Here is what I have:
这是我有的:
Templates:
<body>
{{> resultSession}}
{{> resultMethod}}
</body>
<template name="resultSession">
<button>Click me</button>
<p>Session.get('length') returned {{returned}}</p>
</template>
<template name="resultMethod">
<p>Meteor.call returned {{returned}}</p>
</template>
Client-side:
Template.resultSession.events({
'click button': function () {
Session.set('length', Math.floor((Math.random() * 20) + 1));
}
});
Template.resultSession.helpers({
returned: function () {
return Session.get('length');
}
});
Template.resultMethod.helpers({
returned: function() {
Meteor.call('returnArray', Session.get('length'), function (err, res) {
return res.length;
});
}
});
Server-side:
Meteor.methods({
'returnArray': function (length) {
var arr = [];
arr[length - 1] = 0;
return arr;
}
});
TL;DR
You can look at code and play with it here http://meteorpad.com/pad/AkBZq4ZFjJuQuzztz/Meteor.call-on-Session-change
您可以在这里查看代码并使用它来http://teteorpad.com/pad/AkBZq4ZFjJuQuzztz/Meteor.call-on-Session-change
As you can see, my method accepts number and returns the array with length equal to number.
如您所见,我的方法接受number并返回长度等于number的数组。
The question is how can I make Meteor.call fire each time Session variable changes?
问题是每当Session变量发生变化时,我怎样才能使Meteor.call激活?
P.S. Values are returned to two different templates on purpose
附:值有意返回到两个不同的模板
3 个解决方案
#1
Your reactive code is working perfectly. If you put a console.log in the Meteor.call you will see that the correct answer is coming back from the server.
您的被动代码运行正常。如果你在Meteor.call中放入一个console.log,你会看到正确的答案是从服务器回来的。
Template.resultMethod.helpers({
returned: function() {
Meteor.call('returnArray', Session.get('length'), function (err, res) {
console.log('it came back ' + res.length);
return res.length;
});
}
});
I have put a Session variable into the return from the server, so now you can see that your reactive code works very simply - no need for complicated autorun stuff.
我已经将一个Session变量放入服务器的返回中,所以现在您可以看到您的反应代码非常简单 - 无需复杂的自动运行内容。
<template name="resultMethod">
<p>Meteor.call returned {{returned}}</p>
</template>
Then in the resultMethod helper:
然后在resultMethod帮助器中:
Template.resultMethod.helpers({
returned: function() {
Meteor.call('returnArray', Session.get('length'), function (err, res) {
Session.set('fromServer', res.length + '');
});
return Session.get('fromServer');
}
});
#2
Like @saimeunt said, use Tracker.autorun
就像@saimeunt所说,使用Tracker.autorun
Templates:
<body>
{{> resultSession}}
{{> resultMethod}}
</body>
<template name="resultSession">
<button>Click me</button>
<p>Session.get('length') returned {{returned}}</p>
</template>
<template name="resultMethod">
<p>Meteor.call returned {{returned}}</p>
</template>
And code:
Template.resultMethod.rendered = function() {
this.autorun(function (){
Meteor.call('returnArray', Session.get('length'), function (err, res) {
Session.set('result', res);
});
});
}
Template.resultSession.helpers({
returned: function () {
return Session.get('length');
}
});
Template.resultMethod.helpers({
returned: function() {
return Session.get('result');
}
});
Autorun inside rendered stops when the template is not rendered
在未呈现模板时,在渲染内部自动运行停止
#3
You could simply refactor your code to call the Meteor method on click event ?
您可以简单地重构代码以在Click事件上调用Meteor方法吗?
Template.resultSession.events({
'click button': function () {
var length = Math.floor((Math.random() * 20) + 1);
Session.set('length', length);
Meteor.call('returnArray', length, function (err, res) {
Session.set('result', res.length);
});
}
});
Template.resultSession.helpers({
returned: function () {
return Session.get('length');
}
});
Template.resultMethod.helpers({
returned: function() {
return Session.get('result');
}
});
You could also use Tracker.autorun to track modifications of your Session variable and rerun arbitrary code.
您还可以使用Tracker.autorun跟踪Session变量的修改并重新运行任意代码。
Tracker.autorun(function(){
var length = Session.get("length");
console.log("length new value =", length);
});
#1
Your reactive code is working perfectly. If you put a console.log in the Meteor.call you will see that the correct answer is coming back from the server.
您的被动代码运行正常。如果你在Meteor.call中放入一个console.log,你会看到正确的答案是从服务器回来的。
Template.resultMethod.helpers({
returned: function() {
Meteor.call('returnArray', Session.get('length'), function (err, res) {
console.log('it came back ' + res.length);
return res.length;
});
}
});
I have put a Session variable into the return from the server, so now you can see that your reactive code works very simply - no need for complicated autorun stuff.
我已经将一个Session变量放入服务器的返回中,所以现在您可以看到您的反应代码非常简单 - 无需复杂的自动运行内容。
<template name="resultMethod">
<p>Meteor.call returned {{returned}}</p>
</template>
Then in the resultMethod helper:
然后在resultMethod帮助器中:
Template.resultMethod.helpers({
returned: function() {
Meteor.call('returnArray', Session.get('length'), function (err, res) {
Session.set('fromServer', res.length + '');
});
return Session.get('fromServer');
}
});
#2
Like @saimeunt said, use Tracker.autorun
就像@saimeunt所说,使用Tracker.autorun
Templates:
<body>
{{> resultSession}}
{{> resultMethod}}
</body>
<template name="resultSession">
<button>Click me</button>
<p>Session.get('length') returned {{returned}}</p>
</template>
<template name="resultMethod">
<p>Meteor.call returned {{returned}}</p>
</template>
And code:
Template.resultMethod.rendered = function() {
this.autorun(function (){
Meteor.call('returnArray', Session.get('length'), function (err, res) {
Session.set('result', res);
});
});
}
Template.resultSession.helpers({
returned: function () {
return Session.get('length');
}
});
Template.resultMethod.helpers({
returned: function() {
return Session.get('result');
}
});
Autorun inside rendered stops when the template is not rendered
在未呈现模板时,在渲染内部自动运行停止
#3
You could simply refactor your code to call the Meteor method on click event ?
您可以简单地重构代码以在Click事件上调用Meteor方法吗?
Template.resultSession.events({
'click button': function () {
var length = Math.floor((Math.random() * 20) + 1);
Session.set('length', length);
Meteor.call('returnArray', length, function (err, res) {
Session.set('result', res.length);
});
}
});
Template.resultSession.helpers({
returned: function () {
return Session.get('length');
}
});
Template.resultMethod.helpers({
returned: function() {
return Session.get('result');
}
});
You could also use Tracker.autorun to track modifications of your Session variable and rerun arbitrary code.
您还可以使用Tracker.autorun跟踪Session变量的修改并重新运行任意代码。
Tracker.autorun(function(){
var length = Session.get("length");
console.log("length new value =", length);
});