rendered event handler.
Meteor.typeahead.inject call to activate typeahead plugin for elementes matched by CSS selector available on the page (see demo app).
Write 'data-source' function in your template understandable by typeahead plugin. It seems your 'data-source' function is correct.
Add CSS styles for typeahead input(s)/dropdown to your application. See example here in demo app.
Try this way in your template:
<input type="text" name="country" data-source="country"
data-template="country" data-value-key="name" data-select="selected">
Create template like country.html (for example /client/templates/country.html) which contains:
<template name="country">
<p>{{name}}</p>
</template>
In your client javascript:
Template.createpost.rendered = function() {
Meteor.typeahead.inject();
}
and
Template.createpost.helpers({
country: function() {
return Country.find().fetch().map(function(it){
return {name: it.name};
});
},
selected: function(event, suggestion, datasetName) {
console.log(suggestion); //or anything what you want after selection
}
})
I'm using a $scope.$apply to trigger the view to update based on a changed variable in the scope. However, I have another line in the html that is an ng-include,
<div data-ng-include data-ng-src="'views/partials/_menubar.html'"></div>
error message
When I remove the ng-include and replace it with a static call there is no error. Here is the template that I'm including as well:
<div class="menu" ng-controller="MenuController">
<div style="display: inline-block">
Hello!
</div>
<ul class="menu_dropdown">
<li class="menu_item">Test1</li>
<li class="menu_item">Test2</li>
<li class="menu_item">Test3</li>
</ul>
</div>
The code for menu controller is
app.controller('MenuController', function($scope) {
});
ng-src is used to allow elements that usually have a src (like anchors or images) to apply the src tag only after angular's digest, not for inclusion of templates in ng-include. See ng-include docs and ng-src docs.
A safe way to specify the src using ng-include would be like this:
<div data-ng-include="src='views/partials/_menubar.html'"></div>
or
<div data-ng-include="'views/partials/_menubar.html'"></div>
If you must have the src separately, it's data-src and not data-ng-src:
<div data-ng-include data-src="'views/partials/_menubar.html'"></div>
see plnkr.
edit: To address your error message.. you'll see that message if you've bound a function to the scope which changes every time it is called.
For example, this will cause such an error:
// controller
$scope.getQuote = function(){
return 'someViewName' + Math.ceil(Math.random() * 10) + '.html';
};
// view
<div data-ng-include="{{getQuote}}"></div>
The problem with ng-include was actually a red herring. The real problem was trying to change the window.history, as seen in the thread here. My guess is because the ng-include directive references $location when it attempts to get resources.
I have a the classic "Thread->Posts" model.
In the application, I have a left sidebar with the "Thread" collections. When the user click in a Thread, I want to create another div with the Thread->Posts elements.
Is there any way to do this, conservating the reactivity?
For now, I've got this:
// In the client
Template.threadlist.events({
'click tr': function(event){
Session.set("selectedThread",this);
$("#posts").html( Meteor.render(Template["datathread"]) );
}
})
[...]
Template.datathread.events({
'click input.add-post' : function(event){
var t = Session.get("selectedThread");
Meteor.call("addPost", {"thread":t,"text":"foo","user":"var"},callback})
}
})
[...]
// In the server
addPost: function(param){
var id = Threads.update(param.thread,{ $addToSet: {"posts": {"text":param.text, "user": param.user}}});
return id;
}
The template with the posts is something like this:
<template name="datathread">
{{#each thread.posts}}
{{user}} says: {{text}}
<br />
{{/each}}
</template>
(The "user" and "text" propertis are from the "thread.posts" elements)
With this code, I only get the new values refreshing (F5) the webpage (or executing the 'click tr'event). What I'm doing wrong?
Thank you!
== Edit ==
Ok... Now, with the recomendation of Chistian Fritz, my code its something like this:
// In the client
Template.datathread.thread = function(){
return Session.get("selectedThread");
}
[...]
Template.threadlist.events({
'click tr': function(event){
Session.set("selectedThread",this);
}
});
//In the html
<div class="span5" id="threads">
{{> datathread}}
</div>
<template name="datathread">
{{#if thread}}
<hr />
{{#each thread.posts}}
{{user}} says: {{text}}
<br />
{{/each}}
{{/if}}
</template>
The changes are great (it's so simple!), but the reactivity still doesn't work :(....
The problem is that you are using jQuery to fill your DOM:
$("#posts").html( Meteor.render(Template["datathread"]) );
This breaks the reactivity chain.
You are only showing part of your code, so I can't give you the full solution, but it seems that the datathread template is already using the selectedThread session variable -- which is good. Hence, it might be as easy as using {{> datathread}} in place of the #posts element in your HTML.
EDIT:
One thing that you need to change is the scope you are assuming datathread: it's already the thread itself, if I understand correctly:
<template name="datathread">
<hr />
{{#each posts}}
{{user}} says: {{text}}
<br />
{{/each}}
</template>
Also, the this in the threadlist event handler most certainly won't be the thread. I don't know the data of the tr in the threadlist (can you show that code?), but you will most probably do something like the following:
Session.set("selectedThread", this.id);
And for datathread:
Template.datathread.thread = function(){
return Threads.find({_id: Session.get("selectedThread")});
}
or similar.
I want to implement a search box that changes what it searches based on whichever controller is being used. If you are on the "posts" view it will search the posts api, if you are on the videos view, it searches the videos api. It seems the search box would need its own controller maybe. I'm pretty sure I need to inject a search service into all the model controllers but I'm not exactly sure how to change the url it searches or tie the input to the different controller scopes.
So any ideas how to have a global search box that changes where it searches based on whichever controller is making use of it and tying its state back into a changing view?
To make a resource call dynamic api i would first create two $resources that map to your two endpoints, posts and videos. Then put an ng-change event on your global search that calls a function in your base controller.
This function firsts need to figure out what api to search. Then make the appropriate api call. The important part is in the callback and i think this is what you are looking for.
In the callback you could $broadcast the resp data from your api query. Each of your controllers will be listening for an event with an $on function. The listeners will then populate the correct scope variable with the callback data.
Pseudo below.
Same html layout with ng-change
<html>
<body ng-controller="AppController">
<form>
<label>Search</label>
<input ng-model="global.search" ng-change="apiSearch()" type="text" class="form-control" />
</form>
<div ui-view="posts">
<div ng-controller="PostController">
<p ng-repeat="post in posts | filter: global.search">{{ post.name }}</p>
</div>
</div>
<div ui-view="videos">
<div ng-controller="VideoController">
<p ng-repeat="video in videos | filter: global.search">{{ video.name }}</p>
</div>
</div>
</body>
</html>
AppController
.controller('AppController', function ($scope, PostService, VideoService) {
$scope.apiSearch = function() {
// Determine what service to use. Could look at the current url. Could set value on scope
// every time a controller is hit to know what your current controller is. If you need
// help with this part let me know.
var service = VideoService, eventName = 'video';
if ($rootScope.currentController == 'PostController') {
service = PostService;
eventName = 'post';
}
// Make call to service, service is either PostService or VideoService, based on your logic above.
// This is pseudo, i dont know what your call needs to look like.
service.query({query: $scope.global.search}, function(resp) {
// this is the callback you need to $broadcast the data to the child controllers
$scope.$broadcast(eventName, resp);
});
}
})
Each of your child controllers that display the results.
.controller('PostController', function($scope) {
// anytime an event is broadcasted with "post" as the key, $scope.posts will be populated with the
// callback response from your search api.
$scope.$on('post', function(event, data) {
$scope.posts = data;
});
})
.controller('VideoController', function($scope) {
$scope.$on('video', function(event, data) {
$scope.videos = data;
});
})
Client side filtering.
If you are not looking for anything to crazy that can be achieved in a super simple way for global search. I didnt even know if this would work so i just did a quick test and it does. Obviously this could be solved in a much more detailed and controlled way using services and injecting them where they are needed. But since i don't know excatly what you are looking for i will provide this solution, if you like it, great accept it. If you don't i could probably help you with service injection solution
Quick solution is to have an app wide contoller with $rootScope ng-model. Lets call it global.search.
$rootScope.global = {
search: ''
};
For the app wide search input.
<form>
<label>Search</label>
<input ng-model="global.search" type="text" class="form-control" />
</form>
In separate partials you just need to filter data based on the global.search ng-model. Two examples
<p ng-repeat="post in posts | filter: global.search">{{ post.name }}</p>
Second template with different scope
<p ng-repeat="video in videos | filter: global.search">{{ video.name }}</p>
Note how they both implement | filter: global.search. Whenever global.search changes, any filters in the current view will be changed. So posts will be filtered on the posts view, and videos on the videos view. While still using the same global.search ng-model.
I tested this, it does work. If you need more detail explaining the setup and child controller hierarchy let me know. Here is a quick look at a full template
<html>
<body ng-controller="AppController">
<form>
<label>Search</label>
<input ng-model="global.search" type="text" class="form-control" />
</form>
<div ui-view="posts">
<div ng-controller="PostController">
<p ng-repeat="post in posts | filter: global.search">{{ post.name }}</p>
</div>
</div>
<div ui-view="videos">
<div ng-controller="VideoController">
<p ng-repeat="video in videos | filter: global.search">{{ video.name }}</p>
</div>
</div>
</body>
</html>