I have a SAPUI5 app with two views. One overview page with a smart table and a details page that also contains a smart table. When navigating from overview to detail page I am binding the detail view to a context with:
oView.bindElement("Product(1)");
In the smart table of the detail view product details should be displayed which are available over a Navigation Property.
"Product(1)/ProductDetails"
The problem is that now two sequential backend calls will be triggered. One from the bindElement and the other one is triggert from the smart table.
Is there any possibility to not trigger a backend call when binding the view or can that call be deferred and executed in parallel with the one from the smart table?
I think it's good to separate the backend calls (not put them in the same batch), so that you can have the detail view ready, without waiting for the Smart Table to retrieve the results of the smart table of the detailed view.
However, if you do want to batch all the backend calls, just have a look on class sap.ui.model.odata.v2.ODataListBinding. It's used by the smart table of the detail page. You can use the parameter batchGroupId to specify that you want the request to be bundled in the specified batch. Use the same batch that the one used in bindElement.
Changing the batch of the Smart Table should be possible in callback routine of onBeforeRebindTable, if you do:
oEvent.getParameter("bindingParams").parameters.batchGroupId = "MyBatch"
Related
I would like to do some interesting stuff with the hits that are being displayed based on the search query that user is not only typing into search box but actually filtering using the instant search filters. I have filter based on hierarchical events_location taxonomy. Based on what user selected I would get the info in JS variable that I can then further use to do other operations in the hits div, specifically on each hit card.
So my URL when searching updates like this:
/what-to-see/?q=&idx=sdbeta_posts_events&p=0&hFR%5Btaxonomies_hierarchical.events_calendar.lvl0%5D%5B0%5D=JUL%204&hFR%5Btaxonomies_hierarchical.events_category.lvl0%5D%5B0%5D=All&hFR%5Btaxonomies_hierarchical.events_locations.lvl0%5D%5B0%5D=Paddock%20Stage
I could potentially take the URL and extract the data from it, but I am sure there is more elegant way of working with the query.
In InstantSearch.js, the state is managed by another library called the algoliasearch-helper. Through this library you can read and write the search parameters.
The cleanest to access the helper is to build a custom widget, which is a plain object with lifecycle hooks (initial rendering and the other renderings). You can read more about custom widgets there.
Once you've accessed the helper, you can read and write with the helper API.
This can be found under search.searchParameters
So:
console.log(search.searchParameters);
Will give you whole object that you can then work with.
There is however one issue with this and that is that it works only on initial load. I was unable to make this work or get any data after starting to selecting categories. So if anyone knows how to use this so it updates after each selection please comment bellow.
I will try to be as concise as possible. I'm using Flex/Hibernate technologies for my app. I also use Cairngorm micro-architecture for Flex. Because i'm beginner, i have probably misunderstand something about Caringorm's ModelLocator purpose. I have following problem...
Suppose that we have next data model:
USER ----------------> TOPIC -------------> COMMENT
1 M 1 M
User can start many topics, topics can have many comments etc. It is pretty simple model, just for example. In hibernate, i use EAGER fetching strategy for unidirectional USER->TOPIC and TOPIC->COMMENT relations(here is no question about best practices etc, this is just example of problem).
My ModelLocator looks like this:
...
public class ModelLocator ....
{
//private instance, private constructor, getInstance() etc...
...
//app state
public var users:ArrayCollection;
public var selectedUser:UserVO;
public var selectedTopic:TopicVO;
}
Because i use eager fetching, i can 'walk' through all object graph on my Flex client without hitting the database. This is ok as long as i don't need to insert, update, or delete some of the domain instances. But when that comes, problems with synchronization arise.
For example, if i want to show details about some user from some UserListView, when user(actor) select that user in list, i will take selected index in UserList, get element from users ArrayCollection in ModelLocator at selected index and show details about selected user.
When i want to insert new User, ok, I will save that user in database and in IResponder result method i will add that user in ModelLocator.users ArrayCollection.
But, when i want to add new topic for some user, if i still want to use convenience of EAGER fetching, i need to reload user list again... And to add topic to selected user... And if user is in some other location(indirectly), i need to insert topic there also.
Update is even worst. In that case i need to write even some logic...
My question: is this good way of using ModelLocator in Cairngorm? It seems to me that, because of mentioned, EAGER fetching is somehow pointless. In case of using EAGER fetching, synchronization on Flex client can become big problem. Should I always hit database in order to manipulate with my domain model?
EDIT:
It seems that i didn't make myself clear enough. Excuse me for that.
Ok, i use Spring in technology stack also and DTO(DVO) pattern with flex/spring (de)serializer, but i just wanted to stay out of that because i'm trying to point out how do you stay synchronized with database state in your flex app. I don't even mention multi-user scenario and poling/pushing topic which is, maybe, my solution because i use standard request-response mechanism. I didn't provide some concrete code, because this seems conceptual problem for me, and i use standard Cairngorm terms in order to explain pseudo-names which i use for class names, var names etc.
I'll try to 'simplify' again: you have flex client for administration of above mentioned domain(CRUD for each of domain classes), you have ListOfUsersView(shows list of users with basic infos about them), UserDetailsView(shows user details and list of user topics with delete option for each of topic), InsertNewUserTopicView(form to insert new topic) etc.
Each of view which displays some infos is synchronized with ModelLocator state variables, for example:
ListOfUsersView ------binded to------> users:ArrayCollection in ModelLocator
UserDetailsView ------binded to------> selectedUser:UserVO in ModelLocator
etc.
View state transition look like this:
ListOfUsersView----detailsClick---->UserDetailsView---insertTopic--->InsertTopicView
So when i click on "Details" button in ListOfUsersView, in my logic, i get index of selected row in ListOfUsers, after that i take UserVO object from users:ArrayCollection in ModelLocator at mentioned index, after that i set that UserVO object as selectedUser:UserVO in ModelLocator and after that i change view state to UserDetailsView(it shows user details and selectedUser.topics) which is synchronized with selectedUser:UserVO in ModelLocator.
Now, i click "Insert new topic" button on UserDetailsView which results in InsertTopicView form. I enter some data, click "Save topic"(after successful save, UserDetailsView is shown again) and problem arise.
Because of my EAGER-ly fetched objects, i didn't hit the database in mentioned transitions and because of that there are two places for which i need to be concerned when insert new topic for selected user: one is instance of selectedUser object in users:ArrayCollection (because my logic select users from that collection and shows them in UserDetailsView), and second is selectedUser:UserVO(in order to sync UserDetailsView which comes after successfull save operation).
So, again my question arises... Should i hit database in every transition, should i reload users:ArrayCollection and selectedUser:UserVO after save in order to synchronize database state with flex client, should i take saved topic and on client side, without hitting the database, programmatically pass all places which i need to update or...?
It seems to me that EAGER-ly fetched object with their associations is not good idea. Am i wrong?
Or, to 'simplify' :) again, what should you do in the mentioned scenario? So, you need to handle click on "Save topic" button, and now what...?
Again, i really try to explain this as plastic as possible because i'm confused with this. So, please forgive me for my long post.
From my point of view the point isn't in fetching mode itself but in client/server interaction. From my previous experience with it I've finally found some disadvantages of using pure domain objects (especially with eager fetching) for client/server interaction:
You have to pass all the child collections maybe without necessity to use them on a client side. In your case it is very likely you'll display topics and comments not for all users you get from server. The most like situation you need to display user list then display topics for one of the selected users and then comments for one of the selected topics. But in current implementation you receive all the topics and comments even if they are not needed to display. It is very possible you'll receive all your DB in a single query.
Another problem is it can be very insecure to get all the user data (or some other data) with all fields (emails, addresses, passwords, credit card numbers etc).
I think there can be other reasons not to use pure domain objects especially with eager fetching.
I suggest you to introduce some Mapper (or Assembler) layer to convert your domain objects to Data Transfer Objects aka DTO. So every query to your service layer will receive data from your DAO or Active Record and then convert it to corresponding DTO using corresponding Mapper. So you can get user list without private data and query some additional user details with a separate query.
On a client side you can use these DTOs directly or convert them into client domain objects. You can do it in your Cairngorm responders.
This way you can avoid a lot of your client side problems which you described.
For a Mapper layer you can use Dozer library or create your own lightweight mappers.
Hope this helps!
EDIT
What about your details I'd prefer to get user list with necessary displayable fields like first name and last name (to display in list). Say a list of SimpleUserRepresentationDTO.
Then if user requests user details for editing you request UserDetailsDTO for that user and fill tour selectedUser fields in model with it. The same is for topics.
The only problem is displaying list of users after user details editing. You can:
Request the whole list again. The advantage is you can display changes performed by other users. But if the list is too long it can be very ineffective to query all the users each time even if they are SimpleUserRepresentationDTO with minimal data.
When you get success from server on user details saving you can find corresponding user in model's user list and replace changed details there.
Tell you the truth, there's no good way of using Cairngorm. It's a crap framework.
I'm not too sure exactly what you mean by eager fetching (or what exactly is your problem), but whatever it is, it's still a request/response kind of deal and this shouldn't be a problem per say unless you're not doing something right; in which case I can't see your code.
As for frameworks, I recommend you look at RobotLegs or Parsley.
Look at the "dpHibernate" project. It implements "lazy loading" on the Flex client.
I want to put context-sensitive, dynamic command options on my asp.net pages.
I tried coding my own command structure but it's not very good, and I'm sure there must be a framework for doing this somewhere I can re-use?
Example:
I have a detailsview for some database object, I want to code in the object class what commands are available, based on the state of the object. I then want a UI object I can place on the webform that will pass commands back to the object when user clicks them, or jump to a different link (e.g. when additional parameters are available).
e.g. form might look like this
Product Details
Name: XXXX product
Price: $1.00
Qty: 1
Commands:
> Edit
> New Stock
> Mark as obsolete
So the commands at the bottom would have very little UI code and pass actions back to the object. For example the New Stock command would jump to a new page to ask for a quantity.
I don't know of the framework, but you could create something yourself. Let's say you are using MVP pattern, and assuming that this is a CRUD application, you could tell each view what type of object it is related to, then annotate you object with operations that are available. Then Presenter could call Service to perform the operation. You could name your methods using some convention so that you can wire it up in a Service. It is a lot of work, and unless you have 100s of views it is not worth while. I am building app that is about that size, and I am in process of creating GenericMVP framework, that would make wiring a breeze.
I'm building a Drupal based site that requires the communication of a node ID to a seperate web service. This web service handles the uploading of files to a seperate server (from the one Drupal is on).
This creates a problem where in if I create a new node, the Node ID is not generated until the form is submitted - meaning I can't attach the files until I save the node and open it back up to edit it. I'd like to remove that step.
Is it possible to create a two step node creation process where the basics of the node are submitted and saved, and then the form re-directs to step two where I can attach the files?
I'd also consider an AJAX enabled node submission form - but that seems to add even more complexity to the situation.
Any advice, examples will be appreciated!
you could do this with a multi-step form. see http://pingv.com/blog/ben-jeavons/2009/multi-step-forms-drupal-6-using-variable-functions for the canonical way to do this (besides the code, also check the comments).
you could also do it by adding a second submit handler to the form. the first, default one (node_form_submit) saves your node (including the attached file) the standard Drupal way. the second handler could upload the file to the separate server, do upload error checking, delete the file from the Drupal DB, etc. you can add an additional submit handler to a Drupal 6 form by adding it to the form's #submit property, either in the form definition or via hook_form_alter / hook_form_FORM_ID_alter.
Depending on what exactly you want to do, you might use hook_nodeapi on its 'insert' operation. It is fired after successful node creation, so the node object will contain the newly assigned nid there already.
NOTE: The wording of the API documentation is a bit ambiguous concerning the 'insert' and 'update' operations:
"insert": The node is being created
(inserted in the database).
This sounds like it is right in the middle of the process, whereas the node has already been created at this point.
I guess the node_save function can help you.
I ran into exactly this same issue and did it the wrong way. I added the hook myself.
http://drupal.org/node/313389
alt text http://img3.imageshack.us/img3/1488/advancedsearch.png
I'm building an "Advanced Search" interface in an ASP.NET application. I don't need SO to write this thing for me, but I'm stuck on a specific problem regarding dynamic controls and ViewState. I would like some direction for how to approach this. Here's my situation:
Ingredients:
A serviceable set of API objects representing entities, fields, and searches, which handles constructing a search, generating SQL, and returning the results. So that's all taken care of.
ASP.NET 3.5
Desired Interface Functionality:
(1) On initial page load, the interface gets a preconfigured Search object with a set of SearchCriterion objects. It binds them into a set of controls (see image above.)
Some search items are simpler, like:
Field (DropDownList) | Operator (DropDownList) | Value (TextBox)
Search Criterion controls for some field types have important information stored in viewstate, like:
Field (DropDownList) | Operator (DropDownList) | Value (DropDownList) where the "Value" dropdownlist is populated by a database query.
Some fields are lookups to other Entities, which causes a chain of field selectors, like:
Field (DropDownList) Field (DropDownList) | Operator (DropDownList) | Value
(2) The user modifies the search by:
Adding and Removing search criteria by clicking respective buttons
Configuring existing criteria by changing the Field, Operator, or Value. Changes to Field or Operator will require the control to reconfigure itself by changing the available operators, changing the "Value" input control to a different type, or adding/removing DropDownLists from the "Fields" section if Lookup-type fields are selected/unselected.
(3) Finally, the user hits "Search" to see their results.
The Problem:
As you probably already know if you're answering this question, controls added dynamically to the page disappear on postback. I've created a UserControl that manipulates the control collection and neatly accomplishes step (1) above as you can see in the attached image. (I'm not concerned about style at this point, obviously.)
However on Postback, the controls are all gone, and my Search API object is gone. If I could get the dynamically generated control collection to just play nice and stick in ViewState, I could examine the controls on postback, rebuild the Search object, then handle control events neatly.
Possible Solutions
I could make the Search object serializable and store it in viewstate. Then on page load I could grab it and reconstruct the control collection at page load time. However I'm not sure if this would play nicely with controls raising events, and what happens to the viewstate of Drop-down lists that contain data from the database - could I get it back? It's highly undesirable for me to have to re-query the database on every postback.
I could develop a custom server control (see this link) for this kind of thing... but that is a new topic for me and would involve some learning, plus I'm not totally sure if a custom server control would work any more nicely with non-fixed control collections. Anybody know about that?
I was thinking that I might be able to accomplish this using databound controls - for example I could bind my criterion collection to a repeater which has a fixed control collection (maybe hide the non-used "value" controls, use an inner repeater for the "Field" drop-down lists). Then all the information would stay in ViewState... right?
Any new ideas would be greatly appreciated.
thanks for your help.
b.Fandango
I've been coding for about a day and I got this working beautifully using the third option I suggested in my question - old-school databound controls. Actually I only thought of the idea when I was forced to write out the question in detail - doesn't that just happen to you all the time?
I put my SearchCriterionControl into an asp:Repeater and bound it to my object collection. For the Field Chooser I put an asp:DropDownList inside a nested asp:Repeater and bound the Field array to that. Everything works beautifully, keeps state, actually required very little code. So I never had to dynamically add controls to the page, thank goodness.
Thanks for your suggestions, Ender, Matt and andrewWinn.
Since no one else has taken a stab at this for 2 hours, I'll throw my hat in the ring with a solution that does not rely on viewstate at all (or the ASP.NET model of postbacks).
What if you grabbed all the input values with jQuery and instead of doing a post-back did a post against the page (or a new results.aspx page)? Or, you could make the entire thing asyncrhonous and do an Ajax request against a web method, get fed the results, and populate on the client side as needed?
The unfortunate thing here is you have to reconstruct which type of controls were used to figure construct your search query since that data wont be passed with the viewstate. But I imagine you were already going to have to do some kind of translation of your input data into a query form anyway.
Read here for more information about using jQuery to hit an ASP.NET page method. Remember - page methods must be static (it's an easy oversight).
I'm not sure what you're doing server side to construct your query - but I would highly recommend LINQ. I did a similar "advanced search" function previously, and after a few different attempts found that LINQ was a wonderful tool for this problem, regardless of whether I was hitting SQL with LINQtoSQL or just hitting an in-memory collection of objects.
This worked so well because 1) LINQ is deferred execution and 2) A LINQ query returns another queryable object. The implication here is that you can chain your LINQ queries together as you construct them from your input, instead of having to do a single massive clause translation to SQL or whatever backstore you are using (one of my attempts was constructing SQL clauses with strings, but still passing input data via SQLParameters for SQL injection protection - it was messy and complicated when hand crafted LINQ was orders of magnitude easier to understand and implement).
For example:
List<string> data; // or perhaps your a DB Context for LINQtoSQL?
var query = data.Where(item => item.contains("foo"));
if( {user supplies length search option} )
query = query.Where(item => item.Length < 5);
// etc, etc.
// LINQ doesn't do anything until the query is iterated, at which point
// it will construct the SQL statement without you worrying about details or parameter binding
foreach(string value in query)
; // do something with the results
Because of deferred execution and the queryable return type, you can concatenate LINQ queries to this expression all day long and let it worry about the implementation details (such as converting to a SQL query) at execution time.
I can't provide you with the exact steps that you will need to do, but I HIGHLY suggest looking into asp.net page life cycle. I created a user control as a DLL one time. I had to capture postback data at specific steps in the lifecycle and recreate and rebind the data at other steps. Additionally thinkgs like viewstate are only available at certain points also. I know that I had to override On_init, On_prerender and some other methods.
Sorry I couldn't be more help, but I don't have the code with me (its with an old employer). I hope this helps.
If you are adding controls to the controls tree dynamically, you need to add them on postpack as well. Just call the method that builds the control on Page_Load or Page_Init and the controls should stay on the page on postback.