Meteor when many subscriptions are ready - meteor

I'm creating a chat app. I hope i can add a new "hello" message if i check the messages count of current chat is equal to 0 (Problem #1). Also i have a dictionary as a collection for translation. But t() returns EN variant (Problem #2)
t = function(text) {
var res = Dictionary.findOne({o:text});
return res && res.t || text;
}
Meteor.startup(function () {
Deps.autorun(function () {
Meteor.subscribe('dictionary', Session.get('lang'), function(){
Session.set('dictionaryReady', true);
});
Meteor.subscribe('chats', Session.get('domain'), function(){
if (chatCurrent(Meteor.userId(), Session.get('domain')).count()===0 //true, even is not actually [problem_#1]
&& Session.get('dictionaryReady') //true, but next function t() doesn't work properly [problem #2]
) {
var mudata = Session.get('my_manager') ? udata(Session.get('my_manager'), Session.get('domain')) : null,
hello = mudata && mudata.hello || t('Hello! How I can help you?'),
name = mudata && mudata.name || t('Anna');
Meteor.call('create_message', {chat: Meteor.userId(), to: Meteor.userId(), text: hello, name: name, from: Session.get('my_manager'), domain: Session.get('domain'), last_manager: Session.get('my_manager')});
});
});
});
Problem #1 and Problem #2 everytime when page just loaded. So when i refresh the page i get another "hello message" on default EN locale.

Here is how you can render your template only once your subscriptions are ready. This is a solution taken from meteor kitchen generated code.
first you create a "loading" template
<template name="loading">
<div class="loading">
<i class="fa fa-circle-o-notch fa-4x fa-spin"></i>
</div>
</template>
Second, attach to your template a route controller. Here is a simplified version of it (but it should work):
this.myTemplateController = RouteController.extend({
template: "myTemplate",
onBeforeAction: function() {
this.next();
},
action: function() {
if(this.isReady()) { this.render(); } else { this.render("loading"); }
},
isReady: function() {
var subs = [
Meteor.subscribe("sub1", this.params.yourParam),
Meteor.subscribe("sub2", this.params.yourParam),
Meteor.subscribe("sub3", this.params.yourParam)
];
var ready = true;
_.each(subs, function(sub) {
if(!sub.ready())
ready = false;
});
return ready;
},
data: function() {
return {
params: this.params || {},
yourParamWhatever: Chat.findOne({_id:this.params.yourParam}, {})
};
},
});
Now you should have all your subscriptions ready when your template is loaded.
Concerning the translation, you could have a look at TAPi18n package that I highly recommend. It is quite easy to implement.

Related

Vue doesn't update when computed data change

Context: I have a list of posts with tags, categories from wordpress api. I display these posts with Vue and using computed with a search box to filter the result based on titre, description, tags, and categories
Problem: I am trying to update a computed list when user click on a list of tag available. I add the get and set for computed data like this:
var vm = new Vue({
el: '#blogs',
data: {
search: '',
posts: [],
filterPosts: []
},
beforeMount: function() {
// It should call the data and update
callData();
},
computed: {
filterPosts: {
get: function() {
var self = this;
return self.posts.filter(function(post){
var query = self.search.toLowerCase();
var title = post.title.toLowerCase();
var content = post.content.toLowerCase();
var date = post.date.toLowerCase();
var categories = '';
post.categories.forEach(function(category) {
categories += category.name.toLowerCase();
});
var tags = '';
post.tags.forEach(function(tag){
tags += tag.name.toLowerCase();
});
return title.indexOf(query) !== -1 ||content.indexOf(query) !== -1 || date.indexOf(query) !== -1 || categories.indexOf(query) !== -1 || tags.indexOf(query) !== -1;
});
},
set: function (newValue) {
console.log(newValue);
this.filterPosts = Object.assign({}, newValue);
}
}
},
methods: {
filterByTag: function(tag, event) {
event.preventDefault();
var self = this;
self.filterPosts = self.posts.filter(function(post){
var tags = '';
post.tags.forEach(function(tag){
tags += tag.name.toLowerCase();
});
return tags.indexOf(tag.toLowerCase()) !== -1;
});
}
}
}); // Vue instance
The console.log always output new data based on the function I wrote on methods but Vue didn't re-render the view. I think I didn't do the right way or thought like Vue. Could you please give some insight?
Edit 1
Add full code.
I tried to add filterPosts in data but I received this error from Vue: The computed property "filterPosts" is already defined in data.
Your setter is actually not setting anything, it only logs the new value. You need to store it somewhere.
For example you can store it in the component's data:
data: {
value: 'foo',
},
computed: {
otherValue: {
get() { /*...*/ },
set(newVal) { this.value = newVal },
},
},
But this is definitely not the only possibility, if you use Vuex, the setter can dispatch an action that will then make the computed value get updated. The component will eventually catch the update and show the new value.
computed: {
value: {
get() {
return this.$store.getters.externalData;
},
set(newVal) {
return this.$store.dispatch('modifyingAction', newVal);
},
},
},
The bottomline is you have to trigger a data change in the setter, otherwise your component will not be updated nor will it trigger any rerender.
EDIT (The original answer was updated with full code):
The answer is that unless you want to manually change the list filteredPosts without altering posts, you don't need a get and set function for your computed variable. The behaviour you want can be acheived with this:
const vm = new Vue({
data() {
return {
search: '',
posts: [],
// these should probably be props, or you won't be able to edit the list easily. The result is the same anyway.
};
},
computed: {
filteredPosts() {
return this.posts.filter(function(post) {
... // do the filtering
});
},
},
template: "<ul><li v-for='post in filteredPosts'>{{ post.content }}</li></ul>",
});
This way, if you change the posts or the search variable in data, filteredPosts will get recomputed, and a re-render will be triggered.
After going around and around, I found a solution, I think it may be the right way with Vue now: Update the computed data through its dependencies properties or data.
The set method didn't work for this case so I add an activeTag in data, when I click on a tag, it will change the activeTag and notify the computed filterPost recheck and re-render. Please tell me if we have another way to update the computed data.
var vm = new Vue({
el: '#blogs',
data: {
search: '',
posts: [],
tags: [],
activeTag: ''
},
beforeMount: function() {
// It should call the data and update
callData();
},
computed: {
filterPosts: {
get: function() {
var self = this;
return self.posts.filter(function(post){
var query = self.search.toLowerCase();
var title = post.title.toLowerCase();
var content = post.content.toLowerCase();
var date = post.date.toLowerCase();
var categories = '';
post.categories.forEach(function(category) {
categories += category.name.toLowerCase();
});
var tags = '';
post.tags.forEach(function(tag){
tags += tag.name.toLowerCase();
});
var activeTag = self.activeTag;
if (activeTag !== '') {
return tags.indexOf(activeTag.toLowerCase()) !== -1;
}else{
return title.indexOf(query) !== -1 ||content.indexOf(query) !== -1 || date.indexOf(query) !== -1 || categories.indexOf(query) !== -1 || tags.indexOf(query) !== -1;
}
});
},
set: function (newValue) {
console.log(newValue);
}
}
},
methods: {
filterByTag: function(tag, event) {
event.preventDefault();
var self = this;
self.activeTag = tag;
}
}
}); // Vue instance
Try something like:
data: {
myValue: 'OK'
},
computed: {
filterPosts: {
get: function () {
return this.myValue + ' is OK'
}
set: function (newValue) {
this.myValue = newValue
}
}
}
More:
https://v2.vuejs.org/v2/guide/computed.html#Computed-Setter

Publish and subscribe to a single object Meteor js

How to publish single objects seems not clear enough to me. Please what's the best way to handle this. This code snippet does not display anything on the view.
Helper file
singleSchool: function () {
if (Meteor.userId()) {
let myslug = FlowRouter.getParam('myslug');
var subValues = Meteor.subscribe('SingleSchool', myslug );
if (myslug ) {
let Schools = SchoolDb.findOne({slug: myslug});
if (Schools && subValues.ready()) {
return Schools;
}
}
}
},
Publish file
Meteor.publish('SingleSchool', function (schoolSlug) {
check( schoolSlug, Match.OneOf( String, null, undefined ) );
user = Meteor.users.findOne({_id:this.userId})
if(user) {
if(user.emails[0].verified) {
return SchoolDb.findOne({ slug: schoolSlug, userId: {$lt: this.userId}});
} else {
throw new Meteor.Error('Not authorized');
return false;
}
}
});
template file
<template name="view">
{{#if currentUser}}
{{#if Template.subscriptionsReady }}
{{#with singleSchool}}
{{singleSchool._id}}
{{singleSchool.addschoolname}}
{{/with}}
{{/if}}
{{/if}}
</template>
As you said "This code snippet does not display anything on the view." well, inside Meteor.publish you need to return cursor, not array or any other object.
So use this code:
Meteor.publish('SingleSchool', function (schoolSlug) {
check( schoolSlug, Match.OneOf( String, null, undefined ) );
var user = Meteor.users.findOne({_id:this.userId});
if(!user || !user.emails[0].verified) {
throw new Meteor.Error('Not authorized');
}
return SchoolDb.find({ slug: schoolSlug, userId: {$lt: this.userId}},{limit:1});
});
I would definitely recommend you to go through How to avoid Common Mistakes
When I am concerned only for a single object, I implement this using a meteor method:
Meteor.methods({
"getSingleSchool":function(schoolSlug) {
//... check args and user permissions
return SchoolDb.findOne({ slug: schoolSlug, userId: {$lt: this.userId}});
},
});
Then in the template I run this method in the onCreated autorun part:
Template.view.onCreated(function(){
const instance = this;
instance.state = new ReactiveDict();
instance.autorun(function(){
let my slug = FlowRouter.getParam('myslug');
// load if no loaded yet
if (my slug && !instance.state.get("singleSchool")) {
Meteor.call("getSingleSchool", mySlug, function(err, res){
//handle err if occurred...
this.state.set("singleSchool", res);
}.bind(instance)); //make instance available
}
});
});
The helper then just returns a value, if the school is loaded:
singleSchool: function () {
return Template.instance().state.get("singleSchool");
},

Session object inside global template helpers

Session.set('coursesReady', false); on startup.
UPDATE:
I made it into a simpler problem. Consider the following code.
Inside router.js
Router.route('/', function () {
Meteor.subscribe("courses", function() {
console.log("data ready")
Session.set("coursesReady", true);
});
}
and inside main template Main.js
Template.Main.rendered = function() {
if (Session.get('coursesReady')) {
console.log("inject success");
Meteor.typeahead.inject();
}
The message "inject success" is not printed after "data ready" is printed. How come reactivity does not work here?
Reactivity "didn't work" because rendered only executes once (it isn't reactive). You'd need to wrap your session checks inside of a template autorun in order for them to get reevaluated:
Template.Main.rendered = function() {
this.autorun(function() {
if (Session.get('coursesReady')) {
console.log("inject success");
Meteor.typeahead.inject();
}
});
};
Probably a better solution is to wait on the subscription if you want to ensure your data is loaded prior to rendering the template.
Router.route('/', {
// this template will be rendered until the subscriptions are ready
loadingTemplate: 'loading',
waitOn: function () {
// return one handle, a function, or an array
return Meteor.subscribe('courses');
},
action: function () {
this.render('Main');
}
});
And now your rendered can just do this:
Template.Main.rendered = function() {
Meteor.typeahead.inject();
};
Don't forget to add a loading template.
To Solve Your Problem
Template.registerHelper("course_data", function() {
console.log("course_data helper is called");
if (Session.get('coursesReady')) {
var courses = Courses.find().fetch();
var result = [ { **Changed**
name: 'course-info1',
valueKey: 'titleLong',
local: function() {
return Courses.find().fetch();
},
template: 'Course'
}];
Session.set('courseResult', result); **New line**
return Session.get('courseResult'); **New line**
,
Explanation
The answer is at the return of the helper function needs to have be associated with reactivity in order for Blaze, template renderer, to know when to rerender.
Non-reactive (Doesn't change in the DOM as values changes)
Template.Main.helpers({
course_data: UI._globalHelpers.course_data ** Not reactive
});
Essentially: UI._globalHelpers.course_data returns an array of objects which is not reactive:
return [
{
name: 'course-info1',
valueKey: 'titleLong',
local: function() {
return Courses.find().fetch();
},
template: 'Course'
},
Reactive
From Meteor Documentation:
http://docs.meteor.com/#/full/template_helpers
Template.myTemplate.helpers({
foo: function () {
return Session.get("foo"); ** Reactive
}
});
Returning Session.get function to Blaze is reactive; thus, the template will change as the values changes.

iron-router does not wait for subscription

My router function is defined like this
this.route('time', {
template: "app",
yieldTemplates: { 'appNav': {to: 'top'}, 'time': {to: 'appPage'} },
data: function() {
console.log("data is ready for time " + (personsSub.ready() && tenantsSub.ready() && teamsSub.ready()));
return {
dataReady: personsSub.ready() && tenantsSub.ready() && teamsSub.ready()
}
},
waitOn: function(){
return [personsSub, tenantsSub, teamsSub];
}
});
the 3 subscriptions are:
var personsSub = Meteor.subscribe("allPersons");
var tenantsSub = Meteor.subscribe("allTenants");
var teamsSub = Meteor.subscribe("allTeams");
In the console I can see 2 entries when I navigate to this route
data is ready for time false
data is ready for time true
I obviously did not understand the meaning of waitOn. The expected result is that the data part be only called once and that it be called after all the subscriptions are ´ready´
Try
waitOn: [personsSub, tenantsSub, teamsSub];
Im not sure the function/return is needed.

Internal Server Error trying to update server database in Meteor.js

I've been modifying the example meteor app at http://meteor.com/examples/leaderboard. As you can see in the code bellow, I'm trying to update the score of players upon someone hitting the reset button. This updated fine on the client side but in my console I noticed the error "update failed: 500 -- Internal server error". Upon further inspection I saw that indeed, the server side database was not being updated. Any thoughts? (relevant code is in the reset function but I've posted the rest here just in case)
// Set up a collection to contain player information. On the server,
// it is backed by a MongoDB collection named "players."
Players = new Meteor.Collection("players");
var SORT_OPTIONS = {
name: {name: 1, score: -1},
score: {score: -1, name: 1}
}
var NAMES = [ "Ada Lovelace",
"Grace Hopper",
"Marie Curie",
"Carl Friedrich Gauss",
"Nikola Tesla",
"Claude Shannon" ];
function reset(options) {
if (options && options['seed'] === true) {
for (var i = 0; i < NAMES.length; i++) {
Players.insert({ name: NAMES[i], score: Math.floor(Math.random()*10)*5 });
}
}
if (options && options['restart'] === true) {
Players.update( {},
{ $set: { score: Math.floor(Math.random()*10)*5 } },
{multi: true});
}
}
if (Meteor.is_client) {
Template.leaderboard.players = function () {
var sort_by = SORT_OPTIONS[Session.get("sort_by")]
return Players.find({}, {sort: sort_by});
};
Template.leaderboard.selected_name = function () {
var player = Players.findOne(Session.get("selected_player"));
return player && player.name;
};
Template.player.selected = function () {
return Session.equals("selected_player", this._id) ? "selected" : '';
};
Template.leaderboard.events = {
'click input.inc': function () {
Players.update(Session.get("selected_player"), {$inc: {score: 5}});
},
'click input.sort': function () {
Session.get("sort_by") == "score" ? Session.set("sort_by", "name") : Session.set("sort_by", "score");
},
'click input.reset': function () {
reset({'restart': true});
}
};
Template.player.events = {
'click': function () {
Session.set("selected_player", this._id);
}
};
}
// On server startup, create some players if the database is empty.
if (Meteor.is_server) {
Meteor.startup(function () {
if (Players.find().count() === 0) {
reset({'seed': true});
}
});
}
This also happened to me, but checking the server log, the problem I had was that the $inc modifier requires a number for the argument for the update method, so I made sure it got it with
Number()
Time went by and it now works :) I guess it was some server issue on their demo deploy site.

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