I have Meteor application that uses Iron-Router in which the rendered screen is dynamic based on the URL.
I have two parameters from the URL, station and screen.
In the routing code:
this.render(stationParam+screenParam, {to: 'content'});
However, I want to be able to check if the template stationParam+screenParam exists.
Is this possible?
All templates are stored as a field of a global object, Template. The question then is: How to check if this global object has a given field?
You have multiple ways to do it. My personal favourite using underscore:
if (_.has(Template, stationParam + screenParam)) { /* ... */ }
Underscore is included in Meteor. If you want to use it in a package, don't forget the api.use('underscore') in your describe callback.
See also: Determining if a javascript object has a given property
Related
I'd like to be able to pass the URL of an uploaded image in javascript in the tutorial example making a photoblog in meteor.
In that example (in home.js), the helper for templates that render images returns Images.find(), which is used in the image template (image.html) to output html to show the image via:
<img src="{{url}}" />
This works fine, as does the entire tutorial, including S3. However, I'd like to combine it with another project, and that one will require storing and passing around the url under program control.
It would seem that because the template is able to use {{url}}, that in js, one could, in the simplest case, use Images.findOne().url to get at least the first url. E.g., I have modified the given helper to contain this:
Template.home.helpers({
'images': function() {
console.log("url from home helper: = " + Images.findOne().url); //cannot read url property
return Images.find();
}
});
However, this gets the error "cannot read url property..." (and after that, for some reason, the console prints out a huge batch of source code!!) If the template is able to render the field "url" from the collection image object, why can't js see it?
How can I get at the url in javascript?
the url is the function not the property so you have to use Images.findOne().url() not the Images.findOne().url
or
if you are getting the same error that because your findone method return undefined.
There are the possible issues.
Your Images collection are empty.
You did not publish then images and not subscribe the images.
You may be using this call before uploading the images.
I hope this this may solve your issue.
Is there a way to check if a specific Template has been rendered, other than by using Sessions, i.e. the Template is accessible for other external functions to use?
A good example is that I want to use Blaze.renderWithData, but need to know that the Template is availabel beforehand.
If you want to see if a template has been rendered, put a flag in the onRendered callback. If you don't like Session vars use a reactive var or dict & include the inverse in the onDestroyed. Store that reactive-whatever under your package object's global. As an alternative, if you know where it might be rendered to, you can use Blaze.getView on the element where it should appear and if it returns, you know you have it, e.g. Blaze.getView($('.foo')[0])
Also consider asking yourself why you can't use spacebars or embed the rendering directly in the onRendered callback. Using Blaze.renderWithData is fairly uncommon.
I just noticed that my subscription code "Meteor.subscribe('my-publications')" at the top of my JS file affects ALL my templates, not just the template that the JS file is created for.
This was unexpected because all the demos did it this way.
Where is the subscription code suppose to be in if I want it to affect one template only? Inside Template.name.created()?
Don't assume the only data in minimongo is what is relevant to your template. Be specific when selecting your data for the template.
You have several options as far as subscriptions go, the most common by far is adding a subscription to the waitOn section of your routes definitions. Using waitOn will result in the subscription being unsubscribed when the route is no longer in use.
Router.map(function() {
this.route('route', {
waitOn: function(){ return Meteor.subscribe("yourSub"; }
});
});
You can also subscribe per template. A package I've created for this purpose can be added via
meteor add elevatedevdesign:template-subscriptions
This pattern will also be coming soon as a part of blaze, but with some slight differences in how you call it. This will automatically unsubscribe when the template is no longer active. It also allow's subs-manager to be subscribed to on template destruction.
I'm trying to use a variable in my Blade template, but I always get
ReferenceError: files is not defined
My understanding is that the proper way to pass a variable to a template is something like this (client/ceres.js):
Meteor.startup(function() {
Files = new Meteor.Collection('files');
Template['files'].files = function() {
return Files.find();
}
});
(Copying from the "todos" example)
And then I should be able to use it in my template, views/files.blade:
ul
foreach files as file
li= file.filename
But I guess the variable is passed to the template too late? But if I take my JS out of Meteor.js then Template isn't defined.
So I don't get it. Either my template doesn't exist, or the variable doesn't exist, and it always crashes. How do I pass a simple variable along?
Same error with this:
ul
- for(var i=0; i<files.length; ++i)
li= files[i].filename
This is a known issue with Meteor that is actively being worked on.
The problem is that Meteor prevents smart packages from specifying the load order of files. See issue here.
Because of this issue, it is possible that your client-side JavaScript will run before the templates are loaded. (There is a hack in Meteor that ensures Handlebars templates load before your custom code) For example, Template.foo.helperName = function() { ... } will fail if Template.foo has not yet been defined.
Check the generated HTML (view source) for the initial page load to see if your client-side JavaScript code is loading before the template is defined. If so, you may get an Error like:
TypeError: Cannot set property 'helperName' of undefined`
To workaround this issue, try putting your client-side code in a folder with a different name. I believe that Meteor currently sorts files alphabetically when determining the load order. See the troubleshooting section on this page for more information.
A similar workaround is to utilize Meteor.startup when adding view helpers to your views. That is, you can wrap your Template.foo.helperName = ... stuff in a Meteor.startup call. If you are using a body.blade template, though, you can end up with the opposite problem (i.e. the "catch 22") in which your body.blade template starts rendering before view helpers get setup. In this case, you can get errors since those helpers/variables are not yet defined. The solution here is to avoid using body.blade templates and only render the initial template once all view helpers have been loaded (i.e. at the end of your Meteor.startup routine).
At any rate, all of these workarounds are rather lame. :( But, alas! These issues should be fixed soon.
As soon as Meteor fixes the issue described above, I will modify the Blade smart package to enforce the load order of compiled templates. My apologies for the confusion.
Turns out you can't include files that use Template variables either. i.e., you can't use the include directive in Blade at all if you want to use variables in your template that haven't been initialized by Meteor yet -- you have to insert your template via jQuery/JS after the DOM has loaded. Example:
views/body.blade:
.container
h1 Page Title
#content
views/files.blade:
ul
foreach files as file
- console.log(file);
li= file.filename
client/main.js:
Files = new Meteor.Collection('files');
Template.files.files = function() {
return Files.find();
};
$(function() {
$('#content').html(Meteor.render(Template.files));
});
I have some view which lists my module table entries.
What is the most elegant way to attach a form below the view to add record?
Waht I am trying to do know is:
I created dedicated form in my module:
function my_module_form_add_record($form_state) {
form fields.....
}
I added to the view theme file:
$add_form = drupal_get_form('my_module_form_add_record');
print $add_form;
But I do not like this solution for at least 2 reasons:
I does not work ...
2. Even if it worked - it is depended on the theme file! So if I change the theme - functionality is crashed.
I would like to find more elegant solution to attach form from custom module to the view.
I know of the existence of the "Views Attach" module but it has no option of adding custom forms.
I know also of the existence of the Views Embedded form (and I am usig it) but it is only useful if you want to add form to the every row.
Seems the must be some solution to add record from the view page!
Thanks you for help.
you could use hook_views_pre_render:
This hook is called right before the render process. The query has been executed, and the pre_render() phase has already happened for handlers, so all data should be available.
Adding output to the view can be accomplished by placing text on $view->attachment_before and $view->attachment_after. Altering the content can be achieved by editing the items of $view->result.