vuepress-theme-vdoing/assets/js/181.cf2317ac.js

(window.webpackJsonp=window.webpackJsonp||[]).push([[181],{564:function(s,t,a){"use strict";a.r(t);var n=a(5),e=Object(n.a)({},(function(){var s=this,t=s._self._c;return t("ContentSlotsDistributor",{attrs:{"slot-key":s.$parent.slotKey}},[t("h1",{attrs:{id:"处理响应-header"}},[t("a",{staticClass:"header-anchor",attrs:{href:"#处理响应-header"}},[s._v("#")]),s._v(" 处理响应 header")]),s._v(" "),t("h2",{attrs:{id:"需求分析"}},[t("a",{staticClass:"header-anchor",attrs:{href:"#需求分析"}},[s._v("#")]),s._v(" 需求分析")]),s._v(" "),t("p",[s._v("我们通过 "),t("code",[s._v("XMLHttpRequest")]),s._v(" 对象的 "),t("code",[s._v("getAllResponseHeaders")]),s._v(" 方法获取到的值是如下一段字符串：")]),s._v(" "),t("div",{staticClass:"language- line-numbers-mode"},[t("pre",{pre:!0,attrs:{class:"language-text"}},[t("code",[s._v('date: Fri, 05 Apr 2019 12:40:49 GMT\netag: W/"d-Ssxx4FRxEutDLwo2+xkkxKc4y0k"\nconnection: keep-alive\nx-powered-by: Express\ncontent-length: 13\ncontent-type: application/json; charset=utf-8\n')])]),s._v(" "),t("div",{staticClass:"line-numbers-wrapper"},[t("span",{staticClass:"line-number"},[s._v("1")]),t("br"),t("span",{staticClass:"line-number"},[s._v("2")]),t("br"),t("span",{staticClass:"line-number"},[s._v("3")]),t("br"),t("span",{staticClass:"line-number"},[s._v("4")]),t("br"),t("span",{staticClass:"line-number"},[s._v("5")]),t("br"),t("span",{staticClass:"line-number"},[s._v("6")]),t("br")])]),t("p",[s._v("每一行都是以回车符和换行符 "),t("code",[s._v("\\r\\n")]),s._v(" 结束，它们是每个 "),t("code",[s._v("header")]),s._v(" 属性的分隔符。对于上面这串字符串，我们希望最终解析成一个对象结构：")]),s._v(" "),t("div",{staticClass:"language-json line-numbers-mode"},[t("pre",{pre:!0,attrs:{class:"language-json"}},[t("code",[t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("{")]),s._v("\n  date"),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v(":")]),s._v(" 'Fri"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(",")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token number"}},[s._v("05")]),s._v(" Apr "),t("span",{pre:!0,attrs:{class:"token number"}},[s._v("2019")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token number"}},[s._v("12")]),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v(":")]),t("span",{pre:!0,attrs:{class:"token number"}},[s._v("40")]),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v(":")]),t("span",{pre:!0,attrs:{class:"token number"}},[s._v("49")]),s._v(" GMT'\n  etag"),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v(":")]),s._v(" 'W/"),t("span",{pre:!0,attrs:{class:"token string"}},[s._v('"d-Ssxx4FRxEutDLwo2+xkkxKc4y0k"')]),s._v("'"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(",")]),s._v("\n  connection"),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v(":")]),s._v(" 'keep-alive'"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(",")]),s._v("\n  'x-powered-by'"),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v(":")]),s._v(" 'Express'"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(",")]),s._v("\n  'content-length'"),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v(":")]),s._v(" '"),t("span",{pre:!0,attrs:{class:"token number"}},[s._v("13")]),s._v("'\n  'content-type'"),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v(":")]),s._v(" 'application/json; charset=utf"),t("span",{pre:!0,attrs:{class:"token number"}},[s._v("-8")]),s._v("'\n"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("}")]),s._v("\n")])]),s._v(" "),t("div",{staticClass:"line-numbers-wrapper"},[t("span",{staticClass:"line-number"},[s._v("1")]),t("br"),t("span",{staticClass:"line-number"},[s._v("2")]),t("br"),t("span",{staticClass:"line-number"},[s._v("3")]),t("br"),t("span",{staticClass:"line-number"},[s._v("4")]),t("br"),t("span",{staticClass:"line-number"},[s._v("5")]),t("br"),t("span",{staticClass:"line-number"},[s._v("6")]),t("br"),t("span",{staticClass:"line-number"},[s._v("7")]),t("br"),t("span",{staticClass:"line-number"},[s._v("8")]),t("br")])]),t("h2",{attrs:{id:"parseheaders-函数实现及应用"}},[t("a",{staticClass:"header-anchor",attrs:{href:"#parseheaders-函数实现及应用"}},[s._v("#")]),s._v(" parseHeaders 函数实现及应用")]),s._v(" "),t("p",[s._v("根据需求分析，我们要实现一个 "),t("code",[s._v("parseHeaders")]),s._v(" 工具函数。")]),s._v(" "),t("p",[t("code",[s._v("helpers/headers.ts")]),s._v("：")]),s._v(" "),t("div",{staticClass:"language-typescript line-numbers-mode"},[t("pre",{pre:!0,attrs:{class:"language-typescript"}},[t("code",[t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("export")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("function")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token function"}},[s._v("parseHeaders")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),s._v("headers"),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v(":")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token builtin"}},[s._v("string")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v(":")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token builtin"}},[s._v("any")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("{")]),s._v("\n  "),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("let")]),s._v(" parsed "),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v("=")]),s._v(" Object"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(".")]),t("span",{pre:!0,attrs:{class:"token function"}},[s._v("create")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("null")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),s._v("\n  "),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("if")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v("!")]),s._v("headers"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("{")]),s._v("\n    "),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("return")]),s._v(" parsed\n  "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("}")]),s._v("\n\n  headers"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(".")]),t("span",{pre:!0,attrs:{class:"token function"}},[s._v("split")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),t("span",{pre:!0,attrs:{class:"token string"}},[s._v("'\\r\\n'")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(".")]),t("span",{pre:!0,attrs:{class:"token function"}},[s._v("forEach")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),s._v("line "),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v("=>")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("{")]),s._v("\n    "),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("let")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("[")]),s._v("key"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(",")]),s._v(" val"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("]")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v("=")]),s._v(" line"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(".")]),t("span",{pre:!0,attrs:{class:"token function"}},[s._v("split")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),t("span",{pre:!0,attrs:{class:"token string"}},[s._v("':'")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),s._v("\n    key "),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v("=")]),s._v(" key"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(".")]),t("span",{pre:!0,attrs:{class:"token function"}},[s._v("trim")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(".")]),t("span",{pre:!0,attrs:{class:"token function"}},[s._v("toLowerCase")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),s._v("\n    "),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("if")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v("!")]),s._v("key"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("{")]),s._v("\n      "),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("return")]),s._v("\n    "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("}")]),s._v("\n    "),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("if")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),s._v("val"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("{")]),s._v("\n      val "),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v("=")]),s._v(" val"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(".")]),t("span",{pre:!0,attrs:{class:"token function"}},[s._v("trim")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),s._v("\n    "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("}")]),s._v("\n    parsed"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("[")]),s._v("key"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("]")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v("=")]),s._v(" val\n  "),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("}")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),s._v("\n\n  "),t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("return")]),s._v(" parsed\n"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("}")]),s._v("\n")])]),s._v(" "),t("div",{staticClass:"line-numbers-wrapper"},[t("span",{staticClass:"line-number"},[s._v("1")]),t("br"),t("span",{staticClass:"line-number"},[s._v("2")]),t("br"),t("span",{staticClass:"line-number"},[s._v("3")]),t("br"),t("span",{staticClass:"line-number"},[s._v("4")]),t("br"),t("span",{staticClass:"line-number"},[s._v("5")]),t("br"),t("span",{staticClass:"line-number"},[s._v("6")]),t("br"),t("span",{staticClass:"line-number"},[s._v("7")]),t("br"),t("span",{staticClass:"line-number"},[s._v("8")]),t("br"),t("span",{staticClass:"line-number"},[s._v("9")]),t("br"),t("span",{staticClass:"line-number"},[s._v("10")]),t("br"),t("span",{staticClass:"line-number"},[s._v("11")]),t("br"),t("span",{staticClass:"line-number"},[s._v("12")]),t("br"),t("span",{staticClass:"line-number"},[s._v("13")]),t("br"),t("span",{staticClass:"line-number"},[s._v("14")]),t("br"),t("span",{staticClass:"line-number"},[s._v("15")]),t("br"),t("span",{staticClass:"line-number"},[s._v("16")]),t("br"),t("span",{staticClass:"line-number"},[s._v("17")]),t("br"),t("span",{staticClass:"line-number"},[s._v("18")]),t("br"),t("span",{staticClass:"line-number"},[s._v("19")]),t("br"),t("span",{staticClass:"line-number"},[s._v("20")]),t("br")])]),t("p",[s._v("然后我们使用这个工具函数：")]),s._v(" "),t("p",[t("code",[s._v("xhr.ts")]),s._v("：")]),s._v(" "),t("div",{staticClass:"language-typescript line-numbers-mode"},[t("pre",{pre:!0,attrs:{class:"language-typescript"}},[t("code",[t("span",{pre:!0,attrs:{class:"token keyword"}},[s._v("const")]),s._v(" responseHeaders "),t("span",{pre:!0,attrs:{class:"token operator"}},[s._v("=")]),s._v(" "),t("span",{pre:!0,attrs:{class:"token function"}},[s._v("parseHeaders")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),s._v("request"),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(".")]),t("span",{pre:!0,attrs:{class:"token function"}},[s._v("getAllResponseHeaders")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v("(")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),t("span",{pre:!0,attrs:{class:"token punctuation"}},[s._v(")")]),s._v("\n")])]),s._v(" "),t("div",{staticClass:"line-numbers-wrapper"},[t("span",{staticClass:"line-number"},[s._v("1")]),t("br")])]),t("p",[s._v("接着我们再去看刚才的 demo，发现我们已经把响应的 "),t("code",[s._v("headers")]),s._v(" 字段从字符串解析成对象结构了。那么接下来，我们在解决之前遗留的第二个问题：对响应 "),t("code",[s._v("data")]),s._v(" 字段的处理。")])])}),[],!1,null,null,null);t.default=e.exports}}]);