Handlbars - Can I limit certain helpers to being within other helpers? - handlebars.js

For example I want to use a nested helper like this:
{{#submission}}
{{field}}
{{/submission}}
But I want {{field}} in this case to be a different helper from the one above
{{#post}}
{{field}}
{{/post}}
and maybe even something else if used when not inside either of those (or perhaps just displaying data that passed, and not triggering a helper).
{{field}}
Is this possible, or do I have to make every helper unique?

I'm sorry but every helper has to be unique. If you want to use a different code then you have to do it programmatically by handling a parameter and switching your code depending on your parameter.

Related

What would be the best method of creating a block which outputs a Redstone Signal

I'm wondering what would be the best way to allow a block to send out a specific amount of Redstone output conditionally. While looking through other blocks that gave a Redstone output, I noticed that they were mostly using the getWeakPower() method. However, I noticed that this was a Deprecated method and my IDE formats the method with a strikethrough. Additionally, I also found another method named getStrongPower() (also Deprecated). Which one of these two method would be best to override or would there be a better way to set the Redstone output of a block.
Although these blocks have the #Deprecated annotation to them, the JavaDoc comment states that "Implementing/overriding is fine". These getWeakPower() and getStrongPower() methods are only flagged as being deprecated in the net.minecraft.block.Block class because they are not meant to be accessed from the Block class, instead they are supposed to be accessed from the net.minecraft.block.BlockState class as that will contain the most up to date state of a given block instance.
It seems that most blocks which use Redstone functionality override the getWeakPower() method to control the Redstone output of the block by returning a specific value from 0 to 15 from the method. It’s also possible to separately control the output of each side (only output on one side or different outputs on each side), by using the Direction parameter passed into the method to determine the returned value.
Note: You must override the canProvidePower() method to return true. Otherwise, neighboring blocks will not check the block for a Redstone output and the desired functionality won’t work.

Meteor: Call template helper from other template

I have two templates and I've defined JavaScript helpers and events to go with each. When a button is clicked in template A, one of the things I want to do is call a helper function for template B which will change what's displayed on the screen. Is this possible?
If it's not possible, I'd instead like to reload template B.
How can I do either of these? Do I use Tracker.autorun? Reactive variables? Ideally I would do, inside an event function for template A,
B.helpers.call("helperFunctionFromTemplateB");
There are a lot of solutions to what I think you want to achieve, but the answer really depends on context.
If template A is a child template of B:
You can pass a reference to a ReactiveVar in the parent template down to the child template's data context and modify it using {{>childTemplate reactiveVar=reactiveVar}} where reactiveVar is a helper in the parent template that returns the reference to the reactive variable
If the thing you want to change is in the parent's data context, you can use Template.parentData(n) where nis the amount of levels you want to jump up. While modifying the parent's data may not immediately seem reactive, you can make the data prop reactive by accessing it via Template.currentData()
Use some kind of globally accessible state. The most common answer would probably be to use the Session package and use Session.get('var') and Session.set('var', val).
Use an event emitter. This approach gets +'s for decoupling and reusability, but it's also potentially heavy handed if you only need to modify this variable in one place from one source (i.e. your requirements are simple)
Meteor 1.3 - If you want to make references to your reactive data in multiple places but don't want to create a global like Session, use a ReactiveVar or Reactive Dict (closer to session), create your variable where it makes sense, export it, and import it in your templates/anywhere else to be used.
There's a lot of other solutions, these are just the first that come to mind. If you provide more specific context, I'll provide a code sample of what I think's best and explain why. :)

Render a meteor reactive variable from a database field

If I have a field in my DB that contains a string like "Hello {{currentUser}}," is there a way to allow that value to retain reactivity when rendered into a template? I am also looking to see if I can somehow inject my own variable into the output by running it through a helper and handling string replacement.
Thoughts?
One solution I've come up with thus far:
The message stored in the db is something like: "Hello, [user], how are you?"
I then render the message from the DB as usual with {{#each}} and a predefined template.
When the message is actually rendered, I pass it through a helper. The helper replaces all []'s with <span class="$1"></span> so that I can target each item directly.
Once the message template's rendered() is called, I know that the message body contains the cleaned and prepped content (with the spans), so I use this.$('.user').each() and loop over each instance of the spans.
I've also created a special template in my page called 'placeholderUser' that only contains a call to {{user}}. I've added Template.placeholderUser.user = function(){} to the code to pull through a value and maintain reactivity.
Whew! Now that I have the structure set up, when looping through in the "each," I can call:
UI.insert(UI.render(Template.placeholderUser), el), which will render the template in the given span and maintain all reactivity.
It's super hacky, but it works. Any other, better, solutions out there?

Executing an item in the package as a Dreamweaver Template

Does anybody know if it is possible in a compound template to use a string item in the package and execute it as if were a dreamweaver template? And whether you apply the same method to other mediators (like razor)?
Thanks
Mark
I suspect this is not possible.
Package.EvaluateExpression may be useful, but as the name suggests it'll only work on expressions, not large snippets of code with embedded expressions (i.e. TEL)
Engine.GetMediator expects a Template and returns the appropriate Mediator for it. Your problem then is that the IMediator interface only defines the Transform method, which requires an Engine, a Template and a Package.
I can't think of any elegant ways around these. Maybe write your own Mediator, but that would still expect a Package, not a string, so you'd have to first store the string based Item from another TBB.
My advice: Sounds like you need to go back to the drawing board and find an alternative solution to your problem.
I'm afraid that won't be possible on just any item in the Package, since the Engine expects Templates to be based on Tridion items.
If your Template Item is based on a Tridion Item you can probably get pretty far by starting at the Engine.GetMediator method. If it isn't, you'll have to find some way to turn it into a valid Template object.
Template template = ...
IMediator mediator = engine.GetMediator(template);
mediator.Transform(engine, template, package);
When I have to create a Component object from a Tridion-based Item in the Package, I normally do something like this:
Component component = new Component(item.GetAsXmlDocument().DocumentElement,
engine.GetSession);
I haven't tried, but expect that you can do the same for a Template - given that you start with a valid Item from the Package representing a Template to begin with. You can probably clone the XML from an existing Item or find some other way to fake it.
If you get this to work, it will work across all registered template types. The Engine provides no special treatment for the types that come with Tridion.

ASP.NET: Is it possible to create dynamically-named Javascript functions without using .NET code (ie, VB.NET or C#)?

I have a custom user control (ascx) that contains a textbox and a Javascript-based counter to let the user know many characters they have left to type. In this control is the following:
function GetTextBox() {
return document.getElementById("<%=txNotes.ClientID %>");
}
This worked fine when we only had one instance of this user control on the page, but now we have to support multiple. As you know, having multiple instances of this control on a page will result in multiple GetTextBox() functions, only the last of which will be called no matter what. To support multiple instances, I use this:
if (!string.IsNullOrEmpty(TextBoxName) && !Page.ClientScript.IsClientScriptBlockRegistered(TextBoxName))
{
string Script = string.Format("function Get{0}Notes() {{ return document.getElementById(\"{1}\"); }}",
TextBoxName, txNotes.ClientID);
Page.ClientScript.RegisterClientScriptBlock(GetType(), TextBoxName, Script, true);
}
TextBoxName is a public usercontrol property, so if the developer passes Employee through, it will generate a Javascript function called GetEmployeeNotes(). This works greate because now we can have a unique GetNotes() function.
However, I don't like how it's hardcoded into the codebehind. I would like a markup-based solution for this, something that doesn't require a rebuild of the project in case I want to change the Javascript. Does anyone know of a way to do this?
Edit: I've already thought of creating a separate .js file that I could read with a text reader, but that sounds a bit hacky and I'd like to avoid that if at all possible.
Edit 2: Guard's answer below would work, but I don't want to go that route for the reason I gave beneath his answer. If no one can offer another way to do what I want to do, I will most likely mark his as the answer since it technically does exactly what I am asking.
I'm not a .NET specialist, but isn't it working as a preprocessor?
Isn't it legal to write
function Get<%=Name %>Notes() {...}
?
Why not use a generic function and just pass the id of the corresponding textbox? As in: GetNotes(thisTextBoxId) {...}. Not only would that deal with your problem but also is more DRY.

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