https://github.com/tmeasday/meteor-deps-extensions

https://github.com/tmeasday/meteor-deps-extensions

Last synced: 11 days ago
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• Host: GitHub
• URL: https://github.com/tmeasday/meteor-deps-extensions
• Owner: tmeasday
• Created: 2012-07-25T03:34:31.000Z (over 12 years ago)
• Default Branch: master
• Last Pushed: 2012-09-16T06:41:37.000Z (over 12 years ago)
• Last Synced: 2024-10-25T18:58:33.254Z (about 2 months ago)
• Language: JavaScript
• Size: 102 KB
• Stars: 4
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
#Some reactive helpers for meteor

##Install

Use [meteorite](http://oortcloud.github.com/meteorite/):

Then add via:

```bash

mrt add deps-extensions

```

##Usage

###Adding Reactive Variables

```js

 Meteor.deps.add_reactive_variable(object, 'something', default_value)

```

Which adds three functions to object: object.something(), object.something.set() and object.something.equals() which behave reactively.

###Using reactive contexts

####`repeat`

```js

Meteor.deps.repeat(fn)

```

Repeatedly call `fn`, once each time the dependencies that it uses changes. For example:

```js

Meteor.deps.repeat(function() {

  console.log("current_post_id is: " Session.get('current_post_id'));

});

```

####`isolate`

```js

Meteor.deps.isolate(fn)

```

Kill all reactivity inside `fn`, so that the current context isn't ever invalidated by that code. Returns the result of `fn`. For example:

```js

Meteor.deps.isolate(function() {

  return Comments.find({}, {order: {score: 1}});

});

```

Will return a list of comments that is 'unreactive' and thus won't reorder as the user reads them.

####`await`

```js

 Meteor.deps.await(predicate, cb)

```

Repeatedly (reactively) call `predicate` until it's true, then call `cb` *once only*. For example

```js

Meteor.deps.await(function() { return Router.current_page() === 'home'; }, function() {

  alert('Welcome to my site! Nice to see you!');

});

```

####`memoize`

```js

 Meteor.deps.memoize(fn)

```

Returns a function that wraps `fn` in a context, so that `fn`'s reactivity can be maintained, whilst minimizing the number of calls to it. Example:

```js

var cheapReactiveFn = Meteor.deps.memoize(function() {

  return expensiveReactiveFn();

});

```

Now `reactiveFn` can be called many times, but `expensiveReactiveFn` will only get called once (per value it returns);