Emberjs: best way to iterate through ArrayProxy content? - ember.js

Often, I need to loop through an Ember.ArrayProxy object's content.
Exemple 1, I need to build a list of IDs:
var loc = myArrayProxy.get('length') || 0,
ids = new Array(),
idsList;
while(--loc >= 0) {
var curObject = myArrayProxy.objectAt(loc);
ids.push(curObject.id);
}
idsList = ids.join(',');
Exemple 2, I need to build an Array of primitive objects (not Ember.Object):
var loc = myArrayProxy.get('length') || 0,
newContent = new Array();
while(--loc >= 0) {
var curObject = myArrayProxy.objectAt(loc);
newContent.push({
id: curObject.id,
name: curObject.name
});
}
Question: is there a better way to do this? The "while(--loc >= 0)" seems bad to me.

Ember.ArrayProxy provides many friendly functions (through Ember.Array, Ember.Enumerable, ...). Loops can often be avoided using "forEach". In your 2nd example, you may consider using "map".
Here is a link to Ember.ArrayProxy documentation.
Be sure to look at: Ember.Array and Ember.Enumerable
edit:
For instance, assuming the order of the ids is not relevant, your first example could be written:
var idsList = myArrayProxy.mapProperty('id').join(',');

Related

Get object with the GloabId

Is it possible to find an object in an IFC file using Xbim.Essentials with the GlobalId value?
I saw this kind of code supposing I know the type...But I'd like to first find the object without knowing the type.
var id = "2AswZfru1AdAiKfEdrNPnu";
var theDoor = model.Instances.FirstOrDefault<IIfcDoor>(d => d.GlobalId == id);
Console.WriteLine($"Door ID: {theDoor.GlobalId}, Name: {theDoor.Name}");
I think you can use IIfcProduct interface from
Xbim.Ifc4.Interfaces
like:
var ifcProduct = model.Instances.FirstOrDefault<IIfcProduct>(d => d.GlobalId == id);
should work on walls, slabs, columns etc...

i want to update only single row column value with rollback commit

i want to update only single row column value with rollback commit but when i create table object inside if and pass to insertonsubmit it gives me error,plz help me how can i solve this
var challan = dataContext.Purchase_Challans.Where(t => t.Challan_ID == Convert.ToInt64(ViewState["challanid"]) && t.Company_ID == Convert.ToInt32(Session["CompanyId"])).Select(t => t).ToList();
if (challan.Any())
{
challan.ToList()[0].Inv_DocumentId = dmsPurchaseInvoice.Document_ID;
dataContext.Purchase_Challans.InsertOnSubmit()
dataContext.SubmitChanges();
}
Would be helpful to know more details about the error, but I assume it's because you tell the dataContext to insert an entity that you just retrieved (whereas you want to update it).
Also the code you posted does not even compile and is full of questionable code, like challan.ToList() where it already is a list, or parsing strings inside a delegate.
That said, this code is more straightforward and more likely to work (but to be honest I didn't test it):
var challanId = Convert.ToInt64(ViewState["challanid"]);
var companyId = Convert.ToInt32(ViewState["CompanyId"]);
var challan = dataContext.Purchase_Challans.SingleOrDefault(t => t.Challan_ID == challanId && t.Company_ID == companyId);
if (challan != null)
{
challan.Inv_DocumentId = dmsPurchaseInvoice.Documet_Id;
dataContext.SubmitChanges();
}

Access nth item when iterating Ember object array with for rather than forEach

It made more sense in a particular case today to use a standard for (i = 0.. loop rather than a forEach, but I realised I don't know how to access objects of an Ember Array by number.
So lets say we have:
var order = this.get('order');
var orderItems = order.get('orderItems');
orderItems.forEach(function(orderItem) {
orderItem.set('price', 1000);
});
I thought I could do the equivalent as:
var order = this.get('order');
var orderItems = order.get('orderItems');
for (i = 0; i < orderItems.get('length'); i++) {
orderItems[i].set('price', 1000);
}
but I get orderItems[0] is undefined etc.
How do I access the nth element in an ember array in js?
Ember.js Array provides a objectAt method for accessing the nth element, which you can use for iteration.
Your updated code would look like :
var order = this.get('order');
var orderItems = order.get('orderItems');
for (i = 0; i < orderItems.get('length'); i++) {
orderItems.objectAt(i).set('price', 1000);
}
Check out it's documentation here: http://emberjs.com/api/classes/Ember.Array.html#method_objectAt

How do I query multiple IDs via the ContentSearchManager?

When I have an array of Sitecore IDs, for example TargetIDs from a MultilistField, how can I query the ContentSearchManager to return all the SearchResultItem objects?
I have tried the following which gives an "Only constant arguments is supported." error.
using (var s = Sitecore.ContentSearch.ContentSearchManager.GetIndex("sitecore_master_index").CreateSearchContext())
{
rpt.DataSource = s.GetQueryable<SearchResultItem>().Where(x => f.TargetIDs.Contains(x.ItemId));
rpt.DataBind();
}
I suppose I could build up the Linq query manually with multiple OR queries. Is there a way I can use Sitecore.ContentSearch.Utilities.LinqHelper to build the query for me?
Assuming I got this technique to work, is it worth using it for only, say, 10 items? I'm just starting my first Sitecore 7 project and I have it in mind that I want to use the index as much as possible.
Finally, does the Page Editor support editing fields somehow with a SearchResultItem as the source?
Update 1
I wrote this function which utilises the predicate builder as dunston suggests. I don't know yet if this is actually worth using (instead of Items).
public static List<T> GetSearchResultItemsByIDs<T>(ID[] ids, bool mustHaveUrl = true)
where T : Sitecore.ContentSearch.SearchTypes.SearchResultItem, new()
{
Assert.IsNotNull(ids, "ids");
if (!ids.Any())
{
return new List<T>();
}
using (var s = Sitecore.ContentSearch.ContentSearchManager.GetIndex("sitecore_master_index").CreateSearchContext())
{
var predicate = PredicateBuilder.True<T>();
predicate = ids.Aggregate(predicate, (current, id) => current.Or(p => p.ItemId == id));
var results = s.GetQueryable<T>().Where(predicate).ToDictionary(x => x.ItemId);
var query = from id in ids
let item = results.ContainsKey(id) ? results[id] : null
where item != null && (!mustHaveUrl || item.Url != null)
select item;
return query.ToList();
}
}
It forces the results to be in the same order as supplied in the IDs array, which in my case is important. (If anybody knows a better way of doing this, would love to know).
It also, by default, ensures that the Item has a URL.
My main code then becomes:
var f = (Sitecore.Data.Fields.MultilistField) rootItem.Fields["Main navigation links"];
rpt.DataSource = ContentSearchHelper.GetSearchResultItemsByIDs<SearchResultItem>(f.TargetIDs);
rpt.DataBind();
I'm still curious how the Page Editor copes with SearchResultItem or POCOs in general (my second question), am going to continue researching that now.
Thanks for reading,
Steve
You need to use the predicate builder to create multiple OR queries, or AND queries.
The code below should work.
using (var s = Sitecore.ContentSearch.ContentSearchManager.GetIndex("sitecore_master_index").CreateSearchContext())
{
var predicate = PredicateBuilder.True<SearchResultItem>();
foreach (var targetId in f.Targetids)
{
var tempTargetId = targetId;
predicate = predicate.Or(x => x.ItemId == tempTargetId)
}
rpt.DataSource = s.GetQueryable<SearchResultItem>().Where(predicate);
rpt.DataBind();
}

Reflection on EmberJS objects? How to find a list of property keys without knowing the keys in advance

Is there a way to retrieve the set-at-creations properties of an EmberJS object if you don't know all your keys in advance?
Via the inspector I see all the object properties which appear to be stored in the meta-object's values hash, but I can't seem to find any methods to get it back. For example object.getProperties() needs a key list, but I'm trying to create a generic object container that doesn't know what it will contain in advance, but is able to return information about itself.
I haven't used this in production code, so your mileage may vary, but reviewing the Ember source suggests two functions that might be useful to you, or at least worth reviewing the implementation:
Ember.keys: "Returns all of the keys defined on an object or hash. This is useful when inspecting objects for debugging. On browsers that support it, this uses the native Object.keys implementation." Object.keys documentation on MDN
Ember.inspect: "Convenience method to inspect an object. This method will attempt to convert the object into a useful string description." Source on Github
I believe the simple answer is: you don't find a list of props. At least I haven't been able to.
However I noticed that ember props appear to be prefixed __ember, which made me solve it like this:
for (f in App.model) {
if (App.model.hasOwnProperty(f) && f.indexOf('__ember') < 0) {
console.log(f);
}
};
And it seems to work. But I don't know whether it's 100% certain to not get any bad props.
EDIT: Adam's gist is provided from comments. https://gist.github.com/1817543
var getOwnProperties = function(model){
var props = {};
for(var prop in model){
if( model.hasOwnProperty(prop)
&& prop.indexOf('__ember') < 0
&& prop.indexOf('_super') < 0
&& Ember.typeOf(model.get(prop)) !== 'function'
){
props[prop] = model[prop];
}
}
return props;
}
Neither of these answers are reliable, unfortunately, because any keys paired with a null or undefined value will not be visible.
e.g.
MyClass = Ember.Object.extend({
name: null,
age: null,
weight: null,
height: null
});
test = MyClass.create({name: 'wmarbut'});
console.log( Ember.keys(test) );
Is only going to give you
["_super", "name"]
The solution that I came up with is:
/**
* Method to get keys out of an object into an array
* #param object obj_proto The dumb javascript object to extract keys from
* #return array an array of keys
*/
function key_array(obj_proto) {
keys = [];
for (var key in obj_proto) {
keys.push(key);
}
return keys;
}
/*
* Put the structure of the object that you want into a dumb JavaScript object
* instead of directly into an Ember.Object
*/
MyClassPrototype = {
name: null,
age: null,
weight: null,
height: null
}
/*
* Extend the Ember.Object using your dumb javascript object
*/
MyClass = Ember.Object.extend(MyClassPrototype);
/*
* Set a hidden field for the keys the object possesses
*/
MyClass.reopen({__keys: key_array(MyClassPrototype)});
Using this method, you can now access the __keys field and know which keys to iterate over. This does not, however, solve the problem of objects where the structure isn't known before hand.
I use this:
Ember.keys(Ember.meta(App.YOUR_MODEL.proto()).descs)
None of those answers worked with me. I already had a solution for Ember Data, I was just after one for Ember.Object. I found the following to work just fine. (Remove Ember.getProperties if you only want the keys, not a hash with key/value.
getPojoProperties = function (pojo) {
return Ember.getProperties(pojo, Object.keys(pojo));
},
getProxiedProperties = function (proxyObject) {
// Three levels, first the content, then the prototype, then the properties of the instance itself
var contentProperties = getPojoProperties(proxyObject.get('content')),
prototypeProperties = Ember.getProperties(proxyObject, Object.keys(proxyObject.constructor.prototype)),
objectProperties = getPojoProperties(proxyObject);
return Ember.merge(Ember.merge(contentProperties, prototypeProperties), objectProperties);
},
getEmberObjectProperties = function (emberObject) {
var prototypeProperties = Ember.getProperties(emberObject, Object.keys(emberObject.constructor.prototype)),
objectProperties = getPojoProperties(emberObject);
return Ember.merge(prototypeProperties, objectProperties);
},
getEmberDataProperties = function (emberDataObject) {
var attributes = Ember.get(emberDataObject.constructor, 'attributes'),
keys = Ember.get(attributes, 'keys.list');
return Ember.getProperties(emberDataObject, keys);
},
getProperties = function (object) {
if (object instanceof DS.Model) {
return getEmberDataProperties(object);
} else if (object instanceof Ember.ObjectProxy) {
return getProxiedProperties(object);
} else if (object instanceof Ember.Object) {
return getEmberObjectProperties(object);
} else {
return getPojoProperties(object);
}
};
In my case Ember.keys(someObject) worked, without doing someObject.toJSON().
I'm trying to do something similar, i.e. render a generic table of rows of model data to show columns for each attribute of a given model type, but let the model describe its own fields.
If you're using Ember Data, then this may help:
http://emberjs.com/api/data/classes/DS.Model.html#method_eachAttribute
You can iterate the attributes of the model type and get meta data associated with each attribute.
This worked for me (from an ArrayController):
fields: function() {
var doc = this.get('arrangedContent');
var fields = [];
var content = doc.content;
content.forEach(function(attr, value) {
var data = Ember.keys(attr._data);
data.forEach(function(v) {
if( typeof v === 'string' && $.inArray(v, fields) == -1) {
fields.push(v);
}
});
});
return fields;
}.property('arrangedContent')