{"id":3174,"date":"2017-08-02T10:54:20","date_gmt":"2017-08-02T02:54:20","guid":{"rendered":"http:\/\/www.yewen.us\/blog\/?p=3174"},"modified":"2017-08-02T10:54:20","modified_gmt":"2017-08-02T02:54:20","slug":"wtforms-ignore-default-option-in-stringfield","status":"publish","type":"post","link":"https:\/\/www.yewen.us\/blog\/2017\/08\/wtforms-ignore-default-option-in-stringfield\/","title":{"rendered":"wtforms \u7684 StringField \u91cc\u8bbe\u7f6e default \u65e0\u6548"},"content":{"rendered":"<p>\u5728\u9879\u76ee\u91cc\u4f7f\u7528 wtforms\uff0c\u8bbe\u7f6e\u4e86\u4e00\u4e2a\u5e26\u9ed8\u8ba4\u503c\u7684 StringField\uff0c\u4f46\u63d0\u4ea4\u8868\u5355\u5982\u679c\u6ca1\u6709\u8fd9\u9879\u6216\u503c\u662f\u7a7a\u7684\uff0c\u5219\u8fd4\u56de\u4e3a\u7a7a\uff0c\u5e76\u4e0d\u4f1a\u4f7f\u7528 default \u91cc\u7684\u503c<\/p>\n<p>\u4f8b\u5982\u5b9a\u4e49\u5982\u4e0b\u8868\u5355<\/p>\n<pre class=\"brush: python; title: ; notranslate\" title=\"\">\ndef ListForm(Form):\n    status = StringField(&quot;status&quot;, validators=&#x5B;Optional()], default=&quot;all&quot;)\n<\/pre>\n<p>\u63d0\u4ea4\u4e00\u4e2a\u7a7a\u8bf7\u6c42\uff0c\u8fd4\u56de\u7684 status \u662f\u7a7a\u800c\u4e0d\u662f all\u3002\u53bb\u8ddf\u4ee3\u7801\u5e76\u770b\u4e86\u4e0b GitHub \u4e0a\u7684 issue \u8ba8\u8bba\uff0c\u6309 wtforms \u5b98\u65b9\u7684\u8bf4\u6cd5\uff0c\u8fd9\u662f\u6545\u610f\u8bbe\u8ba1\u6210\u8fd9\u6837\u7684\uff0c\u53c2\u8003\u5982\u4e0b\u5185\u5bb9<\/p>\n<ul>\n<li><a href=\"https:\/\/github.com\/wtforms\/wtforms\/issues\/225\">StringField default value does not work #225<\/a><\/li>\n<li><a href=\"http:\/\/wtforms.readthedocs.io\/en\/latest\/faq.html#why-does-blank-input-not-go-back-to-the-default-value\">http:\/\/wtforms.readthedocs.io\/en\/latest\/faq.html#why-does-blank-input-not-go-back-to-the-default-value<\/a><\/li>\n<\/ul>\n<p>\u5927\u610f\u662f\uff0c\u5982\u679c\u7528\u6237\u8bbe\u7f6e\u4e86\u4e00\u4e2a Field\uff0c\u90a3\u4e48\u4ed6\u5c31\u5e94\u8be5\u6709\u503c\uff0c\u4e0d\u7136\u6211\u4eec\u5c31\u5f3a\u884c\u8bbe\u7f6e\u4e3a\u7a7a<\/p>\n<p>\u4f46\u662f\u8fd9\u4e2a\u903b\u8f91\u72d7\u5c41\u4e0d\u901a\uff0c\u56e0\u4e3a\u9664\u4e86 StringField \u5176\u4ed6\u7684\u7c7b\u578b\u57df\u5c31\u6ca1\u8fd9\u4e2a\u95ee\u9898\uff0c\u6bd4\u5982 IntegerField \u5c31\u662f\u53ef\u4ee5\u8fd9\u4e48\u7528\u800c\u4e14\u80fd\u8fd4\u56de\u6b63\u786e\u7684 default<\/p>\n<pre class=\"brush: python; title: ; notranslate\" title=\"\">\ndef ListForm(Form):\n    status = StringField(&quot;status&quot;, validators=&#x5B;Optional()], default=&quot;all&quot;)\n    x = IntegerField(&quot;x&quot;, validators=&#x5B;Optional()], default=9)\n<\/pre>\n<p>\u6ca1\u529e\u6cd5\u81ea\u5df1\u65b0\u589e\u4e86\u4e00\u4e2a StringFieldWithDefault \u7684\u7c7b\u6765\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff08\u88ab\u8986\u76d6\u7684\u4ee3\u7801\u53ef\u4ee5\u770b\u4e0a\u9762 GitHub Issue \u91cc\u7684\u8ba8\u8bba\uff09<\/p>\n<pre class=\"brush: python; title: ; notranslate\" title=\"\">\nclass StringFieldWithDefault(StringField):\n    def process_formdata(self, valuelist):\n        if valuelist:\n            self.data = valuelist&#x5B;0]\n        else:\n            self.data = self.object_data\n<\/pre>\n<p>\u800c\u4e14 wtforms \u7684\u6570\u636e\u6821\u9a8c\u4e5f\u662f\u8c1c\u4e00\u822c\u7684\u903b\u8f91\uff0c\u6bd4\u5982\u8bbe\u7f6e\u5982\u4e0b<\/p>\n<pre class=\"brush: python; title: ; notranslate\" title=\"\">\ndef ListForm(Form):\n    status = StringField(&quot;status&quot;, validators=&#x5B;Optional(), AnyOf(&#x5B;&quot;all&quot;, &quot;visible&quot;])], default=&quot;all&quot;)\n    x = IntegerField(&quot;x&quot;, validators=&#x5B;DataRequired()])\n<\/pre>\n<p>\u8fd9\u91cc\u4f1a\u51fa\u73b0\u4e24\u4e2a\u95ee\u9898<\/p>\n<p>\u4e00\u662f Optional \u5982\u679c\u53d1\u73b0\u6ca1\u6709\u503c\u6216\u7a7a\uff0c\u662f\u80fd\u901a\u8fc7\u8fd9\u4e2a\u6821\u9a8c\u7684\uff0c\u8fd9\u91cc\u903b\u8f91\u4e5f\u6ca1\u9519\uff0c\u4f46\u662f\u7279\u55b5\u7684 Optional \u5982\u679c\u9047\u5230\u503c\u4e3a\u7a7a\u7684\u65f6\u5019\uff0c\u4f1a\u628a\u4e4b\u524d\u7684\u6240\u6709\u9519\u8bef\u90fd\u6e05\u7a7a\uff0c\u5e76\u4e14\u505c\u6b62\u68c0\u67e5\u540e\u9762\u7684 validator\u3002\u8fd9\u4e2a\u8ff7\u4e00\u822c\u7684\u903b\u8f91\u4f1a\u5bfc\u81f4\u5982\u679c\u4f20\u7684\u7a7a\u5b57\u6bb5\uff0c\u5373\u6ca1\u6709\u6309\u6b63\u5e38\u4eba\u9884\u671f\u7684\u62ff\u5230 default\uff0c\u4e5f\u6ca1\u6709\u53bb\u6267\u884c AnyOf \u7684\u6821\u9a8c\uff0c\u800c\u662f\u76f4\u63a5\u901a\u8fc7\u4e86\u3002\u8fd9\u4e2a\u5b98\u65b9\u65e0\u89e3\uff0c\u4e5f\u4e0d\u6253\u7b97\u4fee\uff0c\u53ea\u8bf4\u5728 3.x \u7684\u65f6\u5019\u8003\u8651\u52a0\u914d\u7f6e\u53c2\u6570\uff0c\u4e0d\u8fc7\u770b\u8fdb\u5ea6\u4e0a\u4e00\u4e2a\u7248\u672c\u5df2\u7ecf\u662f 2015 \u5e74\u53d1\u5e03\u7684 2.1\uff0c\u800c\u4e14 GitHub \u4ed3\u5e93\u5e76\u4e0d\u6d3b\u8dc3\uff0c\u90a3\u4e48\u53ea\u80fd\u5475\u5475\u5475\u5475\uff0c\u7136\u540e\u6362\u81ea\u5df1\u7684 StringFieldWithDefault \u5427<\/p>\n<p>\u4e8c\u662f DataRequired \u4e0d\u662f\u68c0\u67e5 <code>if field.name in formdata<\/code>\uff0c\u800c\u662f\u68c0\u67e5 <code>if field.data<\/code>\uff0c\u8fd9\u5c31\u610f\u5473\u7740\uff0c\u5982\u679c\u4f20\u4e86\u4e00\u4e2a 0 \u7684\u6574\u578b\u53c2\u6570\u7ed9 IntegerField\uff0c\u662f\u901a\u4e0d\u8fc7 DataRequired \u7684\u9a8c\u8bc1\u7684\uff0c\u540c\u7406\u8fd8\u6709\u7a7a\u5b57\u7b26\u4e32\u3002\u8fd9\u4e2a\u53ef\u4ee5\u6539\u7528 InputRequired \u6765\u89e3\u51b3\uff0c\u8fd8\u7b97\u662f\u5b98\u65b9\u7ed9\u4e86\u6761\u6d3b\u8def<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728\u9879\u76ee\u91cc\u4f7f\u7528 wtforms\uff0c\u8bbe\u7f6e\u4e86\u4e00\u4e2a\u5e26\u9ed8\u8ba4\u503c\u7684 StringField\uff0c\u4f46\u63d0\u4ea4\u8868\u5355\u5982\u679c\u6ca1\u6709\u8fd9\u9879\u6216\u503c\u662f\u7a7a\u7684\uff0c [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[7],"tags":[127,655],"class_list":["post-3174","post","type-post","status-publish","format-standard","hentry","category-tech-notes","tag-python","tag-wtforms"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p4aR5e-Pc","_links":{"self":[{"href":"https:\/\/www.yewen.us\/blog\/wp-json\/wp\/v2\/posts\/3174","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.yewen.us\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.yewen.us\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.yewen.us\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.yewen.us\/blog\/wp-json\/wp\/v2\/comments?post=3174"}],"version-history":[{"count":11,"href":"https:\/\/www.yewen.us\/blog\/wp-json\/wp\/v2\/posts\/3174\/revisions"}],"predecessor-version":[{"id":3186,"href":"https:\/\/www.yewen.us\/blog\/wp-json\/wp\/v2\/posts\/3174\/revisions\/3186"}],"wp:attachment":[{"href":"https:\/\/www.yewen.us\/blog\/wp-json\/wp\/v2\/media?parent=3174"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.yewen.us\/blog\/wp-json\/wp\/v2\/categories?post=3174"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.yewen.us\/blog\/wp-json\/wp\/v2\/tags?post=3174"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}