{"id":938,"date":"2023-08-17T09:42:37","date_gmt":"2023-08-17T00:42:37","guid":{"rendered":"http:\/\/www.charleskwon.com\/?p=938"},"modified":"2023-08-18T12:02:39","modified_gmt":"2023-08-18T03:02:39","slug":"why-need-delay-option-of-tawaitweb-prg","status":"publish","type":"post","link":"https:\/\/www.charleskwon.com\/?p=938","title":{"rendered":"Why need delay\/timeout option of TAWaitWeb.prg"},"content":{"rendered":"\n

<\/a><\/p>\n\n\n\n

In the TAWaitWeb class, the argument named ‘nSecond’ is present.<\/p>\n\n\n\n

Upon closer examination, this argument is not for sleep; instead, it is used to set a waiting time within a while loop to check for changes in the value being passed asynchronously.<\/p>\n\n\n\n

Manners<\/em> maketh man<\/em><\/h2>\n\n\n\n
<\/div>\n\n\n\n

There is a bold individual who cannot even analyze source code. This person, hiding behind anonymity, asked where the nSecond option is being used and also employed incorrect expressions. However, I do not engage in battles with fools.

So, in summary, nSecond<\/strong><\/code> in this code functions as a timeout value. The method Query<\/code><\/strong> keeps checking for a response in a loop, but it won’t do this indefinitely \u2013 it will stop and exit the loop if nSecond<\/code><\/strong> milliseconds have passed without a response. This is a common pattern used to prevent a program from waiting forever in situations where a response might never come, thus avoiding potential hangs or freezes in the application.

Alright, I will show you the relevant code again. Please read it over to understand why the nSecond parameter is necessary…<\/p>\n\n\n\n

Code for the wise person.<\/h2>\n\n\n\n
<\/circle><\/circle><\/circle><\/g><\/svg><\/span><\/path><\/path><\/svg><\/span>
METHOD\u00a0<\/span>Query<\/span>(<\/span>\u00a0cQuery<\/span>,<\/span> nSecond<\/span>,<\/span> cReturn\u00a0<\/span>)<\/span>\u00a0CLASS\u00a0TAWaitWeb<\/span><\/span>\n\u00a0 \u00a0\u00a0LOCAL\u00a0nCounter :<\/span>=<\/span>\u00a0<\/span>0<\/span><\/span>\n\u00a0 \u00a0\u00a0LOCAL\u00a0lReturn \u00a0:<\/span>=<\/span> .f.<\/span><\/span>\n\u00a0 \u00a0\u00a0LOCAL\u00a0cEval \u00a0 \u00a0:<\/span>=<\/span>\u00a0<\/span>"<\/span>SendToFWH($QUERY$, 'WebFunc')<\/span>"<\/span><\/span>\n\u00a0 \u00a0\u00a0LOCAL\u00a0nStartSec :<\/span>=<\/span> <\/span>GetTickCount<\/span>()<\/span><\/span>\n<\/span>\n\u00a0 \u00a0\u00a0DEFAULT\u00a0nSecond :<\/span>=<\/span>\u00a0<\/span>500<\/span><\/span>\n<\/span>\n\u00a0 \u00a0 ::bOldBind\u00a0:<\/span>=<\/span> ::oWeb:bOnBind<\/span><\/span>\n\u00a0 \u00a0 ::oWeb:bOnBind\u00a0:<\/span>=<\/span>\u00a0<\/span>{<\/span>\u00a0<\/span>|<\/span> cJson<\/span>,<\/span> cCalls<\/span>,<\/span> ... <\/span>|<\/span> <\/span>::GetBind<\/span>(<\/span>\u00a0cJson<\/span>,<\/span> cCalls<\/span>,<\/span> ...\u00a0<\/span>)<\/span>\u00a0<\/span>}<\/span><\/span>\n<\/span>\n\u00a0 \u00a0 cEval :<\/span>=<\/span> <\/span>STRTRAN<\/span>(<\/span>\u00a0cEval<\/span>,<\/span>\u00a0<\/span>"<\/span>$QUERY$<\/span>"<\/span>,<\/span> cQuery\u00a0<\/span>)<\/span><\/span>\n<\/span>\n\u00a0 \u00a0 ::cReturn\u00a0:<\/span>=<\/span>\u00a0<\/span>""<\/span><\/span>\n<\/span>\n\u00a0 \u00a0\u00a0WHILE\u00a0.T.<\/span><\/span>\n\u00a0 \u00a0 \u00a0 \u00a0 ::oWeb:<\/span>Eval<\/span>(<\/span>\u00a0cEval\u00a0<\/span>)<\/span><\/span>\n<\/span>\n\u00a0 \u00a0 \u00a0 \u00a0\u00a0<\/span>sleep<\/span>(<\/span>100<\/span>)<\/span><\/span>\n\u00a0 \u00a0 \u00a0 \u00a0 <\/span>SysWait<\/span>()<\/span><\/span>\n<\/span>\n\u00a0 \u00a0 \u00a0 \u00a0\u00a0IF\u00a0<\/span>!<\/span>EMPTY<\/span>(<\/span>\u00a0::cReturn\u00a0<\/span>)<\/span><\/span>\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 lReturn :<\/span>=<\/span> .t.<\/span><\/span>\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 EXIT<\/span><\/span>\n\u00a0 \u00a0 \u00a0 \u00a0\u00a0ENDIF\u00a0\u00a0 \u00a0<\/span><\/span>\n<\/span>\n\u00a0 \u00a0 \u00a0 \u00a0\u00a0IF\u00a0<\/span>GetTickCount<\/span>()<\/span>\u00a0<\/span>-<\/span> nStartSec \u00a0<\/span>>=<\/span> nSecond<\/span><\/span>\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0EXIT<\/span><\/span>\n\u00a0 \u00a0 \u00a0 \u00a0\u00a0ENDIF<\/span><\/span>\n\u00a0 \u00a0\u00a0ENDDO\u00a0\u00a0<\/span><\/span>\n<\/span>\n\u00a0 \u00a0 cReturn :<\/span>=<\/span> ::cReturn<\/span><\/span>\n<\/span>\n\u00a0 \u00a0 ::oWeb:bOnBind\u00a0:<\/span>=<\/span> ::bOldBind<\/span><\/span>\n<\/span>\nRETURN\u00a0lReturn<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
<\/div>\n","protected":false},"excerpt":{"rendered":"
In the TAWaitWeb class, the argument named ‘nSecond’ is present. Upon closer examination, this argument is not for…<\/p>\n","protected":false},"author":1,"featured_media":939,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_kadence_starter_templates_imported_post":true,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"footnotes":""},"categories":[4],"tags":[],"class_list":["post-938","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technique-productivity"],"taxonomy_info":{"category":[{"value":4,"label":"Technique"}]},"featured_image_src_large":["https:\/\/www.charleskwon.com\/wp-content\/uploads\/2023\/08\/image-7.png",776,749,false],"author_info":{"display_name":"CharlesKWON","author_link":"https:\/\/www.charleskwon.com\/?author=1"},"comment_info":1,"category_info":[{"term_id":4,"name":"Technique","slug":"technique-productivity","term_group":0,"term_taxonomy_id":4,"taxonomy":"category","description":"","parent":0,"count":8,"filter":"raw","cat_ID":4,"category_count":8,"category_description":"","cat_name":"Technique","category_nicename":"technique-productivity","category_parent":0}],"tag_info":false,"_links":{"self":[{"href":"https:\/\/www.charleskwon.com\/index.php?rest_route=\/wp\/v2\/posts\/938","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.charleskwon.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.charleskwon.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.charleskwon.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.charleskwon.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=938"}],"version-history":[{"count":3,"href":"https:\/\/www.charleskwon.com\/index.php?rest_route=\/wp\/v2\/posts\/938\/revisions"}],"predecessor-version":[{"id":947,"href":"https:\/\/www.charleskwon.com\/index.php?rest_route=\/wp\/v2\/posts\/938\/revisions\/947"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.charleskwon.com\/index.php?rest_route=\/wp\/v2\/media\/939"}],"wp:attachment":[{"href":"https:\/\/www.charleskwon.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=938"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.charleskwon.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=938"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.charleskwon.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=938"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}