• Learn mybatis


    1. About mybatis Learning video: https://www.bilibili.com/vide… Persistence: the process of transforming program data into persistent and transient state Persistence layer: the code block that completes the persistence work, collectively referred to as Dao layer Mybatis: a semi persistent framework to simplify database connection and operation. It is the current mainstream Official website: https://mybatis.org/mybatis-3… 2. The […]

  • Can Linux interrupts be nested?


    This article is reprinted and the copyright belongs to the author. For commercial reprint, please contact the author for authorization. For non-commercial reprint, please indicate the source. Source: WeChat official account Linux yard (id: linuxdev) Q & A Q: can Linux interrupts be nested? A: it used to be nested, but now it’s not! history […]

  • Ajax, promise, async / await differences


    1. Traditional Ajax requests var xhr = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject(“Microsoft.XMLHTTP”) xhr.onreadystatechange = function() { if (xhr.readyState === 4 && xhr.status === 200) { // coding } } xhr.open(“GET”,”xxx”,true) xhr.send() Ajax can only be nested when there is a request in the request. This nested callback will cause poor code readability, which […]

  • About Google’s browser tag video can’t play automatically


    Video can’t play because the browser has blocked it. There are two ways: 1. Add muted mute attribute: <video id=”video” controls muted></video> Obviously, this method is not very friendly. The user needs to turn on the sound button. ~ ~ ~2. Nesting with iframe <video id=”video” controls></video> <iframe id=”ifm” allow=”autoplay” style=”display:none”></iframe> JS code block var […]

  • Problems caused by ng repeat in angular 1. X with drag and drop sorting plug-ins


    As shown in the figure, dragging is not normal. It was found that the cause of the problem wastrack by $indexBut my data rendering needs nestingng-repeat But my data rendering uses nestingng-repeat, need to get the$index <tr ng-repeat=”yAxis in tmpChartData.yAxis track by outIndex” ng-init=”outIndex = $index”> <th>{{outIndex+2}}</th> <th row-index=”{{outIndex+1}}” tabindex=”-1″ editType=”string”> <input type=”text” ng-model=”selectedElement.module.yAxis[outIndex]”> </th> […]

  • Basic usage of SASS


    About sass Sass is a mature, stable and powerful CSS extension language. Fully compatible with all versions of CSS syntax. Sass has two kinds of syntax, one is to.sassFor the syntax of extension, the writing method is indent syntax, that is, instead of using curly braces, the nesting level of selectors is expressed by indenting; […]

  • 58app new homepage’s appbarayout and recyclerview’s fling connection


    Preface In the version before 9.0, the first page did not connect with the bottom recyclerview’s flick, which caused the animation to stop immediately when scrolling to the bottom of appbarlayout when it was flipped up. When we changed the new version of the first page in 9.0, the user reported this problem, so we […]

  • The sub shell mechanism in Bash


    Sub shell Similar to the relationship between parent and child processes, inshellCreated inshellInstances are called childrenshellIn.bashMiddle sonshellIt can be divided into the following two categories: sub-shell: by process replacement, command replacement,(LIST) , |or&Implicitly generated childshellBe calledsub-shellFather.shelladoptforkEstablishsub-shellThereforesub-shellYou can get the fathershellFull copy of code segment, data segment, heap and stack child-shell: by running as an executableshellScript […]

  • Yiyou CMS: notempty of xiaobaixue code


    [basic usage] Name: notempty Function: judge whether a variable is empty. It can be nested in any tag, such as channel, type, etc Syntax: {eyou:notempty name=’$eyou.field.seo_title’ /} {$eyou.field.seo_title} {/eyou:notempty} Document: nothing Parameters: Name = ” variable name Underlying fields: nothing   [more examples] ——————————-Example 1——————————– Description: when the document SEO title is not empty, the […]

  • Four methods of sequential execution of promise asynchronous functions


    A few days ago, I met with a programming problem that required to control the sequential execution of promise. Today, I summarized that there are at least four methods that can be implemented, including promise nesting, through a promise string, generator, async implementation, as follows.The original topic is as follows: //Implement the mergepromise function, and […]

  • Using fetch & promises to realize data interaction (5)


    Through the fourth article In our study, we implemented the use of Ajax for the remote API interface, but left a problem, which caused the callback hell when there was a logical sequence, such as First, the user ID is obtained by sending the user name and password, the user’s song list is obtained according […]

  • What problem does promise solve?


    My GitHub blog https://github.com/zhangxingua/blog We all know that promise solves the problem of callback to hell. When it comes to callback hell, it’s easy to think of the followingMisleading pictures: But what is hell? What’s wrong with it? Is it because nesting doesn’t look good or it’s inconvenient to read? First of all, let’s think […]