I've been using the--quite excellent--playframework and have had trouble finding documentation/examples on how to access a Map data structure from a view, using play's template engine.
To be even more specific, I wish to access the Map as I iterate over a List of objects, e.g.,
#{list items:itemList, as:'item'}
// access the map value using the ${item?.id} as the key
#{/list}
Thank's for looking.
This is a generic solution to iterate on Map in using Play! Framework:
in the controller :
render(map);
in the template:
#{list items:map.keySet(), as:'key'}
${map.get(key)}
#{/list}
The fact that you want to rely on a side List to iterate on your Map suggest me that you are searching a predictible way for your iteration process.
In that case, just remember that iteration will be unpredictable if you don't use an ordered/sorted Map implementation.
HashMap gives you an unsorted, unordered Map
LinkedHashMap maintains insertion order
TreeMap is the only JDK implementation of a sorted Map. By default it allows you to iterate following the natural order of the elements. You can also specify a custom sort order and implements the Comparable interface. This will lead you to override the compareTo() method.
Assuming you do in the Controller:
render(map, itemList); //map is a Map
This should work:
#{list items:itemList, as:'item'}
// access the map value using the ${item?.id} as the key
${map.get(item.?id)}
#{/list}
I don't know anything about the play framework, but this would work in a GSP
#{list items:itemList, as:'item'}
${map[item?.id]}
#{/list}
I'm doing things like that on a map:
*{ Map<User, Integer> shareHolders = ... }*
#{list shareHolders.sort{it.value}.collect {k,v -> k}.reverse(), as:'holder'}
<tr>
<td>${holder.name}</td>
<td>${shareHolders[holder]}</td>
</tr>
#{/list}
Related
In FileNet, using FEM or ACCE, it is possible to use JScript in order to set attributes' values to an object. The official IBM guide provides this example (for Strings):
importClass(Packages.com.filenet.api.property.Properties);
importClass(Packages.com.filenet.api.constants.RefreshMode);
function OnCustomProcess (CEObject)
{
CEObject.refresh();
CEObject.getProperties().putValue("DocumentTitle", "Test1");
CEObject.save(RefreshMode.REFRESH);
}
But is it possible to do the same thing for more complex objects? I'm referring, in particular, to StringList type. There are no examples on the web, and defining a JS-like array doesn't work.
It is definitely possible to do this for more complex objects. Most of it is just following the path you would follow using Java, but changing the name of the variable types to var. Therefore the code for setting the value of a multivalue string property is as follows:
importClass(Packages.com.filenet.api.constants.RefreshMode);
importClass(Packages.com.filenet.api.core.Factory);
function OnCustomProcess (CEObject)
{
CEObject.refresh();
var list = Factory.StringList.createList();
list.add("Value 1");
list.add("Value 2");
CEObject.getProperties().putObjectValue("TestMultiValueProperty1", list);
CEObject.save(RefreshMode.REFRESH);
}
I often use the putObjectValue() method instead of the putValue() method because JavaScript sometimes has problems determining which type safe version of the putValue() it should use.
For a lot of examples you could go to the Global Configuration > Data Design > Add-ons section in the domain tab of the ACCE. The pre- and post-import scripts of the different Add-ons contain a lot of relevant JavaScript code.
The asp-items Razor "TagHelper" will add an <option> to a <select> for each value in the SelectList. I want to modify each of those children.
Specifically I want to disable some of them (i.e. add disabled="disabled").
Even more specifically I want to dynamically disable some of them; I'm using angular so I could ng-disabled="{dynamic_boolean_which_determines_disabled}". This means the option could be disabled at first, but after user makes a change, the option could be disabled (without page reload). Angular should take care of this; I think Angular and TagHelpers should work together in theory...
I expected:
I could somehow access an IEnumerable of the children <option> tags that would be created (i.e. one for each item in the SelectList), iterate the children tags, and SetAttribute("disabled") or SetAttribute("ng-disabled")...
I tried:
Creating my own TagHelper which targets the select[asp-items], and tries to GetChildContentAsync() and/or SetContent to reach an IEnumerable <option> tags and iterate them and process each, but I think this will only let me modify the entire InnerHtml as a string; feels hacky to do a String.replace, but I could do it if that's my only option? i.e. ChildrenContent.Replace("<option", "<option disabled=\"...\"")
Creating my own TagHelper which targets the option elements that are children of the select[asp-items], so I can individually process each. This works, but not on the dynamically-added <option> created by asp-items, it only works on "literal" <option> tags that I actually put into my cshtml markup.
I think this'll work but not ideal:
As I said above, I think I can get the result of TagHelper's dynamic asp-items <option></option> <option></option>, as a string, and do a string replace, but I prefer not to work with strings directly...
I suspect (I haven't tried it) that I could just do the work of asp-items myself; i.e. custom-items. But then I'm recreating the wheel by re-doing the work which asp-items could've done for me?
So I hadn't yet read the "AutoLinkHttpTagHelper" in the example which uses string replacement (specifically RegEx replace) to replace every occurrence of a URL, with an <a> pointed at that URL. The cases are slightly different*, but...
Anyway, here's my solution once I learned to stop worrying and love the string modification:
[HtmlTargetElement("select", Attributes = "asp-items")]
public class AspItemsNgDisabledTagHelper : SelectTagHelper
{
//Need it to process *after* the SelectTagHelper
public override int Order { get; } = int.MaxValue;
//https://learn.microsoft.com/en-us/aspnet/core/mvc/views/tag-helpers/authoring#ProcessAsync
public AspItemsNgDisabledTagHelper(IHtmlGenerator gen) : base(gen) {}
public override void Process(TagHelperContext context, TagHelperOutput output)
{
//Notice I'm getting the PostContent;
//SelectTagHelper leaves its literal content (i.e. in your CSHTML, if there is any) alone ; that's Content
//it only **appends** new options specified; that's PostContent
//Makes sense, but I still wasn't expecting it
var generated_options = output.PostContent.GetContent();
//Note you do NOT need to extend SelectTagHelper as I've done here
//I only did it to take advantage of the asp-for property, to get its Name, so I could pass that to the angular function
var select_for = this.For.Name;
//The heart of the processing is a Regex.Replace, just like
//their example https://learn.microsoft.com/en-us/aspnet/core/mvc/views/tag-helpers/authoring#inspecting-and-retrieving-child-content
var ng_disabled_generated_options = Regex.Replace(
generated_options,
"<option value=\"(\\w+)\">",
$"<option value=\"$1\" ng-disabled=\"is_disabled('{select_for}', '$1')\">");
//Finally, you Set your modified Content
output.PostContent.SetHtmlContent(ng_disabled_generated_options);
}
}
Few learning opportunities:
Was thinking I'd find AspForTagHelper and AspItemsTagHelper, (angular background suggested that the corresponding attributes; asp-for and asp-items, would be separate "directives" aka TagHelper).
In fact, TagHelper "matching" focuses on the element name (unlike angular which can match element name... attribute... class... CSS selector)
Therefore I found what I was looking for in SelectTagHelper, which has For and Items as properties. Makes sense.
As I said above, I extend SelectTagHelper, but that's not necessary to answer my original question. It's only necessary if you want access to the this.For.Name as I've done, but there may even be a way around that (i.e. re-bind its own For property here?)
I got on a distraction thinking I would need to override the SelectTagHelper's behavior to achieve my goals; i.e. Object-Oriented Thinking. In fact, even if I did extend SelectTagHelper, that doesn't stop a separate instance of the base SelectTagHelper from matching and processing the element. In other words, element processing happens in a pipeline.
This explains why extending and calling base.Process(), will result in Select doing its job twice; once when your instance matches, and again when the base instance matched.
(I suppose could've prevented SelectTagHelper from matching by creating a new element name like <asp-items-select>? But, not necessary... I just avoid calling base.Process(). So unless that's a bad practice...)
*Different in this way:
They want to create a tag where none exists, whereas I want to add an attribute a tag which is already there; i.e. the <option>
Though the <option> "tag" is generated by the SelectTagHelper in its PostContent (was expecting to find it in Content), and I don't think tags-generated-in-strings-by-content-mods can be matched with their corresponding TagHelper -- so maybe we really are the same in that we're just dealing with plain old strings
Their "data" aka "model" is implied in the text itself; they find a URL and that URL string becomes a unit of meaning they use. In my case, there is an explicit class for Modeling; the SelectList (<select>) which consists of some SelectListItem (<option>) -- but that class doesn't help me either.
That class only gives me attributes like public bool Disabled (remember, this isn't sufficient for me because the value of disabled could change to true or false within browser; i.e. client-side only), and public SelectListGroup Group -- certainly nothing as nonstandard as ng-disabled, nor a "catch-all" property like Attributes which could let me put arbitrary attributes (ng-disabled or anything else) in there.
I have a Hazelcast instance that organizes data based on map names. The map names are dynamic, so I do not know what they will be until the Hazelcast instance is already started. I now want to store this data in a database via the MapStore functionality, but retain the organization I have setup with the map names. When looking at the MapStore functionality, I do not see any way to retrieve the map or map name that the object came from. Looks like all I get is the key-value pair in the MapStore implementation.
On a broader note, is there any way to get ANY information (not just map name) about the key-value pair needing to be stored? I would like to transfer some knowledge about how to store the data... I know the information when I call map.put(..), but I do not know how to transfer that information to the MapStore call...
I just needed something similar and found that you can implement com.hazelcast.core.MapStoreFactory interface whose 'newMapStore' method gives you the map name and properties from config. From there 'new' your own MapStore implementation passing the map name.
public class MyMapStoreFactory implements MapStoreFactory {
#Override
public MapStore newMapStore(String mapName, Properties properties) {
return new MyMapStoreImplementation(mapName, properties);
}
}
And configure this factory class in hazelcast.xml config like this:
<map name="MapX*">
<map-store enabled="true" initial-mode="EAGER">
<factory-class-name>MyMapStoreFactory</factory-class-name>
</map-store>
</map>
Notice the wildcard on the map name and that <class-name> element must not appear once you set <factory-class-name>.
Tested this with Hazelcast 3.6.1 and it works very fine.
As per my understanding, there is no support out of the box in hazelcast. The following are couple of workarounds I can think of:
Encapsulate the extra information (map name, how to store the data etc) in a context object and store it in a different java map against your key. Use this map in your MapStore implementation later to retrieve respective information which will help you to persist your key,value pairs.
You put operation might look like.
hzMap.put(key, value);
Context context = new Context();
context.setHowToStoreData();
context.setMapName();
// any othe rother information
context.xxx();
// create a unique context key which can be later deduced from (key,value) pair.
contextKey = getUniqueContextKey(key, value);
contextMap.put(contextKey, context);
In your MapStore implementation, you can then make use of this contextMap to retrieve additional values.
Second way would be to encapsulate the information within the (key, value) pair. You can create a new class called CacheEntry to store cache values as well as additional information. You can then later retrieve your cache value as well as additional information from iMap itself.
You put operation might look like.
CacheEntry<YourValueClass> cacheEntry = new CacheEntry<YourValueClass>();
cacheEntry.setValue(value);
cacheEntry.howToStoreData(..);
cacheEntry.setMapName(..);
imap.put(key, cacheEntry);
In your MapStore implementation, you can then make use of the value (which would be a CacheEntry object) itself to retrieve additional information as well as actual value (instance of YourValueClass).
I am implementing my own Map in Java, using a custom class I made.
I already implemented the hashCode and equals without any problem.
I just have a question more related into performance and stuff like that.
So I will check many times in my application if a specific value is inside the map, for that, for that I have to create a object and then use the methods containsKey of Map.
My question is...
Is there any other way? without being always creating the object???
I cant have all the objects in my context universe, so that isn't a way...
I know I can just point the object to 'null' after using it, but still, it's not so elegant, creating objects just to check if there is the same object inside =S
Are there any other conventions?
Thank you very much in advance!
EDIT:
Stuff typed = new Stuff(stuff1, stuff2, (char) stuff3);
if(StuffWarehouse.containsKey(typed))
{
//do stuff
}
//after this I won't want to use that object again so...
typed = null;
I need to perform a search on several entities with the same string then order the results.
I've heard/read a little about FOSElasticaBundle, would this bundle be able to do it? It seems (to me) to have almost to much features for this purpose and I'm not sure it could run on a shared server (hostgator).
The other solution I can think of at the moment is doing the search "manually" (by using join and union) but I'm wondering where should I put such a function: in an existing controller, a new one, a new bundle or somewhere else?
I'm worried as well that this manual solution could come to a cost, especially on some non-indexable fields.
You would do custom entity repositories. Check out the docs. Basically this extends the default FindAll, FindOneBy, etc.
You would have a function like so:
class MyEntityRepository extends Doctrine\ORM\EntityRepository {
public function findByCustomRule(){
//this is mapped to your entity (automatically adds the select)
$queryBuilder = $this->createQueryBuilder('someAlias');
$queryBuilder->orderBy('...');
//this is mapped to any entity
$queryBuilder = $this->getEntityManager()->createQueryBuilder();
$queryBuilder->select('...');
//result
$result = $queryBuilder->getQuery()->getResult();
}
}
This class is defined in the doctrine mapping and lives inside the Entity folder.. Check the docs out and you should get a basic idea.