Guys,
I have two models, Notebook and Note. Note belongs to a notebook and notebook has many notes.
In my application I have a very common 3-columns view, 1st col lists notebooks, and 2nd col lists the notes corresponding to the selected notebook, and the 3rd col contains a form of the currently selected note.
In Spine, I didn't use the relation module. Every time the user selects a notebook, I call get /notebooks/:id/notes to fetch the corresponding notes of the selected notebook and render the note list, and when user click to create a new note, I will create a Spine object of note model with the current selected notebook_id and call save(). It works fine with the existing notebooks.
But there's a problem when a user creates a new notebook. If user click to create a new note inside this new notebook, before the notebook create ajax finishes, I don't have the actually notebook id from the database. So I think I have to wait for the notebook create ajax call back, before then I will block the user from clicking to create a new note.
But from Spine documentation, Alex said: Waiting for a server response goes against the whole concept of an asynchronous user interface.
So, what's the correct way to do this? Am I doing it right?
Thanks a lot.
In some cases it is way more complicated to not wait for a server response. It is up to you to decide when the non-blocking UI is worth the extra development effort and code complexity. In this case it shouldn't be terribly hard to trigger updating the reference ids on notes when the id on the notebook is updated, however it sounds like you wouldn't want to allow attempts to persist the note before that happens. That is doable without a blocking UI though.
Related
As I know that, instead of get() I can use onSapshot() for my queries and listen to the changes(additions, deletions, modifications) for that query. But when there are changes, onSnaphot() returns multiple full documents whether modified, deleted or added (a new snapshot). What I want to do is, to check if new documents have been added matching my query and show a notification to the user that there are new records available, and only when a button is clicked, they should be able to fetch and see the new records. I don't want to fetch from the firestore whole sets of documents when there are changes. I just want to know about those changes and fetch on demand. And fetch only the added ones.
How can I do that? Any ideas?
By the way, I am using react-native for my app.
P.S. - I know, I can run the query periodically and check if the id of the first item in the new query matches the first item id in the previous query, and so I can detect the added records and show my notification/button. But I am looking for a more elegant solution. I think the notification should be triggered from the backend instead of polling the backend periodically.
P.S. 2 - Using cloud functions would not seem to be a logical option since these queries will be different for each user of my app. Which would require running thousands of functions (hopefully more) on the firestore. Or would it?
Thanks!
There is no way in the Firestore API to get notified about changes to a query without actually retrieving the changed documents. But you can of course show just a notification to the user when your onSnapshot callback gets called, and then only show the actual data from those documents when the user chooses to refresh the UI.
On a second note, when you use a snapshot listener the Firestore client will only retrieve the modified documents on additional callbacks.
Say you attach a listener for a query that matches 10 documents. On the first onSnapshot callback, you will get 10 documents and will be charged for 10 document reads. Now say that one of the documents changes. When your onSnapshot callback gets invoked for this, you will see 10 documents again, but will be charged only 1 read - for the document that was changed.
If you only want to process the changes, have a look at the documentation on viewing changes between snapshots, which contains a good example of how to do this with the docChanges() method.
An XPage is used to display the number of points a person has collected, and the number of points remaining (see below).
I have a repeat control which gets a collection of documents meeting a specific criteria. The last column in the control contains 5 digit/form/comboboxes, which are displayed or hidden, according to the number of fields on each document that contain data.
The layout contains gift cards worth a certain amount of points, and the person can select how many of each gift card they want. eg.
Company Available in Values of Points Required Quantity Requested
The Quantity Requested column contains the digit/form/comboboxes. As the person selects values in the checkbox, I want the number of points remaining to be recalculated.
The onChange event of the digit/form/comboboxes calls a function in an Output Script which calls an RPC, which in turn calls an SSJS function. The SSJS function cycles through the documents displayed in the repeat control, gathering the points required information. I then wanted it to also grab the Quantity Requested. I understand from a previous posting that because of the way the digit/form/combox is rendered, I can only get the value using CSJS with dijit.byId and perhaps putting the value in a hidden field and retrieving it from there.
I can't seem to wrap my head around how I will do this when the repeat control will make it possible for there to be many combobox1 and combobox2, etc.
The XPage is not bound to a form, because all the items are just calculated on the fly and then discarded.
What is the best way to do this?
The JSON RPC service can't interact with any changes made in the browser, see https://www.intec.co.uk/json-rpc-service-component-tree-manipulation-openlog/. This could be the cause of your problems.
You may be able to get around it by triggering a partial refresh (POST) before calling the JSON RPC. In theory that might work, because the component tree (server-side map of the XPage) would get updated by the partialRefreshPost and the updates picked up by the JSON RPC. It's possible though that the Restore View picks up a version of the XPage other than the one for the browser, I don't know. I've never investigated that.
It's been a while since I've worked with server java script, I have been doing it the managed bean way with ActionListeners. If you have the data in the UI, then can you avoid server side processing and do it client side?
You can also use the DOM XSP Object like XSP.setSubmittedValue to have a key value pair sent with your post request to the server side, you can only have one... it can be JSON or any other value you set it to from the client side javascript.
I figured out how to do this. If anyone wants the code, let me know and I'll provide it.
I'd been looking at using the Rally API to create an app to do some simple auto-ranking stories based on specific criteria (at the request of / to help out a couple of our Product Owners) in a drag&drop workspace.
I did this by adjusting the "Rank" properties of the sequence of stories (I made sure to keep the rank values within the same overall min / max range as prior to the auto-reorder). I made a call to the API to update each story's rank individually (in quick succession).
Testing the app, I found that sometimes after running the auto-ranking app, some screens (such as the kanban board) would tell me that "drag and drop re-ranking is disabled for manual rank workspaces" (and the kanban would no longer let me drag & drop, although other screens such as the backlog would still let me drag & drop, and the workspace settings were still set to drag & drop). Deleting the stories, or reordering them on the backlog screen would return things back to normal.
After trying a few ideas to solve this, I figured perhaps if I was updating the Rank on a number of stories in quick succession, the back-end might be getting confused with these (potentially several / concurrent) requests. Introducing a delay between each story's API call has seemed to avoid the problem, and to speed things up, I now update a story's rank in the API only after the previous story's rank update has invoked the "updateComplete" function.
Do the assumptions in the last paragraph above make sense based on the backend ranking? Is there any Javascript API call to update multiple stories at once? (Otherwise I'm quite happy with the solution of only calling the API "update rank" after the prior API "rank update" call has returned ok).
That sounds like you discovered a possible issue with the backend ranking. The warning you were getting stems from the board trying to figure out which type of workspace you are in (manual or dnd rank). Since that setting is not currently available via WSAPI the board tries to figure it out based on its data and sometimes gets it wrong.
Currently there is no fully supported/documented way to adjust the ranks of items via WSAPI. The Card Board component in the App SDK uses special rankAbove and rankBelow query string parameters during update calls (which you can see in Firebug or the Chrome dev tools).
How are you currently setting the Rank values?
Ive recently started using Ruby on Rails for a project of mine and have hit some interesting walls. Im using scaffolding but instead of moving to the default show page after i have entered data, i want to instead redirect to another page i have created.
The key is the page is another form and half of that form is made up of values entered in the previous form. So ive guessed that i have to keep that in memory instead of allowing it to be written to the database. My original idea was to query the table and find the last record but with multiple users its probably not advisable.
Can anyone help? Examples would be great or even just to point me in the right direction
Im pretty familier with C++, jave etc, so i understand computer jargon.
thanks
Do you care if the data from the first form is stored in the database before going to the second form? If not you can just set the create action in the controller to redirect to the new page you want. Depending on how you are managing the user session, you could then pull up the information the user stored in the first form. For example if you were using Devise to handle the session, you could have the user enter their username, email and password in the first form, then redirect to a profile form that has a separate email option. You could pre-populate the field to show the user.email, but give the user the option to create a separate email for their profile. In your new action for your profile you would just add #profile.email = current_user.email. Keep in mind, this will allow the user to edit this field separate for both tables.
If you want the data entered in the two forms to point to the same database table, I would recommend looking at using nested attributes. This way, you do not have an email columns in separate tables. Railscasts has a pretty good episode on how to do this. http://railscasts.com/episodes/196-nested-model-form-part-1
You can store all entered in the first form data in session. After redirect you can fill all form inputs from stored data in session and then clear that session data.
I have 2 1/2 years experience of VB.Net, mostly self taught, so please bear with me if I seem rather noobish still and do not know some of the basics. I would recommend you grab a cup of tea before starting on this, as it appears to have got quite long...
I currently have a rather large application (VB.Net website) of over 15000 lines of code at the last count. It does not do retail or anything particularly complex like that - it is literally just a wholesale viewing website with admin frontend, catalogue / catalogue management system and pageview system.
I don't really know much about how .Net applications work in the background - whether they are all loaded on the same thread or if each has its own thread... I just know how to code them, or at least like to think I do... :-)
Basically my application is set up as follows:
There are two different areas - the customer area and the administration frontend.
The main part of the customer frontend is the Catalogue. The MasterPage will load a list of products but that's all, and this is common to all the customer frontend pages.
I tend to work on only one or several parts of the application at a time before uploading the changes. So, for example, I may alter the hierarchy of the Catalogue and change the Catalogue page to match the hierarchy change whilst leaving everything else alone.
The pageview database is getting really quite large and so it is getting rather slow when the application is first requested due to the way it works.
The application timeout is set to 5 minutes - don't know how to change it, I have even tried asking this question on here and seem to remember the solution was quite complex and I was recommended not to change it, but if a customer requests the application 5 minutes after the last page view then it will reload the application from scratch. This means there is a very slow page load whenever it exceeds 5 minutes of inactivity.
I am not sure if this needs consideration to determine how best to split the application up, if at all, but each part of the catalogue system is set up as follows:
A Manager class at the top level, which is used by the admin frontend to add, edit and remove items of the specified type and the customer frontend to retrieve a list of items of the specified type. For example the "RangeManager" will contain a list of product "Ranges" and will be used to interact with these from the customer frontend.
An Item class, for example Range, which contains a list of Attributes. For example Name, Description, Visible, Created, CreatedBy and so on. The form for adding / editing loops through these to display relevant controls for the administrator. For example a Checkbox for BooleanAttribute.
An Attribute class, which can be of type StringAttribute, BooleanAttribute, IntegerAttribute and so on. There are also custom Attributes (not just datatypes) such as RangeAttribute, UserAttribute and so on. These are given a data field which is used to get a piece of data specific to the item it is contained in when it is first requested. Basically the Item is given a DataRow which is stored and accessed by Attributes only when they are first requested.
When one item is requested from a specific manager is requested, the manager will loop through all the items in the database and create a new instance of the item class. For example when a Range is requested from the RangeManager, the RangeManager will loop through all of the DataRows in the Ranges table and create a new instance of Range for each one. As stated above it simply creates a new instance with the DataRow, rather than loading all the data into it there and then. The Attributes themselves fetch the relevant data from the DataRow as and when they're first requested.
It just seems a tad stupid, in my mind, to recompile and upload the entire application every time I fix a minor bug or a spelling mistake for a word which is in the code behind (for example if I set the text of a Label dynamically). A fix / change to the Catalogue page, the way it is now, may mean a customer trying to view the Contact page, which is in no way related to the Catalogue page apart from by having the same MasterPage, cannot do so because the DLL is being uploaded.
Basically my question is, given my current situation, how would people suggest I change the architecture of the application by way of splitting it into multiple applications? I mean would it be just customer / admin, or customer / admin and pageviews, or some other way? Or not at all? Are there any other alternatives which I have not mentioned here? Could web services come in handy here? Like split the catalogue itself into a different application and just have the masterpage for all the other pages use a web service to get the names of the products to list on the left hand side? Am I just way WAY over-complicating things? Judging by the length of this question I probably am, and it wouldn't be the first time... I have tried to keep it short, but I always fail... :-)
Many thanks in advance, and sorry if I have just totally confused you!
Regards,
Richard
15000 LOC is not really all that big.
It sounds like you are not pre-compiling your site for publishing. You may want to read this: http://msdn.microsoft.com/en-us/library/1y1404zt(v=vs.80).aspx
Recompiling and uploading the application is the best way to do it. If all you are changing is your markup, that can be uploaded individually (e.g. changing some html layout in an aspx page).
I don't know what you mean here by application timeout, but if your app domain recycles every 5 minutes, then that doesn't seem right at all. You should look into this.
Also, if you find yourself working on various different parts of the site (i.e. many different changes), but need to deploy only some items in isolation, then you should look into how you are using your source control tools (you are using one, aren't you?). Look into something like GIT and branching/merging.
Start by reading:
Application Architecture Guide