Tutorial by Examples: g

Eloquent also lets you query on defined relationships, as show below: User::whereHas('articles', function (Builder $query) { $query->where('published', '!=', true); })->get(); This requires that your relationship method name is articles in this case. The argument passed into the clos...

It is possible to mount a host directory to a specific path in your container using the -v or --volume command line option. The following example will mount /etc on the host to /mnt/etc in the container: (on linux) docker run -v "/etc:/mnt/etc" alpine cat /mnt/etc/passwd (on windows) do...

$ docker run -e "ENV_VAR=foo" ubuntu /bin/bash Both -e and --env can be used to define environment variables inside of a container. It is possible to supply many environment variables using a text file: $ docker run --env-file ./env.list ubuntu /bin/bash Example environment variable...

Usage: docker logs [OPTIONS] CONTAINER Fetch the logs of a container -f, --follow=false Follow log output --help=false Print usage --since= Show logs since timestamp -t, --timestamps=false Show timestamps --tail=all Number o...

Before Python 3.5+ was released, the asyncio module used generators to mimic asynchronous calls and thus had a different syntax than the current Python 3.5 release. Python 3.x3.5 Python 3.5 introduced the async and await keywords. Note the lack of parentheses around the await func() call. import ...

Bad locking: std::mutex mtx; void bad_lock_example() { mtx.lock(); try { foo(); bar(); if (baz()) { mtx.unlock(); // Have to unlock on each exit point. return; } quux(); mtx.unlock(); // Normal...

By default, containers created with docker run are given a random hostname. You can give the container a different hostname by passing the --hostname flag: docker run --hostname redbox -d ubuntu:14.04

A global publication does not possess a name and does not require a subscription from the connected client and therefore it is available to the connected client as soon as the client connects to the server. To achieve this, one simply names the publication as null like so Meteor.publish(null, func...

This will show the user location on the map Objective-C [self.map setShowsUserLocation:YES]; Swift self.map?.showsUserLocation = true This will track the user location on the map, updating regions according Objective-C [self.map setUserTrackingMode:MKUserTrackingModeFollow]; Swift s...

Adding properties If you'd like to add properties to an existing object, you can use the Add-Member cmdlet. With PSObjects, values are kept in a type of "Note Properties" $object = New-Object -TypeName PSObject -Property @{ Name = $env:username ID = 12 Address...

You may need to expand or shrink your pointer storage space after you have allocated memory to it. The void *realloc(void *ptr, size_t size) function deallocates the old object pointed to by ptr and returns a pointer to an object that has the size specified by size. ptr is the pointer to a memory b...

Since C++14, the standard provides the class template template <class T, T... Ints> class integer_sequence; template <std::size_t... Ints> using index_sequence = std::integer_sequence<std::size_t, Ints...>; and a generating metafunction for it: template <class T, T N&g...

A simple way of selecting between functions at compile time is to dispatch a function to an overloaded pair of functions that take a tag as one (usually the last) argument. For example, to implement std::advance(), we can dispatch on the iterator category: namespace details { template <clas...

git difftool -t meld --dir-diff will show the working directory changes. Alternatively, git difftool -t meld --dir-diff [COMMIT_A] [COMMIT_B] will show the differences between 2 specific commits.

Using the Android API 23 or higher, very often such situation can be seen: This situation is caused by the structural change of the Android API regarding getting the resources. Now the function: public int getColor(@ColorRes int id, @Nullable Theme theme) throws NotFoundException should...

Define a menu in res/menu <?xml version="1.0" encoding="utf-8"?> <menu xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <item android:id="@+id/first_...

If someone else wrote the code you are committing, you can give them credit with the --author option: git commit -m "msg" --author "John Smith <[email protected]>" You can also provide a pattern, which Git will use to search for previous authors: git commit -m &quo...

Python makes it very simple to check whether an item is in a list. Simply use the in operator. lst = ['test', 'twest', 'tweast', 'treast'] 'test' in lst # Out: True 'toast' in lst # Out: False Note: the in operator on sets is asymptotically faster than on lists. If you need to use it ...

To execute operations in a container, use the docker exec command. Sometimes this is called "entering the container" as all commands are executed inside the container. docker exec -it container_id bash or docker exec -it container_id /bin/sh And now you have a shell in your running...

To temporarily mark a file as ignored (pass file as parameter to alias) - type: unwatch = update-index --assume-unchanged To start tracking file again - type: watch = update-index --no-assume-unchanged To list all files that has been temporarily ignored - type: unwatched = "!git ls-fil...